THE HERSCHEL COMPREHENSIVE (U)LIRG EMISSION SURVEY (HERCULES): CO LADDERS, FINE STRUCTURE LINES, AND NEUTRAL GAS COOLING

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, M. J. F.; Van der Werf, P. P.; Israel, F. P.; Meijerink, R. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, SE-43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Charmandaris, V. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, P. Penteli, 15236 Athens (Greece); Evans, A. S. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences (CAS), 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Departamento de Fsica y Matemáticas, Universidad de Alcalá, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Harris, A. I. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Henkel, C. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 16, Bonn, D-53121 (Germany); Isaak, K. G. [Scientific Support Office, ESTEC/SRE-S, Keplerlaan 1, NL-2201 AZ Noordwijk (Netherlands); Kramer, C., E-mail: rosenberg@strw.leidenuniv.nl [Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, E-18012 Granada (Spain); and others

2015-03-10

(Ultra) luminous infrared galaxies ((U)LIRGs) are objects characterized by their extreme infrared (8-1000 μm) luminosities (L {sub LIRG} > 10{sup 11} L {sub ☉} and L {sub ULIRG} > 10{sup 12} L {sub ☉}). The Herschel Comprehensive ULIRG Emission Survey (PI: van der Werf) presents a representative flux-limited sample of 29 (U)LIRGs that spans the full luminosity range of these objects (10{sup 11} L {sub ☉} ≤ L {sub IR} ≤ 10{sup 13} L {sub ☉}). With the Herschel Space Observatory, we observe [C II] 157 μm, [O I] 63 μm, and [O I] 145 μm line emission with Photodetector Array Camera and Spectrometer, CO J = 4-3 through J = 13-12, [C I] 370 μm, and [C I] 609 μm with SPIRE, and low-J CO transitions with ground-based telescopes. The CO ladders of the sample are separated into three classes based on their excitation level. In 13 of the galaxies, the [O I] 63 μm emission line is self absorbed. Comparing the CO excitation to the InfraRed Astronomical Satellite 60/100 μm ratio and to far infrared luminosity, we find that the CO excitation is more correlated to the far infrared colors. We present cooling budgets for the galaxies and find fine-structure line flux deficits in the [C II], [Si II], [O I], and [C I] lines in the objects with the highest far IR fluxes, but do not observe this for CO 4 ≤ J {sub upp} ≤ 13. In order to study the heating of the molecular gas, we present a combination of three diagnostic quantities to help determine the dominant heating source. Using the CO excitation, the CO J = 1-0 linewidth, and the active galactic nucleus (AGN) contribution, we conclude that galaxies with large CO linewidths always have high-excitation CO ladders, and often low AGN contributions, suggesting that mechanical heating is important.

Modeling the HD 32297 Debris Disk With Far-Infrared Herschel Data

Science.gov (United States)

Donaldson, J.K.; Lebreton, J.; Roberge, A.; Augereau, J.-C.; Krivov, A. V.

2013-01-01

HD 32297 is a young A-star (approx. 30 Myr) 112 pc away with a bright edge-on debris disk that has been resolved in scattered light. We observed the HD 32297 debris disk in the far-infrared and sub-millimeter with the Herschel Space Observatory PACS and SPIRE instruments, populating the spectral energy distribution (SED) from 63 to 500 micron..We aimed to determine the composition of dust grains in the HD 32297 disk through SED modeling, using geometrical constraints from the resolved imaging to break the degeneracies inherent in SED modeling. We found the best fitting SED model has two components: an outer ring centered around 110 AU, seen in the scattered light images, and an inner disk near the habitable zone of the star. The outer disk appears to be composed of grains>2 micron consisting of silicates, carbonaceous material, and water ice with an abundance ratio of 1:2:3 respectively and 90% porosity. These grains appear consistent with cometary grains, implying the underlying planetesimal population is dominated by comet-like bodies. We also discuss the 3.7 sigma detection of [C ii] emission at 158 micron with the Herschel PACS instrument, making HD 32297 one of only a handful of debris disks with circumstellar gas detected

THE HERSCHEL ORION PROTOSTAR SURVEY: SPECTRAL ENERGY DISTRIBUTIONS AND FITS USING A GRID OF PROTOSTELLAR MODELS

Energy Technology Data Exchange (ETDEWEB)

Furlan, E. [Infrared Processing and Analysis Center, California Institute of Technology, 770 S. Wilson Ave., Pasadena, CA 91125 (United States); Fischer, W. J. [Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Ali, B. [Space Science Institute, 4750 Walnut Street, Boulder, CO 80301 (United States); Stutz, A. M. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Stanke, T. [ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Tobin, J. J. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Megeath, S. T.; Booker, J. [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606 (United States); Osorio, M. [Instituto de Astrofísica de Andalucía, CSIC, Camino Bajo de Huétor 50, E-18008 Granada (Spain); Hartmann, L.; Calvet, N. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Poteet, C. A. [New York Center for Astrobiology, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, NY 12180 (United States); Manoj, P. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Watson, D. M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Allen, L., E-mail: furlan@ipac.caltech.edu [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States)

2016-05-01

We present key results from the Herschel Orion Protostar Survey: spectral energy distributions (SEDs) and model fits of 330 young stellar objects, predominantly protostars, in the Orion molecular clouds. This is the largest sample of protostars studied in a single, nearby star formation complex. With near-infrared photometry from 2MASS, mid- and far-infrared data from Spitzer and Herschel , and submillimeter photometry from APEX, our SEDs cover 1.2–870 μ m and sample the peak of the protostellar envelope emission at ∼100 μ m. Using mid-IR spectral indices and bolometric temperatures, we classify our sample into 92 Class 0 protostars, 125 Class I protostars, 102 flat-spectrum sources, and 11 Class II pre-main-sequence stars. We implement a simple protostellar model (including a disk in an infalling envelope with outflow cavities) to generate a grid of 30,400 model SEDs and use it to determine the best-fit model parameters for each protostar. We argue that far-IR data are essential for accurate constraints on protostellar envelope properties. We find that most protostars, and in particular the flat-spectrum sources, are well fit. The median envelope density and median inclination angle decrease from Class 0 to Class I to flat-spectrum protostars, despite the broad range in best-fit parameters in each of the three categories. We also discuss degeneracies in our model parameters. Our results confirm that the different protostellar classes generally correspond to an evolutionary sequence with a decreasing envelope infall rate, but the inclination angle also plays a role in the appearance, and thus interpretation, of the SEDs.

Comparison of star formation rates from Hα and infrared luminosity as seen by Herschel

Science.gov (United States)

Domínguez Sánchez, H.; Mignoli, M.; Pozzi, F.; Calura, F.; Cimatti, A.; Gruppioni, C.; Cepa, J.; Sánchez Portal, M.; Zamorani, G.; Berta, S.; Elbaz, D.; Le Floc'h, E.; Granato, G. L.; Lutz, D.; Maiolino, R.; Matteucci, F.; Nair, P.; Nordon, R.; Pozzetti, L.; Silva, L.; Silverman, J.; Wuyts, S.; Carollo, C. M.; Contini, T.; Kneib, J.-P.; Le Fèvre, O.; Lilly, S. J.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Bardelli, S.; Bolzonella, M.; Bongiorno, A.; Caputi, K.; Coppa, G.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovač, K.; Lamareille, F.; Le Borgne, J.-F.; Le Brun, V.; Maier, C.; Magnelli, B.; Pelló, R.; Peng, Y.; Perez-Montero, E.; Ricciardelli, E.; Riguccini, L.; Tanaka, M.; Tasca, L. A. M.; Tresse, L.; Vergani, D.; Zucca, E.

2012-10-01

We empirically MD test the relation between the SFR(LIR) derived from the infrared luminosity, LIR, and the SFR(Hα) derived from the Hα emission line luminosity using simple conversion relations. We use a sample of 474 galaxies at z = 0.06-0.46 with both Hα detection [from 20k redshift Cosmological Evolution (zCOSMOS) survey] and new far-IR Herschel data (100 and 160 μm). We derive SFR(Hα) from the Hα extinction corrected emission line luminosity. We find a very clear trend between E(B - V) and LIR that allows us to estimate extinction values for each galaxy even if the Hβ emission line measurement is not reliable. We calculate the LIR by integrating from 8 up to 1000 μm the spectral energy distribution (SED) that is best fitting our data. We compare the SFR(Hα) with the SFR(LIR). We find a very good agreement between the two star formation rate (SFR) estimates, with a slope of m = 1.01 ± 0.03 in the log SFR(LIR) versus log SFR(Hα) diagram, a normalization constant of a = -0.08 ± 0.03 and a dispersion of σ = 0.28 dex. We study the effect of some intrinsic properties of the galaxies in the SFR(LIR)-SFR(Hα) relation, such as the redshift, the mass, the specific star formation rate (SSFR) or the metallicity. The metallicity is the parameter that affects most the SFR comparison. The mean ratio of the two SFR estimators log[SFR(LIR)/SFR(Hα)] varies by ˜0.6 dex from metal-poor to metal-rich galaxies [8.1 statistics of this sub-sample. Herschel is a European Space Agency (ESA) space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

A Comprehensive Study of ULIRGs in the Herschel Very Wide Field Surveys

Science.gov (United States)

Yan, Haojing

Extreme starbursting galaxies exist at all redshifts, and most of them are so heavily obscured by dust that they are Ultra-Luminous InfraRed Galaxies (ULIRGs) while being faint in optical to near-IR. The latest example is at record-high z=6.337, approaching the end of the reionization. There have been numerous suggestions that understanding ULIRG is critical in constructing a comprehensive picture of galaxy formation history. These range from the hypothesis three decades ago that the ULIRG phase is the prelude to QSO and large ellipticals, to the recent tentative evidence that ULIRG could make a large (if not dominant) contribution to the global star formation rate density (GSFRD) at z>1. However, the exact nature of ULIRG and their role in galaxy assembly still remain illusive, largely due to the limited sample size and the severe source confusion problem in the far-IR (FIR). The very wide field surveys by Herschel have provided the best opportunity to date to systematically study ULIRG beyond the local universe, most importantly because of their wide coverage and high sensitivity to probe large volumes to high redshifts and the multiple FIR bands that allow for direct measurement of the IR luminosities. We propose to construct the largest possible ULIRG sample in these fields at all redshifts, and to study the evolution of ULIRGs. We will concentrate on the HerMES, the H-ATLAS and the HerS programs whose data are already public. While the confusion problem still persists in these Herschel data, we have demonstrated that it is possible to directly use the position priors from optical images to decompose the candidate contributors to a given Herschel source if its S/N suffices (Yan et al. 2014). This is a significant improvement over previous studies where higher-resolution mid-IR (mostly Spitzer MIPS 24-micron) data had to be used as the proxies to the FIR source locations, because (1) such proxy images also suffer from the blending problem in the first place and

SPITZER IMAGING OF STRONGLY LENSED HERSCHEL-SELECTED DUSTY STAR-FORMING GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Ma, Brian; Cooray, Asantha; Calanog, J. A.; Nayyeri, H.; Timmons, N.; Casey, C. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Baes, M. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Chapman, S. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 4R2 (Canada); Dannerbauer, H. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Université Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France); Da Cunha, E. [Center for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn VIC 3122 (Australia); De Zotti, G. [INAF-Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy); Dunne, L.; Michałowski, M. J.; Oteo, I. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Fu, Hai [Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242 (United States); Gonzalez-Nuevo, J. [Departamento de Fisica, Universidad de Oviedo C/ Calvo Sotelo, s/n, E-33007 Oviedo (Spain); Magdis, G. [Department of Astrophysics, Denys Wilkinson Building, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Riechers, D. A. [Department of Astronomy, Cornell University, 220 Space Sciences Building, Ithaca, NY 14853 (United States); Scott, D. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); and others

2015-11-20

We present the rest-frame optical spectral energy distribution (SED) and stellar masses of six Herschel-selected gravitationally lensed dusty, star-forming galaxies (DSFGs) at 1 < z < 3. These galaxies were first identified with Herschel/SPIRE imaging data from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). The targets were observed with Spitzer/IRAC at 3.6 and 4.5 μm. Due to the spatial resolution of the IRAC observations at the level of 2″, the lensing features of a background DSFG in the near-infrared are blended with the flux from the foreground lensing galaxy in the IRAC imaging data. We make use of higher resolution Hubble/WFC3 or Keck/NIRC2 Adaptive Optics imaging data to fit light profiles of the foreground lensing galaxy (or galaxies) as a way to model the foreground components, in order to successfully disentangle the foreground lens and background source flux densities in the IRAC images. The flux density measurements at 3.6 and 4.5 μm, once combined with Hubble/WFC3 and Keck/NIRC2 data, provide important constraints on the rest-frame optical SED of the Herschel-selected lensed DSFGs. We model the combined UV- to millimeter-wavelength SEDs to establish the stellar mass, dust mass, star formation rate, visual extinction, and other parameters for each of these Herschel-selected DSFGs. These systems have inferred stellar masses in the range 8 × 10{sup 10}–4 × 10{sup 11} M{sub ⊙} and star formation rates of around 100 M{sub ⊙} yr{sup −1}. This puts these lensed submillimeter systems well above the SFR-M* relation observed for normal star-forming galaxies at similar redshifts. The high values of SFR inferred for these systems are consistent with a major merger-driven scenario for star formation.

LENS MODELS OF HERSCHEL-SELECTED GALAXIES FROM HIGH-RESOLUTION NEAR-IR OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Calanog, J. A.; Cooray, A.; Ma, B.; Casey, C. M. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Fu, Hai [Department of Physics and Astronomy, University of Iowa, Van Allen Hall, Iowa City, IA 52242 (United States); Wardlow, J. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Amber, S. [Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom); Baker, A. J. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Baes, M. [1 Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281, B-9000 Gent (Belgium); Bock, J. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Bourne, N.; Dye, S. [School of Physics and Astronomy, University of Nottingham, NG7 2RD (United Kingdom); Bussmann, R. S. [Department of Astronomy, Space Science Building, Cornell University, Ithaca, NY 14853-6801 (United States); Chapman, S. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Clements, D. L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Conley, A. [Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States); Dannerbauer, H. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Université Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France); De Zotti, G. [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Dunne, L.; Eales, S. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); and others

2014-12-20

We present Keck-Adaptive Optics and Hubble Space Telescope high resolution near-infrared (IR) imaging for 500 μm bright candidate lensing systems identified by the Herschel Multi-tiered Extragalactic Survey and Herschel Astrophysical Terahertz Large Area Survey. Out of 87 candidates with near-IR imaging, 15 (∼17%) display clear near-IR lensing morphologies. We present near-IR lens models to reconstruct and recover basic rest-frame optical morphological properties of the background galaxies from 12 new systems. Sources with the largest near-IR magnification factors also tend to be the most compact, consistent with the size bias predicted from simulations and previous lensing models for submillimeter galaxies (SMGs). For four new sources that also have high-resolution submillimeter maps, we test for differential lensing between the stellar and dust components and find that the 880 μm magnification factor (μ{sub 880}) is ∼1.5 times higher than the near-IR magnification factor (μ{sub NIR}), on average. We also find that the stellar emission is ∼2 times more extended in size than dust. The rest-frame optical properties of our sample of Herschel-selected lensed SMGs are consistent with those of unlensed SMGs, which suggests that the two populations are similar.

Herschel observations of extraordinary sources: Analysis of the full Herschel/HIFI molecular line survey of sagittarius B2(N)

Energy Technology Data Exchange (ETDEWEB)

Neill, Justin L.; Bergin, Edwin A.; Crockett, Nathan R.; Favre, Cécile; Anderson, Dana E.; Burkhardt, Andrew M.; McNeill, Trevor D. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Lis, Dariusz C.; Emprechtinger, Martin; Monje, Raquel R.; Phillips, Thomas G. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Schilke, Peter; Comito, Claudia; Qin, Sheng-Li [Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln (Germany); Chen, Jo-Hsin [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Harris, Brent J.; Steber, Amanda L.; Vasyunina, Tatiana [Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904 (United States); Lord, Steven D. [National Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); McGuire, Brett A., E-mail: jneill@umich.edu, E-mail: ebergin@umich.edu [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 (United States); and others

2014-07-01

A sensitive broadband molecular line survey of the Sagittarius B2(N) star-forming region has been obtained with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on the Herschel Space Observatory, offering the first high spectral resolution look at this well-studied source in a wavelength region largely inaccessible from the ground (625-157 μm). From the roughly 8000 spectral features in the survey, a total of 72 isotopologues arising from 44 different molecules have been identified, ranging from light hydrides to complex organics, and arising from a variety of environments from cold and diffuse to hot and dense gas. We present a local thermodynamic equilibrium (LTE) model to the spectral signatures of each molecule, constraining the source sizes for hot core species with complementary Submillimeter Array interferometric observations and assuming that molecules with related functional group composition are cospatial. For each molecule, a single model is given to fit all of the emission and absorption features of that species across the entire 480-1910 GHz spectral range, accounting for multiple temperature and velocity components when needed to describe the spectrum. As with other HIFI surveys toward massive star-forming regions, methanol is found to contribute more integrated line intensity to the spectrum than any other species. We discuss the molecular abundances derived for the hot core where the LTE approximation is generally found to describe the spectrum well, in comparison to abundances derived for the same molecules in the Orion KL region from a similar HIFI survey. Notably, we find significantly higher abundances of amine- and amide-bearing molecules (CH{sub 3}NH{sub 2}, CH{sub 2}NH, and NH{sub 2}CHO) toward Sgr B2(N) than Orion KL and lower abundances of some complex oxygen-bearing molecules (CH{sub 3}OCHO in particular). In addition to information on the chemical composition of the hot core, the strong far-infrared dust continuum allows

THE HERSCHEL AND JCMT GOULD BELT SURVEYS: CONSTRAINING DUST PROPERTIES IN THE PERSEUS B1 CLUMP WITH PACS, SPIRE, AND SCUBA-2

Energy Technology Data Exchange (ETDEWEB)

Sadavoy, S. I.; Di Francesco, J.; Johnstone, D.; Fallscheer, C.; Matthews, B. [Department of Physics and Astronomy, University of Victoria, P.O. Box 355, STN CSC, Victoria, BC V8W 3P6 (Canada); Currie, M. J.; Jenness, T. [Joint Astronomy Centre, 660 N. A' ohoku Place, University Park, Hilo, HI 96720 (United States); Drabek, E.; Hatchell, J. [School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Nutter, D. [School of Physics and Astronomy, Cardiff University, Queen' s Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Andre, Ph.; Hennemann, M.; Hill, T.; Koenyves, V. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/Service d' Astrophysique, Saclay, F-91191 Gif-sur-Yvette (France); Arzoumanian, D. [IAS, CNRS (UMR 8617), Universite Paris-Sud 11, Batiment 121, F-91400 Orsay (France); Benedettini, M. [Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, I-00133 Rome (Italy); Bernard, J.-P. [CNRS, IRAP, 9 Av. colonel Roche, BP 44346, F-31028 Toulouse Cedex 4 (France); Duarte-Cabral, A. [Universite de Bordeaux, LAB, UMR 5804, F-33270 Floirac (France); Friesen, R. [Dunlap Institute, University of Toronto, Toronto, ON M5S 3H8 (Canada); Greaves, J. [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Collaboration: JCMT and Herschel Gould Belt Survey teams; and others

2013-04-20

We present Herschel observations from the Herschel Gould Belt Survey and SCUBA-2 science verification observations from the JCMT Gould Belt Survey of the B1 clump in the Perseus molecular cloud. We determined the dust emissivity index using four different techniques to combine the Herschel PACS+SPIRE data at 160-500 {mu}m with the SCUBA-2 data at 450 {mu}m and 850 {mu}m. Of our four techniques, we found that the most robust method was filtering out the large-scale emission in the Herschel bands to match the spatial scales recovered by the SCUBA-2 reduction pipeline. Using this method, we find {beta} Almost-Equal-To 2 toward the filament region and moderately dense material and lower {beta} values ({beta} {approx}> 1.6) toward the dense protostellar cores, possibly due to dust grain growth. We find that {beta} and temperature are more robust with the inclusion of the SCUBA-2 data, improving estimates from Herschel data alone by factors of {approx}2 for {beta} and by {approx}40% for temperature. Furthermore, we find core mass differences of {approx}< 30% compared to Herschel-only estimates with an adopted {beta} = 2, highlighting the necessity of long-wavelength submillimeter data for deriving accurate masses of prestellar and protostellar cores.

GOODS-HERSCHEL: SEPARATING HIGH-REDSHIFT ACTIVE GALACTIC NUCLEI AND STAR-FORMING GALAXIES USING INFRARED COLOR DIAGNOSTICS

Energy Technology Data Exchange (ETDEWEB)

Kirkpatrick, Allison; Pope, Alexandra [Department of Astronomy, University of Massachusetts, Amherst, MA 01002 (United States); Charmandaris, Vassilis [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003, Heraklion (Greece); Daddi, Emmanuele; Elbaz, David; Pannella, Maurilio; Aussel, Herve; Dasyra, Kalliopi; Leiton, Roger [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Hwang, Ho Seong [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Scott, Douglas; Magnelli, Benjamin; Popesso, Paola [Max-Planck-Institut fuer Extraterrestrische Physik (MPE), Postfach 1312, D-85741, Garching (Germany); Altieri, Bruno; Coia, Daniela; Valtchanov, Ivan [Herschel Science Centre, European Space Astronomy Centre, Villanueva de la Canada, E-28691 Madrid (Spain); Dannerbauer, Helmut [Universitaet Wien, Institut fuer Astrophysik, Tuerkenschanzstrasse 17, A-1180 Wien (Austria); Dickinson, Mark; Kartaltepe, Jeyhan [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Magdis, Georgios [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)

2013-02-15

We have compiled a large sample of 151 high-redshift (z = 0.5-4) galaxies selected at 24 {mu}m (S {sub 24} > 100 {mu}Jy) in the GOODS-N and ECDFS fields for which we have deep Spitzer IRS spectroscopy, allowing us to decompose the mid-infrared spectrum into contributions from star formation and activity in the galactic nuclei. In addition, we have a wealth of photometric data from Spitzer IRAC/MIPS and Herschel PACS/SPIRE. We explore how effective different infrared color combinations are at separating our mid-IR spectroscopically determined active galactic nuclei from our star-forming galaxies. We look in depth at existing IRAC color diagnostics, and we explore new color-color diagnostics combining mid-IR, far-IR, and near-IR photometry, since these combinations provide the most detail about the shape of a source's IR spectrum. An added benefit of using a color that combines far-IR and mid-IR photometry is that it is indicative of the power source driving the IR luminosity. For our data set, the optimal color selections are S {sub 250}/S {sub 24} versus S {sub 8}/S {sub 3.6} and S {sub 100}/S {sub 24} versus S {sub 8}/S {sub 3.6}; both diagnostics have {approx}10% contamination rate in the regions occupied primarily by star-forming galaxies and active galactic nuclei, respectively. Based on the low contamination rate, these two new IR color-color diagnostics are ideal for estimating both the mid-IR power source of a galaxy when spectroscopy is unavailable and the dominant power source contributing to the IR luminosity. In the absence of far-IR data, we present color diagnostics using the Wide-field Infrared Survey Explorer mid-IR bands which can efficiently select out high-z (z {approx} 2) star-forming galaxies.

The HERSCHEL/PACS early Data Products

Science.gov (United States)

Wieprecht, E.; Wetzstein, M.; Huygen, R.; Vandenbussche, B.; De Meester, W.

2006-07-01

ESA's Herschel Space Observatory to be launched in 2007, is the first space observatory covering the full far-infrared and submillimeter wavelength range (60 - 670 microns). The Photodetector Array Camera & Spectrometer (PACS) is one of the three science instruments. It contains two Ge:Ga photoconductor arrays and two bolometer arrays to perform imaging line spectroscopy and imaging photometry in the 60 - 210 micron wavelength band. The HERSCHEL ground segment (Herschel Common Science System - HCSS) is implemented using JAVA technology and written in a common effort by the HERSCHEL Science Center and the three instrument teams. The PACS Common Software System (PCSS) is based on the HCSS and used for the online and offline analysis of PACS data. For telemetry bandwidth reasons PACS science data are partially processed on board, compressed, cut into telemetry packets and transmitted to the ground. These steps are instrument mode dependent. We will present the software model which allows to reverse the discrete on board processing steps and evaluate the data. After decompression and reconstruction the detector data and instrument status information are organized in two main PACS Products. The design of these JAVA classes considers the individual sampling rates, data formats, memory and performance optimization aspects and comfortable user interfaces.

Infrared Sky Surveys

Science.gov (United States)

Price, Stephan D.

2009-02-01

A retrospective is given on infrared sky surveys from Thomas Edison’s proposal in the late 1870s to IRAS, the first sensitive mid- to far-infrared all-sky survey, and the mid-1990s experiments that filled in the IRAS deficiencies. The emerging technology for space-based surveys is highlighted, as is the prominent role the US Defense Department, particularly the Air Force, played in developing and applying detector and cryogenic sensor advances to early mid-infrared probe-rocket and satellite-based surveys. This technology was transitioned to the infrared astronomical community in relatively short order and was essential to the success of IRAS, COBE and ISO. Mention is made of several of the little known early observational programs that were superseded by more successful efforts.

"Heart" of Herschel to be presented to media

Science.gov (United States)

2007-09-01

The Herschel mission, equipped with the largest telescope ever launched in space (3.5 m diameter), will give astronomers their best capability yet to explore the universe at far-infrared and sub-millimetre wavelengths. By measuring the light at these wavelengths, scientists see the ‘cold’ universe. Herschel will give them an unprecedented view, allowing them to see deep into star forming regions, galactic centres and planetary systems. In order to achieve its objectives and to be able to detect the faint radiation coming from the coolest objects in the cosmos, otherwise ‘invisible’, Herschel’s detectors must operate at very low and stable temperatures. The spacecraft is equipped so as to cool them close to absolute zero (-273.15 ºC), ranging from -271 ºC to only a few tenths of a degree above absolute zero. To have achieved this particular feature alone is a remarkable accomplishment for European industry and science. The final integration of the various components of the Herschel spacecraft - payload module, cryostat, service module, telescope and solar arrays - will be completed in the next few months. This phase will be followed by a series of tests to get the spacecraft ready for launch at the end of July 2008. Herschel will be launched into space on an Ariane 5 ECA rocket. The launch is shared with Planck, ESA’s mission to study relic radiation from the Big Bang. Media interested to attend the press event are invited to fill in the reply form below. Note for editors The Prime Contractor for the Herschel spacecraft is Thales Alenia Space (Cannes, France). It leads a consortium of industrial partners with Astrium (Germany) responsible for the Extended Payload Module (EPLM, including the Herschel cryostat), Astrium (France) responsible for the telescope, and the Thales Alenia Space industry branch of Torino, Italy, responsible for the Service Module (SVM). There is also a host of subcontractors spread throughout Europe. The three Herschel

THE EXTRAORDINARY FAR-INFRARED VARIATION OF A PROTOSTAR: HERSCHEL/PACS OBSERVATIONS OF LRLL54361

Energy Technology Data Exchange (ETDEWEB)

Balog, Zoltan; Detre, Örs H.; Bouwmann, Jeroen; Nielbock, Markus; Klaas, Ulrich; Krause, Oliver; Henning, Thomas [Max Planck Institute for Astronomy Königstuhl 17, Heidelberg D-69117 (Germany); Muzerolle, James [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Flaherty, Kevin [Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States); Furlan, Elise [Natinal Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Gutermuth, Rob [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Juhasz, Attila [Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333-CA Leiden (Netherlands); Bally, John [CASA, University of Colorado, CB 389, Boulder, CO 80309 (United States); Marton, Gabor, E-mail: balog@mpia.de [Konkoly Observatory, Research Center for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege 15-17, 1121 Budapest (Hungary)

2014-07-10

We report Herschel/Photodetector Array Camera and Spectrometer (PACS) photometric observations at 70 μm and 160 μm of LRLL54361—a suspected binary protostar that exhibits periodic (P = 25.34 days) flux variations at shorter wavelengths (3.6 μm and 4.5 μm) thought to be due to pulsed accretion caused by binary motion. The PACS observations show unprecedented flux variation at these far-infrared wavelengths that are well correlated with the variations at shorter wavelengths. At 70 μm the object increases its flux by a factor of six while at 160 μm the change is about a factor of two, consistent with the wavelength dependence seen in the far-infrared spectra. The source is marginally resolved at 70 μm with varying FWHM. Deconvolved images of the sources show elongations exactly matching the outflow cavities traced by the scattered light observations. The spatial variations are anti-correlated with the flux variation, indicating that a light echo is responsible for the changes in FWHM. The observed far-infrared flux variability indicates that the disk and envelope of this source is periodically heated by the accretion pulses of the central source, and suggests that such long wavelength variability in general may provide a reasonable proxy for accretion variations in protostars.

The first results from the Herschel-HIFI mission

NARCIS (Netherlands)

van der Tak, Floris

2012-01-01

This paper contains a summary of the results from the first years of observations with the HIFI instrument onboard ESA's Herschel space observatory. The paper starts by outlining the goals and possibilities of far-infrared and submillimeter astronomy, the limitations of the Earth's atmosphere, and

Far-infrared photometry of OJ 287 with the Herschel Space Observatory

Science.gov (United States)

Kidger, Mark; Zola, Staszek; Valtonen, Mauri; Lähteenmäki, Anne; Järvelä, Emilia; Tornikoski, Merja; Tammi, Joni; Liakos, Alexis; Poyner, Gary

2018-03-01

Context. The blazar OJ 287 has shown a ≈12 year quasi-periodicity over more than a century, in addition to the common properties of violent variability in all frequency ranges. It is the strongest known candidate to have a binary singularity in its central engine. Aim. We aim to better understand the different emission components by searching for correlated variability in the flux over four decades of frequency measurements. Methods: We combined data at frequencies from the millimetric to the visible to characterise the multifrequency light curve in April and May 2010. This includes the only photometric observations of OJ 287 made with the Herschel Space Observatory: five epochs of data obtained over 33 days at 250, 350, and 500 μm with Herschel-SPIRE. Results: Although we find that the variability at 37 GHz on timescales of a few weeks correlates with the visible to near-IR spectral energy distribution, there is a small degree of reddening in the continuum at lower flux levels that is revealed by the decreasing rate of decline in the light curve at lower frequencies. However, we see no clear evidence that a rapid flare detected in the light curve during our monitoring in the visible to near-IR light curve is seen either in the Herschel data or at 37 GHz, suggesting a low-frequency cut-off in the spectrum of such flares. Conclusions.We see only marginal evidence of variability in the observations with Herschel over a month, although this may be principally due to the poor sampling. The spectral energy distribution between 37 GHz and the visible can be characterised by two components of approximately constant spectral index: a visible to far-IR component of spectral index α = -0.95, and a far-IR to millimetric spectral index of α = -0.43. There is no evidence of an excess of emission that would be consistent with the 60 μmdust bump found in many active galactic nuclei. Herschel is an ESA space observatory with science instruments provided by European

A COOL DUST FACTORY IN THE CRAB NEBULA: A HERSCHEL STUDY OF THE FILAMENTS

Energy Technology Data Exchange (ETDEWEB)

Gomez, H. L.; Clark, C. J. R.; Gomez, E. L.; Gear, W. K. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Krause, O.; Besel, M.-A.; Bouwman, J.; Henning, Th. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Barlow, M. J.; Swinyard, B. M.; Owen, P. J.; Matsuura, M. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Rho, J. [SOFIA Science Center, Universities Space Research Association, NASA Ames Research Center, MS 232, Moffett Field, CA 94035 (United States); Ivison, R. J.; Sibthorpe, B. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Polehampton, E. T. [Space Science and Technology Department, Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX (United Kingdom)

2012-11-20

Whether supernovae are major sources of dust in galaxies is a long-standing debate. We present infrared and submillimeter photometry and spectroscopy from the Herschel Space Observatory of the Crab Nebula between 51 and 670 {mu}m as part of the Mass Loss from Evolved StarS program. We compare the emission detected with Herschel with multiwavelength data including millimeter, radio, mid-infrared, and archive optical images. We carefully remove the synchrotron component using the Herschel and Planck fluxes measured in the same epoch. The contribution from line emission is removed using Herschel spectroscopy combined with Infrared Space Observatory archive data. Several forbidden lines of carbon, oxygen, and nitrogen are detected where multiple velocity components are resolved, deduced to be from the nitrogen-depleted, carbon-rich ejecta. No spectral lines are detected in the SPIRE wavebands; in the PACS bands, the line contribution is 5% and 10% at 70 and 100 {mu}m and negligible at 160 {mu}m. After subtracting the synchrotron and line emission, the remaining far-infrared continuum can be fit with two dust components. Assuming standard interstellar silicates, the mass of the cooler component is 0.24{sup +0.32} {sub -0.08} M {sub Sun} for T = 28.1{sup +5.5} {sub -3.2} K. Amorphous carbon grains require 0.11 {+-} 0.01 M {sub Sun} of dust with T = 33.8{sup +2.3} {sub -1.8} K. A single temperature modified blackbody with 0.14 M {sub Sun} and 0.08 M {sub Sun} for silicate and carbon dust, respectively, provides an adequate fit to the far-infrared region of the spectral energy distribution but is a poor fit at 24-500 {mu}m. The Crab Nebula has condensed most of the relevant refractory elements into dust, suggesting the formation of dust in core-collapse supernova ejecta is efficient.

A far-infrared spectroscopic survey of intermediate redshift (ultra) luminous infrared galaxies

International Nuclear Information System (INIS)

Magdis, Georgios E.; Rigopoulou, D.; Hopwood, R.; Clements, D.; Huang, J.-S.; Farrah, D.; Pearson, C.; Alonso-Herrero, Almudena; Bock, J. J.; Cooray, A.; Griffin, M. J.; Oliver, S.; Perez Fournon, I.; Riechers, D.; Swinyard, B. M.; Thatte, N.; Scott, D.; Valtchanov, I.; Vaccari, M.

2014-01-01

We present Herschel far-IR photometry and spectroscopy as well as ground-based CO observations of an intermediate redshift (0.21 ≤ z ≤ 0.88) sample of Herschel-selected (ultra)-luminous infrared galaxies (L IR > 10 11.5 L ☉ ). With these measurements, we trace the dust continuum, far-IR atomic line emission, in particular [C II] 157.7 μm, as well as the molecular gas of z ∼ 0.3 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) and perform a detailed investigation of the interstellar medium of the population. We find that the majority of Herschel-selected intermediate redshift (U)LIRGs have L C II /L FIR ratios that are a factor of about 10 higher than that of local ULIRGs and comparable to that of local normal and high-z star-forming galaxies. Using our sample to bridge local and high-z [C II] observations, we find that the majority of galaxies at all redshifts and all luminosities follow an L C II –L FIR relation with a slope of unity, from which local ULIRGs and high- z active-galactic-nucleus-dominated sources are clear outliers. We also confirm that the strong anti-correlation between the L C II /L FIR ratio and the far-IR color L 60 /L 100 observed in the local universe holds over a broad range of redshifts and luminosities, in the sense that warmer sources exhibit lower L C II /L FIR at any epoch. Intermediate redshift ULIRGs are also characterized by large molecular gas reservoirs and by lower star formation efficiencies compared to that of local ULIRGs. The high L C II /L FIR ratios, the moderate star formation efficiencies (L IR /L CO ′ or L IR /M H 2 ), and the relatively low dust temperatures of our sample (which are also common characteristics of high-z star-forming galaxies with ULIRG-like luminosities) indicate that the evolution of the physical properties of (U)LIRGs between the present day and z > 1 is already significant by z ∼ 0.3.

A Herschel-Resolved Debris Disk Around the Nearby G Star HIP 32480

Science.gov (United States)

Stapelfeldt, K.

2011-01-01

The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a G0 star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grainsize of approximately 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

Herschel Observations of Extraordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey toward Orion KL. I. Methods

NARCIS (Netherlands)

Crockett, Nathan R.; Bergin, Edwin A.; Neill, Justin L.; Favre, Cécile; Schilke, Peter; Lis, Dariusz C.; Bell, Tom A.; Blake, Geoffrey; Cernicharo, José; Emprechtinger, Martin; Esplugues, Gisela B.; Gupta, Harshal; Kleshcheva, Maria; Lord, Steven; Marcelino, Nuria; McGuire, Brett A.; Pearson, John; Phillips, Thomas G.; Plume, Rene; van der Tak, Floris; Tercero, Belén; Yu, Shanshan

We present a comprehensive analysis of a broadband spectral line survey of the Orion Kleinmann-Low nebula (Orion KL), one of the most chemically rich regions in the Galaxy, using the HIFI instrument on board the Herschel Space Observatory. This survey spans a frequency range from 480 to 1907 GHz at

CAN DUST EMISSION BE USED TO ESTIMATE THE MASS OF THE INTERSTELLAR MEDIUM IN GALAXIES-A PILOT PROJECT WITH THE HERSCHEL REFERENCE SURVEY

Energy Technology Data Exchange (ETDEWEB)

Eales, Stephen; Smith, Matthew W. L.; Auld, Robbie; Davies, Jon; Gear, Walter; Gomez, Haley [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Baes, Maarten; De Looze, Ilse; Gentile, Gianfranco; Fritz, Jacopo [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, George J. [UK ALMA Regional Centre Node, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Bianchi, Simone [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Boselli, Alessandro; Ciesla, Laure [Laboratoire d' Astrophysique de Marseilles, UMR6110 CNRS, 38 rue F. Joliot-Curie, F-1338 Marseilles (France); Clements, David [Astrophysics Group, Imperial College, Blackett Lab, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Cortese, Luca [European Southern Observatory, Karl-Schwarzschild-Strasse 2 D-85748, Garching bei Munchen (Germany); Galametz, Maud [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hughes, Tom [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Madden, Suzanne [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d' Astrophysique, F-91191 Gif sur Yvette (France); and others

2012-12-20

The standard method for estimating the mass of the interstellar medium (ISM) in a galaxy is to use the 21 cm line to trace the atomic gas and the CO 1-0 line to trace the molecular gas. In this paper, we investigate the alternative technique of using the continuum dust emission to estimate the mass of gas in all phases of the ISM. Using Herschel observations of 10 galaxies from the Herschel Reference Survey and the Herschel Virgo Cluster Survey, we show that the emission detected by Herschel is mostly from dust that has a temperature and emissivity index similar to that of dust in the local ISM in our galaxy, with the temperature generally increasing toward the center of each galaxy. We calibrate the dust method using the CO and 21 cm observations to provide an independent estimate of the mass of hydrogen in each galaxy, solving the problem of the uncertain ''X-factor'' for the CO observations by minimizing the dispersion in the ratio of the masses estimated using the two methods. With the calibration for the dust method and the estimate of the X-factor produced in this way, the dispersion in the ratio of the two gas masses is 25%. The calibration we obtain for the dust method is similar to those obtained from Herschel observations of M31 and from Planck observations of the Milky Way. We discuss the practical problems in using this method.

THE HERSCHEL DIGIT SURVEY OF WEAK-LINE T TAURI STARS: IMPLICATIONS FOR DISK EVOLUTION AND DISSIPATION

International Nuclear Information System (INIS)

Cieza, Lucas A.; Olofsson, Johan; Henning, Thomas; Harvey, Paul M.; Evans, Neal J. II; Najita, Joan; Merín, Bruno; Liebhart, Armin; Güdel, Manuel; Augereau, Jean-Charles; Pinte, Christophe

2013-01-01

As part of the 'Dust, Ice, and Gas In Time (DIGIT)' Herschel Open Time Key Program, we present Herschel photometry (at 70, 160, 250, 350, and 500 μm) of 31 weak-line T Tauri star (WTTS) candidates in order to investigate the evolutionary status of their circumstellar disks. Of the stars in our sample, 13 had circumstellar disks previously known from infrared observations at shorter wavelengths, while 18 of them had no previous evidence for a disk. We detect a total of 15 disks as all previously known disks are detected at one or more Herschel wavelengths and two additional disks are identified for the first time. The spectral energy distributions (SEDs) of our targets seem to trace the dissipation of the primordial disk and the transition to the debris disk regime. Of the 15 disks, 7 appear to be optically thick primordial disks, including 2 objects with SEDs indistinguishable from those of typical Classical T Tauri stars, 4 objects that have significant deficit of excess emission at all IR wavelengths, and 1 'pre-transitional' object with a known gap in the disk. Despite their previous WTTS classification, we find that the seven targets in our sample with optically thick disks show evidence for accretion. The remaining eight disks have weaker IR excesses similar to those of optically thin debris disks. Six of them are warm and show significant 24 μm Spitzer excesses, while the last two are newly identified cold debris-like disks with photospheric 24 μm fluxes, but significant excess emission at longer wavelengths. The Herschel photometry also places strong constraints on the non-detections, where systems with F 70 /F 70,* ∼> 5-15 and L disk /L * ∼> 10 –3 to 10 –4 can be ruled out. We present preliminary models for both the optically thick and optically thin disks and discuss our results in the context of the evolution and dissipation of circumstellar disks.

THE HERSCHEL DIGIT SURVEY OF WEAK-LINE T TAURI STARS: IMPLICATIONS FOR DISK EVOLUTION AND DISSIPATION

Energy Technology Data Exchange (ETDEWEB)

Cieza, Lucas A. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Olofsson, Johan; Henning, Thomas [Max Planck Institute fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany); Harvey, Paul M.; Evans, Neal J. II [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Najita, Joan [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 86719 (United States); Merin, Bruno [Herschel Science Centre, European Space Astronomy Centre, ESA, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Liebhart, Armin; Guedel, Manuel [Department of Astronomy, University of Vienna, Tuerkenschanzstr. 17, A-1180 Vienna (Austria); Augereau, Jean-Charles; Pinte, Christophe, E-mail: lcieza@ifa.hawaii.edu [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique (IPAG) UMR 5274, BP 53, F-38041 Grenoble cedex 9 (France)

2013-01-10

As part of the 'Dust, Ice, and Gas In Time (DIGIT)' Herschel Open Time Key Program, we present Herschel photometry (at 70, 160, 250, 350, and 500 {mu}m) of 31 weak-line T Tauri star (WTTS) candidates in order to investigate the evolutionary status of their circumstellar disks. Of the stars in our sample, 13 had circumstellar disks previously known from infrared observations at shorter wavelengths, while 18 of them had no previous evidence for a disk. We detect a total of 15 disks as all previously known disks are detected at one or more Herschel wavelengths and two additional disks are identified for the first time. The spectral energy distributions (SEDs) of our targets seem to trace the dissipation of the primordial disk and the transition to the debris disk regime. Of the 15 disks, 7 appear to be optically thick primordial disks, including 2 objects with SEDs indistinguishable from those of typical Classical T Tauri stars, 4 objects that have significant deficit of excess emission at all IR wavelengths, and 1 'pre-transitional' object with a known gap in the disk. Despite their previous WTTS classification, we find that the seven targets in our sample with optically thick disks show evidence for accretion. The remaining eight disks have weaker IR excesses similar to those of optically thin debris disks. Six of them are warm and show significant 24 {mu}m Spitzer excesses, while the last two are newly identified cold debris-like disks with photospheric 24 {mu}m fluxes, but significant excess emission at longer wavelengths. The Herschel photometry also places strong constraints on the non-detections, where systems with F {sub 70}/F {sub 70,*} {approx}> 5-15 and L {sub disk}/L {sub *} {approx}> 10{sup -3} to 10{sup -4} can be ruled out. We present preliminary models for both the optically thick and optically thin disks and discuss our results in the context of the evolution and dissipation of circumstellar disks.

HERSCHEL REVEALS MASSIVE COLD CLUMPS IN NGC 7538

Energy Technology Data Exchange (ETDEWEB)

Fallscheer, C.; Di Francesco, J.; Sadavoy, S. [Department of Physics and Astronomy, University of Victoria, P.O. Box 355, STN CSC, Victoria, BC V8W 3P6 (Canada); Reid, M. A. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Martin, P. G.; Nguyen-Luong, Q. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Hill, T.; Hennemann, M.; Motte, F.; Men' shchikov, A.; Andre, Ph.; Konyves, V.; Sauvage, M. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/Service d' Astrophysique, Saclay, F-91191 Gif-sur-Yvette (France); Ward-Thompson, D.; Kirk, J. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston, Lancashire, PR1 2HE (United Kingdom); Griffin, M. [School of Physics and Astronomy, Cardiff University, Queen' s Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Rygl, K. L. J.; Benedettini, M. [INAF, Istituto di Astrofisica e Planetologia Spaziali, Area di Ricerca di Tor Vergata, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Schneider, N. [Universite de Bordeaux, LAB, UMR 5804, F-33270, Floirac (France); Anderson, L. D. [Laboratoire d' Astrophysique de Marseille, CNRS/INSU, Universite de Provence, F-13388 Marseille Cedex 13 (France); and others

2013-08-20

We present the first overview of the Herschel observations of the nearby high-mass star-forming region NGC 7538, taken as part of the Herschel imaging study of OB young stellar objects (HOBYS) Key Programme. These PACS and SPIRE maps cover an approximate area of one square degree at five submillimeter and far-infrared wavebands. We have identified 780 dense sources and classified 224 of those. With the intention of investigating the existence of cold massive starless or class 0-like clumps that would have the potential to form intermediate- to high-mass stars, we further isolate 13 clumps as the most likely candidates for follow-up studies. These 13 clumps have masses in excess of 40 M{sub Sun} and temperatures below 15 K. They range in size from 0.4 pc to 2.5 pc and have densities between 3 Multiplication-Sign 10{sup 3} cm{sup -3} and 4 Multiplication-Sign 10{sup 4} cm{sup -3}. Spectral energy distributions are then used to characterize their energetics and evolutionary state through a luminosity-mass diagram. NGC 7538 has a highly filamentary structure, previously unseen in the dust continuum of existing submillimeter surveys. We report the most complete imaging to date of a large, evacuated ring of material in NGC 7538 which is bordered by many cool sources.

THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy

Science.gov (United States)

Ramos-Medina, J.; Sánchez Contreras, C.; García-Lario, P.; Rodrigo, C.; da Silva Santos, J.; Solano, E.

2018-03-01

This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 μm) with the Herschel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the catalogue of interactively reprocessed Photoconductor Array Camera and Spectrometer (PACS) spectra covering the 55-200 μm range for 114 stars in this category for which PACS range spectroscopic data is available in the Herschel Science Archive (HSA). Our sample includes objects spanning a range of evolutionary stages, from the asymptotic giant branch to the planetary nebula phase, displaying a wide variety of chemical and physical properties. The THROES/PACS catalogue is accessible via a dedicated web-based interface and includes not only the science-ready Herschel spectroscopic data for each source, but also complementary photometric and spectroscopic data from other infrared observatories, namely IRAS, ISO, or AKARI, at overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset that can be used by the scientific community in the future to deepen our knowledge and understanding of these latest stages of the evolution of low-to-intermediate mass stars. The THROES/PACS catalogue is accessible at http://https://throes.cab.inta-csic.es/

William and Caroline Herschel pioneers in late 18th-century astronomy

CERN Document Server

Hoskin, Michael

2013-01-01

This beautifully structured book presents the essentials of William and Caroline Herschel's pioneering achievements in late 18th-century astronomy. Michael Hoskin shows that William Herschel was the first observational cosmologist and one of the first observers to attack the sidereal universe beyond the solar system:Herschel built instruments far better than any being used at the royal observatory. Aided by his sister Caroline, he commenced a great systematic survey that led to his discovery of Uranus in 1781.Unlike observers before him, whose telescopes did not reveal them as astronomical obj

ANALYSIS OF THE HERSCHEL /HEXOS SPECTRAL SURVEY TOWARD ORION SOUTH: A MASSIVE PROTOSTELLAR ENVELOPE WITH STRONG EXTERNAL IRRADIATION

Energy Technology Data Exchange (ETDEWEB)

Tahani, K.; Plume, R. [Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4 (Canada); Bergin, E. A. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Tolls, V. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Phillips, T. G.; Lis, D. C. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Caux, E. [Université de Toulouse, UPS-OMP, IRAP, F-31028 Toulouse (France); Cabrit, S.; Pagani, L. [LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, F-75014, Paris (France); Goicoechea, J. R. [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC). Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid (Spain); Goldsmith, P. F.; Pearson, J. C. [Jet Propulsion Laboratory, Caltech, Pasadena, CA 91109 (United States); Johnstone, D. [National Research Council Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Menten, K. M. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Müller, H. S. P.; Ossenkopf-Okada, V. [I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln (Germany); Tak, F. F. S. van der, E-mail: ktahani@ucalgary.ca [SRON Netherlands Institute for Space Research, P.O. Box 800, 9700 AV, Groningen (Netherlands)

2016-11-20

We present results from a comprehensive submillimeter spectral survey toward the source Orion South, based on data obtained with the Heterodyne Instrument for the Far-Infrared instrument on board the Herschel Space Observatory , covering the frequency range of 480 to 1900 GHz. We detect 685 spectral lines with signal-to-noise ratios (S/Ns) > 3 σ , originating from 52 different molecular and atomic species. We model each of the detected species assuming conditions of Local Thermodynamic Equilibrium. This analysis provides an estimate of the physical conditions of Orion South (column density, temperature, source size, and V {sub LSR}). We find evidence for three different cloud components: a cool ( T {sub ex} ∼ 20–40 K), spatially extended (>60″), and quiescent (Δ V {sub FWHM} ∼ 4 km s{sup -1}) component; a warmer ( T {sub ex} ∼ 80–100 K), less spatially extended (∼30″), and dynamic (Δ V {sub FWHM} ∼ 8 km s{sup -1}) component, which is likely affected by embedded outflows; and a kinematically distinct region ( T {sub ex} > 100 K; V {sub LSR} ∼ 8 km s{sup -1}), dominated by emission from species that trace ultraviolet irradiation, likely at the surface of the cloud. We find little evidence for the existence of a chemically distinct “hot-core” component, likely due to the small filling factor of the hot core or hot cores within the Herschel beam. We find that the chemical composition of the gas in the cooler, quiescent component of Orion South more closely resembles that of the quiescent ridge in Orion-KL. The gas in the warmer, dynamic component, however, more closely resembles that of the Compact Ridge and Plateau regions of Orion-KL, suggesting that higher temperatures and shocks also have an influence on the overall chemistry of Orion South.

Water in low-mass star-forming regions with Herschel

DEFF Research Database (Denmark)

Kristensen, L. E.; Visser, R.; Van Dishoeck, E. F.

2010-01-01

"Water In Star-forming regions with Herschel" (WISH) is a key programme dedicated to studying the role of water and related species during the star-formation process and constraining the physical and chemical properties of young stellar objects. The Heterodyne Instrument for the Far-Infrared (HIF...

On-board Data Processing to Lower Bandwidth Requirements on an Infrared Astronomy Satellite: Case of Herschel-PACS Camera

Directory of Open Access Journals (Sweden)

Christian Reimers

2005-09-01

Full Text Available This paper presents a new data compression concept, “on-board processing,” for infrared astronomy, where space observatories have limited processing resources. The proposed approach has been developed and tested for the PACS camera from the European Space Agency (ESA mission, Herschel. Using lossy and lossless compression, the presented method offers high compression ratio with a minimal loss of potentially useful scientific data. It also provides higher signal-to-noise ratio than that for standard compression techniques. Furthermore, the proposed approach presents low algorithmic complexity such that it is implementable on the resource-limited hardware. The various modules of the data compression concept are discussed in detail.

The protostar OMC-2 FIR 4: Results from the CHESS Herschel/HIFI spectral survey

Science.gov (United States)

Kama, Mihkel; Lopez-Sepulcre, Ana; Ceccarelli, Cecilia; Dominik, Carsten; Caux, Emmanuel; Fuente, Asuncion

2013-07-01

The intermediate-mass protostar OMC-2 FIR 4 in Orion is the focus of several ongoing studies, including a CHESS key programme Herschel/HIFI spectral survey. In this poster, we review recent CHESS results on this source, including the properties of the central hot core, the presence of a compact outflow, the spatial variation of the chemical composition, and the discovery of a tenuous foreground cloud. The HIFI spectrum of FIR 4 contains 719 lines from 40 species and isotopologs. Cooling by lines detectable with our sensitivity contributes 2% of the total in the 480 to 1900 GHz range. The total line flux is dominated by CO, followed by H2O and CH3OH. Initial comparisons with spectral surveys of other sources will also be presented.

The SPT+Herschel+ALMA+Spitzer Legacy Survey: The stellar content of high redshift strongly lensed systems

Science.gov (United States)

Vieira, Joaquin; Ashby, Matt; Carlstrom, John; Chapman, Scott; DeBreuck, Carlos; Fassnacht, Chris; Gonzalez, Anthony; Phadke, Kedar; Marrone, Dan; Malkan, Matt; Reuter, Cassie; Rotermund, Kaja; Spilker, Justin; Weiss, Axel

2018-05-01

The South Pole Telescope (SPT) has systematically identified 90 high-redshift strongly gravitationally lensed submillimeter galaxies (SMGs) in a 2500 square-degree cosmological survey of the millimeter (mm) sky. These sources are selected by their extreme mm flux, which is largely independent of redshift and lensing configuration. We are undertaking a comprehensive and systematic followup campaign to use these "cosmic magnifying glasses" to study the infrared background in unprecedented detail, inform the condition of the interstellar medium in starburst galaxies at high redshift, and place limits on dark matter substructure. Here we ask for 115.4 hours of deep Spitzer/IRAC imaging to complete our survey of 90 systems to a uniform depth of 30min integrations at 3.6um and 60min at 4.5um. In our sample of 90 systems, 16 have already been fully observed, 30 have been partially observed, and 44 have not been observed at all. Our immediate goals are to: 1) constrain the specific star formation rates of the background high-redshift submillimeter galaxies by combining these Spitzer observations with our APEX, Herschel, and ALMA data, 2) robustly determine the stellar masses and mass-to-light ratios of all the foreground lensing galaxies in the sample by combining these observations with our VLT and Gemini data, the Dark Energy Survey, and ALMA; and 3) provide complete, deep, and uniform NIR coverage of our entire sample of lensed systems to characterize the environments of high redshift SMGs, maximize the discovery potential for additional spectacular and rare sources, and prepare for JWST. This program will provide the cornerstone data set for two PhD theses: Kedar Phadke at Illinois will lead the analysis of stellar masses for the background SMGs, and Kaja Rotermund at Dalhousie will lead the analysis of stellar masses for the foreground lenses.

The impact of clustering and angular resolution on far-infrared and millimeter continuum observations

Science.gov (United States)

Béthermin, Matthieu; Wu, Hao-Yi; Lagache, Guilaine; Davidzon, Iary; Ponthieu, Nicolas; Cousin, Morgane; Wang, Lingyu; Doré, Olivier; Daddi, Emanuele; Lapi, Andrea

2017-11-01

Follow-up observations at high-angular resolution of bright submillimeter galaxies selected from deep extragalactic surveys have shown that the single-dish sources are comprised of a blend of several galaxies. Consequently, number counts derived from low- and high-angular-resolution observations are in tension. This demonstrates the importance of resolution effects at these wavelengths and the need for realistic simulations to explore them. We built a new 2 deg2 simulation of the extragalactic sky from the far-infrared to the submillimeter. It is based on an updated version of the 2SFM (two star-formation modes) galaxy evolution model. Using global galaxy properties generated by this model, we used an abundance-matching technique to populate a dark-matter lightcone and thus simulate the clustering. We produced maps from this simulation and extracted the sources, and we show that the limited angular resolution of single-dish instruments has a strong impact on (sub)millimeter continuum observations. Taking into account these resolution effects, we are reproducing a large set of observables, as number counts and their evolution with redshift and cosmic infrared background power spectra. Our simulation consistently describes the number counts from single-dish telescopes and interferometers. In particular, at 350 and 500 μm, we find that the number counts measured by Herschel between 5 and 50 mJy are biased towards high values by a factor 2, and that the redshift distributions are biased towards low redshifts. We also show that the clustering has an important impact on the Herschel pixel histogram used to derive number counts from P(D) analysis. We find that the brightest galaxy in the beam of a 500 μm Herschel source contributes on average to only 60% of the Herschel flux density, but that this number will rise to 95% for future millimeter surveys on 30 m-class telescopes (e.g., NIKA2 at IRAM). Finally, we show that the large number density of red Herschel sources

The Herschel objects and how to observe them exploring sir William Herschel's star clusters, nebulae, and galaxies

CERN Document Server

Mullaney, James

2007-01-01

Deep-sky observers are always on the lookout for new observing challenges. "The Herschel Objects, and How to Observe them" offers an exciting opportunity to retrace the footsteps of Sir William Herschel, discoverer of Uranus and arguably the greatest visual observer and celestial explorer that ever lived!Following a biography of Herschel that details his life and the telescopes he used, this practical observer's guide lists all the most impressive of Herschel's star clusters, nebulae and galaxies.More than 600 of the brightest of the objects that Herschel observed are covered, and there are detailed descriptions and images of almost 200 of the very best Herschel objects for amateur astronomers.

Simbol-X: Synergies with JWST, ALMA and Herschel

Science.gov (United States)

Maiolino, R.

2009-05-01

I discuss the synergies between Simbol-X and three among the major astronomical facilities that, in the next decade, will be operative in the infrared-millimeter spectral range, namely JWST, Herschel and ALMA. I first provide a brief overview of the main features and observing capabilities offered by these facilities. Then I will discuss a few research fields (mostly extragalactic) that will geatly benefit of the joint exploitation of Simbol-X and these IR-mm observatories.

Calibration of a novel type of bolometer arrays for the Herschel space observatory

International Nuclear Information System (INIS)

Billot, Nicolas

2007-01-01

The Herschel mission is a major project at the core of the European Space Agency (ESA) scientific program. The space telescope will perform observations of the universes in the far-infrared regime of the electromagnetic spectrum, which still remains little-known today. Among the many research institutes involved in the development and exploitation of this challenging observatory, the CEA designed a novel type of bolometric detectors to equip the photometer of the PACS instrument on-board the Herschel satellite. During my thesis, my task was twofold, I developed a characterisation procedure that takes advantage of unique features of CEA filled bolometer arrays and I applied it to calibrate the PACS photometer and optimize its performances in the various observing modes open to the scientific community. In this manuscript, I present the basics of infrared astronomy from its very beginning in 1800 to the European Space Agency's Herschel Space Observatory. Then, I describe past and present developments in cryogenic bolometers, emphasising new concepts introduced by CEA. I follow with an explanation of the working principles of CEA bolometer arrays, a prerequisite to grasp the strategy of the characterisation procedure that we developed. Then I expose and analyse thoroughly the results that we obtained during the calibration campaign of the PACS photometer. Finally, I express detector performances in terms of 'observational' performances that future PACS users can comprehend. (author) [fr

Submillimeter H2O and H2O+emission in lensed ultra- and hyper-luminous infrared galaxies at z 2-4

NARCIS (Netherlands)

Yang, C.; Omont, A.; Beelen, A.; González-Alfonso, E.; Neri, R.; Gao, Y.; van der Werf, P.; Weiß, A.; Gavazzi, R.; Falstad, N.; Baker, A. J.; Bussmann, R. S.; Cooray, A.; Cox, P.; Dannerbauer, H.; Dye, S.; Guélin, M.; Ivison, R.; Krips, M.; Lehnert, M.; Michałowski, M. J.; Riechers, D. A.; Spaans, M.; Valiante, E.

2016-01-01

We report rest-frame submillimeter H2O emission line observations of 11 ultra- or hyper-luminous infrared galaxies (ULIRGs or HyLIRGs) at z 2-4 selected among the brightest lensed galaxies discovered in the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS). Using the IRAM NOrthern

Resolving the structure of the Galactic foreground using Herschel measurements and the Kriging technique

Science.gov (United States)

Pinter, S.; Bagoly, Z.; Balázs, L. G.; Horvath, I.; Racz, I. I.; Zahorecz, S.; Tóth, L. V.

2018-05-01

Investigating the distant extragalactic Universe requires a subtraction of the Galactic foreground. One of the major difficulties deriving the fine structure of the galactic foreground is the embedded foreground and background point sources appearing in the given fields. It is especially so in the infrared. We report our study subtracting point sources from Herschel images with Kriging, an interpolation method where the interpolated values are modelled by a Gaussian process governed by prior covariances. Using the Kriging method on Herschel multi-wavelength observations the structure of the Galactic foreground can be studied with much higher resolution than previously, leading to a better foreground subtraction at the end.

The Herschel/HIFI spectral survey of OMC-2 FIR 4 (CHESS). An overview of the 480 to 1902 GHz range

Science.gov (United States)

Kama, M.; López-Sepulcre, A.; Dominik, C.; Ceccarelli, C.; Fuente, A.; Caux, E.; Higgins, R.; Tielens, A. G. G. M.; Alonso-Albi, T.

2013-08-01

Context. Broadband spectral surveys of protostars offer a rich view of the physical, chemical and dynamical structure and evolution of star-forming regions. The Herschel Space Observatory opened up the terahertz regime to such surveys, giving access to the fundamental transitions of many hydrides and to the high-energy transitions of many other species. Aims: A comparative analysis of the chemical inventories and physical processes and properties of protostars of various masses and evolutionary states is the goal of the Herschel CHEmical Surveys of Star forming regions (CHESS) key program. This paper focusses on the intermediate-mass protostar, OMC-2 FIR 4. Methods: We obtained a spectrum of OMC-2 FIR 4 in the 480 to 1902 GHz range with the HIFI spectrometer onboard Herschel and carried out the reduction, line identification, and a broad analysis of the line profile components, excitation, and cooling. Results: We detect 719 spectral lines from 40 species and isotopologs. The line flux is dominated by CO, H2O, and CH3OH. The line profiles are complex and vary with species and upper level energy, but clearly contain signatures from quiescent gas, a broad component likely due to an outflow, and a foreground cloud. Conclusions: We find abundant evidence for warm, dense gas, as well as for an outflow in the field of view. Line flux represents 2% of the 7 L⊙ luminosity detected with HIFI in the 480 to 1250 GHz range. Of the total line flux, 60% is from CO, 13% from H2O and 9% from CH3OH. A comparison with similar HIFI spectra of other sources is set to provide much new insight into star formation regions, a case in point being a difference of two orders of magnitude in the relative contribution of sulphur oxides to the line cooling of Orion KL and OMC-2 FIR 4. Appendix A is available in electronic form at http://www.aanda.org

VizieR Online Data Catalog: Herschel FIR spectra of GOALS galaxies (Diaz-Santos+, 2017)

Science.gov (United States)

Diaz-Santos, T.; Armus, L.; Charmandaris, V.; Lu, N.; Stierwalt, S.; Stacey, G.; Malhotra, S.; van der Werf, P. P.; Howell, J. H.; Privon, G. C.; Mazzarella, J. M.; Goldsmith, P. F.; Murphy, E. J.; Barcos-Munoz, L.; Linden, S. T.; Inami, H.; Larson, K. L.; Evans, A. S.; Appleton, P.; Iwasawa, K.; Lord, S.; Sanders, D. B.; Surace, J. A.

2018-04-01

We have obtained FIR spectroscopic observations for 200 luminous infrared galaxies (LIRG) systems from the Great Observatories All-Sky LIRG Survey (GOALS; Armus+ 2009PASP..121..559A) using the Integral Field Spectrometer (IFS) of the PACS instrument on board Herschel. Since some targets contain multiple components, there are 241 individual galaxies with available spectra in at least one emission line. Most of the data were collected as part of our OT1 and OT2 programs (OT1larmus1, OT2larmus1; P.I.: L. Armus), accounting for more than 200hr of observing time in total. Additional observations that are publicly available in the Herschel archive were included from various projects. The main programs from where these complementary data were gathered are KPGTesturm1 (P.I.: E. Sturm), KPOTpvanderw1 (PI: P. van der Werf), and OT1dweedman1 (P.I.: D. Weedman). The IFS on PACS is able to perform simultaneous spectroscopy in the 51-73 or 70-105um and the 102-210um ranges. In addition to the PACS/IFS spectra, we obtained observations of the [NII]205 emission line using the SPIRE FTS for 121 galaxies in the GOALS sample (Lu+ 2017, J/ApJS/230/1 ; OT1nlu1; P.I.: N. Lu). As part of the Spitzer GOALS legacy program, all galaxies observed with Herschel/PACS have available Spitzer/IRS low-resolution, R~60-120 (SL module: 5.2-14.5um; LL module: 14-38um), and medium-resolution, R~600 (SH module: 9.9-19.6um; LH module: 18.7-37.2um), slit spectroscopy. (3 data files).

The Herschel/HIFI unbiased spectral survey of the solar-mass protostar IRAS16293

Science.gov (United States)

Bottinelli, S.; Caux, E.; Cecarelli, C.; Kahane, C.

2012-03-01

Unbiased spectral surveys are powerful tools to study the chemistry and the physics of star forming regions, because they can provide a complete census of the molecular content and the observed lines probe the physical structure of the source. While unbiased surveys at the millimeter and sub-millimeter wavelengths observable from ground-based telescopes have previously been performed towards several high-mass protostars, very little data exist on low-mass protostars, with only one such ground-based survey carried out towards this kind of object. However, since low-mass protostars are believed to resemble our own Sun's progenitor, the information provided by spectral surveys is crucial in order to uncover the birth mechanisms of low-mass stars and hence of our Sun. To help fill up this gap in our understanding, we carried out an almost complete spectral survey towards the solar-type protostar IRAS16293-2422 with the HIFI instrument onboard Herschel. The observations covered a range of about 700 GHz, in which a few hundreds lines were detected with more than 3σ confidence interval certainty and identified. All the detected lines which were free from obvious blending effects were fitted with Gaussians to estimate their basic kinematic properties. Contrarily to what is observed in the millimeter range, no lines from complex organic molecules have been observed. In this work, we characterize the different components of IRAS16293-2422 (a known binary at least) by analyzing the numerous emission and absorption lines identified.

Total molecular gas masses of Planck - Herschel selected strongly lensed hyper luminous infrared galaxies

Science.gov (United States)

Harrington, K. C.; Yun, M. S.; Magnelli, B.; Frayer, D. T.; Karim, A.; Weiß, A.; Riechers, D.; Jiménez-Andrade, E. F.; Berman, D.; Lowenthal, J.; Bertoldi, F.

2018-03-01

We report the detection of CO(1-0) line emission from seven Planck and Herschel selected hyper luminous ({L_{IR (8-1000{μ m})} > 10^{13} L_{⊙}) infrared galaxies with the Green Bank Telescope (GBT). CO(1-0) measurements are a vital tool to trace the bulk molecular gas mass across all redshifts. Our results place tight constraints on the total gas content of these most apparently luminous high-z star-forming galaxies (apparent IR luminosities of LIR > 1013 - 14 L⊙), while we confirm their predetermined redshifts measured using the Large Millimeter Telescope, LMT (zCO = 1.33-3.26). The CO(1-0) lines show similar profiles as compared to Jup = 2-4 transitions previously observed with the LMT. We report enhanced infrared to CO line luminosity ratios of = 110 ± 22 L_{⊙} (K km s^{-1} pc^{-2})^{-1} compared to normal star-forming galaxies, yet similar to those of well-studied IR-luminous galaxies at high-z. We find average brightness temperature ratios of 〈 r21〉 = 0.93 (2 sources), 〈 r31〉 = 0.34 (5 sources), and 〈 r41〉 = 0.18 (1 source). The r31 and r41 values are roughly half the average values for SMGs. We estimate the total gas mass content as {μ M_{H2} = (0.9-27.2) × 10^{11} (α _CO/0.8) M_{⊙}, where μ is the magnification factor and αCO is the CO line luminosity to molecular hydrogen gas mass conversion factor. The rapid gas depletion times, = 80} Myr, reveal vigorous starburst activity, and contrast the Gyr depletion time-scales observed in local, normal star-forming galaxies.

The Herschel Virgo Cluster Survey. XVII. SPIRE point-source catalogs and number counts

Science.gov (United States)

Pappalardo, Ciro; Bendo, George J.; Bianchi, Simone; Hunt, Leslie; Zibetti, Stefano; Corbelli, Edvige; di Serego Alighieri, Sperello; Grossi, Marco; Davies, Jonathan; Baes, Maarten; De Looze, Ilse; Fritz, Jacopo; Pohlen, Michael; Smith, Matthew W. L.; Verstappen, Joris; Boquien, Médéric; Boselli, Alessandro; Cortese, Luca; Hughes, Thomas; Viaene, Sebastien; Bizzocchi, Luca; Clemens, Marcel

2015-01-01

Aims: We present three independent catalogs of point-sources extracted from SPIRE images at 250, 350, and 500 μm, acquired with the Herschel Space Observatory as a part of the Herschel Virgo Cluster Survey (HeViCS). The catalogs have been cross-correlated to consistently extract the photometry at SPIRE wavelengths for each object. Methods: Sources have been detected using an iterative loop. The source positions are determined by estimating the likelihood to be a real source for each peak on the maps, according to the criterion defined in the sourceExtractorSussextractor task. The flux densities are estimated using the sourceExtractorTimeline, a timeline-based point source fitter that also determines the fitting procedure with the width of the Gaussian that best reproduces the source considered. Afterwards, each source is subtracted from the maps, removing a Gaussian function in every position with the full width half maximum equal to that estimated in sourceExtractorTimeline. This procedure improves the robustness of our algorithm in terms of source identification. We calculate the completeness and the flux accuracy by injecting artificial sources in the timeline and estimate the reliability of the catalog using a permutation method. Results: The HeViCS catalogs contain about 52 000, 42 200, and 18 700 sources selected at 250, 350, and 500 μm above 3σ and are ~75%, 62%, and 50% complete at flux densities of 20 mJy at 250, 350, 500 μm, respectively. We then measured source number counts at 250, 350, and 500 μm and compare them with previous data and semi-analytical models. We also cross-correlated the catalogs with the Sloan Digital Sky Survey to investigate the redshift distribution of the nearby sources. From this cross-correlation, we select ~2000 sources with reliable fluxes and a high signal-to-noise ratio, finding an average redshift z ~ 0.3 ± 0.22 and 0.25 (16-84 percentile). Conclusions: The number counts at 250, 350, and 500 μm show an increase in

A survey of the molecular ISM properties of nearby galaxies using the Herschel FTS

Energy Technology Data Exchange (ETDEWEB)

Kamenetzky, J. [Also at Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA. (United States); Rangwala, N. [Visiting Scientist, Space Science and Astrobiology Division, NASA Ames Research Center. (United States); Glenn, J.; Maloney, P. R.; Conley, A., E-mail: jkamenetzky@as.arizona.edu [Center for Astrophysics and Space Astronomy, University of Colorado at Boulder, 389-UCB, Boulder, CO (United States)

2014-11-10

The {sup 12}CO J = 4 → 3 to J = 13 → 12 lines of the interstellar medium from nearby galaxies, newly observable with the Herschel SPIRE Fourier transform spectrometer, offer an opportunity to study warmer, more luminous molecular gas than that traced by {sup 12}CO J = 1 → 0. Here we present a survey of 17 nearby infrared-luminous galaxy systems (21 pointings). In addition to photometric modeling of dust, we modeled full {sup 12}CO spectral line energy distributions from J = 1 → 0 to J = 13 → 12 with two components of warm and cool CO gas, and included LTE analysis of [C I], [C II], [N II], and H{sub 2} lines. CO is emitted from a low-pressure/high-mass component traced by the low-J lines and a high-pressure/low-mass component that dominates the luminosity. We found that, on average, the ratios of the warm/cool pressure, mass, and {sup 12}CO luminosity are 60 ± 30, 0.11 ± 0.02, and 15.6 ± 2.7. The gas-to-dust-mass ratios are <120 throughout the sample. The {sup 12}CO luminosity is dominated by the high-J lines and is 4 × 10{sup –4} L {sub FIR} on average. We discuss systematic effects of single-component and multi-component CO modeling (e.g., single-component J ≤ 3 models overestimate gas pressure by ∼0.5 dex), as well as compare to Galactic star-forming regions. With this comparison, we show the molecular interstellar medium of starburst galaxies is not simply an ensemble of Galactic-type giant molecular clouds. The warm gas emission is likely dominated by regions resembling the warm extended cloud of Sgr B2.

The DENIS & 2MASS Near Infrared Surveys

OpenAIRE

Mamon, Gary

1996-01-01

The DENIS and 2MASS near infrared surveys are presented. Their applications in extragalactic astronomy and cosmology are listed. The prospects for a rapid spectroscopic followup survey of a near infrared selected sample of nearly $10^5$ galaxies are illustrated with Monte-Carlo simulations.

WTS: A near-infrared transit survey

Directory of Open Access Journals (Sweden)

Hodgkin Simon

2013-04-01

Full Text Available The WFCAM Transit Survey is a transiting planet survey running on the United Kingdom Infrared Telescope targeting M dwarf stars in the near infrared. The survey has been operating since 2007 and gathering photometric time series of about 15000 M dwarf stars brighter than J = 17 mag. We identified and followed-up planet candidates from the most complete field and found two hot Jupiters around non-M dwarf hosts (WTS-1b & WTS-2b but found no planets around the M dwarfs.

WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope : The next generation wide-field spectroscopy facility for the William Herschel Telescope

NARCIS (Netherlands)

Dalton, Gavin; Trager, Scott C.; Abrams, Don Carlos; Carter, David; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; MacIntosh, Mike; Evans, Chris; Lewis, Ian; Navarro, Ramon; Agocs, Tibor; Dee, Kevin; Rousset, Sophie; Tosh, Ian; Middleton, Kevin; Pragt, Johannes; Terrett, David; Brock, Matthew; Benn, Chris; Verheijen, Marc; Cano Infantes, Diego; Bevil, Craige; Steele, Iain; Mottram, Chris; Bates, Stuart; Gribbin, Francis J.; Rey, Jürg; Rodriguez, Luis Fernando; Delgado, Jose Miguel; Guinouard, Isabelle; Walton, Nic; Irwin, Michael J.; Jagourel, Pascal; Stuik, Remko; Gerlofsma, Gerrit; Roelfsma, Ronald; Skillen, Ian; Ridings, Andy; Balcells, Marc; Daban, Jean-Baptiste; Gouvret, Carole; Venema, Lars; Girard, Paul

We present the preliminary design of the WEAVE next generation spectroscopy facility for the William Herschel Telescope (WHT), principally targeting optical ground-based follow up of upcoming ground-based (LOFAR) and spacebased (Gaia) surveys. WEAVE is a multi-object and multi-IFU facility utilizing

EVIDENCE FOR A WIDE RANGE OF ULTRAVIOLET OBSCURATION IN z {approx} 2 DUSTY GALAXIES FROM THE GOODS-HERSCHEL SURVEY

Energy Technology Data Exchange (ETDEWEB)

Penner, Kyle [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Dickinson, Mark; Dey, Arjun; Kartaltepe, Jeyhan [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Pope, Alexandra [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Magnelli, Benjamin [Max Planck Institut fuer Extraterrestrische Physik, Postfach 1312, D-85741 Garching (Germany); Pannella, Maurilio; Aussel, Herve; Daddi, Emanuele; Elbaz, David [Laboratoire AIM Paris-Saclay, CEA/DSM/Irfu-CNRS-Universite Paris Diderot, CEA-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France); Altieri, Bruno; Coia, Daniela [Herschel Science Center, European Space Astronomy Center, Villanueva de la Canada, E-28691 Madrid (Spain); Buat, Veronique [Laboratoire d' Astrophysique de Marseille, OAMP, Universite Aix-marseille, CNRS, 38 rue Frederic Joliot-Curie, F-13388 Marseille Cedex 13 (France); Bussmann, Shane; Hwang, Ho Seong [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Charmandaris, Vassilis [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Dannerbauer, Helmut [Institut fuer Astronomie, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria); Lin Lihwai [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 106, Taiwan (China); Magdis, Georgios [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Morrison, Glenn, E-mail: kpenner@as.arizona.edu [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); and others

2012-11-01

Dusty galaxies at z {approx} 2 span a wide range of relative brightness between rest-frame mid-infrared (8 {mu}m) and ultraviolet wavelengths. We attempt to determine the physical mechanism responsible for this diversity. Dust-obscured galaxies (DOGs), which have rest-frame mid-IR to UV flux density ratios {approx}> 1000, might be abnormally bright in the mid-IR, perhaps due to prominent emission from active galactic nuclei and/or polycyclic aromatic hydrocarbons, or abnormally faint in the UV. We use far-infrared data from the GOODS-Herschel survey to show that most DOGs with 10{sup 12} L {sub Sun} {approx}< L {sub IR} {approx}< 10{sup 13} L {sub Sun} are not abnormally bright in the mid-IR when compared to other dusty galaxies with similar IR (8-1000 {mu}m) luminosities. We observe a relation between the median IR to UV luminosity ratios and the median UV continuum power-law indices for these galaxies, and we find that only 24% have specific star formation rates that indicate the dominance of compact star-forming regions. This circumstantial evidence supports the idea that the UV- and IR-emitting regions in these galaxies are spatially coincident, which implies a connection between the abnormal UV faintness of DOGs and dust obscuration. We conclude that the range in rest-frame mid-IR to UV flux density ratios spanned by dusty galaxies at z {approx} 2 is due to differing amounts of UV obscuration. Of galaxies with these IR luminosities, DOGs are the most obscured. We attribute differences in UV obscuration to either (1) differences in the degree of alignment between the spatial distributions of dust and massive stars or (2) differences in the total dust content.

The VISTA Carina Nebula Survey. II. Spatial distribution of the infrared-excess-selected young stellar population

Science.gov (United States)

Zeidler, P.; Preibisch, T.; Ratzka, T.; Roccatagliata, V.; Petr-Gotzens, M. G.

2016-01-01

We performed a deep wide-field (6.76 sq. deg) near-infrared survey with the VISTA telescope that covers the entire extent of the Carina nebula complex (CNC). The point-source catalog created from these data contains around four million individual objects down to masses of 0.1 M⊙. We present a statistical study of the large-scale spatial distribution and an investigation of the clustering properties of infrared-excesses objects, which are used to trace disk-bearing young stellar objects (YSOs). A selection based on a near-infrared (J-H) versus (H-Ks) color-color diagram shows an almost uniform distribution over the entire observed area. We interpret this as a result of the very high degree of background contamination that arises from the Carina Nebula's location close to the Galactic plane. Complementing the VISTA near-infrared catalog with Spitzer IRAC mid-infrared photometry improves the situation of the background contamination considerably. We find that a (J-H) versus (Ks- [4.5]) color-color diagram is well suited to tracing the population of YSO-candidates (cYSOs) by their infrared excess. We identify 8781 sources with strong infrared excess, which we consider as cYSOs. This sample is used to investigate the spatial distribution of the cYSOs with a nearest-neighbor analysis. The surface density distribution of cYSOs agrees well with the shape of the clouds as seen in our Herschel far-infrared survey. The strong decline in the surface density of excess sources outside the area of the clouds supports the hypothesis that our excess-selected sample consists predominantly of cYSOs with a low level of background contamination. This analysis allows us to identify 14 groups of cYSOs outside the central area.Our results suggest that the total population of cYSOs in the CNC comprises about 164 000 objects, with a substantial fraction (~35%) located in the northern, still not well studied parts. Our cluster analysis suggests that roughly half of the cYSOs constitute a

Herschel images of Fomalhaut: an extrasolar Kuiper belt at the height of its dynamical activity

NARCIS (Netherlands)

Acke, B.; Min, M.; Dominik, C.; Vandenbussche, B.; Sibthorpe, B.; Waelkens, C.; Olofsson, G.; Degroote, P.; Smolders, K.; Pantin, E.; Barlow, M.J.; Blommaert, J.A.D.L.; Brandeker, A.; De Meester, W.; Dent, W.R.F.; Exter, K.; Di Francesco, J.; Fridlund, M.; Gear, W.K.; Glauser, A.M.; Greaves, J.S.; Harvey, P.M.; Henning, T.; Hogerheijde, M.; Holland, W.S.; Huygen, R.; Ivison, R.J.; Jean, C.; Liseau, R.; Naylor, D.A.; Pilbratt, G.L.; Polehampton, E.T.; Regibo, S.; Royer, P.; Sicilia-Aguilar, A.; Swinyard, B.M.

2012-01-01

Context. Fomalhaut is a young (2 ± 1 × 108 years), nearby (7.7 pc), 2 M⊙ star that is suspected to harbor an infant planetary system, interspersed with one or more belts of dusty debris. Aims. We present far-infrared images obtained with the Herschel Space Observatory with an angular resolution

Fine structure of Galactic foreground ISM towards high-redshift AGN - utilizing Herschel PACS and SPIRE data

Science.gov (United States)

Perger, K.; Pinter, S.; Frey, S.; Tóth, L. V.

2018-05-01

One of the most certain ways to determine star formation rate in galaxies is based on far infrared (FIR) measurements. To decide the origin of the observed FIR emission, subtracting the Galactic foreground is a crucial step. We utilized Herschel photometric data to determine the hydrogen column densities in three galactic latitude regions, at b = 27°, 50° and -80°. We applied a pixel-by-pixel fit to the spectral energy distribution (SED) for the images aquired from parallel PACS-SPIRE observations in all three sky areas. We determined the column densities with resolutions 45'' and 6', and compared the results with values estimated from the IRAS dust maps. Column densities at 27° and 50° galactic latitudes determined from the Herschel data are in a good agreement with the literature values. However, at the highest galactic latitude we found that the column densities from the Herschel data exceed those derived from the IRAS dust map.

The Seahorse Nebula: New views of the filamentary infrared dark cloud G304.74+01.32 from SABOCA, Herschel, and WISE

Science.gov (United States)

Miettinen, O.

2018-02-01

Context. Filamentary molecular clouds, such as many of the infrared dark clouds (IRDCs), can undergo hierarchical fragmentation into substructures (clumps and cores) that can eventually collapse to form stars. Aims: We aim to determine the occurrence of fragmentation into cores in the clumps of the filamentary IRDC G304.74+01.32 (hereafter, G304.74). We also aim to determine the basic physical characteristics (e.g. mass, density, and young stellar object (YSO) content) of the clumps and cores in G304.74. Methods: We mapped the G304.74 filament at 350 μm using the Submillimetre APEX Bolometer Camera (SABOCA) bolometer. The new SABOCA data have a factor of 2.2 times higher resolution than our previous Large APEX BOlometer CAmera (LABOCA) 870 μm map of the cloud (9″ vs. 19\\farcs86). We also employed the Herschel far-infrared (IR) and submillimetre, and Wide-field Infrared Survey Explorer (WISE) IR imaging data available for G304.74. The WISE data allowed us to trace the IR emission of the YSOs associated with the cloud. Results: The SABOCA 350 μm data show that G304.74 is composed of a dense filamentary structure with a mean width of only 0.18 ± 0.05 pc. The percentage of LABOCA clumps that are found to be fragmented into SABOCA cores is 36% ± 16%, but the irregular morphology of some of the cores suggests that this multiplicity fraction could be higher. The WISE data suggest that 65% ± 18% of the SABOCA cores host YSOs. The mean dust temperature of the clumps, derived by comparing the Herschel 250, 350, and 500 μm flux densities, was found to be 15.0 ± 0.8 K. The mean mass, beam-averaged H2 column density, and H2 number density of the LABOCA clumps are estimated to be 55 ± 10M⊙, (2.0 ± 0.2) × 1022 cm-2, and (3.1 ± 0.2) × 104 cm-3. The corresponding values for the SABOCA cores are 29 ± 3M⊙, (2.9 ± 0.3) × 1022 cm-2, and (7.9 ± 1.2) × 104 cm-3. The G304.74 filament is estimated to be thermally supercritical by a factor of ≳ 3.5 on the scale

High-J CO survey of low-mass protostars observed with Herschel-HIFI

DEFF Research Database (Denmark)

Yıldız, U. A.; Kristensen, L. E.; van Dishoeck, E. F.

2013-01-01

with Herschel (WISH) key program. This is the first large spectrally resolved high-J CO survey conducted for these types of sources. Complementary lower J CO maps were observed using ground-based telescopes, such as the JCMT and APEX and convolved to matching beam sizes. Results: The 12CO 10-9 line is detected...... the 13CO and 12CO excitation temperatures, due to lack of UV heating and outflow components in those models. The H2O 110 - 101/CO 10-9 intensity ratio does not change significantly with velocity, in contrast to the H2O/CO 3-2 ratio, indicating that CO 10-9 is the lowest transition for which the line...

The star-forming cores in the centre of the Trifid nebula (M 20): from Herschel to the near-infrared

Science.gov (United States)

Tapia, M.; Persi, P.; Román-Zúñiga, C.; Elia, D.; Giovannelli, F.; Sabau-Graziati, L.

2018-04-01

A new detailed infrared (IR) study of eight star-forming dense condensations (TCs) in M 20, the Trifid nebula, is presented. The aim is to determine the physical properties of the dust in such globules and establish the presence and properties of their embedded protostellar and/or young stellar population. For this, we analysed new Herschel far-IR and Calar Alto near-IR images of the region, combined with Spitzer Infrared Array Camera (Spitzer/IRAC) archival observations. We confirm the presence of several young stellar objects (YSOs), most with mid-IR colours of Class II sources in all but one of the observed cores. Five TCs are dominated in the far-IR by Class I sources with bolometric luminosities between 100 and 500 L⊙. We report the discovery of a possible counterjet to HH 399 and its protostellar engine inside the photodissociation region TC2, as well as a bipolar outflow system, signposted by symmetric H2 emission knots, embedded in TC3. The present results are compatible with previous suggestions that star formation has been active in the region for some 3 × 105 yr, and that the most recent events in some of these TCs may have been triggered by the expansion of the H II region. We also obtained a revised value for the distance to M 20 of 2.0 ± 0.1 kpc.

GOODS-HERSCHEL AND CANDELS: THE MORPHOLOGIES OF ULTRALUMINOUS INFRARED GALAXIES AT z ∼ 2

International Nuclear Information System (INIS)

Kartaltepe, Jeyhan S.; Dickinson, Mark; Alexander, David M.; Bell, Eric F.; Dahlen, Tomas; Lotz, Jennifer; Elbaz, David; Wiklind, Tommy; Faber, S. M.; Aussel, Herve; Bethermin, Matthieu; Bournaud, Frederic; Dannerbauer, Helmut; McIntosh, Daniel H.; Altieri, Bruno; Charmandaris, Vassilis; Conselice, Christopher J.; Cooray, Asantha; Davé, Romeel; Dunlop, James

2012-01-01

Using deep 100 and 160 μm observations in GOODS-South from GOODS-Herschel, combined with high-resolution HST/WFC3 near-infrared imaging from CANDELS, we present the first detailed morphological analysis of a complete, far-infrared (FIR) selected sample of 52 ultraluminous infrared galaxies (ULIRGs; L IR > 10 12 L ☉ ) at z ∼ 2. We also make use of a comparison sample of galaxies with lower IR luminosities but with the same redshift and H-band magnitude distribution. Our visual classifications of these two samples indicate that the fractions of objects with disk and spheroid morphologies are roughly the same but that there are significantly more mergers, interactions, and irregular galaxies among the ULIRGs (72 +5 –7 % versus 32 ± 3%). The combination of disk and irregular/interacting morphologies suggests that early-stage interactions, minor mergers, and disk instabilities could play an important role in ULIRGs at z ∼ 2. We compare these fractions with those of a z ∼ 1 sample selected from GOODS-H and COSMOS across a wide luminosity range and find that the fraction of disks decreases systematically with L IR while the fraction of mergers and interactions increases, as has been observed locally. At comparable luminosities, the fraction of ULIRGs with various morphological classifications is similar at z ∼ 2 and z ∼ 1, though there are slightly fewer mergers and slightly more disks at higher redshift. We investigate the position of the z ∼ 2 ULIRGs, along with 70 z ∼ 2 LIRGs, on the specific star formation rate versus redshift plane, and find 52 systems to be starbursts (i.e., they lie more than a factor of three above the main-sequence relation). We find that many of these systems are clear interactions and mergers (∼50%) compared to only 24% of systems on the main sequence relation. If irregular disks are included as potential minor mergers, then we find that up to ∼73% of starbursts are involved in a merger or interaction at some level

GOODS-HERSCHEL AND CANDELS: THE MORPHOLOGIES OF ULTRALUMINOUS INFRARED GALAXIES AT z {approx} 2

Energy Technology Data Exchange (ETDEWEB)

Kartaltepe, Jeyhan S.; Dickinson, Mark [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Alexander, David M. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Dahlen, Tomas; Lotz, Jennifer [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Elbaz, David; Wiklind, Tommy [Joing ALMA Observatory, ESO, Santiago (Chile); Faber, S. M.; Aussel, Herve; Bethermin, Matthieu; Bournaud, Frederic; Dannerbauer, Helmut [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Universite Paris Diderot, CE-Saclay, F-91191 Gif-sur-Yvette (France); McIntosh, Daniel H. [University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Altieri, Bruno [Herschel Science Centre, European Space Astronomy Centre, Villanueva de la Canada, E-28691 Madrid (Spain); Charmandaris, Vassilis [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Conselice, Christopher J. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Dave, Romeel [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Dunlop, James, E-mail: jeyhan@noao.edu [Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); and others

2012-09-20

Using deep 100 and 160 {mu}m observations in GOODS-South from GOODS-Herschel, combined with high-resolution HST/WFC3 near-infrared imaging from CANDELS, we present the first detailed morphological analysis of a complete, far-infrared (FIR) selected sample of 52 ultraluminous infrared galaxies (ULIRGs; L{sub IR} > 10{sup 12} L{sub Sun }) at z {approx} 2. We also make use of a comparison sample of galaxies with lower IR luminosities but with the same redshift and H-band magnitude distribution. Our visual classifications of these two samples indicate that the fractions of objects with disk and spheroid morphologies are roughly the same but that there are significantly more mergers, interactions, and irregular galaxies among the ULIRGs (72{sup +5}{sub -7}% versus 32 {+-} 3%). The combination of disk and irregular/interacting morphologies suggests that early-stage interactions, minor mergers, and disk instabilities could play an important role in ULIRGs at z {approx} 2. We compare these fractions with those of a z {approx} 1 sample selected from GOODS-H and COSMOS across a wide luminosity range and find that the fraction of disks decreases systematically with L{sub IR} while the fraction of mergers and interactions increases, as has been observed locally. At comparable luminosities, the fraction of ULIRGs with various morphological classifications is similar at z {approx} 2 and z {approx} 1, though there are slightly fewer mergers and slightly more disks at higher redshift. We investigate the position of the z {approx} 2 ULIRGs, along with 70 z {approx} 2 LIRGs, on the specific star formation rate versus redshift plane, and find 52 systems to be starbursts (i.e., they lie more than a factor of three above the main-sequence relation). We find that many of these systems are clear interactions and mergers ({approx}50%) compared to only 24% of systems on the main sequence relation. If irregular disks are included as potential minor mergers, then we find that up to {approx

An extended Herschel drop-out source in the center of AS1063 : a normal dusty galaxy at z = 6.1 or SZ substructures?

NARCIS (Netherlands)

Boone, F.; Clément, B.; Richard, J.; Schaerer, D.; Lutz, D.; Weiß, A.; Zemcov, M.; Egami, E.; Rawle, T.; Walth, G.; Kneib, J.; Combes, F.; Smail, I.; Swinbank, A.; Altieri, B.; Blain, A.; Chapman, S.; Dessauges-Zavadsky, M.; Ivison, R.; Knudsen, K.; Omont, A.; Pelló, R.; Pérez-González, P.; Valtchanov, I.; Werf, van der P.P.; Zamojski, M.

2013-01-01

In the course of our 870 {$μ$}m APEX/LABOCA follow-up of the Herschel Lensing Survey we have detected a source in AS1063 (RXC J2248.7-4431) that has no counterparts in any of the Herschel PACS/SPIRE bands, it is a Herschel ''drop-out'' with S$_{870}$/S$_{500}$ {ge} 0.5. The 870 {$μ$}m emission is

Detection of warm water vapour in Taurus protoplanetary discs by Herschel

NARCIS (Netherlands)

Riviere-Marichalar, P.; Menard, F.; Thi, W. F.; Kamp, I.; Montesinos, B.; Meeus, G.; Woitke, P.; Howard, C.; Sandell, G.; Podio, L.; Dent, W. R. F.; Mendigutia, I.; Pinte, C.; White, G. J.; Barrado, D.

Line spectra of 68 Taurus T Tauri stars were obtained with the Herschel-PACS (Photodetector Array Camera and Spectrometer) instrument as part of the GASPS (GAS evolution in Protoplanetary Systems) survey of protoplanetary discs. A careful examination of the linescans centred on the [OI] 63.18 mu m

Data processing pipeline for Herschel HIFI

NARCIS (Netherlands)

Shipman, R. F.; Beaulieu, S. F.; Teyssier, D.; Morris, P.; Rengel, M.; McCoey, C.; Edwards, K.; Kester, D.; Lorenzani, A.; Coeur-Joly, O.; Melchior, M.; Xie, J.; Sanchez, E.; Zaal, P.; Avruch, I.; Borys, C.; Braine, J.; Comito, C.; Delforge, B.; Herpin, F.; Hoac, A.; Kwon, W.; Lord, S. D.; Marston, A.; Mueller, M.; Olberg, M.; Ossenkopf, V.; Puga, E.; Akyilmaz-Yabaci, M.

2017-01-01

Context. The HIFI instrument on the Herschel Space Observatory performed over 9100 astronomical observations, almost 900 of which were calibration observations in the course of the nearly four-year Herschel mission. The data from each observation had to be converted from raw telemetry into

Herschel/HIFI Observations of a New Interstellar Water Maser : The 532-441 Transition at 620.701 GHz

NARCIS (Netherlands)

Neufeld, David A.; Wu, Yuanwei; Kraus, Alex; Menten, Karl M.; Tolls, Volker; Melnick, Gary J.; Nagy, Zsofia

2013-01-01

Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have performed mapping observations of the 620.701 GHz 5(32)-4(41) transition of ortho-H2O within a similar to 1'.5 x 1'.5 region encompassing the Kleinmann-Low nebula in Orion (Orion-KL), and pointed observations

HERSCHEL PACS OBSERVATIONS AND MODELING OF DEBRIS DISKS IN THE TUCANA-HOROLOGIUM ASSOCIATION

Energy Technology Data Exchange (ETDEWEB)

Donaldson, J. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Roberge, A. [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Chen, C. H. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Augereau, J.-C.; Menard, F. [UJF - Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Dent, W. R. F. [ALMA, Avda Apoquindo 3846, Piso 19, Edificio Alsacia, Las Condes, Santiago (Chile); Eiroa, C.; Meeus, G. [Dpt. Fisica Teorica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Krivov, A. V. [Astrophysikalishes Institut, Friedrich-Schiller-Universitaet Jena, Schillergaesschen 2-3, 07745 Jena (Germany); Mathews, G. S. [Institute for Astronomy (IfA), University of Hawaii, 2680 Woodlawn Dr., Honolulu, HI 96822 (United States); Riviere-Marichalar, P. [Centro de Astrobiologia Depto. Astrofisica (CSIC-INTA), POB 78, 28691 Villanueva de la Canada (Spain); Sandell, G., E-mail: jessd@astro.umd.edu [SOFIA-USRA, NASA Ames Research Center, Building N232, Rm. 146, Moffett Field, CA 94035 (United States)

2012-07-10

We present Herschel PACS photometry of 17 B- to M-type stars in the 30 Myr old Tucana-Horologium Association. This work is part of the Herschel Open Time Key Programme 'Gas in Protoplanetary Systems'. 6 of the 17 targets were found to have infrared excesses significantly greater than the expected stellar IR fluxes, including a previously unknown disk around HD30051. These six debris disks were fitted with single-temperature blackbody models to estimate the temperatures and abundances of the dust in the systems. For the five stars that show excess emission in the Herschel PACS photometry and also have Spitzer IRS spectra, we fit the data with models of optically thin debris disks with realistic grain properties in order to better estimate the disk parameters. The model is determined by a set of six parameters: surface density index, grain size distribution index, minimum and maximum grain sizes, and the inner and outer radii of the disk. The best-fitting parameters give us constraints on the geometry of the dust in these systems, as well as lower limits to the total dust masses. The HD105 disk was further constrained by fitting marginally resolved PACS 70 {mu}m imaging.

Charles Darwin and John Herschel

Science.gov (United States)

Warner, B.

2009-11-01

The influence of John Herschel on the philosophical thoughts of Charles Darwin, both through the former's book, Natural Philosophy, and through their meeting in 1836 at the Cape of Good Hope, is discussed. With Herschel having himself speculated on evolution just a few months before he met Darwin, it is probable that he stimulated at least the beginnings of the latter's lifelong work on the subject.

Infrared Testing of the Wide-field Infrared Survey Telescope Grism Using Computer Generated Holograms

Science.gov (United States)

Dominguez, Margaret Z.; Content, David A.; Gong, Qian; Griesmann, Ulf; Hagopian, John G.; Marx, Catherine T; Whipple, Arthur L.

2017-01-01

Infrared Computer Generated Holograms (CGHs) were designed, manufactured and used to measure the performance of the grism (grating prism) prototype which includes testing Diffractive Optical Elements (DOE). The grism in the Wide Field Infrared Survey Telescope (WFIRST) will allow the surveying of a large section of the sky to find bright galaxies.

Characterizing the Energetics of the Youngest Protostars: FIFI-LS Spectroscopy of Herschel-Identified Extreme Class 0 objects in Orion

Science.gov (United States)

Megeath, S.

2014-10-01

We propose FIFI-LS spectroscopy observations toward 3 of the youngest known Herschel- detected Class 0 protostars in the Orion molecular clouds. Characterization of the far-IR spectrum toward these PACS Bright Red Sources (PBRS) is imperative: this is the only observational means to characterize the complete energetics of the outflow in the earliest stages of the star formation process. We have already obtained Herschel-PACS spectroscopy for 8/14 PBRS; for these, the CO rotation temperatures are systematically lower than the larger samples of 'more typical' protostars observed. Furthermore, all of the Herschel-detected PBRS also have CARMA CO (J=1-0) outflow maps, enabling us to identify tentative trends between the detection and morphology (compact or extended) of the CO outflow and the presence or lack of far-infrared emission lines. Moreover, we only convincingly detect [OI] emission toward the source with the brightest outflow emission; thus, [OI] may not be universally present in protostellar outflows. However, due to the small-numbers with PACS spectroscopy, it is unclear if these trends are real and the three proposed PBRS have outflow maps of varying morphologies, but no far-infrared spectra. The results from this program will provide a firm observational footing for the presence or lack of such trends and will strengthen the connection of the far-IR emission lines to the outflow.

REGIONAL VARIATIONS IN THE DENSE GAS HEATING AND COOLING IN M51 FROM HERSCHEL FAR-INFRARED SPECTROSCOPY

Energy Technology Data Exchange (ETDEWEB)

Parkin, T. J.; Wilson, C. D.; Schirm, M. R. P.; Foyle, K. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Baes, M.; De Looze, I. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Boquien, M.; Boselli, A. [Laboratoire d' Astrophysique de Marseille-LAM, Université d' Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Cormier, D. [Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Karczewski, O. Ł. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lebouteiller, V.; Madden, S. C.; Sauvage, M. [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Roussel, H. [Institut d' Astrophysique de Paris, UMR7095 CNRS, Université Pierre and Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France); Spinoglio, L., E-mail: parkintj@mcmaster.ca [Istituto di Astrofisica e Planetologia Spaziali, INAF-IAPS, Via Fosso del Cavaliere 100, I-00133 Roma (Italy)

2013-10-20

We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in M51, [C II](158 μm), [N II](122 and 205 μm), [O I](63 and 145 μm), and [O III](88 μm). We compare the observed flux of these lines with the predicted flux from a photon-dominated region model to determine characteristics of the cold gas such as density, temperature, and the far-ultraviolet (FUV) radiation field, G{sub 0}, resolving details on physical scales of roughly 600 pc. We find an average [C II]/F{sub TIR} of 4 × 10{sup –3}, in agreement with previous studies of other galaxies. A pixel-by-pixel analysis of four distinct regions of M51 shows a radially decreasing trend in both the FUV radiation field, G{sub 0}, and the hydrogen density, n, peaking in the nucleus of the galaxy, and then falling off out to the arm and interarm regions. We see for the first time that the FUV flux and gas density are similar in the differing environments of the arm and interarm regions, suggesting that the inherent physical properties of the molecular clouds in both regions are essentially the same.

AN ANALYSIS OF THE ENVIRONMENTS OF FU ORIONIS OBJECTS WITH HERSCHEL

Energy Technology Data Exchange (ETDEWEB)

Green, Joel D.; Evans, Neal J. II; Merello, Manuel [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Kospal, Agnes [European Space Agency (ESA/ESTEC), Keplerlaan 1, 2200-AG Noordwijk (Netherlands); Herczeg, Gregory [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Quanz, Sascha P. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Henning, Thomas; Bouwman, Jeroen [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Van Kempen, Tim A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Gyeonggi 446-701 (Korea, Republic of); Dunham, Michael M. [Department of Astronomy, Yale University, New Haven, CT (United States); Meeus, Gwendolyn [Departamento de Fisica Teorica, Universidad Autonoma de Madrid, Campus Cantoblanco (Spain); Chen, Jo-hsin [Jet Propulsion Laboratory, Pasadena, CA (United States); Guedel, Manuel; Liebhart, Armin [Department of Astrophysics, University of Vienna (Austria); Skinner, Stephen L., E-mail: joel@astro.as.utexas.edu [Center for Astrophysics and Space Astronomy (CASA), University of Colorado, Boulder, CO 80309-0389 (United States)

2013-08-01

We present Herschel-HIFI, SPIRE, and PACS 50-670 {mu}m imaging and spectroscopy of six FU Orionis-type objects and candidates (FU Orionis, V1735 Cyg, V1515 Cyg, V1057 Cyg, V1331 Cyg, and HBC 722), ranging in outburst date from 1936 to 2010, from the 'FOOSH' (FU Orionis Objects Surveyed with Herschel) program, as well as ancillary results from Spitzer Infrared Spectrograph and the Caltech Submillimeter Observatory. In their system properties (L{sub bol}, T{sub bol}, and line emission), we find that FUors are in a variety of evolutionary states. Additionally, some FUors have features of both Class I and II sources: warm continuum consistent with Class II sources, but rotational line emission typical of Class I, far higher than Class II sources of similar mass/luminosity. Combining several classification techniques, we find an evolutionary sequence consistent with previous mid-IR indicators. We detect [O I] in every source at luminosities consistent with Class 0/I protostars, much greater than in Class II disks. We detect transitions of {sup 13}CO (J{sub up} of 5-8) around two sources (V1735 Cyg and HBC 722) but attribute them to nearby protostars. Of the remaining sources, three (FU Ori, V1515 Cyg, and V1331 Cyg) exhibit only low-lying CO, but one (V1057 Cyg) shows CO up to J = 23 {yields} 22 and evidence for H{sub 2}O and OH emission, at strengths typical of protostars rather than T Tauri stars. Rotational temperatures for 'cool' CO components range from 20 to 81 K, for {approx} 10{sup 50} total CO molecules. We detect [C I] and [N II] primarily as diffuse emission.

The scientific legacy of William Herschel

CERN Document Server

2018-01-01

This book presents a modern scholarly analysis of issues associated with England’s most famous astronomer, William Herschel. The world’s leading experts on Herschel, discoverer of the planet Uranus, here offer their combined wisdom on many aspects of his life and astronomical research. Solar system topics include comets, Earth’s Moon, and the spurious moons of Uranus, all objects whose observation was pioneered by Herschel.  The contributors examine his study of the structure of the Milky Way and an in-depth look at the development of the front view telescopes he built. The popular subject of extraterrestrial life is looked at from the point of view of both William Herschel and his son John, both of whom had an interest in the topic. William’s personal development through the educational system of the late eighteenth-century is also explored, and the wide range of verse and satire in various languages associated with his discoveries is collected here for the first time. Hershel worked at a time of i...

AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

International Nuclear Information System (INIS)

Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

2013-01-01

We performed a near-infrared spectroscopic survey toward an area of ∼10 deg 2 of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R ∼ 20) spectra in 2-5 μm for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 μm, and 67% of the sources also have photometric data up to 24 μm. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 μm can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near-infrared

HERSCHEL-ATLAS: TOWARD A SAMPLE OF {approx}1000 STRONGLY LENSED GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Nuevo, J.; Lapi, A.; Bressan, S.; Danese, L.; De Zotti, G.; Cai, Z.-Y.; Fan, L. [SISSA, Via Bonomea 265, I-34136 Trieste (Italy); Fleuren, S.; Sutherland, W. [School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Negrello, M. [Department of Physical Sciences, Open University, Milton Keynes MK7 6AA (United Kingdom); Baes, M. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Baker, A. J. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Clements, D. L. [Astrophysics Group, Imperial College, Blackett Lab, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Dannerbauer, H. [Institut fuer Astronomie, Universitaet Wien, Tuerkenschanzstrasse 17, 1180 Wien, Oesterreich (Austria); Dunne, L.; Dye, S. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Eales, S. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Frayer, D. T. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Harris, A. I., E-mail: gnuevo@sissa.it [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); and others

2012-04-10

While the selection of strongly lensed galaxies (SLGs) with 500 {mu}m flux density S{sub 500} > 100 mJy has proven to be rather straightforward, for many applications it is important to analyze samples larger than the ones obtained when confining ourselves to such a bright limit. Moreover, only by probing to fainter flux densities is it possible to exploit strong lensing to investigate the bulk of the high-z star-forming galaxy population. We describe HALOS (the Herschel-ATLAS Lensed Objects Selection), a method for efficiently selecting fainter candidate SLGs, reaching a surface density of {approx_equal} 1.5-2 deg{sup -2}, i.e., a factor of about 4-6 higher than that at the 100 mJy flux limit. HALOS will allow the selection of up to {approx}1000 candidate SLGs (with amplifications {mu} {approx}> 2) over the full H-ATLAS survey area. Applying HALOS to the H-ATLAS Science Demonstration Phase field ({approx_equal} 14.4 deg{sup 2}) we find 31 candidate SLGs, whose candidate lenses are identified in the VIKING near-infrared catalog. Using the available information on candidate sources and candidate lenses we tentatively estimate a {approx_equal} 72% purity of the sample. As expected, the purity decreases with decreasing flux density of the sources and with increasing angular separation between candidate sources and lenses. The redshift distribution of the candidate lensed sources is close to that reported for most previous surveys for lensed galaxies, while that of candidate lenses extends to redshifts substantially higher than found in the other surveys. The counts of candidate SLGs are also in good agreement with model predictions. Even though a key ingredient of the method is the deep near-infrared VIKING photometry, we show that H-ATLAS data alone allow the selection of a similarly deep sample of candidate SLGs with an efficiency close to 50%; a slightly lower surface density ({approx_equal} 1.45 deg{sup -2}) can be reached with a {approx}70% efficiency.

Pilot aerial infrared roof top survey. Final report

Energy Technology Data Exchange (ETDEWEB)

1979-10-15

A summary is presented of a pilot aerial infrared roof top study conducted by the Minnesota Energy Agency. Infrared surveys of 27 Minnesota cities were conducted during the fall and winter of the 1976-1977 heating season. In addition, conventional daytime color photographs were taken of several cities. Film processing was done by the Environmental Protection Agency. The University of Minnesota conducted ground tests to verify the aerial infrared imagery. Thermograph dissemination centers were established in each city and training seminars and materials were prepared and delivered to dissemination center staff. A survey of homeowners who viewed their thermograph at a dissemination center were used to determine the energy savings resulting from the program. An Aerial Infrared Program Users Manual was prepared by the Energy Agency and the Remote Sensing Institute of Brookings, South Dakota.

The Herschel Multi-Tiered Extragalactic Survey: SPIRE-mm Photometric Redshifts

Science.gov (United States)

Roseboom, I. G.; Ivison, R. J.; Greve, T. R.; Amblard, A.; Arumugam, V.; Auld, R.; Aussel, H.; Bethermin, M.; Blain, A.; Block, J.;

Data processing pipeline for Herschel HIFI

Science.gov (United States)

Shipman, R. F.; Beaulieu, S. F.; Teyssier, D.; Morris, P.; Rengel, M.; McCoey, C.; Edwards, K.; Kester, D.; Lorenzani, A.; Coeur-Joly, O.; Melchior, M.; Xie, J.; Sanchez, E.; Zaal, P.; Avruch, I.; Borys, C.; Braine, J.; Comito, C.; Delforge, B.; Herpin, F.; Hoac, A.; Kwon, W.; Lord, S. D.; Marston, A.; Mueller, M.; Olberg, M.; Ossenkopf, V.; Puga, E.; Akyilmaz-Yabaci, M.

2017-12-01

Context. The HIFI instrument on the Herschel Space Observatory performed over 9100 astronomical observations, almost 900 of which were calibration observations in the course of the nearly four-year Herschel mission. The data from each observation had to be converted from raw telemetry into calibrated products and were included in the Herschel Science Archive. Aims: The HIFI pipeline was designed to provide robust conversion from raw telemetry into calibrated data throughout all phases of the HIFI missions. Pre-launch laboratory testing was supported as were routine mission operations. Methods: A modular software design allowed components to be easily added, removed, amended and/or extended as the understanding of the HIFI data developed during and after mission operations. Results: The HIFI pipeline processed data from all HIFI observing modes within the Herschel automated processing environment as well as within an interactive environment. The same software can be used by the general astronomical community to reprocess any standard HIFI observation. The pipeline also recorded the consistency of processing results and provided automated quality reports. Many pipeline modules were in use since the HIFI pre-launch instrument level testing. Conclusions: Processing in steps facilitated data analysis to discover and address instrument artefacts and uncertainties. The availability of the same pipeline components from pre-launch throughout the mission made for well-understood, tested, and stable processing. A smooth transition from one phase to the next significantly enhanced processing reliability and robustness. Herschel was an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

On the insignificance of Herschel's sunspot correlation

Science.gov (United States)

Love, Jeffrey J.

2013-08-01

We examine William Herschel's hypothesis that solar-cycle variation of the Sun's irradiance has a modulating effect on the Earth's climate and that this is, specifically, manifested as an anticorrelation between sunspot number and the market price of wheat. Since Herschel first proposed his hypothesis in 1801, it has been regarded with both interest and skepticism. Recently, reports have been published that either support Herschel's hypothesis or rely on its validity. As a test of Herschel's hypothesis, we seek to reject a null hypothesis of a statistically random correlation between historical sunspot numbers, wheat prices in London and the United States, and wheat farm yields in the United States. We employ binary-correlation, Pearson-correlation, and frequency-domain methods. We test our methods using a historical geomagnetic activity index, well known to be causally correlated with sunspot number. As expected, the measured correlation between sunspot number and geomagnetic activity would be an unlikely realization of random data; the correlation is "statistically significant." On the other hand, measured correlations between sunspot number and wheat price and wheat yield data would be very likely realizations of random data; these correlations are "insignificant." Therefore, Herschel's hypothesis must be regarded with skepticism. We compare and contrast our results with those of other researchers. We discuss procedures for evaluating hypotheses that are formulated from historical data.

The Andromeda Optical and Infrared Disk Survey

Science.gov (United States)

Sick, J.; Courteau, S.; Cuillandre, J.-C.

2014-03-01

The Andromeda Optical and Infrared Disk Survey has mapped M31 in u* g' r' i' JKs wavelengths out to R = 40 kpc using the MegaCam and WIRCam wide-field cameras on the Canada-France-Hawaii Telescope. Our survey is uniquely designed to simultaneously resolve stars while also carefully reproducing the surface brightness of M31, allowing us to study M31's global structure in the context of both resolved stellar populations and spectral energy distributions. We use the Elixir-LSB method to calibrate the optical u* g' r' i' images by building real-time maps of the sky background with sky-target nodding. These maps are stable to μg ≲ 28.5 mag arcsec-2 and reveal warps in the outer M31 disk in surface brightness. The equivalent WIRCam mapping in the near-infrared uses a combination of sky-target nodding and image-to-image sky offset optimization to produce stable surface brightnesses. This study enables a detailed analysis of the systematics of spectral energy distribution fitting with near-infrared bands where asymptotic giant branch stars impose a significant, but ill-constrained, contribution to the near-infrared light of a galaxy. Here we present panchromatic surface brightness maps and initial results from our near-infrared resolved stellar catalog.

Time-series surveys and pulsating stars: The near-infrared perspective

Directory of Open Access Journals (Sweden)

Matsunaga Noriyuki

2017-01-01

Full Text Available The purpose of this review is to discuss the advantages and problems of nearinfrared surveys in observing pulsating stars in the Milky Way. One of the advantages of near-infrared surveys, when compared to optical counterparts, is that the interstellar extinction is significantly smaller. As we see in this review, a significant volume of the Galactic disk can be reached by infrared surveys but not by optical ones. Towards highly obscured regions in the Galactic mid-plane, however, the interstellar extinction causes serious problems even with near-infrared data in understanding the observational results. After a review on previous and current near-infrared surveys, we discuss the effects of the interstellar extinction in optical (including Gaia to near-infrared broad bands based on a simple calculation using synthetic spectral energy distribution. We then review the recent results on classical Cepheids towards the Galactic center and the bulge, as a case study, to see the impact of the uncertainty in the extinction law. The extinction law, i.e. the wavelength dependency of the extinction, is not fully characterized, and its uncertainty makes it hard to make the correction. Its characterization is an urgent task in order to exploit the outcomes of ongoing large-scale surveys of pulsating stars, e.g. for drawing a map of pulsating stars across the Galactic disk.

Germanium blocked impurity band far infrared detectors

International Nuclear Information System (INIS)

Rossington, C.S.

1988-04-01

The infrared portion of the electromagnetic spectrum has been of interest to scientist since the eighteenth century when Sir William Herschel discovered the infrared as he measured temperatures in the sun's spectrum and found that there was energy beyond the red. In the late nineteenth century, Thomas Edison established himself as the first infrared astronomer to look beyond the solar system when he observed the star Arcturus in the infrared. Significant advances in infrared technology and physics, long since Edison's time, have resulted in many scientific developments, such as the Infrared Astronomy Satellite (IRAS) which was launched in 1983, semiconductor infrared detectors for materials characterization, military equipment such as night-vision goggles and infrared surveillance equipment. It is now planned that cooled semiconductor infrared detectors will play a major role in the ''Star Wars'' nuclear defense scheme proposed by the Reagan administration

Spatially resolved imaging of the two-component η Crv debris disk with Herschel

Energy Technology Data Exchange (ETDEWEB)

Duchêne, G.; Arriaga, P.; Kalas, P. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Wyatt, M.; Kennedy, G. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Sibthorpe, B. [SRON Netherlands Institute for Space Research, P.O. Box 800, 9700 AV Groningen (Netherlands); Lisse, C. [JHU-APL, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Holland, W. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Wisniewski, J. [H.L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Clampin, M. [NASA Goddard Space Flight Center, Code 681, Greenbelt, MD 20771 (United States); Pinte, C. [UMI-FCA, CNRS/INSU, France (UMI 3386) (France); Wilner, D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Booth, M. [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); Horner, J. [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia); Matthews, B. [National Research Council of Canada Herzberg Astronomy and Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Greaves, J. [SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS (United Kingdom)

2014-04-01

We present far-infrared and submillimeter images of the η Crv debris disk system obtained with Herschel and SCUBA-2, as well as Hubble Space Telescope visible and near-infrared coronagraphic images. In the 70 μm Herschel image, we clearly separate the thermal emission from the warm and cold belts in the system, find no evidence for a putative dust population located between them, and precisely determine the geometry of the outer belt. We also find marginal evidence for azimuthal asymmetries and a global offset of the outer debris ring relative to the central star. Finally, we place stringent upper limits on the scattered light surface brightness of the outer ring. Using radiative transfer modeling, we find that it is impossible to account for all observed properties of the system under the assumption that both rings contain dust populations with the same properties. While the outer belt is in reasonable agreement with the expectations of steady-state collisional cascade models, albeit with a minimum grain size that is four times larger than the blow-out size, the inner belt appears to contain copious amounts of small dust grains, possibly below the blow-out size. This suggests that the inner belt cannot result from a simple transport of grains from the outer belt and rather supports a more violent phenomenon as its origin. We also find that the emission from the inner belt has not declined over three decades, a much longer timescale than its dynamical timescale, which indicates that the belt is efficiently replenished.

H-ATLAS: THE COSMIC ABUNDANCE OF DUST FROM THE FAR-INFRARED BACKGROUND POWER SPECTRUM

Energy Technology Data Exchange (ETDEWEB)

Thacker, Cameron; Cooray, Asantha; Smidt, Joseph; De Bernardis, Francesco; Mitchell-Wynne, K. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Amblard, A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Auld, R.; Eales, S.; Pascale, E. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, CF24 3AA (United Kingdom); Baes, M.; Michalowski, M. J. [Sterrenkundig Observatorium, Universiteit Gent, KrijgslAAn 281 S9, B-9000 Gent (Belgium); Clements, D. L.; Dariush, A.; Hopwood, R. [Physics Department, Imperial College London, South Kensington campus, London, SW7 2AZ (United Kingdom); De Zotti, G. [INAF, Osservatorio Astronomico di Padova, Vicolo Osservatorio 5, I-35122 Padova (Italy); Dunne, L.; Maddox, S. [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Hoyos, C. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Ibar, E. [UK Astronomy Technology Centre, The Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Jarvis, M. [Astrophysics, Department of Physics, Keble Road, Oxford, OX1 3RH (United Kingdom); and others

2013-05-01

We present a measurement of the angular power spectrum of the cosmic far-infrared background (CFIRB) anisotropies in one of the extragalactic fields of the Herschel Astrophysical Terahertz Large Area Survey at 250, 350, and 500 {mu}m bands. Consistent with recent measurements of the CFIRB power spectrum in Herschel-SPIRE maps, we confirm the existence of a clear one-halo term of galaxy clustering on arcminute angular scales with large-scale two-halo term of clustering at 30 arcmin to angular scales of a few degrees. The power spectrum at the largest angular scales, especially at 250 {mu}m, is contaminated by the Galactic cirrus. The angular power spectrum is modeled using a conditional luminosity function approach to describe the spatial distribution of unresolved galaxies that make up the bulk of the CFIRB. Integrating over the dusty galaxy population responsible for the background anisotropies, we find that the cosmic abundance of dust, relative to the critical density, to be between {Omega}{sub dust} = 10{sup -6} and 8 Multiplication-Sign 10{sup -6} in the redshift range z {approx} 0-3. This dust abundance is consistent with estimates of the dust content in the universe using quasar reddening and magnification measurements in the Sloan Digital Sky Survey.

Characterizing interstellar filaments as revealed by the Herschel Gould Belt survey: Insights into the initial conditions for star formation

International Nuclear Information System (INIS)

Arzoumanian, Doris

2012-01-01

This thesis aims to characterize the physical properties of interstellar filaments imaged in nearby molecular clouds with the Herschel Space Observatory as part of the Herschel Gould Belt survey. In order to get insight into the formation and evolution of interstellar filaments I analyzed, during my PhD work, a large sample of filaments detected in various nearby clouds. The observed density profiles of the filaments show a power law behavior at large radii and their dust temperature profiles show a drop towards the center. The filaments are characterized by a narrow distribution of de-convolved inner widths, centered around a typical value of ∼ 0.1 pc, while they span more than three orders of magnitude in central column density. This typical filament width corresponds to the sonic scale below which interstellar turbulence becomes subsonic in diffuse gas, which may suggest that the filaments form as a result of the dissipation of large-scale turbulence. While the turbulent fragmentation picture provides a plausible mechanism for forming interstellar filaments, the fact that pre-stellar cores tend to form in dense, gravitationally unstable filaments suggests that gravity is a major driver in the subsequent evolution of the dense supercritical filaments. The latter hypothesis is supported by molecular line observations with the IRAM 30 m telescope, which show an increase in the non-thermal velocity dispersion of supercritical filaments as a function of their central column density, suggesting that self gravitating filaments grow in mass per unit length by accretion of background material while at the same time fragmenting into star-forming cores. (author) [fr

Herschel Observations of Extraordinary Sources: Analysi sof the HIFI 1.2 THz Wide Spectral Survey toward Orion KL II. Chemical Implications

Science.gov (United States)

Crockett, N. R.; Bergin, E. A.; Neill, J. L.; Favre, C.; Blake, G. A.; Herbst, E.; Anderson, D. E.; Hassel, G. E.

2015-06-01

We present chemical implications arising from spectral models fit to the Herschel/HIFI spectral survey toward the Orion Kleinmann-Low nebula (Orion KL). We focus our discussion on the eight complex organics detected within the HIFI survey utilizing a novel technique to identify those molecules emitting in the hottest gas. In particular, we find the complex nitrogen bearing species CH3CN, C2H3CN, C2H5CN, and NH2CHO systematically trace hotter gas than the oxygen bearing organics CH3OH, C2H5OH, CH3OCH3, and CH3OCHO, which do not contain nitrogen. If these complex species form predominantly on grain surfaces, this may indicate N-bearing organics are more difficult to remove from grain surfaces than O-bearing species. Another possibility is that hot (Tkin ∼ 300 K) gas phase chemistry naturally produces higher complex cyanide abundances while suppressing the formation of O-bearing complex organics. We compare our derived rotation temperatures and molecular abundances to chemical models, which include gas-phase and grain surface pathways. Abundances for a majority of the detected complex organics can be reproduced over timescales ≳105 years, with several species being underpredicted by less than 3σ. Derived rotation temperatures for most organics, furthermore, agree reasonably well with the predicted temperatures at peak abundance. We also find that sulfur bearing molecules that also contain oxygen (i.e., SO, SO2, and OCS) tend to probe the hottest gas toward Orion KL, indicating the formation pathways for these species are most efficient at high temperatures. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Herschel/HIFI spectral line survey of the Orion Bar. Temperature and density differentiation near the PDR surface

Science.gov (United States)

Nagy, Z.; Choi, Y.; Ossenkopf-Okada, V.; van der Tak, F. F. S.; Bergin, E. A.; Gerin, M.; Joblin, C.; Röllig, M.; Simon, R.; Stutzki, J.

2017-03-01

Context. Photon dominated regions (PDRs) are interfaces between the mainly ionized and mainly molecular material around young massive stars. Analysis of the physical and chemical structure of such regions traces the impact of far-ultraviolet radiation of young massive stars on their environment. Aims: We present results on the physical and chemical structure of the prototypical high UV-illumination edge-on Orion Bar PDR from an unbiased spectral line survey with a wide spectral coverage which includes lines of many important gas coolants such as [Cii], [Ci], and CO and other key molecules such as H2CO, H2O, HCN, HCO+, and SO. Methods: A spectral scan from 480-1250 GHz and 1410-1910 GHz at 1.1 MHz resolution was obtained by the HIFI instrument on board the Herschel Space Observatory. We obtained physical parameters for the observed molecules. For molecules with multiple transitions we used rotational diagrams to obtain excitation temperatures and column densities. For species with a single detected transition we used an optically thin LTE approximation. In the case of species with available collisional rates, we also performed a non-LTE analysis to obtain kinetic temperatures, H2 volume densities, and column densities. Results: About 120 lines corresponding to 29 molecules (including isotopologues) have been detected in the Herschel/HIFI line survey, including 11 transitions of CO, 7 transitions of 13CO, 6 transitions of C18O, 10 transitions of H2CO, and 6 transitions of H2O. The rotational temperatures are in the range between 22 and 146 K and the column densities are in the range between 1.8 × 1012 cm-2 and 4.5 × 1017 cm-2. For species with at least three detected transitions and available collisional excitation rates we derived a best fit kinetic temperature and H2 volume density. Most species trace kinetic temperatures in the range between 100 and 150 K and H2 volume densities in the range between 105 and 106 cm-3. The species with temperatures and

Herschel GASPS spectral observations of T Tauri stars in Taurus. Unraveling far-infrared line emission from jets and discs

NARCIS (Netherlands)

Alonso-Martínez, M.; Riviere-Marichalar, P.; Meeus, G.; Kamp, I.; Fang, M.; Podio, L.; Dent, W. R. F.; Eiroa, C.

2017-01-01

Context. At early stages of stellar evolution young stars show powerful jets and/or outflows that interact with protoplanetary discs and their surroundings. Despite the scarce knowledge about the interaction of jets and/or outflows with discs, spectroscopic studies based on Herschel and ISO data

THE SPITZER LOCAL VOLUME LEGACY: SURVEY DESCRIPTION AND INFRARED PHOTOMETRY

International Nuclear Information System (INIS)

Dale, D. A.; Cohen, S. A.; Johnson, L. C.; Schuster, M. D.; Calzetti, D.; Engelbracht, C. W.; Kennicutt, R. C.; Block, M.; Marble, A. R.; Gil de Paz, A.; Lee, J. C.; Begum, A.; Dalcanton, J. J.; Funes, J. G.; Gordon, K. D.; Johnson, B. D.; Sakai, S.; Skillman, E. D.; Van Zee, L.; Walter, F.

2009-01-01

The survey description and the near-, mid-, and far-infrared flux properties are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a Spitzer Space Telescope legacy program that surveys the local universe out to 11 Mpc, built upon a foundation of ultraviolet, Hα, and Hubble Space Telescope imaging from 11HUGS (11 Mpc Hα and Ultraviolet Galaxy Survey) and ANGST (ACS Nearby Galaxy Survey Treasury). LVL covers an unbiased, representative, and statistically robust sample of nearby star-forming galaxies, exploiting the highest extragalactic spatial resolution achievable with Spitzer. As a result of its approximately volume-limited nature, LVL augments previous Spitzer observations of present-day galaxies with improved sampling of the low-luminosity galaxy population. The collection of LVL galaxies shows a large spread in mid-infrared colors, likely due to the conspicuous deficiency of 8 μm polycyclic aromatic hydrocarbon emission from low-metallicity, low-luminosity galaxies. Conversely, the far-infrared emission tightly tracks the total infrared emission, with a dispersion in their flux ratio of only 0.1 dex. In terms of the relation between the infrared-to-ultraviolet ratio and the ultraviolet spectral slope, the LVL sample shows redder colors and/or lower infrared-to-ultraviolet ratios than starburst galaxies, suggesting that reprocessing by dust is less important in the lower mass systems that dominate the LVL sample. Comparisons with theoretical models suggest that the amplitude of deviations from the relation found for starburst galaxies correlates with the age of the stellar populations that dominate the ultraviolet/optical luminosities.

Recent achievements on the development of the HERSCHEL/PACS bolometer arrays

International Nuclear Information System (INIS)

Billot, N.; Agnese, P.; Boulade, O.; Cigna, C.; Doumayrou, E.; Horeau, B.; Lepennec, J.; Martignac, J.; Pornin, J.-L.; Reveret, V.; Rodriguez, L.; Sauvage, M.; Simoens, F.; Vigroux, L.

2006-01-01

A new type of bolometer arrays sensitive in the far Infrared and Submillimeter range has been developed and manufactured by CEA/LETI/SLIR since 1997. These arrays will be integrated in the PACS instrument (Photodetector Array Camera and Spectrometer) of ESA's Herschel Space Observatory (launch date 2007). The main innovations of CEA bolometers are their collective manufacturing technique (production of 3-side buttable 16x16 arrays) and their high mapping efficiency (large format detector and instantaneous Nyquist sampling). The measured NEP is 2.10 -16 W/Hz and the thermometric passband about 4-5Hz. In this article we describe CEA bolometers and present the results obtained during the last test campaign

Recent achievements on the development of the HERSCHEL/PACS bolometer arrays

Energy Technology Data Exchange (ETDEWEB)

Billot, N. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France)]. E-mail: nbillot@cea.fr; Agnese, P. [CEA/LETI Grenoble, 17 Avenue des Martyrs, 38054 Grenoble (France); Boulade, O. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Cigna, C. [CEA/LETI Grenoble, 17 Avenue des Martyrs, 38054 Grenoble (France); Doumayrou, E. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Horeau, B. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Lepennec, J. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Martignac, J. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Pornin, J.-L. [CEA/LETI Grenoble, 17 Avenue des Martyrs, 38054 Grenoble (France); Reveret, V. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Rodriguez, L. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Sauvage, M. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Simoens, F. [CEA/LETI Grenoble, 17 Avenue des Martyrs, 38054 Grenoble (France); Vigroux, L. [CEA/Saclay/SAp, UMR CEA/CNRS/UP7 Laboratoire AIM, Bat. 709, l' Orme des merisiers, 91191 Gif-sur-Yvette (France); Institut d' Astrophysique de Paris, 75014 Paris (France)

2006-11-01

A new type of bolometer arrays sensitive in the far Infrared and Submillimeter range has been developed and manufactured by CEA/LETI/SLIR since 1997. These arrays will be integrated in the PACS instrument (Photodetector Array Camera and Spectrometer) of ESA's Herschel Space Observatory (launch date 2007). The main innovations of CEA bolometers are their collective manufacturing technique (production of 3-side buttable 16x16 arrays) and their high mapping efficiency (large format detector and instantaneous Nyquist sampling). The measured NEP is 2.10{sup -16}W/Hz and the thermometric passband about 4-5Hz. In this article we describe CEA bolometers and present the results obtained during the last test campaign.

ALMA observations of lensed Herschel sources: testing the dark matter halo paradigm

Science.gov (United States)

Amvrosiadis, A.; Eales, S. A.; Negrello, M.; Marchetti, L.; Smith, M. W. L.; Bourne, N.; Clements, D. L.; De Zotti, G.; Dunne, L.; Dye, S.; Furlanetto, C.; Ivison, R. J.; Maddox, S. J.; Valiante, E.; Baes, M.; Baker, A. J.; Cooray, A.; Crawford, S. M.; Frayer, D.; Harris, A.; Michałowski, M. J.; Nayyeri, H.; Oliver, S.; Riechers, D. A.; Serjeant, S.; Vaccari, M.

2018-04-01

With the advent of wide-area submillimetre surveys, a large number of high-redshift gravitationally lensed dusty star-forming galaxies have been revealed. Because of the simplicity of the selection criteria for candidate lensed sources in such surveys, identified as those with S500 μm > 100 mJy, uncertainties associated with the modelling of the selection function are expunged. The combination of these attributes makes submillimetre surveys ideal for the study of strong lens statistics. We carried out a pilot study of the lensing statistics of submillimetre-selected sources by making observations with the Atacama Large Millimeter Array (ALMA) of a sample of strongly lensed sources selected from surveys carried out with the Herschel Space Observatory. We attempted to reproduce the distribution of image separations for the lensed sources using a halo mass function taken from a numerical simulation that contains both dark matter and baryons. We used three different density distributions, one based on analytical fits to the haloes formed in the EAGLE simulation and two density distributions [Singular Isothermal Sphere (SIS) and SISSA] that have been used before in lensing studies. We found that we could reproduce the observed distribution with all three density distributions, as long as we imposed an upper mass transition of ˜1013 M⊙ for the SIS and SISSA models, above which we assumed that the density distribution could be represented by a Navarro-Frenk-White profile. We show that we would need a sample of ˜500 lensed sources to distinguish between the density distributions, which is practical given the predicted number of lensed sources in the Herschel surveys.

The Geometry of the Infrared and X-Ray Obscurer in a Dusty Hyperluminous Quasar

DEFF Research Database (Denmark)

Farrah, Duncan; Baloković, Mislav; Stern, Daniel

2016-01-01

We study the geometry of the active galactic nucleus (AGN) obscurer in IRAS 09104+4109, an IR-luminous, radio-intermediate FR-I source at z = 0.442, using infrared data from Spitzer and Herschel, X-ray data from NuSTAR, Swift, Suzaku, and Chandra, and an optical spectrum from Palomar. The infrare...

Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way

OpenAIRE

Molinari, S.; Swinyard, B.; Bally, J.; Barlow, M.; Bernard, J. P.; Martin, P.; Moore, T.; Noriega-Crespo, A.; Plume, R.; Testi, L.; Zavagno, A.; Abergel, A.; Ali, B.; Anderson, L.; André, P.

2010-01-01

We present the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key-project that will map the inner Galactic Plane of the Milky Way in 5 bands. We outline our data reduction strategy and present some science highlights on the two observed 2{\\deg} x 2{\\deg} tiles approximately centered at l=30{\\deg} and l=59{\\deg}. The two regions are extremely rich in intense and highly structured extended emission which shows a widespread organization in filaments. Sourc...

Advancing toward far-infrared interferometry in space through coordinated international efforts

NARCIS (Netherlands)

Leisawitz, D.; Baryshev, A.; Griffin, M. J.; Helmich, F. P.; Ivison, R. J.; Rinehart, S. A.; Savini, G.; Shibai, H.

2013-01-01

The international far-infrared astrophysics community is eager to follow up Spitzer and Herschel observations with sensitive, high-resolution imaging and spectroscopy, for such measurements are needed to understand merger-driven star formation, Active Galactic Nuclei, chemical enrichment in

First Results from the $Herschel$ and ALMA Spectroscopic Surveys of the SMC: The Relationship Between [CII]-bright Gas and CO-bright Gas at Low Metallicity

OpenAIRE

Jameson, Katherine E.; Bolatto, Alberto D.; Wolfire, Mark; Warren, Steven R.; Herrera-Camus, Rodrigo; Croxall, Kevin; Pellegrini, Eric; Smith, John-David; Rubio, Monica; Indebetouw, Remy; Israel, Frank P.; Meixner, Margaret; Roman-Duval, Julia; van Loon, Jacco Th.; Muller, Erik

2018-01-01

The Small Magellanic Cloud (SMC) provides the only laboratory to study the structure of molecular gas at high resolution and low metallicity. We present results from the Herschel Spectroscopic Survey of the SMC (HS$^{3}$), which mapped the key far-IR cooling lines [CII], [OI], [NII], and [OIII] in five star-forming regions, and new ALMA 7m-array maps of $^{12}$CO and $^{13}$CO $(2-1)$ with coverage overlapping four of the five HS$^{3}$ regions. We detect [CII] and [OI] throughout all of the r...

HERSCHEL OBSERVATIONS AND UPDATED SPECTRAL ENERGY DISTRIBUTIONS OF FIVE SUNLIKE STARS WITH DEBRIS DISKS

International Nuclear Information System (INIS)

Dodson-Robinson, Sarah E.; Su, Kate Y. L.; Bryden, Geoff; Harvey, Paul; Green, Joel D.

2016-01-01

Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R  > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R  > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14″ along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS point-spread function size (50% of energy enclosed within radius 4.″23). HD 105211 also has a 24 μ m infrared excess, which was previously overlooked, because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius a min  ∼ 3 μ m, although a min is larger than the radiation-pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of a model blackbody disk. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 2 × 10 −5  ⩽  L / L ⊙  ⩽ 2 × 10 −4 , consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.

HERSCHEL OBSERVATIONS AND UPDATED SPECTRAL ENERGY DISTRIBUTIONS OF FIVE SUNLIKE STARS WITH DEBRIS DISKS

Energy Technology Data Exchange (ETDEWEB)

Dodson-Robinson, Sarah E. [Department of Physics and Astronomy, University of Delaware, 217 Sharp Lab, Newark, DE 19716 (United States); Su, Kate Y. L. [Steward Observatory, Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bryden, Geoff [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Harvey, Paul; Green, Joel D., E-mail: sdr@udel.edu [Astronomy Department, University of Texas, 2515 Speedway Drive C1400, Austin, TX 78712 (United States)

2016-12-20

Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R  > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R  > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular extent of >14″ along the major axis, and the disks of HD 33636, HD 50554, and HD 52265 are extended beyond the PACS point-spread function size (50% of energy enclosed within radius 4.″23). HD 105211 also has a 24 μ m infrared excess, which was previously overlooked, because of a poorly constrained photospheric model. Archival Spitzer IRS observations indicate that the disks have small grains of minimum radius a {sub min} ∼ 3 μ m, although a {sub min} is larger than the radiation-pressure blowout size in all systems. If modeled as single-temperature blackbodies, the disk temperatures would all be <60 K. Our radiative transfer models predict actual disk radii approximately twice the radius of a model blackbody disk. We find that the Herschel photometry traces dust near the source population of planetesimals. The disk luminosities are in the range 2 × 10{sup −5} ⩽  L / L {sub ⊙} ⩽ 2 × 10{sup −4}, consistent with collisions in icy planetesimal belts stirred by Pluto-size dwarf planets.

Herschel/HIFI line surveys: Discovery of interstellar chloronium (H{sub 2}Cl{sup +})

Energy Technology Data Exchange (ETDEWEB)

Lis, Dariusz C., E-mail: dcl@caltech.edu [California Institute of Technology, Cahill Center for Astronomy and Astrophysics MC 301-17, Pasadena, CA 91125 (United States)

2015-01-22

Prior to the launch of Herschel, HCl was the only chlorine-containing molecule detected in the interstellar medium (ISM). However, chemical models have identified chloronium, H{sub 2}Cl{sup +}, as a relatively abundant species that is potentially detectable. H{sub 2}Cl{sup +} was predicted to be most abundant in the environments where the ultraviolet radiation is strong: in diffuse clouds, or near the surfaces of dense clouds illuminated by nearby O and B stars. The HIFI instrument on Herschel provided the first detection of H{sub 2}Cl{sup +} in the ISM. The 2{sub 12}-1{sub 01} lines of ortho-H{sub 2}{sup 35}Cl{sup +} and ortho-H{sub 2}{sup 37}Cl{sup +} were detected in absorption toward NGC 6334I, and the 1{sub 11}-0{sub 00} transition of para-H{sub 2}{sup 35}Cl{sup +} was detected in absorption toward NGC 6334I and Sgr B2(S). The derived HCl/H{sub 2}Cl{sup +} column density ratios, ∼1-10, are within the range predicted by models of diffuse and dense Photon Dominated Regions (PDRs). However, the observed H{sub 2}Cl{sup +} column densities, in excess of 10{sup 13} cm{sup −2}, are significantly higher than the model predictions. These observations demonstrate the outstanding spectroscopic capabilities of HIFI for detecting new interstellar molecules and providing key constraints for astrochemical models.

The complete far-infrared and submillimeter spectrum of the Class 0 protostar Serpens SMM1 obtained with Herschel

DEFF Research Database (Denmark)

R. Goicoechea, Javier; Cernicharo, J.; Karska, A.

2012-01-01

We present the first complete 55-671 um spectral scan of a low-mass Class 0 protostar (Serpens SMM1) taken with the PACS and SPIRE spectrometers on board Herschel. More than 145 lines have been detected, most of them rotationally excited lines of 12CO (full ladder from J=4-3 to 42-41), H2O, OH, 13...

The Herschel–ATLAS Data Release 2, Paper I. Submillimeter and Far-infrared Images of the South and North Galactic Poles: The Largest Herschel Survey of the Extragalactic Sky

Science.gov (United States)

Smith, Matthew W. L.; Ibar, Edo; Maddox, Steve J.; Valiante, Elisabetta; Dunne, Loretta; Eales, Stephen; Dye, Simon; Furlanetto, Christina; Bourne, Nathan; Cigan, Phil; Ivison, Rob J.; Gomez, Haley; Smith, Daniel J. B.; Viaene, Sébastien

2017-12-01

We present the largest submillimeter images that have been made of the extragalactic sky. The Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) is a survey of 660 deg2 with the PACS and SPIRE cameras in five photometric bands: 100, 160, 250, 350, and 500 μm. In this paper we present the images from our two largest fields, which account for ∼75% of the survey. The first field is 180.1 deg2 in size, centered on the north Galactic pole (NGP), and the second is 317.6 deg2 in size, centered on the south Galactic pole. The NGP field serendipitously contains the Coma cluster. Over most (∼80%) of the images, the pixel noise, including both instrumental noise and confusion noise, is approximately 3.6, and 3.5 mJy pix‑1 at 100 and 160 μm, and 11.0, 11.1 and 12.3 mJy beam‑1 at 250, 350 and 500 μm, respectively, but reaches lower values in some parts of the images. If a matched filter is applied to optimize point-source detection, our total 1σ map sensitivity is 5.7, 6.0, and 7.3 mJy at 250, 350, and 500 μm, respectively. We describe the results of an investigation of the noise properties of the images. We make the most precise estimate of confusion in SPIRE maps to date, finding values of 3.12 ± 0.07, 4.13 ± 0.02, and 4.45 ± 0.04 mJy beam‑1 at 250, 350, and 500 μm in our un-convolved maps. For PACS we find an estimate of the confusion noise in our fast-parallel observations of 4.23 and 4.62 mJy beam‑1 at 100 and 160 μm. Finally, we give recipes for using these images to carry out photometry, both for unresolved and extended sources.

Infrared Astronomy and Education: Linking Infrared Whole Sky Mapping with Teacher and Student Research

Science.gov (United States)

Borders, Kareen; Mendez, Bryan; Thaller, Michelle; Gorjian, Varoujan; Borders, Kyla; Pitman, Peter; Pereira, Vincent; Sepulveda, Babs; Stark, Ron; Knisely, Cindy; Dandrea, Amy; Winglee, Robert; Plecki, Marge; Goebel, Jeri; Condit, Matt; Kelly, Susan

The Spitzer Space Telescope and the recently launched WISE (Wide Field Infrared Survey Explorer) observe the sky in infrared light. Among the objects WISE will study are asteroids, the coolest and dimmest stars, and the most luminous galaxies. Secondary students can do authentic research using infrared data. For example, students will use WISE data to mea-sure physical properties of asteroids. In order to prepare students and teachers at this level with a high level of rigor and scientific understanding, the WISE and the Spitzer Space Tele-scope Education programs provided an immersive teacher professional development workshop in infrared astronomy.The lessons learned from the Spitzer and WISE teacher and student pro-grams can be applied to other programs engaging them in authentic research experiences using data from space-borne observatories such as Herschel and Planck. Recently, WISE Educator Ambassadors and NASA Explorer School teachers developed and led an infrared astronomy workshop at Arecibo Observatory in PuertoRico. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance and age of objects in the Universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and the Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. We will outline specific steps for sec-ondary astronomy professional development, detail student involvement in infrared telescope data analysis, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional secondary professional development and student involvement in infrared astronomy. Funding was

Candidate high-z protoclusters among the Planck compact sources, as revealed by Herschel-SPIRE

Science.gov (United States)

Greenslade, J.; Clements, D. L.; Cheng, T.; De Zotti, G.; Scott, D.; Valiante, E.; Eales, S.; Bremer, M. N.; Dannerbauer, H.; Birkinshaw, M.; Farrah, D.; Harrison, D. L.; Michałowski, M. J.; Valtchanov, I.; Oteo, I.; Baes, M.; Cooray, A.; Negrello, M.; Wang, L.; van der Werf, P.; Dunne, L.; Dye, S.

2018-05-01

By determining the nature of all the Planck compact sources within 808.4 deg2 of large Herschel surveys, we have identified 27 candidate protoclusters of dusty star-forming galaxies (DSFGs) that are at least 3σ overdense in either 250, 350, or 500 μm sources. We find roughly half of all the Planck compact sources are resolved by Herschel into multiple discrete objects, with the other half remaining unresolved by Herschel. We find a significant difference between versions of the Planck catalogues, with earlier releases hosting a larger fraction of candidate protoclusters and Galactic cirrus than later releases, which we ascribe to a difference in the filters used in the creation of the three catalogues. We find a surface density of DSFG candidate protoclusters of (3.3 ± 0.7) × 10-2 sources deg-2, in good agreement with previous similar studies. We find that a Planck colour selection of S857/S545 1. Our candidate protoclusters are a factor of 5 times brighter at 353 GHz than expected from simulations, even in the most conservative estimates. Further observations are needed to confirm whether these candidate protoclusters are physical clusters, multiple protoclusters along the line of sight, or chance alignments of unassociated sources.

GOODS-HERSCHEL: IMPACT OF ACTIVE GALACTIC NUCLEI AND STAR FORMATION ACTIVITY ON INFRARED SPECTRAL ENERGY DISTRIBUTIONS AT HIGH REDSHIFT

Energy Technology Data Exchange (ETDEWEB)

Kirkpatrick, Allison; Pope, Alexandra [Department of Astronomy, University of Massachusetts, Amherst, MA 01002 (United States); Alexander, David M. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Charmandaris, Vassilis [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003, Heraklion (Greece); Daddi, Emmanuele; Elbaz, David; Gabor, Jared; Mullaney, James; Pannella, Maurilio; Aussel, Herve; Bournaud, Frederic; Dasyra, Kalliopi [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Dickinson, Mark [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Hwang, Ho Seong [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Ivison, Rob [UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Scott, Douglas [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Altieri, Bruno; Coia, Daniela [Herschel Science Centre, European Space Astronomy Centre, Villanueva de la Canada, E-28691 Madrid (Spain); Buat, Veronique [Laboratoire d' Astrophysique de Marseille (LAM), Universite d' Aix-Marseille, CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Dannerbauer, Helmut, E-mail: kirkpatr@astro.umass.edu [Institut fuer Astrophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Wien (Austria); and others

2012-11-10

We explore the effects of active galactic nuclei (AGNs) and star formation activity on the infrared (0.3-1000 {mu}m) spectral energy distributions (SEDs) of luminous infrared galaxies from z = 0.5 to 4.0. We have compiled a large sample of 151 galaxies selected at 24 {mu}m (S {sub 24} {approx}> 100 {mu}Jy) in the GOODS-N and ECDFS fields for which we have deep Spitzer IRS spectroscopy, allowing us to decompose the mid-IR spectrum into contributions from star formation and AGN activity. A significant portion ({approx}25%) of our sample is dominated by an AGN (>50% of the mid-IR luminosity) in the mid-IR. Based on the mid-IR classification, we divide our full sample into four sub-samples: z {approx} 1 star-forming (SF) sources, z {approx} 2 SF sources, AGNs with clear 9.7 {mu}m silicate absorption, and AGNs with featureless mid-IR spectra. From our large spectroscopic sample and wealth of multi-wavelength data, including deep Herschel imaging at 100, 160, 250, 350, and 500 {mu}m, we use 95 galaxies with complete spectral coverage to create a composite SED for each sub-sample. We then fit a two-temperature component modified blackbody to the SEDs. We find that the IR SEDs have similar cold dust temperatures, regardless of the mid-IR power source, but display a marked difference in the warmer dust temperatures. We calculate the average effective temperature of the dust in each sub-sample and find a significant ({approx}20 K) difference between the SF and AGN systems. We compare our composite SEDs to local templates and find that local templates do not accurately reproduce the mid-IR features and dust temperatures of our high-redshift systems. High-redshift IR luminous galaxies contain significantly more cool dust than their local counterparts. We find that a full suite of photometry spanning the IR peak is necessary to accurately account for the dominant dust temperature components in high-redshift IR luminous galaxies.

ARNICA, the Arcetri near-infrared camera: Astronomical performance assessment.

Science.gov (United States)

Hunt, L. K.; Lisi, F.; Testi, L.; Baffa, C.; Borelli, S.; Maiolino, R.; Moriondo, G.; Stanga, R. M.

1996-01-01

The Arcetri near-infrared camera ARNICA was built as a users' instrument for the Infrared Telescope at Gornergrat (TIRGO), and is based on a 256x256 NICMOS 3 detector. In this paper, we discuss ARNICA's optical and astronomical performance at the TIRGO and at the William Herschel Telescope on La Palma. Optical performance is evaluated in terms of plate scale, distortion, point spread function, and ghosting. Astronomical performance is characterized by camera efficiency, sensitivity, and spatial uniformity of the photometry.

A NEAR-INFRARED SPECTROSCOPIC SURVEY OF COOL WHITE DWARFS IN THE SLOAN DIGITAL SKY SURVEY

International Nuclear Information System (INIS)

Kilic, Mukremin; Kowalski, Piotr M.; Von Hippel, Ted

2009-01-01

We present near-infrared photometric observations of 15 and spectroscopic observations of 38 cool white dwarfs (WDs). This is the largest near-infrared spectroscopic survey of cool WDs to date. Combining the Sloan Digital Sky Survey photometry and our near-infrared data, we perform a detailed model atmosphere analysis. The spectral energy distributions of our objects are explained fairly well by model atmospheres with temperatures ranging from 6300 K down to 4200 K. Two WDs show significant absorption in the infrared, and are best explained with mixed H/He atmosphere models. Based on the up-to-date model atmosphere calculations by Kowalski and Saumon, we find that the majority of the stars in our sample have hydrogen-rich atmospheres. We do not find any pure helium atmosphere WDs below 5000 K, and we find a trend of increasing hydrogen to helium ratio with decreasing temperature. These findings present an important challenge to understanding the spectral evolution of WDs.

OH far-infrared emission from low- and intermediate-mass protostars surveyed with Herschel-PACS

DEFF Research Database (Denmark)

Wampfler, Susanne Franziska; Bruderer, S.; Karska, A.

2013-01-01

fluxes nor their broad line widths, strongly suggesting an outflow origin. Slab excitation models indicate that the observed excitation temperature can either be reached if the OH molecules are exposed to a strong far-infrared continuum radiation field or if the gas temperature and density...... are sufficiently high. Using realistic source parameters and radiation fields, it is shown for the case of Ser SMM1 that radiative pumping plays an important role in transitions arising from upper level energies higher than 300 K. The compact emission in the low-mass sources and the required presence of a strong...

Footprint Database and web services for the Herschel space observatory

Science.gov (United States)

Verebélyi, Erika; Dobos, László; Kiss, Csaba

2015-08-01

Using all telemetry and observational meta-data, we created a searchable database of Herschel observation footprints. Data from the Herschel space observatory is freely available for everyone but no uniformly processed catalog of all observations has been published yet. As a first step, we unified the data model for all three Herschel instruments in all observation modes and compiled a database of sky coverage information. As opposed to methods using a pixellation of the sphere, in our database, sky coverage is stored in exact geometric form allowing for precise area calculations. Indexing of the footprints allows for very fast search among observations based on pointing, time, sky coverage overlap and meta-data. This enables us, for example, to find moving objects easily in Herschel fields. The database is accessible via a web site and also as a set of REST web service functions which makes it usable from program clients like Python or IDL scripts. Data is available in various formats including Virtual Observatory standards.

Who Invented the Word Asteroid: William Herschel or Stephen Weston?

Science.gov (United States)

Cunningham, Clifford J.; Orchiston, Wayne

2011-11-01

William Herschel made the first serious study of 1 Ceres and 2 Pallas in the year 1802. He was moved by their dissimilarities to the other planets to coin a new term to distinguish them. For this purpose he enlisted the aid of his good friends William Watson and Sir Joseph Banks. Watson gave him a long list of possible names, which Herschel rejected. With a lifetime of experience classifying and naming newly found objects in nature, Banks became the man both Erasmus Darwin (in 1781) and William Herschel (in 1802) turned to for sage advice in developing a new descriptive language. In the case of Ceres and Pallas, Banks turned the task over to his friend, the noted philologist Stephen Weston, FRS. It has recently been stated by a noted British historian that it was Weston - not Herschel - who coined the term 'asteroid' to collectively describe Ceres and Pallas. This claim is investigated, and parallels are drawn in the use of neologism in astronomy and botany.

ULTRALUMINOUS INFRARED GALAXIES IN THE WISE AND SDSS SURVEYS

International Nuclear Information System (INIS)

Su, Shanshan; Kong, Xu; Li, Jinrong; Fang, Guanwen

2013-01-01

In this paper, we present a large catalog of 419 Ultraluminous infrared galaxies (ULIRGs), carefully selected from the Wide-field Infrared Survey Explorer mid-infrared data and the Sloan Digital Sky Survey eighth data release, and classify them into three subsamples, based on their emission line properties: H II-like ULIRGs, Seyfert 2 ULIRGs, and composite ULIRGs. We apply our new efficient spectral synthesis technique, which is based on mean field approach to Bayesian independent component analysis (MF-ICA) method, to the galaxy integrated spectra. We also analyze the stellar population properties, including percentage contribution, stellar age, and stellar mass, for these three types of ULIRGs, and explore the evolution among them. We find no significant difference between the properties of stellar populations in ULIRGs with or without active galactic nucleus components. Our results suggest that there is no evolutionary link among these three type ULIRGs

HerMES: THE FAR-INFRARED EMISSION FROM DUST-OBSCURED GALAXIES

International Nuclear Information System (INIS)

Calanog, J. A.; Wardlow, J.; Fu, Hai; Cooray, A.; Assef, R. J.; Bock, J.; Riechers, D.; Schulz, B.; Casey, C. M.; Conley, A.; Farrah, D.; Oliver, S. J.; Roseboom, I. G.; Ibar, E.; Kartaltepe, J.; Magdis, G.; Rigopoulou, D.; Marchetti, L.; Pérez-Fournon, I.; Scott, Douglas

2013-01-01

Dust-obscured galaxies (DOGs) are an ultraviolet-faint, infrared-bright galaxy population that reside at z ∼ 2 and are believed to be in a phase of dusty star-forming and active galactic nucleus (AGN) activity. We present far-infrared (far-IR) observations of a complete sample of DOGs in the 2 deg 2 of the Cosmic Evolution Survey. The 3077 DOGs have (z) = 1.9 ± 0.3 and are selected from 24 μm and r + observations using a color cut of r + – [24] ≥ 7.5 (AB mag) and S 24 ≥ 100 μJy. Based on the near-IR spectral energy distributions, 47% are bump DOGs (star formation dominated) and 10% are power-law DOGs (AGN-dominated). We use SPIRE far-IR photometry from the Herschel Multi-tiered Extragalactic Survey to calculate the IR luminosity and characteristic dust temperature for the 1572 (51%) DOGs that are detected at 250 μm (≥3σ). For the remaining 1505 (49%) that are undetected, we perform a median stacking analysis to probe fainter luminosities. Herschel-detected and undetected DOGs have average luminosities of (2.8 ± 0.4) × 10 12 L ☉ and (0.77 ± 0.08) × 10 12 L ☉ , and dust temperatures of (33 ± 7) K and (37 ± 5) K, respectively. The IR luminosity function for DOGs with S 24 ≥ 100 μJy is calculated, using far-IR observations and stacking. DOGs contribute 10%-30% to the total star formation rate (SFR) density of the universe at z = 1.5-2.5, dominated by 250 μm detected and bump DOGs. For comparison, DOGs contribute 30% to the SFR density for all z = 1.5-2.5 galaxies with S 24 ≥ 100 μJy. DOGs have a large scatter about the star formation main sequence and their specific SFRs show that the observed phase of star formation could be responsible for their total observed stellar mass at z ∼ 2

HerMES: THE FAR-INFRARED EMISSION FROM DUST-OBSCURED GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Calanog, J. A.; Wardlow, J.; Fu, Hai; Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Assef, R. J. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Bock, J.; Riechers, D.; Schulz, B. [California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Casey, C. M. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Conley, A. [Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States); Farrah, D.; Oliver, S. J.; Roseboom, I. G. [Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom); Ibar, E. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Kartaltepe, J. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Magdis, G.; Rigopoulou, D. [Department of Astrophysics, Denys Wilkinson Building, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Marchetti, L. [Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom); Pérez-Fournon, I. [Instituto de Astrofísica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Scott, Douglas [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); and others

2013-09-20

Dust-obscured galaxies (DOGs) are an ultraviolet-faint, infrared-bright galaxy population that reside at z ∼ 2 and are believed to be in a phase of dusty star-forming and active galactic nucleus (AGN) activity. We present far-infrared (far-IR) observations of a complete sample of DOGs in the 2 deg{sup 2} of the Cosmic Evolution Survey. The 3077 DOGs have (z) = 1.9 ± 0.3 and are selected from 24 μm and r {sup +} observations using a color cut of r {sup +} – [24] ≥ 7.5 (AB mag) and S{sub 24} ≥ 100 μJy. Based on the near-IR spectral energy distributions, 47% are bump DOGs (star formation dominated) and 10% are power-law DOGs (AGN-dominated). We use SPIRE far-IR photometry from the Herschel Multi-tiered Extragalactic Survey to calculate the IR luminosity and characteristic dust temperature for the 1572 (51%) DOGs that are detected at 250 μm (≥3σ). For the remaining 1505 (49%) that are undetected, we perform a median stacking analysis to probe fainter luminosities. Herschel-detected and undetected DOGs have average luminosities of (2.8 ± 0.4) × 10{sup 12} L{sub ☉} and (0.77 ± 0.08) × 10{sup 12} L{sub ☉}, and dust temperatures of (33 ± 7) K and (37 ± 5) K, respectively. The IR luminosity function for DOGs with S{sub 24} ≥ 100 μJy is calculated, using far-IR observations and stacking. DOGs contribute 10%-30% to the total star formation rate (SFR) density of the universe at z = 1.5-2.5, dominated by 250 μm detected and bump DOGs. For comparison, DOGs contribute 30% to the SFR density for all z = 1.5-2.5 galaxies with S{sub 24} ≥ 100 μJy. DOGs have a large scatter about the star formation main sequence and their specific SFRs show that the observed phase of star formation could be responsible for their total observed stellar mass at z ∼ 2.

Project overview and update on WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope

NARCIS (Netherlands)

Dalton, Gavin; Trager, Scott; Abrams, Don Carlos; Bonifacio, Piercarlo; López Aguerri, J. Alfonso; Middleton, Kevin; Benn, Chris; Dee, Kevin; Sayède, Frédéric; Lewis, Ian; Pragt, Johan; Pico, Sergio; Walton, Nic; Rey, Juerg; Allende Prieto, Carlos; Peñate, José; Lhome, Emilie; Agócs, Tibor; Alonso, José; Terrett, David; Brock, Matthew; Gilbert, James; Ridings, Andy; Guinouard, Isabelle; Verheijen, Marc A.W.; Tosh, Ian; Rogers, Kevin; Steele, Iain; Stuik, Remko; Tromp, Neils; Jasko, Attila; Kragt, Jan; Lesman, Dirk; Mottram, Chris; Bates, Stuart; Gribbin, Frank; Rodriguez, Luis Fernando; Delgado, José M.; Martin, Carlos; Cano, Diego; Navarro, Ramón; Irwin, Mike; Lewis, Jim; Gonzalez Solares, Eduardo; O'Mahony, Neil; Bianco, Andrea; Zurita, Christina; ter Horst, Rik; Molinari, Emilio; Lodi, Marcello; Guerra, José; Vallenari, Antonella; Baruffolo, Andrea

We present an overview of and status report on the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT). WEAVE principally targets optical ground-based follow up of upcoming ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE is a multi-object and multi-IFU

The Footprint Database and Web Services of the Herschel Space Observatory

Science.gov (United States)

Dobos, László; Varga-Verebélyi, Erika; Verdugo, Eva; Teyssier, David; Exter, Katrina; Valtchanov, Ivan; Budavári, Tamás; Kiss, Csaba

2016-10-01

Data from the Herschel Space Observatory is freely available to the public but no uniformly processed catalogue of the observations has been published so far. To date, the Herschel Science Archive does not contain the exact sky coverage (footprint) of individual observations and supports search for measurements based on bounding circles only. Drawing on previous experience in implementing footprint databases, we built the Herschel Footprint Database and Web Services for the Herschel Space Observatory to provide efficient search capabilities for typical astronomical queries. The database was designed with the following main goals in mind: (a) provide a unified data model for meta-data of all instruments and observational modes, (b) quickly find observations covering a selected object and its neighbourhood, (c) quickly find every observation in a larger area of the sky, (d) allow for finding solar system objects crossing observation fields. As a first step, we developed a unified data model of observations of all three Herschel instruments for all pointing and instrument modes. Then, using telescope pointing information and observational meta-data, we compiled a database of footprints. As opposed to methods using pixellation of the sphere, we represent sky coverage in an exact geometric form allowing for precise area calculations. For easier handling of Herschel observation footprints with rather complex shapes, two algorithms were implemented to reduce the outline. Furthermore, a new visualisation tool to plot footprints with various spherical projections was developed. Indexing of the footprints using Hierarchical Triangular Mesh makes it possible to quickly find observations based on sky coverage, time and meta-data. The database is accessible via a web site http://herschel.vo.elte.hu and also as a set of REST web service functions, which makes it readily usable from programming environments such as Python or IDL. The web service allows downloading footprint data

STAR FORMATION RATES IN RESOLVED GALAXIES: CALIBRATIONS WITH NEAR- AND FAR-INFRARED DATA FOR NGC 5055 AND NGC 6946

Energy Technology Data Exchange (ETDEWEB)

Li Yiming; Crocker, Alison F.; Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Wilson, Christine D. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Kennicutt, Robert C.; Galametz, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Murphy, Eric J. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Brandl, Bernhard R.; Groves, B. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Draine, B. T. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Johnson, B. D. [Institut d' Astrophysique de Paris, UMR7095 CNRS, Universite Pierre and Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France); Armus, L. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Gordon, K. D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Croxall, K. [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Dale, D. A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Engelbracht, C. W.; Hinz, J. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hao, C.-N. [Tianjin Astrophysics Center, Tianjin Normal University, Tianjin 300387 (China); Helou, G. [NASA Herschel Science Center, IPAC, California Institute of Technology, Pasadena, CA 91125 (United States); Hunt, L. K., E-mail: yimingl@astro.umass.edu [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); and others

2013-05-10

We use the near-infrared Br{gamma} hydrogen recombination line as a reference star formation rate (SFR) indicator to test the validity and establish the calibration of the Herschel/PACS 70 {mu}m emission as a SFR tracer for sub-galactic regions in external galaxies. Br{gamma} offers the double advantage of directly tracing ionizing photons and of being relatively insensitive to the effects of dust attenuation. For our first experiment, we use archival Canada-France-Hawaii Telescope Br{gamma} and Ks images of two nearby galaxies: NGC 5055 and NGC 6946, which are also part of the Herschel program KINGFISH (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel). We use the extinction corrected Br{gamma} emission to derive the SFR(70) calibration for H II regions in these two galaxies. A comparison of the SFR(70) calibrations at different spatial scales, from 200 pc to the size of the whole galaxy, reveals that about 50% of the total 70 {mu}m emission is due to dust heated by stellar populations that are unrelated to the current star formation. We use a simple model to qualitatively relate the increase of the SFR(70) calibration coefficient with decreasing region size to the star formation timescale. We provide a calibration for an unbiased SFR indicator that combines the observed H{alpha} with the 70 {mu}m emission, also for use in H II regions. We briefly analyze the PACS 100 and 160 {mu}m maps and find that longer wavelengths are not as good SFR indicators as 70 {mu}m, in agreement with previous results. We find that the calibrations show about 50% difference between the two galaxies, possibly due to effects of inclination.

STAR FORMATION RATES IN RESOLVED GALAXIES: CALIBRATIONS WITH NEAR- AND FAR-INFRARED DATA FOR NGC 5055 AND NGC 6946

International Nuclear Information System (INIS)

Li Yiming; Crocker, Alison F.; Calzetti, Daniela; Wilson, Christine D.; Kennicutt, Robert C.; Galametz, M.; Murphy, Eric J.; Brandl, Bernhard R.; Groves, B.; Draine, B. T.; Johnson, B. D.; Armus, L.; Gordon, K. D.; Croxall, K.; Dale, D. A.; Engelbracht, C. W.; Hinz, J.; Hao, C.-N.; Helou, G.; Hunt, L. K.

2013-01-01

We use the near-infrared Brγ hydrogen recombination line as a reference star formation rate (SFR) indicator to test the validity and establish the calibration of the Herschel/PACS 70 μm emission as a SFR tracer for sub-galactic regions in external galaxies. Brγ offers the double advantage of directly tracing ionizing photons and of being relatively insensitive to the effects of dust attenuation. For our first experiment, we use archival Canada-France-Hawaii Telescope Brγ and Ks images of two nearby galaxies: NGC 5055 and NGC 6946, which are also part of the Herschel program KINGFISH (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel). We use the extinction corrected Brγ emission to derive the SFR(70) calibration for H II regions in these two galaxies. A comparison of the SFR(70) calibrations at different spatial scales, from 200 pc to the size of the whole galaxy, reveals that about 50% of the total 70 μm emission is due to dust heated by stellar populations that are unrelated to the current star formation. We use a simple model to qualitatively relate the increase of the SFR(70) calibration coefficient with decreasing region size to the star formation timescale. We provide a calibration for an unbiased SFR indicator that combines the observed Hα with the 70 μm emission, also for use in H II regions. We briefly analyze the PACS 100 and 160 μm maps and find that longer wavelengths are not as good SFR indicators as 70 μm, in agreement with previous results. We find that the calibrations show about 50% difference between the two galaxies, possibly due to effects of inclination.

Near infrared face recognition: A literature survey

Czech Academy of Sciences Publication Activity Database

Farokhi, Sajad; Flusser, Jan; Sheikh, U. U.

2016-01-01

Roč. 21, č. 1 (2016), s. 1-17 ISSN 1574-0137 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Literature survey * Biometrics * Face recognition * Near infrared * Illumination invariant Subject RIV: JD - Computer Applications, Robotics http://library.utia.cas.cz/separaty/2016/ZOI/flusser-0461834.pdf

THE HIGH-RESOLUTION INFRARED SPECTRUM OF HCl{sup +}

Energy Technology Data Exchange (ETDEWEB)

Doménech, J. L.; Herrero, V. J.; Tanarro, I. [Molecular Physics Department, Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain); Drouin, B. J. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Cernicharo, J., E-mail: jl.domenech@csic.es [Molecular Astrophysics Group, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain)

2016-12-20

The chloroniumyl cation, HCl{sup +}, has been recently identified in space from Herschel 's spectra. A joint analysis of extensive vis-UV spectroscopy emission data together with a few high-resolution and high-accuracy millimeter-wave data provided the necessary rest frequencies to support the astronomical identification. Nevertheless, the analysis did not include any infrared (IR) vibration–rotation data. Furthermore, with the end of the Herschel mission, IR observations from the ground may be one of the few available means to further study this ion in space. In this work, we provide a set of accurate rovibrational transition wavenumbers, as well as a new and improved global fit of vis-UV, IR, and millimeter-wave spectroscopy laboratory data, that will aid in future studies of this molecule.

The WIRED Survey. 2; Infrared Excesses in the SDSS DR7 White Dwarf Catalog

Science.gov (United States)

Debes, John H.; Hoard, D. W.; Wachter, Stefanie; Leisawitz, David T.; Cohen, Martin

2011-01-01

With the launch of the Wide-field Infrar.ed Survey Explorer (WISE), a new era of detecting planetary debris and brown dwarfs (BDs) around white dwarfs (WDs) has begun with the WISE InfraRed Excesses around Degenerates (WIRED) Survey. The WIRED Survey is sensitive to substellar objects and dusty debris around WDs out to distances exceeding 100 pc, well beyond the completeness level of local WDs. In this paper, we present a cross-correlation of the preliminary Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) WD catalog between the WISE, Two-Micron All Sky Survey (2MASS), UKIRT Infrared Deep Sky Survey (UKIDSS), and SDSS DR7 photometric catalogs. From -18,000 input targets, there are WISE detections comprising 344 "naked" WDs (detection of the WD photosphere only), 1020 candidate WD+M dwarf binaries, 42 candidate WD+BD systems, 52 candidate WD+dust disk systems, and 69 targets with indeterminate infrared excess. We classified all of the detected targets through spectral energy distribution model fitting of the merged optical, near-IR, and WISE photometry. Some of these detections could be the result of contaminating sources within the large (approx. 6") WISE point-spread function; we make a preliminary estimate for the rates of contamination for our WD+BD and WD+disk candidates and provide notes for each target of interest. Each candidate presented here should be confirmed with higher angular resolution infrared imaging or infrared spectroscopy. We also present an overview of the observational characteristics of the detected WDs in the WISE photometric bands, including the relative frequencies of candidate WD+M, WD+BD, and WD+disk systems.

Searching the stars the story of Caroline Herschel

CERN Document Server

Ogilvie, Marilyn B

2011-01-01

Caroline Herschel is best known as the less significant sister of the astronomer William Herschel. Yet the romantic notion of her tirelessly working for her brother while he made his studies of the heavens, documenting his discoveries so he could achieve greatness in the scientific world, couldn't be further from the truth. When Caroline wasn't working as her brother's assistant, she was sweeping the stars with her own small telescope given to her by William. Not only did she unearth three important nebulae, but she discovered no fewer than eight comets in her own right. When William beca

Herschel SPIRE FTS spectral line source calibrators

DEFF Research Database (Denmark)

Hopwood, Rosalind; Polehampton, Edward; Valtchanov, Ivan

2015-01-01

We present a summary of the Herschel SPIRE/FTS calibration programme to monitor the repeatability of spectral lines. Observations of planetary nebulae and post-AGB stars are used to assess repeatability and model the asymmetry of the instrument line shape.......We present a summary of the Herschel SPIRE/FTS calibration programme to monitor the repeatability of spectral lines. Observations of planetary nebulae and post-AGB stars are used to assess repeatability and model the asymmetry of the instrument line shape....

Wide Field Infrared Survey Telescope [WFIRST]: telescope design and simulated performance

Science.gov (United States)

Goullioud, R.; Content, D. A.; Kuan, G. M.; Moore, J. D.; Chang, Z.; Sunada, E. T.; Villalvazo, J.; Hawk, J. P.; Armani, N. V.; Johnson, E. L.; Powell, C. A.

2012-09-01

The Wide Field Infrared Survey Telescope (WFIRST) mission concept was ranked first in new space astrophysics missions by the Astro2010 Decadal Survey, incorporating the Joint Dark Energy Mission payload concept and multiple science white papers. This mission is based on a space telescope at L2 studying exoplanets [via gravitational microlensing], probing dark energy, and surveying the near infrared sky. Since the release of the Astro2010 Decadal Survey, the team has been working with the WFIRST Science Definition Team to refine mission and payload concepts. We present the current interim reference mission point design of the payload, based on the use of a 1.3m unobscured aperture three mirror anastigmat form, with focal imaging and slit-less spectroscopy science channels. We also present the first results of Structural/Thermal/Optical performance modeling of the telescope point design.

FIRBACK Far Infrared Survey with ISO: Data Reduction, Analysis and First Results

OpenAIRE

Dole, Herve; Lagache, Guilaine; Puget, Jean-Loup; Gispert, Richard; Aussel, H.; Bouchet, F. R.; Ciliegi, C.; Clements, D. L.; Cesarsky, C.; Desert, F-X; Elbaz, D.; Franceschini, A.; Guiderdoni, B.; Harwit, M.; Laureijs, R.

1999-01-01

FIRBACK is one of the deepest cosmological surveys performed in the far infrared, using ISOPHOT. We describe this survey, its data reduction and analysis. We present the maps of fields at 175 microns. We point out some first results: source identifications with radio and mid infrared, and source counts at 175 microns. These two results suggest that half of the FIRBACK sources are probably at redshifts greater than 1. We also present briefly the large follow-up program.

A 'private adventure'? John Herschel's Cape voyage and the production of the 'Cape Results'

Science.gov (United States)

Ruskin, Steven William

2002-07-01

This dissertation considers the life of John Herschel (1792 1871) from the years 1833 to 1847. In 1833 Herschel sailed from London to Cape Town, southern Africa, to undertake (at his own expense) an astronomical exploration of the southern heavens, as well as a terrestrial exploration of the area around Cape Town. After his return to England in 1838, he was highly esteemed and became Britain's most recognized scientist. In 1847 his southern hemisphere astronomical observations were published as the Cape Results. The main argument of this dissertation is that Herschel's voyage, and the publication of the Cape Results, in addition to their contemporary scientific importance, were also significant for nineteenth-century politics and culture. This dissertation is a two-part dissertation. The first part is entitled “John Herschel's Cape Voyage: Private Science, Public Imagination, and the Ambitions of Empire”; and the second part, “The Production of the Cape Results.” In the first part it is demonstrated that the reason for Herschel's cultural renown was the popular notion that his voyage to the Cape was a project aligned with the imperial ambitions of the British government. By leaving England for one of its colonies, and pursuing there a significant scientific project, Herschel was seen in the same light as other British men of science who had also undertaken voyages of exploration and discovery. It is then demonstrated, in the second part of this work, that the production of the Cape Results, in part because of Herschel's status as Britain's scientific figurehead, was a significant political and cultural event. In addition to the narrow area of Herschel scholarship, this dissertation touches on other areas of research in the history of science as well: science and culture, science and empire, science and politics, and what has been called the “new” history of scientific books.

Herschel-ATLAS: A Binary HyLIRG Pinpointing a Cluster of Starbursting Protoellipticals

Science.gov (United States)

Ivison, R.J.; Swinbank, A.M.; Smail, Ian; Harris, A. I.; Bussmann, R. S.; Cooray, A.; Cox, P.; Fu, H.; Kovacs, A.; Krips, M.;

Updated 34-band Photometry for the SINGS/KINGFISH Samples of Nearby Galaxies

International Nuclear Information System (INIS)

Dale, D. A.; Turner, J. A.; Cook, D. O.; Roussel, H.; Armus, L.; Helou, G.; Bolatto, A. D.; Boquien, M.; Brown, M. J. I.; Calzetti, D.; Looze, I. De; Galametz, M.; Gordon, K. D.; Groves, B. A.; Jarrett, T. H.; Herrera-Camus, R.; Hinz, J. L.; Hunt, L. K.; Kennicutt, R. C.; Murphy, E. J.

2017-01-01

We present an update to the ultraviolet-to-radio database of global broadband photometry for the 79 nearby galaxies that comprise the union of the KINGFISH (Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel ) and SINGS ( Spitzer Infrared Nearby Galaxies Survey) samples. The 34-band data set presented here includes contributions from observational work carried out with a variety of facilities including GALEX , SDSS, Pan-STARRS1, NOAO , 2MASS, Wide-Field Infrared Survey Explorer , Spitzer , Herschel , Planck , JCMT , and the VLA. Improvements of note include recalibrations of previously published SINGS BVR C I C and KINGFISH far-infrared/submillimeter photometry. Similar to previous results in the literature, an excess of submillimeter emission above model predictions is seen primarily for low-metallicity dwarf or irregular galaxies. This 33-band photometric data set for the combined KINGFISH+SINGS sample serves as an important multiwavelength reference for the variety of galaxies observed at low redshift. A thorough analysis of the observed spectral energy distributions is carried out in a companion paper.

Updated 34-band Photometry for the SINGS/KINGFISH Samples of Nearby Galaxies

Energy Technology Data Exchange (ETDEWEB)

Dale, D. A.; Turner, J. A. [Department of Physics and Astronomy, University of Wyoming, Laramie WY (United States); Cook, D. O. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena CA (United States); Roussel, H. [Institut d’Astrophysique de Paris, Sorbonne Universités, Paris (France); Armus, L.; Helou, G. [Spitzer Science Center, California Institute of Technology, Pasadena, CA (United States); Bolatto, A. D. [Department of Astronomy, University of Maryland, College Park, MD (United States); Boquien, M. [Unidad de Astronomía, Universidad de Antofagasta, Antofagasta (Chile); Brown, M. J. I. [School of Physics and Astronomy, Monash University, Victoria 3800 (Australia); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst MA (United States); Looze, I. De [Sterrenkundig Observatorium, Universiteit Gent, Gent (Belgium); Galametz, M. [European Southern Observatory, Garching (Germany); Gordon, K. D. [Space Telescope Science Institute, Baltimore MD (United States); Groves, B. A. [Research School of Astronomy and Astrophysics, Australian National University, Canberra (Australia); Jarrett, T. H. [Astronomy Department, University of Capetown, Rondebosch (South Africa); Herrera-Camus, R. [Max-Planck-Institut für Extraterrestrische Physik, Garching (Germany); Hinz, J. L. [Steward Observatory, University of Arizona, Tucson AZ (United States); Hunt, L. K. [INAF—Osservatorio Astrofisico di Arcetri, Firenze (Italy); Kennicutt, R. C. [Institute of Astronomy, University of Cambridge, Cambridge (United Kingdom); Murphy, E. J., E-mail: ddale@uwyo.edu [National Radio Astronomy Observatory, Charlottesville, VA (United States); and others

2017-03-01

We present an update to the ultraviolet-to-radio database of global broadband photometry for the 79 nearby galaxies that comprise the union of the KINGFISH (Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel ) and SINGS ( Spitzer Infrared Nearby Galaxies Survey) samples. The 34-band data set presented here includes contributions from observational work carried out with a variety of facilities including GALEX , SDSS, Pan-STARRS1, NOAO , 2MASS, Wide-Field Infrared Survey Explorer , Spitzer , Herschel , Planck , JCMT , and the VLA. Improvements of note include recalibrations of previously published SINGS BVR {sub C} I {sub C} and KINGFISH far-infrared/submillimeter photometry. Similar to previous results in the literature, an excess of submillimeter emission above model predictions is seen primarily for low-metallicity dwarf or irregular galaxies. This 33-band photometric data set for the combined KINGFISH+SINGS sample serves as an important multiwavelength reference for the variety of galaxies observed at low redshift. A thorough analysis of the observed spectral energy distributions is carried out in a companion paper.

THE BOLOCAM GALACTIC PLANE SURVEY. VIII. A MID-INFRARED KINEMATIC DISTANCE DISCRIMINATION METHOD

Energy Technology Data Exchange (ETDEWEB)

Ellsworth-Bowers, Timothy P.; Glenn, Jason; Battersby, Cara; Ginsburg, Adam; Bally, John [CASA, University of Colorado, UCB 389, University of Colorado, Boulder, CO 80309 (United States); Rosolowsky, Erik [Department of Physics and Astronomy, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7 (Canada); Mairs, Steven [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 1A1 (Canada); Evans, Neal J. II [Department of Astronomy, University of Texas, 1 University Station C1400, Austin, TX 78712 (United States); Shirley, Yancy L., E-mail: timothy.ellsworthbowers@colorado.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

2013-06-10

We present a new distance estimation method for dust-continuum-identified molecular cloud clumps. Recent (sub-)millimeter Galactic plane surveys have cataloged tens of thousands of these objects, plausible precursors to stellar clusters, but detailed study of their physical properties requires robust distance determinations. We derive Bayesian distance probability density functions (DPDFs) for 770 objects from the Bolocam Galactic Plane Survey in the Galactic longitude range 7. Degree-Sign 5 {<=} l {<=} 65 Degree-Sign . The DPDF formalism is based on kinematic distances, and uses any number of external data sets to place prior distance probabilities to resolve the kinematic distance ambiguity (KDA) for objects in the inner Galaxy. We present here priors related to the mid-infrared absorption of dust in dense molecular regions and the distribution of molecular gas in the Galactic disk. By assuming a numerical model of Galactic mid-infrared emission and simple radiative transfer, we match the morphology of (sub-)millimeter thermal dust emission with mid-infrared absorption to compute a prior DPDF for distance discrimination. Selecting objects first from (sub-)millimeter source catalogs avoids a bias towards the darkest infrared dark clouds (IRDCs) and extends the range of heliocentric distance probed by mid-infrared extinction and includes lower-contrast sources. We derive well-constrained KDA resolutions for 618 molecular cloud clumps, with approximately 15% placed at or beyond the tangent distance. Objects with mid-infrared contrast sufficient to be cataloged as IRDCs are generally placed at the near kinematic distance. Distance comparisons with Galactic Ring Survey KDA resolutions yield a 92% agreement. A face-on view of the Milky Way using resolved distances reveals sections of the Sagittarius and Scutum-Centaurus Arms. This KDA-resolution method for large catalogs of sources through the combination of (sub-)millimeter and mid-infrared observations of molecular

'Land-marks of the universe': John Herschel against the background of positional astronomy.

Science.gov (United States)

Case, Stephen

2015-01-01

John Herschel (1792-1871) was the leading British natural philosopher of the nineteenth century, widely known and regarded for his work in philosophy, optics and chemistry as well as his important research and popular publications on astronomy. To date, however, there exists no extended treatment of his astronomical career. This paper, part of a larger study exploring Herschel's contributions to astronomy, examines his work in the context of positional astronomy, the dominant form of astronomical practice throughout his lifetime. Herschel, who did not himself practice positional astronomy and who was known for his non-meridional observations of specific stellar objects, was nonetheless a strong advocate for positional astronomy-but for very different reasons than the terrestrial applications to which it was most often put. For Herschel, the star catalogues of positional astronomy were the necessary observational foundation upon which information about the stars as physical objects could be constructed. Positional astronomy practiced in the great national observatories was not about navigation or timekeeping; it was a way to standardize stellar observations and make them useful data for constructing theories of the stars themselves. For Herschel, the seeds of the new astronomy emerged from the practices of the old.

SPIRITS: SPitzer InfraRed Intensive Transients Survey

Science.gov (United States)

Kasliwal, Mansi; Jencson, Jacob; Lau, Ryan; Masci, Frank; Helou, George; Williams, Robert; Bally, John; Bond, Howard; Whitelock, Patricia; Cody, Ann Marie; Gehrz, Robert; Tinyanont, Samaporn; Smith, Nathan; Surace, Jason; Armus, Lee; Cantiello, Matteo; Langer, Norbert; Levesque, Emily; Mohamed, Shazrene; Ofek, Eran; Parthasarathy, Mudumba; van Dyk, Schuyler; Boyer, Martha; Phillips, Mark; Hsiao, Eric; Morrell, Nidia; Perley, Dan; Gonzalez, Consuelo; Contreras, Carlos; Jones, Olivia; Ressler, Michael; Adams, Scott; Moore, Anna; Cook, David; Fox, Ori; Johansson, Joel; Khan, Rubab; Monson, Andrew; Hankins, Matthew; Goldman, Steven; Jacob, Jencson

2018-05-01

Spitzer is pioneering a systematic exploration of the dynamic infrared sky. Our SPitzer InfraRed Intensive Transients Survey (SPIRITS) has already discovered 78 explosive transients and 2457 eruptive variables. Of these 78 infrared transients, 60 are so red that they are devoid of optical counterparts and we call them SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). The nature of SPRITEs is unknown and progress on deciphering the explosion physics depends on mid-IR spectroscopy. Multiple physical origins have been proposed including stellar merger, birth of a massive binary, electron capture supernova and stellar black hole formation. Hence, we propose a modest continuation of SPIRITS, focusing on discovering and monitoring SPRITEs, in preparation for follow-up with the James Webb Space Telescope (JWST). As the SPRITEs evolve and cool, the bulk of the emission shifts to longer wavelengths. MIRI aboard JWST will be the only available platform in the near future capable of characterizing SPRITEs out to 28 um. Specifically, the low resolution spectrometer would determine dust mass, grain chemistry, ice abundance and energetics to disentangle the proposed origins. The re-focused SPIRITS program consists of continued Spitzer monitoring of those 106 luminous galaxies that are known SPRITE hosts or are most likely to host new SPRITEs. Scaling from the SPIRITS discovery rate, we estimate finding 10 new SPRITEs and 2-3 new supernovae in Cycle 14. The SPIRITS team remains committed to extensive ground-based follow-up. The Spitzer observations proposed here are essential for determining the final fates of active SPRITEs as well as bridging the time lag between the current SPIRITS survey and JWST launch.

Continued monitoring of aeolian activity within Herschel Crater, Mars

Science.gov (United States)

Cardinale, Marco; Pozzobon, Riccardo; Michaels, Timothy; Bourke, Mary C.; Okubo, Chris H.; Chiara Tangari, Anna; Marinangeli, Lucia

2017-04-01

In this work, we study a dark dune field on the western side of Herschel crater, a 300 km diameter impact basin located near the Martian equator (14.4°S, 130°E), where the ripple and dune motion reflects the actual atmospheric wind conditions. We develop an integrated analysis using (1) automated ripple mapping that yields ripple orientations and evaluates the spatial variation of actual atmospheric wind conditions within the dunes, (2) an optical cross-correlation that allows us to quantify an average ripple migration rate of 0.42 m per Mars year, and (3) mesoscale climate modeling with which we compare the observed aeolian changes with modeled wind stresses and directions. Our observations are consistent with previous work [1] [2] that detected aeolian activity in the western part of the crater. It also demonstrates that not only are the westerly Herschel dunes movable, but that predominant winds from the north are able to keep the ripples and dunes active within most (if not all) of Herschel crater in the current atmospheric conditions. References: [1] Cardinale, M., Silvestro, S., Vaz, D.A., Michaels, T., Bourke, M.C., Komatsu, G., Marinangeli, L., 2016. Present-day aeolian activity in Herschel Crater, Mars. Icarus 265, 139-148. doi:10.1016/j.icarus.2015.10.022. [2] Runyon, K.D., Bridges, N.T., Ayoub, F., Newman, C.E. and Quade, J.J., 2017. An integrated model for dune morphology and sand fluxes on Mars. Earth and Planetary Science Letters, 457, pp.204-212.

Probing the nuclear and circumnuclear activity of NGC 1365 in the infrared

Science.gov (United States)

Alonso-Herrero, A.; Sánchez-Portal, M.; Ramos Almeida, C.; Pereira-Santaella, M.; Esquej, P.; García-Burillo, S.; Castillo, M.; González-Martín, O.; Levenson, N.; Hatziminaoglou, E.; Acosta-Pulido, J. A.; González-Serrano, J. I.; Pović, M.; Packham, C.; Pérez-García, A. M.

2012-09-01

We present new far-infrared (70-500 μm) Herschel Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) imaging observations as well as new mid-IR Gemini/Thermal-Region Camera Spectrograph imaging (8.7 and 18.3 μm) and spectroscopy of the inner Lindblad resonance (ILR) region (R Linares Senior Research Fellow.

HERSCHEL/PACS SURVEY OF PROTOPLANETARY DISKS IN TAURUS/AURIGA—OBSERVATIONS OF [O I] AND [C II], AND FAR-INFRARED CONTINUUM

International Nuclear Information System (INIS)

Howard, Christian D.; Sandell, Göran; Vacca, William D.; Duchêne, Gaspard; Mathews, Geoffrey; Augereau, Jean-Charles; Ménard, Francois; Pinte, Christophe; Podio, Linda; Thi, Wing-Fai; Barrado, David; Riviere-Marichalar, Pablo; Dent, William R. F.; Eiroa, Carlos; Meeus, Gwendolyn; Grady, Carol; Roberge, Aki; Kamp, Inga; Vicente, Silvia; Williams, Jonathan P.

2013-01-01

The Herschel Space Observatory was used to observe ∼120 pre-main-sequence stars in Taurus as part of the GASPS Open Time Key project. Photodetector Array Camera and Spectrometer was used to measure the continuum as well as several gas tracers such as [O I] 63 μm, [O I] 145 μm, [C II] 158 μm, OH, H 2 O, and CO. The strongest line seen is [O I] at 63 μm. We find a clear correlation between the strength of the [O I] 63 μm line and the 63 μm continuum for disk sources. In outflow sources, the line emission can be up to 20 times stronger than in disk sources, suggesting that the line emission is dominated by the outflow. The tight correlation seen for disk sources suggests that the emission arises from the inner disk (<50 AU) and lower surface layers of the disk where the gas and dust are coupled. The [O I] 63 μm is fainter in transitional stars than in normal Class II disks. Simple spectral energy distribution models indicate that the dust responsible for the continuum emission is colder in these disks, leading to weaker line emission. [C II] 158 μm emission is only detected in strong outflow sources. The observed line ratios of [O I] 63 μm to [O I] 145 μm are in the regime where we are insensitive to the gas-to-dust ratio, neither can we discriminate between shock or photodissociation region emission. We detect no Class III object in [O I] 63 μm and only three in continuum, at least one of which is a candidate debris disk

UltraVISTA : a new ultra-deep near-infrared survey in COSMOS

NARCIS (Netherlands)

McCracken, H. J.; Milvang-Jensen, B.; Dunlop, J.; Franx, M.; Fynbo, J. P. U.; Le Fevre, O.; Holt, J.; Caputi, K. I.; Goranova, Y.; Buitrago, F.; Emerson, J. P.; Freudling, W.; Hudelot, P.; Lopez-Sanjuan, C.; Magnard, F.; Mellier, Y.; Moller, P.; Nilsson, K. K.; Sutherland, W.; Tasca, L.; Zabl, J.

In this paper we describe the first data release of the UltraVISTA near-infrared imaging survey of the COSMOS field. We summarise the key goals and design of the survey and provide a detailed description of our data reduction techniques. We provide stacked, sky-subtracted images in YJHK(s) and

Do the Herschel cold clouds in the Galactic halo embody its dark matter?

NARCIS (Netherlands)

Nieuwenhuizen, T.M.; van Heusden, E.F.G.; Liska, M.T.P.

2012-01-01

Recent Herschel/SPIRE (Spectral and Photometric Imaging Receiver) maps of the Small and Large Magellanic Clouds (SMC, LMC) exhibit, in each, thousands of clouds. Observed at 250 μm, they must be cold, T ~ 15 K, hence the name 'Herschel cold clouds' (HCCs). From the observed rotational velocity

First discoveries of z ˜ 6 quasars with the Kilo-Degree Survey and VISTA Kilo-Degree Infrared Galaxy survey

NARCIS (Netherlands)

Venemans, B. P.; Verdoes Kleijn, G. A.; Mwebaze, J.; Valentijn, E. A.; Bañados, E.; Decarli, R.; de Jong, J. T. A.; Findlay, J. R.; Kuijken, K. H.; Barbera, F. La; Mc Farland, John; McMahon, R. G.; Napolitano, N.; Sikkema, G.; Sutherland, W. J.

2015-01-01

We present the results of our first year of quasar search in the ongoing ESO public Kilo-Degree Survey (KiDS) and VISTA Kilo-Degree Infrared Galaxy (VIKING) surveys. These surveys are among the deeper wide-field surveys that can be used to uncover large numbers of z ˜ 6 quasars. This allows us to

Exploring the Dust Content of Galactic Winds with Herschel. II. Nearby Dwarf Galaxies*

Science.gov (United States)

McCormick, Alexander; Veilleux, Sylvain; Meléndez, Marcio; Martin, Crystal L.; Bland-Hawthorn, Joss; Cecil, Gerald; Heitsch, Fabian; Müller, Thomas; Rupke, David S. N.; Engelbracht, Chad

2018-03-01

We present results from analysis of deep Herschel Space Observatory observations of six nearby dwarf galaxies known to host galactic-scale winds. The superior far-infrared sensitivity and angular resolution of Herschel have allowed detection of cold circumgalactic dust features beyond the stellar components of the host galaxies traced by Spitzer 4.5 μm images. Comparisons of these cold dust features with ancillary data reveal an imperfect spatial correlation with the ionized gas and warm dust wind components. We find that typically ˜10-20% of the total dust mass in these galaxies resides outside of their stellar disks, but this fraction reaches ˜60% in the case of NGC 1569. This galaxy also has the largest metallicity (O/H) deficit in our sample for its stellar mass. Overall, the small number of objects in our sample precludes drawing strong conclusions on the origin of the circumgalactic dust. We detect no statistically significant trends with star formation properties of the host galaxies, as might be expected if the dust were lifted above the disk by energy inputs from on-going star formation activity. Although a case for dust entrained in a galactic wind is seen in NGC 1569, in all cases, we cannot rule out the possibility that some of the circumgalactic dust might be associated instead with gas accreted or removed from the disk by recent galaxy interaction events, or that it is part of the outer gas-rich portion of the disk that lies below the sensitivity limit of the Spitzer 4.5 μm data.

THE RELATION BETWEEN COOL CLUSTER CORES AND HERSCHEL-DETECTED STAR FORMATION IN BRIGHTEST CLUSTER GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Rawle, T. D.; Egami, E.; Rex, M.; Fiedler, A.; Haines, C. P.; Pereira, M. J.; Portouw, J.; Walth, G. [Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Edge, A. C. [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Smith, G. P. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Altieri, B.; Valtchanov, I. [Herschel Science Centre, ESAC, ESA, P.O. Box 78, Villanueva de la Canada, 28691 Madrid (Spain); Perez-Gonzalez, P. G. [Departamento de Astrofisica, Facultad de CC. Fisicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Van der Werf, P. P. [Sterrewacht Leiden, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Zemcov, M., E-mail: trawle@as.arizona.edu [Department of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-03-01

We present far-infrared (FIR) analysis of 68 brightest cluster galaxies (BCGs) at 0.08 < z < 1.0. Deriving total infrared luminosities directly from Spitzer and Herschel photometry spanning the peak of the dust component (24-500 {mu}m), we calculate the obscured star formation rate (SFR). 22{sup +6.2}{sub -5.3}% of the BCGs are detected in the far-infrared, with SFR = 1-150 M{sub Sun} yr{sup -1}. The infrared luminosity is highly correlated with cluster X-ray gas cooling times for cool-core clusters (gas cooling time <1 Gyr), strongly suggesting that the star formation in these BCGs is influenced by the cluster-scale cooling process. The occurrence of the molecular gas tracing H{alpha} emission is also correlated with obscured star formation. For all but the most luminous BCGs (L{sub TIR} > 2 Multiplication-Sign 10{sup 11} L{sub Sun }), only a small ({approx}<0.4 mag) reddening correction is required for SFR(H{alpha}) to agree with SFR{sub FIR}. The relatively low H{alpha} extinction (dust obscuration), compared to values reported for the general star-forming population, lends further weight to an alternate (external) origin for the cold gas. Finally, we use a stacking analysis of non-cool-core clusters to show that the majority of the fuel for star formation in the FIR-bright BCGs is unlikely to originate from normal stellar mass loss.

A UNIFIED EMPIRICAL MODEL FOR INFRARED GALAXY COUNTS BASED ON THE OBSERVED PHYSICAL EVOLUTION OF DISTANT GALAXIES

International Nuclear Information System (INIS)

Béthermin, Matthieu; Daddi, Emanuele; Sargent, Mark T.; Elbaz, David; Mullaney, James; Pannella, Maurilio; Magdis, Georgios; Hezaveh, Yashar; Le Borgne, Damien; Buat, Véronique; Charmandaris, Vassilis; Lagache, Guilaine; Scott, Douglas

2012-01-01

We reproduce the mid-infrared to radio galaxy counts with a new empirical model based on our current understanding of the evolution of main-sequence (MS) and starburst (SB) galaxies. We rely on a simple spectral energy distribution (SED) library based on Herschel observations: a single SED for the MS and another one for SB, getting warmer with redshift. Our model is able to reproduce recent measurements of galaxy counts performed with Herschel, including counts per redshift slice. This agreement demonstrates the power of our 2-Star-Formation Modes (2SFM) decomposition in describing the statistical properties of infrared sources and their evolution with cosmic time. We discuss the relative contribution of MS and SB galaxies to the number counts at various wavelengths and flux densities. We also show that MS galaxies are responsible for a bump in the 1.4 GHz radio counts around 50 μJy. Material of the model (predictions, SED library, mock catalogs, etc.) is available online.

INFRARED SPECTRA AND PHOTOMETRY OF COMPLETE SAMPLES OF PALOMAR-GREEN AND TWO MICRON ALL SKY SURVEY QUASARS

Energy Technology Data Exchange (ETDEWEB)

Shi, Yong [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Rieke, G. H.; Su, K. Y. L. [Department of Astronomy And Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Ogle, P. M. [Infrared Processing and Analysis Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Balog, Z., E-mail: yshipku@gmail.com [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

2014-10-01

As a step toward a comprehensive overview of the infrared (IR) diagnostics of the central engines and host galaxies of quasars at low redshift, we present Spitzer Space Telescope spectroscopic (5-40 μm) and photometric (24, 70, and 160 μm) measurements of all Palomar-Green (PG) quasars at z < 0.5 and Two Micron All Sky Survey (2MASS) quasars at z < 0.3. We supplement these data with Herschel measurements at 160 μm. The sample is composed of 87 optically selected PG quasars and 52 near-IR-selected 2MASS quasars. Here we present the data, measure the prominent spectral features, and separate emission due to star formation from that emitted by the dusty circumnuclear torus. We find that the mid-IR (5-30 μm) spectral shape for the torus is largely independent of quasar IR luminosity with scatter in the spectral energy distribution (SED) shape of ≲0.2 dex. Except for the silicate features, no large difference is observed between PG (unobscured—silicate emission) and 2MASS (obscured—silicate absorption) quasars. Only mild silicate features are observed in both cases. When in emission, the peak wavelength of the silicate feature tends to be longer than 9.7 μm, possibly indicating effects on grain properties near the active galactic nucleus. The IR color is shown to correlate with the equivalent width of the aromatic features, indicating that the slope of the quasar mid- to far-IR SED is to first order driven by the fraction of radiation from star formation in the IR bands.

MID-INFRARED SELECTION OF ACTIVE GALACTIC NUCLEI WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER. I. CHARACTERIZING WISE-SELECTED ACTIVE GALACTIC NUCLEI IN COSMOS

International Nuclear Information System (INIS)

Stern, Daniel; Assef, Roberto J.; Eisenhardt, Peter; Benford, Dominic J.; Blain, Andrew; Cutri, Roc; Griffith, Roger L.; Jarrett, T. H.; Masci, Frank; Tsai, Chao-Wei; Yan, Lin; Dey, Arjun; Lake, Sean; Petty, Sara; Wright, E. L.; Stanford, S. A.; Harrison, Fiona; Madsen, Kristin

2012-01-01

The Wide-field Infrared Survey Explorer (WISE) is an extremely capable and efficient black hole finder. We present a simple mid-infrared color criterion, W1 – W2 ≥ 0.8 (i.e., [3.4]–[4.6] ≥0.8, Vega), which identifies 61.9 ± 5.4 active galactic nucleus (AGN) candidates per deg 2 to a depth of W2 ∼ 15.0. This implies a much larger census of luminous AGNs than found by typical wide-area surveys, attributable to the fact that mid-infrared selection identifies both unobscured (type 1) and obscured (type 2) AGNs. Optical and soft X-ray surveys alone are highly biased toward only unobscured AGNs, while this simple WISE selection likely identifies even heavily obscured, Compton-thick AGNs. Using deep, public data in the COSMOS field, we explore the properties of WISE-selected AGN candidates. At the mid-infrared depth considered, 160 μJy at 4.6 μm, this simple criterion identifies 78% of Spitzer mid-infrared AGN candidates according to the criteria of Stern et al. and the reliability is 95%. We explore the demographics, multiwavelength properties and redshift distribution of WISE-selected AGN candidates in the COSMOS field.

Evolution of interstellar dust in light of Herschel Space Observatory data

International Nuclear Information System (INIS)

Arab, Heddy

2012-01-01

Interstellar dust grains are nanometer to micrometer sized particles. Although a weak proportion of the total interstellar mass is at solid state, dust plays a fundamental role in the evolution of the interstellar medium (ISM) and of the galaxy itself. Grains can be observed in the UV and visible wavelength through extinction whereas their emission is in the infrared to submillimeter range. Astrophysical observations combined to numerical models and laboratory studies of dust analogs improve our comprehension of the nature and the physics of interstellar grains. For example, evidence of dust evolution in the interstellar medium are now numerous, even if the physical processes responsible of this evolution are still poorly understood. Understanding how grains evolve with physical conditions requires observations of various environments. Photodissociation regions (PDRs) are zones of the ISM where the radiation field and the local density vary on short spatial scales (∼10''- 20''). Moreover the many gas tracers offer the opportunity to constraint efficiently the physical conditions within PDRs. Past missions such as ISO and Spitzer allow to study the evolution of dust in the near-Infrared range. At longer wavelengths, where the emission is dominated by the grains at thermal equilibrium with the radiation, instruments rarely resolved the spatial emission in PDRs. PACS and SPIRE instruments onboard Herschel Space Observatory provide spectro-photometric data between 70 and 500 μm. Their high spatial resolution (from 5 to 35 arcmin) makes these observations ideal for the study of dust evolution in PDRs. We present here an analysis of Herschel observations of three PDRs: the Orion Bar, the Horsehead and NGC 7023 East, characterized by different physical conditions. By combining these data with shorter wavelength observations from Spitzer, we can study the dust emission spectrum from 3.6 to 500 μm at different positions within the PDR. Intensity profiles are extracted

HIFISTARS Herschel/HIFI observations of VY Canis Majoris. Molecular-line inventory of the envelope around the largest known star

Science.gov (United States)

Alcolea, J.; Bujarrabal, V.; Planesas, P.; Teyssier, D.; Cernicharo, J.; De Beck, E.; Decin, L.; Dominik, C.; Justtanont, K.; de Koter, A.; Marston, A. P.; Melnick, G.; Menten, K. M.; Neufeld, D. A.; Olofsson, H.; Schmidt, M.; Schöier, F. L.; Szczerba, R.; Waters, L. B. F. M.

2013-11-01

Aims: The study of the molecular gas in the circumstellar envelopes of evolved stars is normally undertaken by observing lines of CO (and other species) in the millimetre-wave domain. In general, the excitation requirements of the observed lines are low at these wavelengths, and therefore these observations predominantly probe the cold outer envelope while studying the warm inner regions of the envelopes normally requires sub-millimetre (sub-mm) and far-infrared (FIR) observational data. Methods: To gain insight into the physical conditions and kinematics of the warm (100-1000 K) gas around the red hyper-giant VY CMa, we performed sensitive high spectral resolution observations of molecular lines in the sub-mm/FIR using the HIFI instrument of the Herschel Space Observatory. We observed CO, H2O, and other molecular species, sampling excitation energies from a few tens to a few thousand K. These observations are part of the Herschel guaranteed time key program HIFISTARS. Results: We detected the J = 6-5, J = 10-9, and J = 16-15 lines of 12CO and 13CO at ~100, 300, and 750 K above the ground state (and the 13CO J = 9-8 line). These lines are crucial for improving the modelling of the internal layers of the envelope around VY CMa. We also detected 27 lines of H2O and its isotopomers, and 96 lines of species such as NH3, SiO, SO, SO2 HCN, OH and others, some of them originating from vibrationally excited levels. Three lines were not unambiguously assigned. Conclusions: Our observations confirm that VY CMa's envelope must consist of two or more detached components. The molecular excitation in the outer layers is significantly lower than in the inner ones, resulting in strong self-absorbed profiles in molecular lines that are optically thick in this outer envelope, for instance, low-lying lines of H2O. Except for the most abundant species, CO and H2O, most of the molecular emission detected at these sub-mm/FIR wavelengths arise from the central parts of the envelope. The

Origins Space Telescope: 3D infrared surveys of star formation and black hole growth in galaxies over cosmic time

Science.gov (United States)

Pope, Alexandra; Armus, Lee; bradford, charles; Origins Space Telescope STDT

2018-01-01

In the coming decade, new telescope facilities and surveys aim to provide a 3D map of the unobscured Universe over cosmic time. However, much of galaxy formation and evolution occurs behind dust, and is only observable through infrared observations. Previous extragalactic infrared surveys were fundamentally limited to a 2D mapping of the most extreme populations of galaxies due to spatial resolution and sensitivity. The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies sponsored by NASA to provide input to the 2020 Astronomy and Astrophysics Decadal survey. OST is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum, which will achieve spectral line sensitivities up to 1000 times deeper than previous infrared facilities. With powerful instruments such as the Medium Resolution Survey Spectrometer (MRSS), capable of simultaneous imaging and spectroscopy, the extragalactic infrared sky can finally be surveyed in 3D. In addition to spectroscopic redshifts, the rich suite of lines in the infrared provides unique diagnostics of the ongoing star formation (both obscured and unobscured) and the central supermassive black hole growth. In this poster, we present a simulated extragalactic survey with OST/MRSS which will detect millions of galaxies down to well below the knee of the infrared luminosity function. We demonstrate how this survey can map the coeval star formation and black hole growth in galaxies over cosmic time.

PACS and SPIRE photometer maps of M33 : First results of the HERschel M33 Extended Survey (HERM33ES)

NARCIS (Netherlands)

Kramer, C.; Buchbender, C.; Xilouris, E. M.; Boquien, M.; Braine, J.; Calzetti, D.; Lord, S.; Mookerjea, B.; Quintana-Lacaci, G.; Relano, M.; Stacey, G.; Tabatabaei, F. S.; Verley, S.; Aalto, S.; Akras, S.; Albrecht, M.; Anderl, S.; Beck, R.; Bertoldi, F.; Combes, F.; Dumke, M.; Garcia-Burillo, S.; Gonzalez, M.; Gratier, P.; Guesten, R.; Henkel, C.; Israel, F. P.; Koribalski, B.; Lundgren, A.; Martin-Pintado, J.; Roellig, M.; Rosolowsky, E.; Schuster, K. F.; Sheth, K.; Sievers, A.; Stutzki, J.; Tilanus, R.P.J.; van der Tak, F.; Wiedner, M. C.; van der Werf, Paul P.

Context. Within the framework of the HERM33ES key program, we are studying the star forming interstellar medium in the nearby, metal-poor spiral galaxy M33, exploiting the high resolution and sensitivity of Herschel. Aims. We use PACS and SPIRE maps at 100, 160, 250, 350, and 500 mu m wavelength, to

THE HERSCHEL AND IRAM CHESS SPECTRAL SURVEYS OF THE PROTOSTELLAR SHOCK L1157-B1: FOSSIL DEUTERATION

International Nuclear Information System (INIS)

Codella, C.; Fontani, F.; Vasta, M.; Ceccarelli, C.; Lefloch, B.; Kahane, C.; Taquet, V.; Wiesenfeld, L.; Busquet, G.; Caselli, P.; Lis, D.; Viti, S.

2012-01-01

We present the first study of deuteration toward the protostellar shock L1157-B1, based on spectral surveys performed with the Herschel-HIFI and IRAM 30 m telescopes. The L1157 outflow is driven by a low-mass Class 0 protostar and is considered the prototype of the so-called chemically active outflows. The young (2000 yr), bright blueshifted bow shock, B1, is an ideal laboratory for studying the gas chemically enriched by the release of dust mantles due to the passage of a shock. A total of 12 emission lines (up to E u = 63 K) of CH 2 DOH, HDCO, and DCN are detected. In addition, two lines of NH 2 D and HDO are tentatively reported. To estimate the deuteration, we also extracted from our spectral survey emission lines of non-deuterated isotopologues ( 13 CH 3 OH, H 2 13 CO, H 13 CN, H 2 13 CO, and NH 3 ). We infer higher deuteration fractions for CH 3 OH (D/H = 0.2-2 × 10 –2 ) and H 2 CO (5-8 × 10 –3 ) than for H 2 O (0.4-2 × 10 –3 ), HCN (∼10 –3 ), and ammonia (≤3 × 10 –2 ). The measurement of deuteration of water, formaldehyde, and methanol in L1157-B1 provides a fossil record of the gas before it was shocked by the jet driven by the protostar. A comparison with gas-grain models indicates that the gas passed through a low-density (≤10 3 cm –3 ) phase, during which the bulk of water ices formed, followed by a phase of increasing density, up to 3 × 10 4 cm –3 , during which formaldehyde and methanol ices formed.

Herschel observations of extraordinary sources: Analysis of the HIFI 1.2 THz wide spectral survey toward orion KL. I. method

Energy Technology Data Exchange (ETDEWEB)

Crockett, Nathan R.; Bergin, Edwin A.; Neill, Justin L.; Favre, Cécile [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Schilke, Peter [Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln (Germany); Lis, Dariusz C.; Emprechtinger, Martin; Phillips, Thomas G. [Cahill Center for Astronomy and Astrophysics 301-17, California Institute of Technology, Pasadena, CA 91125 (United States); Bell, Tom A.; Cernicharo, José; Esplugues, Gisela B. [Centro de Astrobiología (CSIC/INTA), Laboratiorio de Astrofísica Molecular, Ctra. de Torrejón a Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Blake, Geoffrey; Kleshcheva, Maria [Division of Geological and Planetary Sciences, California Institute of Technology, MS 150-21, Pasadena, CA 91125 (United States); Gupta, Harshal; Pearson, John [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Lord, Steven [Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States); Marcelino, Nuria [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); McGuire, Brett A. [Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena, CA 91125 (United States); Plume, Rene [Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4 (Canada); Van der Tak, Floris [SRON Netherlands Institute for Space Research, P.O. Box 800, 9700 AV Groningen (Netherlands); and others

2014-06-01

We present a comprehensive analysis of a broadband spectral line survey of the Orion Kleinmann-Low nebula (Orion KL), one of the most chemically rich regions in the Galaxy, using the HIFI instrument on board the Herschel Space Observatory. This survey spans a frequency range from 480 to 1907 GHz at a resolution of 1.1 MHz. These observations thus encompass the largest spectral coverage ever obtained toward this high-mass star-forming region in the submillimeter with high spectral resolution and include frequencies >1 THz, where the Earth's atmosphere prevents observations from the ground. In all, we detect emission from 39 molecules (79 isotopologues). Combining this data set with ground-based millimeter spectroscopy obtained with the IRAM 30 m telescope, we model the molecular emission from the millimeter to the far-IR using the XCLASS program, which assumes local thermodynamic equilibrium (LTE). Several molecules are also modeled with the MADEX non-LTE code. Because of the wide frequency coverage, our models are constrained by transitions over an unprecedented range in excitation energy. A reduced χ{sup 2} analysis indicates that models for most species reproduce the observed emission well. In particular, most complex organics are well fit by LTE implying gas densities are high (>10{sup 6} cm{sup –3}) and excitation temperatures and column densities are well constrained. Molecular abundances are computed using H{sub 2} column densities also derived from the HIFI survey. The distribution of rotation temperatures, T {sub rot}, for molecules detected toward the hot core is significantly wider than the compact ridge, plateau, and extended ridge T {sub rot} distributions, indicating the hot core has the most complex thermal structure.

Wide-field Infrared Survey Explorer Observations of the Evolution of Massive Star-forming Regions

OpenAIRE

Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Assef, R. J.

2012-01-01

We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from th...

The HIFI spectral survey of AFGL 2591 (CHESS). II. Summary of the survey

Science.gov (United States)

Kaźmierczak-Barthel, M.; van der Tak, F. F. S.; Helmich, F. P.; Chavarría, L.; Wang, K.-S.; Ceccarelli, C.

2014-07-01

Aims: This paper presents the richness of submillimeter spectral features in the high-mass star forming region AFGL 2591. Methods: As part of the Chemical Herschel Survey of Star Forming Regions (CHESS) key programme, AFGL 2591 was observed by the Herschel (HIFI) instrument. The spectral survey covered a frequency range from 480 to 1240 GHz as well as single lines from 1267 to 1901 GHz (i.e. CO, HCl, NH3, OH, and [CII]). Rotational and population diagram methods were used to calculate column densities, excitation temperatures, and the emission extents of the observed molecules associated with AFGL 2591. The analysis was supplemented with several lines from ground-based JCMT spectra. Results: From the HIFI spectral survey analysis a total of 32 species were identified (including isotopologues). Although the lines are mostly quite weak (∫TmbdV ~ few K km s-1), 268 emission and 16 absorption lines were found (excluding blends). Molecular column densities range from 6 × 1011 to 1 × 1019 cm-2 and excitation temperatures from 19 to 175 K. Cold (e.g. HCN, H2S, and NH3 with temperatures below 70 K) and warm species (e.g. CH3OH, SO2) in the protostellar envelope can be distinguished. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix A is available in electronic form at http://www.aanda.org

SpS1-Preparing for the harvest from large infrared surveys

Science.gov (United States)

Padgett, Deborah L.

2010-11-01

During the past decade, there has been a revolution in the availability of multi-wavelength astronomical surveys. From the Sloan Digital Sky Survey (SDSS) to the NRAO VLA Sky Survey (NVSS), astronomical research based on publicly accessible datasets is becoming standard practice in the community. Beginning with the Infrared Astronomical Satellite (IRAS) mission, infrared surveys have played a critical role in stellar astronomy by identifying cool and dusty stars worthy of spectroscopic characterization. IRAS' four photometric bands at 12, 25, 60, and 100 μm were ideal for detecting dusty circumstellar material. All-sky surveys like IRAS reveal the brightest members of each class of rare objects, optimizing their follow-up strategy. The case of debris disks around main sequence stars demonstrates this utility. IRAS detected dust disks around four nearby stars, Beta Pictoris, Fomalhaut, Epsilon Eridani, and Vega. The “Fabulous Four” remain the best studied debris disks, despite hundreds of additional examples discovered by the Spitzer Space Telescope. In the nearly 30 years since IRAS was launched, its highly reliable catalog of just 250000 sources, modest by modern standards, with arcminute scale resolution and 0.3 - 1 Jy sensitivity, has generated over 10,000 references in ADS. This is a success story by any measure.

DISENTANGLING THE ENVIRONMENT OF THE FU ORIONIS CANDIDATE HBC 722 WITH HERSCHEL

International Nuclear Information System (INIS)

Green, Joel D.; Evans, Neal J. II; Merello, Manuel; Pooley, David; Kospal, Agnes; Van Kempen, Tim A.; Van Dishoeck, Ewine; Herczeg, Gregory; Quanz, Sascha P.; Henning, Thomas; Bouwman, Jeroen; Lee, Jeong-Eun; Dunham, Michael M.; Meeus, Gwendolyn; Chen, Jo-Hsin; Guedel, Manuel; Skinner, Stephen L.; Rebull, Luisa M.; Guieu, Sylvain

2011-01-01

We analyze the submillimeter emission surrounding the new FU Orionis-type object, HBC 722. We present the first epoch of observations of the active environs of HBC 722, with imaging and spectroscopy from PACS, SPIRE, and HIFI on board the Herschel Space Observatory, as well as CO J = 2-1 and 350 μm imaging (SHARC-II) with the Caltech Submillimeter Observatory. The primary source of submillimeter continuum emission in the region-2MASS 20581767+4353310-is located 16'' south-southeast of the optical flaring source while the optical and near-infrared emission is dominated by HBC 722. A bipolar outflow extends over HBC 722; the most likely driver is the submillimeter source. We detect warm (100 K) and hot (246 K) CO emission in the surrounding region, evidence of outflow-driven heating in the vicinity. The region around HBC 722 itself shows little evidence of heating driven by the new outbursting source itself.

The Herschel Multi-Tiered Extragalactic Survey: SPIRE-mm Photometric Redshifts

Science.gov (United States)

Roseboom, I. G.; Ivison, R. J.; Greve, T. R.; Amblard, A.; Arumugam, V.; Auld, R.; Aussel, H.; Bethermin, M.; Blain, A.; Bock, J.;

OT2_smalhotr_3: Herschel Extreme Lensing Line Observations (HELLO)

Science.gov (United States)

Malhotra, S.

2011-09-01

We request 59.8 hours of Herschel time to observe 20 normal star-forming galaxies in the [CII] 158 micron and [OI] 63 micron lines. These galaxies lie at high redshift (1Herschel offers the unique opportunity to study both lines with high sensitivity throughout this epoch (using HIFI for [CII] and PACS for [OI]). These two lines are the main cooling lines of the atomic medium. By measuring their fluxes, we will measure (1) the cooling efficiency of gas, (2) gas densities and temperatures near starforming regions, and (3) gas pressures, which are important to drive the winds that provide feedback to starformation processes. By combining the proposed observations with existing multiwavelength data on these objects, we will obtain as complete a picture of galaxy-scale star formation and ISM physical conditions at high redshifts as we have at z=0. Then perhaps we can understand why star formation and AGN activity peaked at this epoch. In Herschel cycle OT1, 49 high redshift IR luminous galaxies were approved for spectroscopy, but only two so-called normal galaxies were included. This is an imbalance that should be corrected, to balance Herschel's legacy.

CANDELS : THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

NARCIS (Netherlands)

Grogin, Norman A.; Kocevski, Dale D.; Faber, S. M.; Ferguson, Henry C.; Koekemoer, Anton M.; Riess, Adam G.; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Brown, Thomas M.; Caputi, Karina I.; Casertano, Stefano; Cassata, Paolo; Castellano, Marco; Challis, Peter; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Cooray, Asantha Roshan; Croton, Darren J.; Daddi, Emanuele; Dahlen, Tomas; Dave, Romeel; de Mello, Duilia F.; Dekel, Avishai; Dickinson, Mark; Dolch, Timothy; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Fontana, Adriano; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Haeussler, Boris; Hopkins, Philip F.; Huang, Jia-Sheng; Huang, Kuang-Han; Jha, Saurabh W.; Kartaltepe, Jeyhan S.; Kirshner, Robert P.; Koo, David C.; Lai, Kamson; Lee, Kyoung-Soo; Li, Weidong; Lotz, Jennifer M.; Lucas, Ray A.; Madau, Piero; McCarthy, Patrick J.; McGrath, Elizabeth J.; McIntosh, Daniel H.; McLure, Ross J.; Mobasher, Bahram; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Niemi, Sami-Matias; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Rajan, Abhijith; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rodney, Steven A.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Strolger, Louis-Gregory; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; van der Wel, Arjen; Villforth, Carolin; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yan, Hao-Jing; Yun, Min S.

2011-01-01

The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8-1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the

HERSCHEL SPECTROSCOPIC OBSERVATIONS OF LITTLE THINGS DWARF GALAXIES

International Nuclear Information System (INIS)

Cigan, Phil; Young, Lisa; Cormier, Diane; Lebouteiller, Vianney; Madden, Suzanne; Hunter, Deidre; Brinks, Elias; Elmegreen, Bruce; Schruba, Andreas; Heesen, Volker

2016-01-01

We present far-infrared (FIR) spectral line observations of five galaxies from the Little Things sample: DDO 69, DDO 70, DDO 75, DDO 155, and WLM. While most studies of dwarfs focus on bright systems or starbursts due to observational constraints, our data extend the observed parameter space into the regime of low surface brightness dwarf galaxies with low metallicities and moderate star formation rates. Our targets were observed with Herschel at the [C ii] 158 μm, [O i] 63 μm, [O iii] 88 μm, and [N ii] 122 μm emission lines using the PACS Spectrometer. These high-resolution maps allow us for the first time to study the FIR properties of these systems on the scales of larger star-forming complexes. The spatial resolution in our maps, in combination with star formation tracers, allows us to identify separate photodissociation regions (PDRs) in some of the regions we observed. Our systems have widespread [C ii] emission that is bright relative to continuum, averaging near 0.5% of the total infrared (TIR) budget—higher than in solar-metallicity galaxies of other types. [N ii] is weak, suggesting that the [C ii] emission in our galaxies comes mostly from PDRs instead of the diffuse ionized interstellar medium (ISM). These systems exhibit efficient cooling at low dust temperatures, as shown by ([O i]+[C ii])/TIR in relation to 60 μm/100 μm, and low [O i]/[C ii] ratios which indicate that [C ii] is the dominant coolant of the ISM. We observe [O iii]/[C ii] ratios in our galaxies that are lower than those published for other dwarfs, but similar to levels noted in spirals

HERSCHEL SPECTROSCOPIC OBSERVATIONS OF LITTLE THINGS DWARF GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Cigan, Phil; Young, Lisa [Physics Department, New Mexico Institute of Mining and Technology, Socorro, NM 87801 (United States); Cormier, Diane [Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Lebouteiller, Vianney; Madden, Suzanne [Laboratoire AIM, CEA/DSM—CNRS—Université Paris Diderot, Irfu/Service d’Astrophysique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Hunter, Deidre [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Brinks, Elias [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, AL10 9AB (United Kingdom); Elmegreen, Bruce [IBM T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Hts., NY 10598 (United States); Schruba, Andreas [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Heesen, Volker, E-mail: pcigan@alumni.nmt.edu [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Collaboration: LITTLE THINGS Team

2016-01-15

We present far-infrared (FIR) spectral line observations of five galaxies from the Little Things sample: DDO 69, DDO 70, DDO 75, DDO 155, and WLM. While most studies of dwarfs focus on bright systems or starbursts due to observational constraints, our data extend the observed parameter space into the regime of low surface brightness dwarf galaxies with low metallicities and moderate star formation rates. Our targets were observed with Herschel at the [C ii] 158 μm, [O i] 63 μm, [O iii] 88 μm, and [N ii] 122 μm emission lines using the PACS Spectrometer. These high-resolution maps allow us for the first time to study the FIR properties of these systems on the scales of larger star-forming complexes. The spatial resolution in our maps, in combination with star formation tracers, allows us to identify separate photodissociation regions (PDRs) in some of the regions we observed. Our systems have widespread [C ii] emission that is bright relative to continuum, averaging near 0.5% of the total infrared (TIR) budget—higher than in solar-metallicity galaxies of other types. [N ii] is weak, suggesting that the [C ii] emission in our galaxies comes mostly from PDRs instead of the diffuse ionized interstellar medium (ISM). These systems exhibit efficient cooling at low dust temperatures, as shown by ([O i]+[C ii])/TIR in relation to 60 μm/100 μm, and low [O i]/[C ii] ratios which indicate that [C ii] is the dominant coolant of the ISM. We observe [O iii]/[C ii] ratios in our galaxies that are lower than those published for other dwarfs, but similar to levels noted in spirals.

Exploring the dust content of galactic winds with Herschel - II. Nearby dwarf galaxies

Science.gov (United States)

McCormick, Alexander; Veilleux, Sylvain; Meléndez, Marcio; Martin, Crystal L.; Bland-Hawthorn, Joss; Cecil, Gerald; Heitsch, Fabian; Müller, Thomas; Rupke, David S. N.; Engelbracht, Chad

2018-06-01

We present the results from an analysis of deep Herschel Space Observatory observations of six nearby dwarf galaxies known to host galactic-scale winds. The superior far-infrared sensitivity and angular resolution of Herschel have allowed detection of cold circumgalactic dust features beyond the stellar components of the host galaxies traced by Spitzer 4.5 μm images. Comparisons of these cold dust features with ancillary data reveal an imperfect spatial correlation with the ionized gas and warm dust wind components. We find that typically ˜10-20 per cent of the total dust mass in these galaxies resides outside of their stellar discs, but this fraction reaches ˜60 per cent in the case of NGC 1569. This galaxy also has the largest metallicity (O/H) deficit in our sample for its stellar mass. Overall, the small number of objects in our sample precludes drawing strong conclusions on the origin of the circumgalactic dust. We detect no statistically significant trends with star formation properties of the host galaxies, as might be expected if the dust were lifted above the disc by energy inputs from ongoing star formation activity. Although a case for dust entrained in a galactic wind is seen in NGC 1569, in all cases, we cannot rule out the possibility that some of the circumgalactic dust might be associated instead with gas accreted or removed from the disc by recent galaxy interaction events, or that it is part of the outer gas-rich portion of the disc that lies below the sensitivity limit of the Spitzer 4.5 μm data.

DIGIT survey of far-infrared lines from protoplanetary discs : II. CO

NARCIS (Netherlands)

Meeus, Gwendolyn; Salyk, Colette; Bruderer, Simon; Fedele, Davide; Maaskant, Koen; Evans, Neal J.; van Dishoeck, Ewine F.; Montesinos, Benjamin; Herczeg, Greg; Bouwman, Jeroen; Green, Joel D.; Dominik, Carsten; Henning, Thomas; Vicente, Silvia

2013-01-01

CO is an important component of a protoplanetary disc as it is one of the most abundant gas phase species. Furthermore, observations of CO transitions can be used as a diagnostic of the gas, tracing conditions in both the inner and outer disc. We present Herschel/PACS spectroscopy of a sample of 22

DIGIT survey of far-infrared lines from protoplanetary discs. II. CO

NARCIS (Netherlands)

Meeus, G.; Salyk, C.; Bruderer, S.; Fedele, D.; Maaskant, K.M.; Evans, N.; Dishoeck, van E.F.; Montesinos, B.; Herczeg, G.; Bouwman, J.; Green, J.; Dominik, C.; Henning, T.; Vicente, S.

2013-01-01

CO is an important component of a protoplanetary disc as it is one of the most abundant gas phase species. Furthermore, observations of CO transitions can be used as a diagnostic of the gas, tracing conditions in both the inner and outer disc. We present Herschel/PACS spectroscopy of a sample of 22

Analysis of the Herschel/HIFI 1.2 THz Wide Spectral Survey of the Orion Kleinmann-Low Nebula

Science.gov (United States)

Crockett, Nathan R.

This dissertation presents a comprehensive analysis of a broad band spectral line survey of the Orion Kleinmann-Low nebula (Orion KL), one of the most chemically rich regions in the Galaxy, using the HIFI instrument on board the Herschel Space Observatory. This survey spans a frequency range from 480 to 1907 GHz at a resolution of 1.1 MHz. These observations thus encompass the largest spectral coverage ever obtained toward this massive star forming region in the sub-mm with high spectral resolution, and include frequencies >1 THz where the Earth's atmosphere prevents observations from the ground. In all, we detect emission from 36 molecules (76 isotopologues). Combining this dataset with ground based mm spectroscopy obtained with the IRAM 30 m telescope, we model the molecular emission assuming local thermodynamic equilibrium (LTE). Because of the wide frequency coverage, our models are constrained over an unprecedented range in excitation energy, including states at or close to ground up to energies where emission is no longer detected. A χ2 analysis indicates that most of our models reproduce the observed emission well. In particular complex organics, some with thousands of transitions, are well fit by LTE models implying that gas densities are high (>10^6 cm^-3) and excitation temperatures and column densities are well constrained. Molecular abundances are computed using H2 column densities also derived from the HIFI survey. The rotation temperature distribution of molecules detected toward the hot core is much wider relative to the compact ridge, plateau, and extended ridge. We find that complex N-bearing species, cyanides in particular, systematically probe hotter gas than complex O-bearing species. This indicates complex N-bearing molecules may be more difficult to remove from grain surfaces or that hot gas phase formation routes are important for these species. We also present a detailed non-LTE analysis of H2S emission toward the hot core which suggests

History of infrared detectors

Science.gov (United States)

Rogalski, A.

2012-09-01

This paper overviews the history of infrared detector materials starting with Herschel's experiment with thermometer on February 11th, 1800. Infrared detectors are in general used to detect, image, and measure patterns of the thermal heat radiation which all objects emit. At the beginning, their development was connected with thermal detectors, such as thermocouples and bolometers, which are still used today and which are generally sensitive to all infrared wavelengths and operate at room temperature. The second kind of detectors, called the photon detectors, was mainly developed during the 20th Century to improve sensitivity and response time. These detectors have been extensively developed since the 1940's. Lead sulphide (PbS) was the first practical IR detector with sensitivity to infrared wavelengths up to ˜3 μm. After World War II infrared detector technology development was and continues to be primarily driven by military applications. Discovery of variable band gap HgCdTe ternary alloy by Lawson and co-workers in 1959 opened a new area in IR detector technology and has provided an unprecedented degree of freedom in infrared detector design. Many of these advances were transferred to IR astronomy from Departments of Defence research. Later on civilian applications of infrared technology are frequently called "dual-use technology applications." One should point out the growing utilisation of IR technologies in the civilian sphere based on the use of new materials and technologies, as well as the noticeable price decrease in these high cost technologies. In the last four decades different types of detectors are combined with electronic readouts to make detector focal plane arrays (FPAs). Development in FPA technology has revolutionized infrared imaging. Progress in integrated circuit design and fabrication techniques has resulted in continued rapid growth in the size and performance of these solid state arrays.

FAR-INFRARED EXTINCTION MAPPING OF INFRARED DARK CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Lim, Wanggi [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Tan, Jonathan C. [Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611 (United States)

2014-01-10

Progress in understanding star formation requires detailed observational constraints on the initial conditions, i.e., dense clumps and cores in giant molecular clouds that are on the verge of gravitational instability. Such structures have been studied by their extinction of near-infrared and, more recently, mid-infrared (MIR) background light. It has been somewhat more of a surprise to find that there are regions that appear as dark shadows at far-infrared (FIR) wavelengths as long as ∼100 μm! Here we develop analysis methods of FIR images from Spitzer-MIPS and Herschel-PACS that allow quantitative measurements of cloud mass surface density, Σ. The method builds on that developed for MIR extinction mapping by Butler and Tan, in particular involving a search for independently saturated, i.e., very opaque, regions that allow measurement of the foreground intensity. We focus on three massive starless core/clumps in the Infrared Dark Cloud (IRDC) G028.37+00.07, deriving mass surface density maps from 3.5 to 70 μm. A by-product of this analysis is the measurement of the spectral energy distribution of the diffuse foreground emission. The lower opacity at 70 μm allows us to probe to higher Σ values, up to ∼1 g cm{sup –2} in the densest parts of the core/clumps. Comparison of the Σ maps at different wavelengths constrains the shape of the MIR-FIR dust opacity law in IRDCs. We find that it is most consistent with the thick ice mantle models of Ossenkopf and Henning. There is tentative evidence for grain ice mantle growth as one goes from lower to higher Σ regions.

FAR-INFRARED EXTINCTION MAPPING OF INFRARED DARK CLOUDS

International Nuclear Information System (INIS)

Lim, Wanggi; Tan, Jonathan C.

2014-01-01

Progress in understanding star formation requires detailed observational constraints on the initial conditions, i.e., dense clumps and cores in giant molecular clouds that are on the verge of gravitational instability. Such structures have been studied by their extinction of near-infrared and, more recently, mid-infrared (MIR) background light. It has been somewhat more of a surprise to find that there are regions that appear as dark shadows at far-infrared (FIR) wavelengths as long as ∼100 μm! Here we develop analysis methods of FIR images from Spitzer-MIPS and Herschel-PACS that allow quantitative measurements of cloud mass surface density, Σ. The method builds on that developed for MIR extinction mapping by Butler and Tan, in particular involving a search for independently saturated, i.e., very opaque, regions that allow measurement of the foreground intensity. We focus on three massive starless core/clumps in the Infrared Dark Cloud (IRDC) G028.37+00.07, deriving mass surface density maps from 3.5 to 70 μm. A by-product of this analysis is the measurement of the spectral energy distribution of the diffuse foreground emission. The lower opacity at 70 μm allows us to probe to higher Σ values, up to ∼1 g cm –2 in the densest parts of the core/clumps. Comparison of the Σ maps at different wavelengths constrains the shape of the MIR-FIR dust opacity law in IRDCs. We find that it is most consistent with the thick ice mantle models of Ossenkopf and Henning. There is tentative evidence for grain ice mantle growth as one goes from lower to higher Σ regions

The Space Infrared Interferometric Telescope (SPIRIT)

Science.gov (United States)

Leisawitz, David T.

2014-01-01

The far-infrared astrophysics community is eager to follow up Spitzer and Herschel observations with sensitive, high-resolution imaging and spectroscopy, for such measurements are needed to understand merger-driven star formation and chemical enrichment in galaxies, star and planetary system formation, and the development and prevalence of water-bearing planets. The Space Infrared Interferometric Telescope (SPIRIT) is a wide field-of-view space-based spatio-spectral interferometer designed to operate in the 25 to 400 micron wavelength range. This talk will summarize the SPIRIT mission concept, with a focus on the science that motivates it and the technology that enables it. Without mentioning SPIRIT by name, the astrophysics community through the NASA Astrophysics Roadmap Committee recently recommended this mission as the first in a series of space-based interferometers. Data from a laboratory testbed interferometer will be used to illustrate how the spatio-spectral interferometry technique works.

How bright planets became dim stars: planetary speculations in John Herschel's double star astronomy.

Science.gov (United States)

Case, Stephen

2014-03-01

Previous research on the origins of double star astronomy in the early nineteenth century emphasized the role mathematical methods and instrumentation played in motivating early observations of these objects. The work of the British astronomer John Herschel, however, shows that questions regarding the physical nature of double stars were also important. In particular, an analysis of John Herschel's early work on double stars illustrates the way in which speculations regarding these objects were shaped by assumptions of the properties of stars themselves. For Herschel, a major consideration in double star astronomy was distinguishing between types of double stars. Optical doubles were useful in determining parallax while binary doubles were not. In practice, classification of a specific double star pair into one of these categories was based on the assumption that stars were of approximately the same luminosity and thus differences in relative brightness between stars were caused by difference in distances. Such assumptions, though ultimately abandoned, would lead Herschel in the 1830s to advance the possibility that the dim companion stars in certain double star pairs were not stars at all but in fact planets. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Infrared-Radio Correlation of Dusty Star Forming Galaxies at High Redshift

Science.gov (United States)

Lower, Sidney; Vieira, Joaquin Daniel; Jarugula, Sreevani

2018-01-01

Far-infrared (FIR) and radio continuum emission in galaxies are related by a common origin: massive stars and the processes triggered during their birth, lifetime, and death. FIR emission is produced by cool dust, heated by the absorption of UV emission from massive stars, which is then re-emitted in the FIR. Thermal free-free radiation emitted from HII regions dominates the spectral energy density (SED) of galaxies at roughly 30 GHz, while non-thermal synchrotron radiation dominates at lower frequencies. At low redshift, the infrared radio correlation (IRC, or qIR) holds as a tight empirical relation for many star forming galaxy types, but until recently, there has not been sensitive enough radio observations to extend this relation to higher redshifts. Many selection biases cloud the results of these analyses, leaving the evolution of the IRC with redshift ambiguous. In this poster, I present CIGALE fitted spectral energy distributions (SEDs) for 24 gravitationally-lensed sources selected in the mm-wave from the South Pole Telescope (SPT) survey. I fit the IRC from infrared and submillimeter fluxes obtained with Herschel, Atacama Pathfinder Experiment (APEX), and SPT and radio fluxes obtained with ATCA at 2.1, 5.5, 9, and 30 GHz. This sample of SPT sources has a spectroscopic redshift range of 2.1poster, I will present the results of this study and compare our results to various results in the literature.

GTC/OSIRIS SPECTROSCOPIC IDENTIFICATION OF A FAINT L SUBDWARF IN THE UKIRT INFRARED DEEP SKY SURVEY

International Nuclear Information System (INIS)

Lodieu, N.; Osorio, M. R. Zapatero; MartIn, E. L.; Solano, E.; Aberasturi, M.

2010-01-01

We present the discovery of an L subdwarf in 234 deg 2 common to the UK InfraRed Telescope (UKIRT) Infrared Deep Sky Survey Large Area Survey Data Release 2 and the Sloan Digital Sky Survey Data Release 3. This is the fifth L subdwarf announced to date, the first one identified in the UKIRT Infrared Deep Sky Survey, and the faintest known. The blue optical and near-infrared colors of ULAS J135058.86+081506.8 and its overall spectra energy distribution are similar to the known mid-L subdwarfs. Low-resolution optical (700-1000 nm) spectroscopy with the Optical System for Imaging and low Resolution Integrated Spectroscopy spectrograph on the 10.4 m Gran Telescopio de Canarias reveals that ULAS J135058.86+081506.8 exhibits a strong K I pressure-broadened line at 770 nm and a red slope longward of 800 nm, features characteristics of L-type dwarfs. From direct comparison with the four known L subdwarfs, we estimate its spectral type to be sdL4-sdL6 and derive a distance in the interval 94-170 pc. We provide a rough estimate of the space density for mid-L subdwarfs of 1.5 x 10 -4 pc -3 .

An X-ray and infrared survey of the Lynds 1228 cloud core

Energy Technology Data Exchange (ETDEWEB)

Skinner, Stephen L. [CASA, University of Colorado, Boulder, CO 80309-0389 (United States); Rebull, Luisa [Spitzer Science Center/Caltech, M/S 220-6, 1200 East California Blvd., Pasadena, CA 91125 (United States); Güdel, Manuel, E-mail: stephen.skinner@colorado.edu, E-mail: rebull@ipac.caltech.edu, E-mail: manuel.guedel@univie.ac.at [Department of Astrophysics, University of Vienna, Türkenschanzstr. 17, A-1180 Vienna (Austria)

2014-04-01

The nearby Lynds 1228 (L1228) dark cloud at a distance of ∼200 pc is known to harbor several young stars including the driving sources of the giant HH 199 and HH 200 Herbig-Haro (HH) outflows. L1228 has previously been studied at optical, infrared, and radio wavelengths but not in X-rays. We present results of a sensitive 37 ks Chandra ACIS-I X-ray observation of the L1228 core region. Chandra detected 60 X-ray sources, most of which are faint (<40 counts) and non-variable. Infrared counterparts were identified for 53 of the 60 X-ray sources using archival data from the Two Micron All-Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer. Object classes were assigned using mid-IR colors for those objects with complete photometry, most of which were found to have colors consistent with extragalactic background sources. Seven young stellar object candidates were identified including the class I protostar HH 200-IRS which was detected as a faint hard X-ray source. No X-ray emission was detected from the luminous protostar HH 199-IRS. We summarize the X-ray and infrared properties of the detected sources and provide IR spectral energy distribution modeling of high-interest objects including the protostars driving the HH outflows.

HERSCHEL -RESOLVED OUTER BELTS OF TWO-BELT DEBRIS DISKS—EVIDENCE OF ICY GRAINS

Energy Technology Data Exchange (ETDEWEB)

Morales, F. Y.; Bryden, G.; Werner, M. W.; Stapelfeldt, K. R., E-mail: Farisa@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

2016-11-01

We present dual-band Herschel /PACS imaging for 59 main-sequence stars with known warm dust ( T {sub warm} ∼ 200 K), characterized by Spitzer . Of 57 debris disks detected at Herschel wavelengths (70 and/or 100 and 160 μ m), about half have spectral energy distributions (SEDs) that suggest two-ring disk architectures mirroring that of the asteroid–Kuiper Belt geometry; the rest are consistent with single belts of warm, asteroidal material. Herschel observations spatially resolve the outer/cold dust component around 14 A-type and 4 solar-type stars with two-belt systems, 15 of which for the first time. Resolved disks are typically observed with radii >100 AU, larger than expected from a simple blackbody fit. Despite the absence of narrow spectral features for ice, we find that the shape of the continuum, combined with resolved outer/cold dust locations, can help constrain the grain size distribution and hint at the dust’s composition for each resolved system. Based on the combined Spitzer /IRS+Multiband Imaging Photometer (5-to-70 μ m) and Herschel /PACS (70-to-160 μ m) data set, and under the assumption of idealized spherical grains, we find that over half of resolved outer/cold belts are best fit with a mixed ice/rock composition. Minimum grain sizes are most often equal to the expected radiative blowout limit, regardless of composition. Three of four resolved systems around the solar-type stars, however, tend to have larger minimum grains compared to expectation from blowout ( f {sub MB} = a {sub min}/ a {sub BOS} ∼ 5). We also probe the disk architecture of 39 Herschel -unresolved systems by modeling their SEDs uniformly, and find them to be consistent with 31 single- and 8 two-belt debris systems.

Herschel/HIFI observations of high-J CO lines in the NGC 1333 low-mass star-forming region

DEFF Research Database (Denmark)

Yildiz, U. A.; van Dishoeck, E. F.; Kristensen, L. E.

2010-01-01

Herschel/HIFI observations of high-J lines (up to Ju = 10) of 12CO, 13CO and C18O are presented toward three deeply embedded low-mass protostars, NGC 1333 IRAS 2A, IRAS 4A, and IRAS 4B, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. The spectrally-resolved......Herschel/HIFI observations of high-J lines (up to Ju = 10) of 12CO, 13CO and C18O are presented toward three deeply embedded low-mass protostars, NGC 1333 IRAS 2A, IRAS 4A, and IRAS 4B, obtained as part of the Water In Star-forming regions with Herschel (WISH) key program. The spectrally....... Their intensities require a jump in the CO abundance at an evaporation temperature around 25 K, thus providing new direct evidence for a CO ice evaporation zone around low-mass protostars. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia...... and with important participation from NASA.Appendices and acknowledgements (pages 5 to 7) are only available in electronic form at http://www.aanda.org...

New DSH planetary nebulae and candidates from optical and infrared surveys

International Nuclear Information System (INIS)

Kronberger, Matthias; Jacoby, George H; Alves, Filipe; Patchick, Dana; Parker, Quentin A; Bojicic, Ivan; Frew, David J; Acker, Agnes; Eigenthaler, Paul; Harmer, Dianne; Reid, Warren; Schedler, Johannes

2016-01-01

To date, the planetary nebula (PN) survey of the Deep Sky Hunters collaboration has led to the detection of more than 250 previously unknown candidate planetary nebulae (PNe). About 60% of them were found during the past two years and are expected to be true, likely or possible PNe because careful vetting has already thrown out more doubtful objects. The majority of the new PN candidates are located within the boundaries of the SHS and IPHAS Ha surveys and were discovered by combining MIR data from the WideField Infrared Survey Explorer (WISE) with optical data from the IPHAS, SHS and DSS surveys, and UV data from the Galaxy Evolution Explorer(GALEX). (paper)

THE HERSCHEL AND IRAM CHESS SPECTRAL SURVEYS OF THE PROTOSTELLAR SHOCK L1157-B1: FOSSIL DEUTERATION

Energy Technology Data Exchange (ETDEWEB)

Codella, C.; Fontani, F.; Vasta, M. [INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Ceccarelli, C.; Lefloch, B.; Kahane, C.; Taquet, V.; Wiesenfeld, L. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Busquet, G. [INAF - Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, I-00133, Roma (Italy); Caselli, P. [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Lis, D. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Viti, S., E-mail: codella@rcetri.astro.it [Department of Physics and Astronomy, University College London, London (United Kingdom)

2012-09-20

We present the first study of deuteration toward the protostellar shock L1157-B1, based on spectral surveys performed with the Herschel-HIFI and IRAM 30 m telescopes. The L1157 outflow is driven by a low-mass Class 0 protostar and is considered the prototype of the so-called chemically active outflows. The young (2000 yr), bright blueshifted bow shock, B1, is an ideal laboratory for studying the gas chemically enriched by the release of dust mantles due to the passage of a shock. A total of 12 emission lines (up to E{sub u} = 63 K) of CH{sub 2}DOH, HDCO, and DCN are detected. In addition, two lines of NH{sub 2}D and HDO are tentatively reported. To estimate the deuteration, we also extracted from our spectral survey emission lines of non-deuterated isotopologues ({sup 13}CH{sub 3}OH, H{sub 2} {sup 13}CO, H{sup 13}CN, H{sub 2} {sup 13}CO, and NH{sub 3}). We infer higher deuteration fractions for CH{sub 3}OH (D/H = 0.2-2 Multiplication-Sign 10{sup -2}) and H{sub 2}CO (5-8 Multiplication-Sign 10{sup -3}) than for H{sub 2}O (0.4-2 Multiplication-Sign 10{sup -3}), HCN ({approx}10{sup -3}), and ammonia ({<=}3 Multiplication-Sign 10{sup -2}). The measurement of deuteration of water, formaldehyde, and methanol in L1157-B1 provides a fossil record of the gas before it was shocked by the jet driven by the protostar. A comparison with gas-grain models indicates that the gas passed through a low-density ({<=}10{sup 3} cm{sup -3}) phase, during which the bulk of water ices formed, followed by a phase of increasing density, up to 3 Multiplication-Sign 10{sup 4} cm{sup -3}, during which formaldehyde and methanol ices formed.

Herschel Studies of the Evolution and Environs of Young Stars in the DIGIT, WISH, and FOOSH Programs

Science.gov (United States)

Green, Joel D.; DIGIT OT Key Project Team; WISH GT Key Project Team; FOOSH OT1 Team

2012-01-01

The Herschel Space Observatory has enabled us to probe the physical conditions of outer disks, envelopes, and outflows of young stellar objects, including embedded objects, Herbig Ae/Be disks, and T Tauri disks. We will report on results from three projects, DIGIT, WISH, and FOOSH. The DIGIT (Dust, Ice, and Gas in Time) program (PI: Neal Evans) utilizes the full spectral range of the PACS instrument to explore simultaneously the solid and gas-phase chemistry around sources in all of these stages. WISH (Water in Star Forming Regions with Herschel, PI Ewine van Dishoeck) focuses on observations of key lines with HIFI and line scans of selected spectral regions with PACS. FOOSH (FU Orionis Objects Surveyed with Herschel, PI Joel Green) studies FU Orionis objects with full range PACS and SPIRE scans. DIGIT includes examples of low luminosity protostars, while FOOSH studies the high luminosity objects during outburst states. Rotational ladders of highly excited CO and OH emission are detected in both disks and protostars. The highly excited lines are more commonly seen in the embedded phases, where there appear to be two temperature components. Intriguingly, water is frequently detected in spectra of embedded sources, but not in the disk spectra. In addition to gas features, we explore the extent of the newly detected 69 um forsterite dust feature in both T Tauri and Herbig Ae/Be stars. When analyzed along with the Spitzer-detected dust features, these provide constraints on a population of colder crystalline material. We will present some models of individual sources, as well as some broad statistics of the emission from these stages of star and planet formation.

Groundwater discharge mapping at Altnabreac by thermal infrared linescan surveying

International Nuclear Information System (INIS)

Brereton, N.R.; Hall, D.H.

1983-07-01

A thermal infra-red linescan survey has been carried out of the area around Altnabreac, Caithness. The objectives of the survey were: to assess the applicability of the technique to the location of springs discharging from peat covered crystalline rocks; to provide the locations of springs for a subsequent geochemical sampling programme; and to gain clearer understanding of the ground water circulation patterns in the area. The number and distribution of springs located by the survey has proved to be far greater than had been previously anticipated and the capabilities of the technique have been clearly demonstrated. The results, together with other geochemical and hydrogeological data, indicate that the majority of the springs represent near surface recent groundwaters circulating within the moraine deposits and weathered granite. (author)

Red but not dead: unveiling the star-forming far-infrared spectral energy distribution of SpARCS brightest cluster galaxies at 0 < z < 1.8

Science.gov (United States)

Bonaventura, N. R.; Webb, T. M. A.; Muzzin, A.; Noble, A.; Lidman, C.; Wilson, G.; Yee, H. K. C.; Geach, J.; Hezaveh, Y.; Shupe, D.; Surace, J.

2017-08-01

We present the results of a Spitzer/Herschel infrared photometric analysis of the largest (716) and the highest-redshift (z = 1.8) sample of brightest cluster galaxies (BCGs), those from the Spitzer Adaptation of the Red-Sequence Cluster Survey Given the tension that exists between model predictions and recent observations of BCGs at z energy distributions (SEDs) to a variety of model templates in the literature, we identify the major sources of their infrared energy output, in multiple redshift bins between 0 solar masses per year down to z = 0.5. This discovery challenges the accepted belief that BCGs should only passively evolve through a series of gas-poor, minor mergers since z ˜ 4, but agrees with an improved semi-analytic model of hierarchical structure formation that predicts star-forming BCGs throughout the epoch considered. We attribute the star formation inferred from the stacked infrared SEDs to both major and minor 'wet' (gas-rich) mergers, based on a lack of key signatures (to date) of cooling-flow-induced star formation, as well as a number of observational and simulation-based studies that support this scenario.

Spitzer Imaging of Planck-Herschel Dusty Proto-Clusters at z=2-3

Science.gov (United States)

Cooray, Asantha; Ma, Jingzhe; Greenslade, Joshua; Kubo, Mariko; Nayyeri, Hooshang; Clements, David; Cheng, Tai-An

2018-05-01

We have recently introduced a new proto-cluster selection technique by combing Herschel/SPIRE imaging data and Planck/HFIk all-sky survey point source catalog. These sources are identified as Planck point sources with clumps of Herschel source over-densities with far-IR colors comparable to z=0 ULIRGS redshifted to z=2 to 3. The selection is sensitive to dusty starbursts and obscured QSOs and we have recovered couple of the known proto-clusters and close to 30 new proto-clusters. The candidate proto-clusters selected from this technique have far-IR flux densities several times higher than those that are optically selected, such as using LBG selection, implying that the member galaxies are in a special phase of heightened dusty starburst and dusty QSO activity. This far-IR luminous phase may be short but likely to be necessary piece to understand the whole stellar mass assembly history of clusters. Moreover, our photo-clusters are missed in optical selections, suggesting that optically selected proto-clusters alone do not provide adequate statistics and a comparison of the far-IR and optical selected clusters may reveal the importance of the dusty stellar mass assembly. Here, we propose IRAC observations of six of the highest priority new proto-clusters, to establish the validity of the technique and to determine the total stellar mass through SED models. For a modest observing time the science program will have a substantial impact on an upcoming science topic in cosmology with implications for observations with JWST and WFIRST to understand the mass assembly in the universe.

THE SPITZER MID-INFRARED ACTIVE GALACTIC NUCLEUS SURVEY. I. OPTICAL AND NEAR-INFRARED SPECTROSCOPY OF OBSCURED CANDIDATES AND NORMAL ACTIVE GALACTIC NUCLEI SELECTED IN THE MID-INFRARED

Energy Technology Data Exchange (ETDEWEB)

Lacy, M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Ridgway, S. E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Gates, E. L. [UCO/Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Nielsen, D. M. [Department of Astronomy, University of Wisconsin, 475 N. Charter Street, Madison, WI 53706 (United States); Petric, A. O. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Sajina, A. [Department of Physics and Astronomy, Tuffs University, 212 College Avenue, Medford, MA 02155 (United States); Urrutia, T. [Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Cox Drews, S. [946 Mangrove Avenue 102, Sunnyvale, CA 94086 (United States); Harrison, C. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Seymour, N. [CSIRO, P.O. Box 76, Epping, NSW 1710 (Australia); Storrie-Lombardi, L. J. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

2013-10-01

We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate active galactic nuclei (AGNs) selected in the mid-infrared. This survey selects both normal and obscured AGNs closely matched in luminosity across a wide range, from Seyfert galaxies with bolometric luminosities L {sub bol} ∼ 10{sup 10} L {sub ☉} to highly luminous quasars (L {sub bol} ∼ 10{sup 14} L {sub ☉}), all with redshifts ranging from 0 to 4.3. Samples of candidate AGNs were selected with mid-infrared color cuts at several different 24 μm flux density limits to ensure a range of luminosities at a given redshift. The survey consists of 786 candidate AGNs and quasars, of which 672 have spectroscopic redshifts and classifications. Of these, 137 (20%) are type 1 AGNs with blue continua, 294 (44%) are type 2 objects with extinctions A{sub V} ∼> 5 toward their AGNs, 96 (14%) are AGNs with lower extinctions (A{sub V} ∼ 1), and 145 (22%) have redshifts, but no clear signs of AGN activity in their spectra. Of the survey objects 50% have L {sub bol} > 10{sup 12} L {sub ☉}, in the quasar regime. We present composite spectra for type 2 quasars and objects with no signs of AGN activity in their spectra. We also discuss the mid-infrared—emission-line luminosity correlation and present the results of cross correlations with serendipitous X-ray and radio sources. The results show that: (1) obscured objects dominate the overall AGN population, (2) mid-infrared selected AGN candidates exist which lack AGN signatures in their optical spectra but have AGN-like X-ray or radio counterparts, and (3) X-ray and optical classifications of obscured and unobscured AGNs often differ.

VizieR Online Data Catalog: Herschel FIR observations of NGC3603 (Di Cecco+, 2015)

Science.gov (United States)

di Cecco, A.; Faustini, F.; Paresce, F.; Correnti, M.; Calzoletti, L.

2015-06-01

The cloud complex surrounding NGC 3603 YC was observed by Herschel SPIRE/PACS during the Hi-GAL Survey (Molinari et al. 2010A&A...518L.100M, 2010PASP..122..314M), a Key Programme that mapped the Galactic plane in five photometric bands (70, 160, 250, 350, and 500um). The MSX (Egan et al. 2003AAS...203.5708E) images were taken at (wavelengths) 8.3, 12.1, 14.7, and 21.3um using the scan observing mode, and the WISE (Wright et al. 2010AJ....140.1868W) images were acquired in freeze-frame scan mode at 3.4, 4.6, 12, and 22um. (2 data files).

Revealing the ISM in high redshift starburst galaxies: An analysis of Herschel PACS and SPIRE FTS spectroscopic observations of HerMES and H-ATLAS-selected lensed galaxies

Science.gov (United States)

Cooray, Asantha

In the quest to develop a fundamental understanding of galaxy formation and evolution, observations of dusty star-forming galaxies (DSFGs) promise significant progress this decade. The importance of DSFGs is highlighted by the fact that half of the energy emitted by extragalactic sources emerges as dust-reprocessed light at infrared (IR) to sub millimeter wavelength. In the post-herschel\\ era, we are now at a unique position to tackle some of the key questions on galaxy formation and evolution because of the large area Herschel's Key Project surveys (HerMES and H-ATLAS). In particular those surveys have allowed us to identify a sample of 250 strongly gravitationally lensed DSFGs at z > 1. They give us a unique opportunity to dissect the detailed structures and kinematics of DSFGs. The Herschel Science Archive also contains individual follow up data on 44 and 25 of the brightest sources with SPIRE-FTS and PACS, respectively, in the spectroscopy mode, taking over 250 hours in four open-time programs. Only one of the 44 SPIRE FTS targets has yet to appear in the published literature. One of the four include an open-time 2 PACS spectroscopy program that was led at UCI by a former postdoc from the PI's group. That program was initially approved at Priority 2 in 2011, but was triggered in late 2012 and achieved 100% completion during the last two weeks of Herschel lifetime in May 2013. This archival analysis, interpretation, and modeling program involves two parts: (i) PACS spectroscopy in 50 to 200 microns of 25 lensed galaxies in the fine-structure emission lines [SiII]34, [SIII]33, [OIV]26, [OIII]52, [NIII]57 and [OI]63, and the molecular hydrogen H_2 S(0) and S(1). (ii) SPIRE FTS spectroscopy of 44 lensed galaxies, including above 25, over the wavelength range of 200 to 600 microns targeting [CII]158, [OIII]88, [OI]63/145, and [NI]122. The analysis will lead to a better understanding of the ISM of starbursting galaxies that span 1 research supports Goal 2 of the

"TNOs are Cool": A survey of the trans-Neptunian region. XII. Thermal light curves of Haumea, 2003 VS2 and 2003 AZ84 with Herschel/PACS

Science.gov (United States)

Santos-Sanz, P.; Lellouch, E.; Groussin, O.; Lacerda, P.; Müller, T. G.; Ortiz, J. L.; Kiss, C.; Vilenius, E.; Stansberry, J.; Duffard, R.; Fornasier, S.; Jorda, L.; Thirouin, A.

2017-08-01

Context. Time series observations of the dwarf planet Haumea and the Plutinos 2003 VS2 and 2003 AZ84 with Herschel/PACS are presented in this work. Thermal emission of these trans-Neptunian objects (TNOs) were acquired as part of the "TNOs are Cool" Herschel Space Observatory key programme. Aims: We search for the thermal light curves at 100 and 160 μm of Haumea and 2003 AZ84, and at 70 and 160 μm for 2003 VS2 by means of photometric analysis of the PACS data. The goal of this work is to use these thermal light curves to obtain physical and thermophysical properties of these icy Solar System bodies. Methods: When a thermal light curve is detected, it is possible to derive or constrain the object thermal inertia, phase integral and/or surface roughness with thermophysical modeling. Results: Haumea's thermal light curve is clearly detected at 100 and 160 μm. The effect of the reported dark spot is apparent at 100 μm. Different thermophysical models were applied to these light curves, varying the thermophysical properties of the surface within and outside the spot. Although no model gives a perfect fit to the thermal observations, results imply an extremely low thermal inertia (0.73) for Haumea's surface. We note that the dark spot region appears to be only weakly different from the rest of the object, with modest changes in thermal inertia and/or phase integral. The thermal light curve of 2003 VS2 is not firmly detected at 70 μm and at 160 μm but a thermal inertia of (2 ± 0.5) MKS can be derived from these data. The thermal light curve of 2003 AZ84 is not firmly detected at 100 μm. We apply a thermophysical model to the mean thermal fluxes and to all the Herschel/PACS and Spitzer/MIPS thermal data of 2003 AZ84, obtaining a close to pole-on orientation as the most likely for this TNO. Conclusions: For the three TNOs, the thermal inertias derived from light curve analyses or from the thermophysical analysis of the mean thermal fluxes confirm the generally small

NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

International Nuclear Information System (INIS)

Zapatero Osorio, M. R.; Bejar, V. J. S.; Rebolo, R.; Acosta-Pulido, J. A.; Manchado, A.; Pena Ramirez, K.; Goldman, B.; Caballero, J. A.

2011-01-01

We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust clouds, anomalous red infrared colors, or low-gravity atmospheres. The polarimetric data were acquired with the LIRIS instrument on the William Herschel Telescope. We also provide mid-infrared photometry in the interval 3.4-24 μm for some targets obtained with Spitzer and WISE, which has allowed us to confirm the peculiar red colors of five sources in the sample. We can impose modest upper limits of 0.9% and 1.8% on the linear polarization degree for seven targets with a confidence of 99%. Only one source, 2MASS J02411151-0326587 (L0), appears to be strongly polarized (P ∼ 3%) in the J band with a significance level of P/σ P ∼ 10. The likely origin of its linearly polarized light and rather red infrared colors may reside in a surrounding disk with an asymmetric distribution of grains. Given its proximity (66 ± 8 pc), this object becomes an excellent target for the direct detection of the disk.

CONTINUOUS MID-INFRARED STAR FORMATION RATE INDICATORS: DIAGNOSTICS FOR 0 < z < 3 STAR-FORMING GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Battisti, A. J.; Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Johnson, B. D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Elbaz, D., E-mail: abattist@astro.umass.edu [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu, CNRS, Université Paris Diderot, Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France)

2015-02-20

We present continuous, monochromatic star formation rate (SFR) indicators over the mid-infrared wavelength range of 6–70 μm. We use a sample of 58 star-forming galaxies (SFGs) in the Spitzer–SDSS–GALEX Spectroscopic Survey at z < 0.2, for which there is a rich suite of multi-wavelength photometry and spectroscopy from the ultraviolet through to the infrared. The data from the Spitzer Infrared Spectrograph (IRS) of these galaxies, which spans 5–40 μm, is anchored to their photometric counterparts. The spectral region between 40–70 μm is interpolated using dust model fits to the IRS spectrum and Spitzer 70 and 160 μm photometry. Since there are no sharp spectral features in this region, we expect these interpolations to be robust. This spectral range is calibrated as a SFR diagnostic using several reference SFR indicators to mitigate potential bias. Our band-specific continuous SFR indicators are found to be consistent with monochromatic calibrations in the local universe, as derived from Spitzer, WISE, and Herschel photometry. Our local composite template and continuous SFR diagnostics are made available for public use through the NASA/IPAC Infrared Science Archive (IRSA) and have typical dispersions of 30% or less. We discuss the validity and range of applicability for our SFR indicators in the context of unveiling the formation and evolution of galaxies. Additionally, in the era of the James Webb Space Telescope this will become a flexible tool, applicable to any SFG up to z ∼ 3.

Thermal/vacuum measurements of the Herschel space telescope by close-range photogrammetry

Science.gov (United States)

Parian, J. Amiri; Cozzani, A.; Appolloni, M.; Casarosa, G.

2017-11-01

In the frame of the development of a videogrammetric system to be used in thermal vacuum chambers at the European Space Research and Technology Centre (ESTEC) and other sites across Europe, the design of a network using micro-cameras was specified by the European Space agency (ESA)-ESTEC. The selected test set-up is the photogrammetric test of the Herschel Satellite Flight Model in the ESTEC Large Space Simulator. The photogrammetric system will be used to verify the Herschel Telescope alignment and Telescope positioning with respect to the Cryostat Vacuum Vessel (CVV) inside the Large Space Simulator during Thermal-Vacuum/Thermal-Balance test phases. We designed a close-range photogrammetric network by heuristic simulation and a videogrammetric system with an overall accuracy of 1:100,000. A semi-automated image acquisition system, which is able to work at low temperatures (-170°C) in order to acquire images according to the designed network has been constructed by ESA-ESTEC. In this paper we will present the videogrammetric system and sub-systems and the results of real measurements with a representative setup similar to the set-up of Herschel spacecraft which was realized in ESTEC Test Centre.

First results of Herschel-PACS observations of Neptune

NARCIS (Netherlands)

Lellouch, E.; Hartogh, P.; Feuchtgruber, H.; Vandenbussche, B.; de Graauw, Th.; Moreno, R.; Jarchow, C.; Cavalie, T.; Orton, G.; Banaszkiewicz, M.; Blecka, M. I.; Bockelee-Morvan, D.; Crovisier, J.; Encrenaz, T.; Fulton, T.; Kueppers, M.; Lara, L. M.; Lis, D. C.; Medvedev, A. S.; Rengel, M.; Sagawa, H.; Swinyard, B.; Szutowicz, S.; Bensch, F.; Bergin, E.; Billebaud, F.; Biver, N.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Courtin, R.; Davis, G. R.; Decin, L.; Encrenaz, P.; Gonzalez, A.; Jehin, E.; Kidger, M.; Naylor, D.; Portyankina, G.; Schieder, R.; Sidher, S.; Thomas, N.; de Val-Borro, M.; Verdugo, E.; Waelkens, C.; Aarts, H.; Comito, C.; Kawamura, J. H.; Maestrini, A.; Peacocke, T.; Teipen, R.; Tils, T.; Wildeman, K.; Walker, H.; Blake, G.A.

2010-01-01

We report on the initial analysis of a Herschel-PACS full range spectrum of Neptune, covering the 51-220 mu m range with a mean resolving power of similar to 3000, and complemented by a dedicated observation of CH(4) at 120 mu m. Numerous spectral features due to HD (R(0) and R(1)), H(2)O, CH(4),

GOT C+: A Herschel Space Observatory Key Program to Study the Diffuse ISM

Science.gov (United States)

Langer, William; Velusamy, T.; Goldsmith, P. F.; Li, D.; Pineda, J.; Yorke, H.

2010-01-01

Star formation activity is regulated by pressures in the interstellar medium, which in turn depend on heating and cooling rates, modulated by the gravitational potential, and shock and turbulent pressures. To understand these processes we need information about the diffuse atomic and diffuse molecular gas cloud properties. The ionized carbon CII fine structure line at 1.9 THz is an important tracer of the atomic gas in the diffuse regions and the atomic to molecular cloud transformation. Furthermore, C+ is a major ISM coolant, the Galaxy's strongest emission line, with a total luminosity about a 1000 times that of CO J=1-0. Galactic Observations of the Terahertz C+ Line (GOT C+) is a Herschel Space Observatory Open Time Key Program to study the diffuse interstellar medium by sampling CII line emission throughout the Galactic disk. GOT C+ will obtain high spectral resolution CII using the Heterodyne Instrument for the Far Infrared (HIFI) instrument. It employees deep integrations, wide velocity coverage (350 km s-1) with 0.22 km s-1 resolution, and systematic sparse sampling of the Galactic disk together with observations of selected targets, of over 900 lines of sight. It will be a resource of the atomic gas properties, in the (a) Galactic disk, (b) Galaxy's central 300pc, (c) Galactic warp, (d) high latitude HI clouds, and (e) Photon Dominated Regions (PDRs). Along with HI, CO isotopes, and CI spectra, our C+ data will provide the astronomical community with a rich statistical database of diffuse cloud properties, for understanding the role of barometric pressure and turbulence in cloud evolution in the Galactic ISM and, by extension, other galaxies. The GOT C+ project will provide a template for future even larger-scale CII surveys. This research was conducted at the Jet Propulsion Laboratory, California Institute of Technology and is supported by a NASA grant.

HERSCHEL OBSERVATIONS OF MAJOR MERGER PAIRS AT z = 0: DUST MASS AND STAR FORMATION

International Nuclear Information System (INIS)

Cao, Chen; Xu, Cong Kevin; Lu, Nanyao; Mazzarella, Joe; Domingue, Donovan; Ronca, Joseph; Jacques, Allison; Buat, Veronique; Cheng, Yi-Wen; Gao, Yu; Huang, Jiasheng; Jarrett, Thomas H.; Lisenfeld, Ute; Sun, Wei-Hsin; Wu, Hong; Yun, Min S.

2016-01-01

We present Herschel PACS and SPIRE far-infrared (FIR) and submillimeter imaging observations for a large K-band selected sample of 88 close major-merger pairs of galaxies (H-KPAIRs) in 6 photometric bands (70, 100, 160, 250, 350, and 500 μm). Among 132 spiral galaxies in the 44 spiral–spiral (S+S) pairs and 44 spiral–elliptical (S+E) pairs, 113 are detected in at least 1 Herschel band. The star formation rate (SFR) and dust mass (M dust ) are derived from the IR SED fitting. The mass of total gas (M gas ) is estimated by assuming a constant dust-to-gas mass ratio of 0.01. Star-forming spiral galaxies (SFGs) in S+S pairs show significant enhancements in both specific star formation rate (sSFR) and star formation efficiency (SFE), while having nearly the same gas mass compared to control galaxies. On the other hand, for SFGs in S+E pairs, there is no significant sSFR enhancement and the mean SFE enhancement is significantly lower than that of SFGs in S+S pairs. This suggests an important role for the disk–disk collision in the interaction-induced star formation. The M gas of SFGs in S+E pairs is marginally lower than that of their counterparts in both S+S pairs and the control sample. Paired galaxies with and without interaction signs do not differ significantly in their mean sSFR and SFE. As found in previous works, this much larger sample confirms that the primary and secondary spirals in S+S pairs follow a Holmberg effect correlation on sSFR

Near-infrared imaging survey of faint companions around young dwarfs in the Pleiades cluster

International Nuclear Information System (INIS)

Itoh, Yoichi; Funayama, Hitoshi; Hashiguchi, Toshio; Oasa, Yumiko; Hayashi, Masahiko; Fukagawa, Misato; Currie, Thayne

2011-01-01

We conducted a near-infrared imaging survey of 11 young dwarfs in the Pleiades cluster using the Subaru Telescope and the near-infrared coronagraph imager. We found ten faint point sources, with magnitudes as faint as 20 mag in the K-band, with around seven dwarfs. Comparison with the Spitzer archive images revealed that a pair of the faint sources around V 1171 Tau is very red in infrared wavelengths, which indicates very low-mass young stellar objects. However, the results of our follow-up proper motion measurements implied that the central star and the faint sources do not share common proper motions, suggesting that they are not physically associated.

Dust Abundance Variations in the Magellanic Clouds: Probing the Life-cycle of Metals with All-sky Surveys

Science.gov (United States)

Roman-Duval, Julia; Bot, Caroline; Chastenet, Jeremy; Gordon, Karl

2017-06-01

Observations and modeling suggest that dust abundance (gas-to-dust ratio, G/D) depends on (surface) density. Variations of the G/D provide timescale constraints for the different processes involved in the life cycle of metals in galaxies. Recent G/D measurements based on Herschel data suggest a factor of 5-10 decrease in dust abundance between the dense and diffuse interstellar media (ISM) in the Magellanic Clouds. However, the relative nature of the Herschel measurements precludes definitive conclusions as to the magnitude of those variations. We investigate variations of the dust abundance in the LMC and SMC using all-sky far-infrared surveys, which do not suffer from the limitations of Herschel on their zero-point calibration. We stack the dust spectral energy distribution (SED) at 100, 350, 550, and 850 microns from IRAS and Planck in intervals of gas surface density, model the stacked SEDs to derive the dust surface density, and constrain the relation between G/D and gas surface density in the range 10-100 M ⊙ pc-2 on ˜80 pc scales. We find that G/D decreases by factors of 3 (from 1500 to 500) in the LMC and 7 (from 1.5× {10}4 to 2000) in the SMC between the diffuse and dense ISM. The surface-density-dependence of G/D is consistent with elemental depletions, and with simple modeling of the accretion of gas-phase metals onto dust grains. This result has important implications for the sub-grid modeling of galaxy evolution, and for the calibration of dust-based gas-mass estimates, both locally and at high redshift.

Biorheological Model on Flow of Herschel-Bulkley Fluid through a Tapered Arterial Stenosis with Dilatation.

Science.gov (United States)

Priyadharshini, S; Ponalagusamy, R

2015-01-01

An analysis of blood flow through a tapered artery with stenosis and dilatation has been carried out where the blood is treated as incompressible Herschel-Bulkley fluid. A comparison between numerical values and analytical values of pressure gradient at the midpoint of stenotic region shows that the analytical expression for pressure gradient works well for the values of yield stress till 2.4. The wall shear stress and flow resistance increase significantly with axial distance and the increase is more in the case of converging tapered artery. A comparison study of velocity profiles, wall shear stress, and flow resistance for Newtonian, power law, Bingham-plastic, and Herschel-Bulkley fluids shows that the variation is greater for Herschel-Bulkley fluid than the other fluids. The obtained velocity profiles have been compared with the experimental data and it is observed that blood behaves like a Herschel-Bulkley fluid rather than power law, Bingham, and Newtonian fluids. It is observed that, in the case of a tapered stenosed tube, the streamline pattern follows a convex pattern when we move from r/R = 0 to r/R = 1 and it follows a concave pattern when we move from r/R = 0 to r/R = -1. Further, it is of opposite behaviour in the case of a tapered dilatation tube which forms new information that is, for the first time, added to the literature.

A NuSTAR survey of nearby ultraluminous infrared galaxies

DEFF Research Database (Denmark)

Teng, Stacy H.; Rigby, Jane R.; Stern, Daniel

2015-01-01

We present a Nuclear Spectroscopic Telescope Array (NuSTAR), Chandra, and XMM-Newton survey of nine of the nearest ultraluminous infrared galaxies (ULIRGs). The unprecedented sensitivity of NuSTAR at energies above 10 keV enables spectral modeling with far better precision than was previously......] line luminosity than do Seyfert 1 galaxies. We identify IRAS 08572+3915 as another candidate intrinsically X-ray weak source, similar to Mrk 231. We speculate that the X-ray weakness of IRAS 08572+3915 is related to its powerful outflow observed at other wavelengths....

a Question of Mass : Accounting for all the Dust in the Crab Nebula with the Deepest Far Infrared Maps

Science.gov (United States)

Matar, J.; Nehmé, C.; Sauvage, M.

2017-12-01

Supernovae represent significant sources of dust in the interstellar medium. In this work, deep far-infrared (FIR) observations of the Crab Nebula are studied to provide a new and reliable constraint on the amount of dust present in this supernova remnant. Deep exposures between 70 and 500 μm taken by PACS and SPIRE instruments on-board the Herschel Space Telescope, compiling all observations of the nebula including PACS observing mode calibration, are refined using advanced processing techniques, thus providing the most accurate data ever generated by Herschel on the object. We carefully find the intrinsic flux of each image by masking the source and creating a 2D polynomial fit to deduce the background emission. After subtracting the estimated non-thermal synchrotron component, two modified blackbodies were found to best fit the remaining infrared continuum, the cold component with T_c = 8.3 ± 3.0 K and M_d = 0.27 ± 0.05 M_{⊙} and the warmer component with T_w = 27.2 ± 1.3 K and M_d = (1.3 ± 0.4) ×10^{-3} M_{⊙}.

Herschel-ATLAS : Planck sources in the phase 1 fields

NARCIS (Netherlands)

Herranz, D.; González-Nuevo, J.; Clements, D.; De, Zotti G.; Lopez-Caniego, M.; Lapi, A.; Rodighiero, G.; Danese, L.; Fu, H.; Cooray, A.; Baes, M.; Bendo, G.; Bonavera, L.; Carrera, F.; Dole, H.; Eales, S.; Ivison, R.; Jarvis, M.; Lagache, G.; Massardi, M.; Michalowski, M.; Negrello, M.; Rigby, E.E.; Scott, D.; Valiante, E.; Valtchanov, I.; Werf, van der P.P.; Auld, R.; Buttiglione, S.; Dariush, A.; Dunne, L.; Hopwood, R.; Hoyos, C.; Ibar, E.; Maddox, S.

2013-01-01

We present the results of a cross-correlation of the Planck Early Release Compact Source catalogue (ERCSC) with the catalogue of Herschel-ATLAS sources detected in the phase 1 fields, covering 134.55{deg}$^{2}$. There are 28 ERCSC sources detected by Planck at 857 GHz in this area. As many as 16 of

A near-infrared survey for pre-main sequence stars in Taurus

Science.gov (United States)

Gomez, Mercedes; Kenyon, Scott J.; Hartmann, Lee

1994-01-01

We present a near-infrared survey of approximately 2 sq deg covering parts of L1537, L1538, and Heiles cloud 2 in the Taurus-Auriga molecular cloud. Although this study is more sensitive than previous attempts to identify pre-main sequence stars in Taurus-Auriga, our survey regions contain only one new optically visible, young star. We did find several candidate embedded protostars; additional 10 micrometer photometry is necessary to verify the pre-main sequence nature of these sources. Our results--combined with those of previous surveys--show that the L1537/L1538 clouds contain no pre-main sequence stars. These two clouds are less dense than the active star formation sites in Taurus-Auriga, which suggests a cloud must achieve a threshold density to form stars.

The Type Ia Supernova Rate in Radio and Infrared Galaxies from the CFHT Supernova Legacy Survey

OpenAIRE

Graham, M. L.; Pritchet, C. J.; Sullivan, M.; Howell, D. A.; Gwyn, S. D. J.; Astier, P.; Balland, C.; Basa, S.; Carlberg, R. G.; Conley, A.; Fouchez, D.; Guy, J.; Hardin, D.; Hook, I. M.; Pain, R.

2009-01-01

We have combined the large SN Ia database of the Canada-France-Hawaii Telescope Supernova Legacy Survey and catalogs of galaxies with photometric redshifts, VLA 1.4 GHz radio sources, and Spitzer infrared sources. We present eight SNe Ia in early-type host galaxies which have counterparts in the radio and infrared source catalogs. We find the SN Ia rate in subsets of radio and infrared early-type galaxies is ~1-5 times the rate in all early-type galaxies, and that any enhancement is always

The unforgotten sisters female astronomers and scientists before Caroline Herschel

CERN Document Server

Bernardi, Gabriella

2016-01-01

Taking inspiration from Siv Cedering’s poem in the form of a fictional letter from Caroline Herschel that refers to “my long, lost sisters, forgotten in the books that record our science”, this book tells the lives of twenty-five female scientists, with specific attention to astronomers and mathematicians. Each of the presented biographies is organized as a kind of "personal file" which sets the biographee’s life in its historical context, documents her main works, highlights some curious facts, and records citations about her. The selected figures are among the most representative of this neglected world, including such luminaries as Hypatia of Alexandra, Hildegard of Bingen, Elisabetha Hevelius, and Maria Gaetana Agnesi. They span a period of about 4000 years, from En HeduAnna, the Akkadian princess, who was one of the first recognized female astronomers, to the dawn of the era of modern astronomy with Caroline Herschel and Mary Somerville. The book will be of interest to all who wish to learn more ...

The Herschel-PACS Legacy of Low-mass Protostars: The Properties of Warm and Hot Gas Components and Their Origin in Far-UV Illuminated Shocks

Science.gov (United States)

Karska, Agata; Kaufman, Michael J.; Kristensen, Lars E.; van Dishoeck, Ewine F.; Herczeg, Gregory J.; Mottram, Joseph C.; Tychoniec, Łukasz; Lindberg, Johan E.; Evans, Neal J., II; Green, Joel D.; Yang, Yao-Lun; Gusdorf, Antoine; Itrich, Dominika; Siódmiak, Natasza

2018-04-01

Recent observations from Herschel allow the identification of important mechanisms responsible both for the heating of the gas that surrounds low-mass protostars and for its subsequent cooling in the far-infrared. Shocks are routinely invoked to reproduce some properties of the far-IR spectra, but standard models fail to reproduce the emission from key molecules, e.g., H2O. Here, we present the Herschel Photodetector Array Camera and Spectrometer (PACS) far-IR spectroscopy of 90 embedded low-mass protostars (Class 0/I). The Herschel-PACS spectral maps, covering ∼55–210 μm with a field of view of ∼50″, are used to quantify the gas excitation conditions and spatial extent using rotational transitions of H2O, high-J CO, and OH, as well as [O I] and [C II]. We confirm that a warm (∼300 K) CO reservoir is ubiquitous and that a hotter component (760 ± 170 K) is frequently detected around protostars. The line emission is extended beyond ∼1000 au spatial scales in 40/90 objects, typically in molecular tracers in Class 0 and atomic tracers in Class I objects. High-velocity emission (≳90 km s‑1) is detected in only 10 sources in the [O I] line, suggesting that the bulk of [O I] arises from gas that is moving slower than typical jets. Line flux ratios show an excellent agreement with models of C-shocks illuminated by ultraviolet (UV) photons for pre-shock densities of ∼105 cm‑3 and UV fields 0.1–10 times the interstellar value. The far-IR molecular and atomic lines are a unique diagnostic of feedback from UV emission and shocks in envelopes of deeply embedded protostars.

Inventing a space mission the story of the Herschel space observatory

CERN Document Server

Minier, Vincent; Bontems, Vincent; de Graauw, Thijs; Griffin, Matt; Helmich, Frank; Pilbratt, Göran; Volonte, Sergio

2017-01-01

This book describes prominent technological achievements within a very successful space science mission: the Herschel space observatory. Focusing on the various processes of innovation it offers an analysis and discussion of the social, technological and scientific context of the mission that paved the way to its development. It addresses the key question raised by these processes in our modern society, i.e.: how knowledge management of innovation set the conditions for inventing the future? In that respect the book is based on a transdisciplinary analysis of the programmatic complexity of Herschel, with inputs from space scientists, managers, philosophers, and engineers. This book is addressed to decision makers, not only in space science, but also in other industries and sciences using or building large machines. It is also addressed to space engineers and scientists as well as students in science and management.

Red, redder, reddest: SCUBA-2 imaging of colour-selected Herschel sources

Science.gov (United States)

Duivenvoorden, S.; Oliver, S.; Scudder, J. M.; Greenslade, J.; Riechers, D. A.; Wilkins, S. M.; Buat, V.; Chapman, S. C.; Clements, D. L.; Cooray, A.; Coppin, K. E. K.; Dannerbauer, H.; De Zotti, G.; Dunlop, J. S.; Eales, S. A.; Efstathiou, A.; Farrah, D.; Geach, J. E.; Holland, W. S.; Hurley, P. D.; Ivison, R. J.; Marchetti, L.; Petitpas, G.; Sargent, M. T.; Scott, D.; Symeonidis, M.; Vaccari, M.; Vieira, J. D.; Wang, L.; Wardlow, J.; Zemcov, M.

2018-06-01

High-redshift, luminous, dusty star-forming galaxies (DSFGs) constrain the extremity of galaxy formation theories. The most extreme are discovered through follow-up on candidates in large area surveys. Here, we present extensive 850 μm SCUBA-2 follow-up observations of 188 red DSFG candidates from the Herschel Multitiered Extragalactic Survey (HerMES) Large Mode Survey, covering 274 deg2. We detected 87 per cent with a signal-to-noise ratio >3 at 850 μm. We introduce a new method for incorporating the confusion noise in our spectral energy distribution fitting by sampling correlated flux density fluctuations from a confusion limited map. The new 850 μm data provide a better constraint on the photometric redshifts of the candidates, with photometric redshift errors decreasing from σz/(1 + z) ≈ 0.21 to 0.15. Comparison spectroscopic redshifts also found little bias ( = 0.08). The mean photometric redshift is found to be 3.6 with a dispersion of 0.4 and we identify 21 DSFGs with a high probability of lying at z > 4. After simulating our selection effects we find number counts are consistent with phenomenological galaxy evolution models. There is a statistically significant excess of WISE-1 and SDSS sources near our red galaxies, giving a strong indication that lensing may explain some of the apparently extreme objects. Nevertheless, our sample includes examples of galaxies with the highest star formation rates in the Universe (≫103 M⊙ yr-1).

Mission Concept for the Single Aperture Far-Infrared (SAFIR) Observatory

Science.gov (United States)

Benford, Dominic J.; Amato, Michael J.; Mather, John C.; Moseley, S. Harvey, Jr.

2004-01-01

We have developed a preliminary but comprehensive mission concept for SAFIR, as a 10 m-class far-infrared and submillimeter observatory that would begin development later in this decade to meet the needs outlined above. Its operating temperature ( or approx. 40 microns. This would provide a point source sensitivity improvement of several orders of magnitude over that of the Spitzer Space Telescope (previously SIRTF) or the Herschel Space Observatory. Additionally, it would have an angular resolution 12 times finer than that of Spitzer and three times finer than Herschel. This sensitivity and angular resolution are necessary to perform imaging and spectroscopic studies of individual galaxies in the early universe. We have considered many aspects of the SAFIR mission, including the telescope technology (optical design, materials, and packaging), detector needs and technologies, cooling method and required technology developments, attitude and pointing, power systems, launch vehicle, and mission operations. The most challenging requirements for this mission are operating temperature and aperture size of the telescope, and the development of detector arrays. SAFIR can take advantage of much of the technology under development for JWST, but with much less stringent requirements on optical accuracy.

NASA/IPAC Infrared Science Archive (IRSA) in the 2020s.

Science.gov (United States)

Desai, Vandana; Rebull, Luisa M.; IRSA Team

2018-06-01

I will discuss challenges faced by IRSA in the next decade due to changes in our user base: the dissolution of wavelength boundaries among astronomers, and the education of astronomers as data scientists. While the fraction of astronomers who use infrared data has increased drastically in the era of Spitzer, Herschel, and WISE, most people who do science with those data sets don’t use infrared data exclusively or identify as “Infrared astronomers”. Our archive, and others, need to be responsive to the needs of an increasingly multiwavelength community, and those exploring time domain astronomy. That means making the archives interlink seamlessly, while preserving expert knowledge so that data don’t get misused. As astronomical data sets grow in volume, users will increasingly expect server side resources, including both storage and analysis resources. These expectations come with a host of ramifications, from cost to security. Our archives must be built to satisfy the needs of both the power user and the beginning astronomer. I will discuss how IRSA plans to meet the evolving needs of our user community.

Nondimensional quasi-steady analysis of magnetorheological dampers utilizing a Herschel-Bulkley model with preyield viscosity

Science.gov (United States)

John, Shaju; Wereley, Norman M.

2003-07-01

Dampers based on electrorheological (ER) and magnetorheolgical (MR) fluids can be analyzed under assumptions of quasi-steady, fully developed flow behavior. Models that have been used to characterize ER and MR dampers include the Bingham-plastic, the Herschel-Bulkley and biviscous models. In the Bingham-plastic and the Herschel-Bulkley models, the fluid exhibits rigid behavior in the preyield flow region. The difference between these two models lie in the modeling of the postyield behavior. In the case of the Bingham-plastic model, the postyield behavior is such that the shear stress is proportional to the shear rate. In contrast, the Herschel-Bulkley model assumes that the shear stress is proportional to a power law of the shearrate. In the biciscous model, the relationship between the shear stres and shear rate is linear in both the preyield and postyield regions with constant values of viscosities for the two regions. However, the preyield flow behavior exhibits a much high viscosity than that in the postyield. In the propose model, the assumption of preyield rigid behavior within the Herschel-Bulkley model has been relaxed while the postyield relationship based on the power law has been retained. Here the fluid undergoes Newtonian preyield viscous flow and has a non-Newtonian postyield behavior. Based on this model, we have analyzed the performance of a rectangular duct ER or MR valve. Typical results include shear stress and velocity profiles across the valve gap, equivalent damping and damping coefficients.

Biorheological Model on Flow of Herschel-Bulkley Fluid through a Tapered Arterial Stenosis with Dilatation

Directory of Open Access Journals (Sweden)

S. Priyadharshini

2015-01-01

Full Text Available An analysis of blood flow through a tapered artery with stenosis and dilatation has been carried out where the blood is treated as incompressible Herschel-Bulkley fluid. A comparison between numerical values and analytical values of pressure gradient at the midpoint of stenotic region shows that the analytical expression for pressure gradient works well for the values of yield stress till 2.4. The wall shear stress and flow resistance increase significantly with axial distance and the increase is more in the case of converging tapered artery. A comparison study of velocity profiles, wall shear stress, and flow resistance for Newtonian, power law, Bingham-plastic, and Herschel-Bulkley fluids shows that the variation is greater for Herschel-Bulkley fluid than the other fluids. The obtained velocity profiles have been compared with the experimental data and it is observed that blood behaves like a Herschel-Bulkley fluid rather than power law, Bingham, and Newtonian fluids. It is observed that, in the case of a tapered stenosed tube, the streamline pattern follows a convex pattern when we move from r/R=0 to r/R=1 and it follows a concave pattern when we move from r/R=0 to r/R=-1. Further, it is of opposite behaviour in the case of a tapered dilatation tube which forms new information that is, for the first time, added to the literature.

HERSCHEL EXTREME LENSING LINE OBSERVATIONS: [C ii] VARIATIONS IN GALAXIES AT REDSHIFTS z = 1–3

Energy Technology Data Exchange (ETDEWEB)

Malhotra, Sangeeta; Rhoads, James E.; Yang, Huan [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Finkelstein, K.; Finkelstein, Steven [University of Texas, Austin, TX 78712 (United States); Carilli, Chris [National Radio Astronomy Observatory, Socorro, NM (United States); Combes, Françoise [Observatoire de Paris, LERMA, CNRS, 61 Avenue de l’Observatoire, F-75014 Paris (France); Dassas, Karine; Guillard, Pierre; Nesvadba, Nicole [Institut d’Astrophysique Spatiale, Centre Universitaire d’Orsay (France); Frye, Brenda [Steward Observatory, University of Arizona, Tucson, AZ (United States); Gerin, Maryvonne [LERMA,24 rue Lhomond, F-75231 Paris Cedex 05 (France); Rigby, Jane [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Shin, Min-Su [Oxford University, Oxford, OX1 3PA (United Kingdom); Spaans, Marco [Kapteyn Astronomical Institute, University of Groningen, Groningen (Netherlands); Strauss, Michael A. [Department of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton, NJ 08544 (United States); Papovich, Casey, E-mail: malhotra@asu.edu [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics, Texas A and M University, College Station, TX 77843 (United States)

2017-01-20

We observed the [C ii] line in 15 lensed galaxies at redshifts 1 < z < 3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3 σ or better. High magnifications enable even modestly luminous galaxies to be detected in [C ii] with Herschel . The [C ii] luminosity in this sample ranges from 8 × 10{sup 7} L {sub ⊙} to 3.7 × 10{sup 9} L {sub ⊙} (after correcting for magnification), confirming that [C ii] is a strong tracer of the ISM at high redshifts. The ratio of the [C ii] line to the total far-infrared (FIR) luminosity serves as a measure of the ratio of gas to dust cooling and thus the efficiency of the grain photoelectric heating process. It varies between 3.3% and 0.09%. We compare the [C ii]/FIR ratio to that of galaxies at z = 0 and at high redshifts and find that they follow similar trends. The [C ii]/FIR ratio is lower for galaxies with higher dust temperatures. This is best explained if increased UV intensity leads to higher FIR luminosity and dust temperatures, but gas heating does not rise due to lower photoelectric heating efficiency. The [C ii]/FIR ratio shows weaker correlation with FIR luminosity. At low redshifts highly luminous galaxies tend to have warm dust, so the effects of dust temperature and luminosity are degenerate. Luminous galaxies at high redshifts show a range of dust temperatures, showing that [C ii]/FIR correlates most strongly with dust temperature. The [C ii] to mid-IR ratio for the HELLO sample is similar to the values seen for low-redshift galaxies, indicating that small grains and PAHs dominate the heating in the neutral ISM, although some of the high [CII]/FIR ratios may be due to turbulent heating.

HERSCHEL EXTREME LENSING LINE OBSERVATIONS: [C ii] VARIATIONS IN GALAXIES AT REDSHIFTS z = 1–3

International Nuclear Information System (INIS)

Malhotra, Sangeeta; Rhoads, James E.; Yang, Huan; Finkelstein, K.; Finkelstein, Steven; Carilli, Chris; Combes, Françoise; Dassas, Karine; Guillard, Pierre; Nesvadba, Nicole; Frye, Brenda; Gerin, Maryvonne; Rigby, Jane; Shin, Min-Su; Spaans, Marco; Strauss, Michael A.; Papovich, Casey

2017-01-01

We observed the [C ii] line in 15 lensed galaxies at redshifts 1 < z < 3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3 σ or better. High magnifications enable even modestly luminous galaxies to be detected in [C ii] with Herschel . The [C ii] luminosity in this sample ranges from 8 × 10 7 L ⊙ to 3.7 × 10 9 L ⊙ (after correcting for magnification), confirming that [C ii] is a strong tracer of the ISM at high redshifts. The ratio of the [C ii] line to the total far-infrared (FIR) luminosity serves as a measure of the ratio of gas to dust cooling and thus the efficiency of the grain photoelectric heating process. It varies between 3.3% and 0.09%. We compare the [C ii]/FIR ratio to that of galaxies at z = 0 and at high redshifts and find that they follow similar trends. The [C ii]/FIR ratio is lower for galaxies with higher dust temperatures. This is best explained if increased UV intensity leads to higher FIR luminosity and dust temperatures, but gas heating does not rise due to lower photoelectric heating efficiency. The [C ii]/FIR ratio shows weaker correlation with FIR luminosity. At low redshifts highly luminous galaxies tend to have warm dust, so the effects of dust temperature and luminosity are degenerate. Luminous galaxies at high redshifts show a range of dust temperatures, showing that [C ii]/FIR correlates most strongly with dust temperature. The [C ii] to mid-IR ratio for the HELLO sample is similar to the values seen for low-redshift galaxies, indicating that small grains and PAHs dominate the heating in the neutral ISM, although some of the high [CII]/FIR ratios may be due to turbulent heating.

RAPID INFRARED VARIABILITY OF THREE RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES: A VIEW FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

Energy Technology Data Exchange (ETDEWEB)

Jiang Ning; Zhou Hongyan; Wang Tinggui; Dong Xiaobo; Jiang Peng [Key Laboratory for Research in Galaxies and Cosmology, University of Science and Technology of China, Chinese Academy of Science, Hefei, Anhui 230026 (China); Ho, Luis C. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Yuan Weimin [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Ji Tuo; Tian Qiguo, E-mail: jnac@mail.ustc.edu.cn [Polar Research Institute of China, 451 Jinqiao Road, Pudong, Shanghai 200136 (China)

2012-11-10

Using newly released data from the Wide-field Infrared Survey Explorer, we report the discovery of rapid infrared variability in three radio-loud narrow-line Seyfert 1 galaxies (NLS1s) selected from the 23 sources in the sample of Yuan et al. J0849+5108 and J0948+0022 clearly show intraday variability, while J1505+0326 has a longer measurable timescale within 180 days. Their variability amplitudes, corrected for measurement errors, are {approx}0.1-0.2 mag. The detection of intraday variability restricts the size of the infrared-emitting region to {approx}10{sup -3} pc, significantly smaller than the scale of the torus but consistent with the base of a jet. The three variable sources are exceptionally radio-loud, have the highest radio brightness temperature among the whole sample, and all show detected {gamma}-ray emission in Fermi/LAT observations. Their spectral energy distributions resemble those of low-energy-peaked blazars, with a synchrotron peak around infrared wavelengths. This result strongly confirms the view that at least some radio-loud NLS1s are blazars with a relativistic jet close to our line of sight. The beamed synchrotron emission from the jet contributes significantly to and probably dominates the spectra in the infrared and even optical bands.

Spitzer sage survey of the large magellanic cloud. II. Evolved stars and infrared color-magnitude diagrams

NARCIS (Netherlands)

Blum, R. D.; Mould, J. R.; Olsen, K. A.; Frogel, J. A.; Meixner, M.; Markwick-Kemper, F.; Indebetouw, R.; Whitney, B.; Meade, M.; Babler, B.; Churchwell, E. B.; Gordon, K.; Engelbracht, C.; For, B. -Q.; Misselt, K.; Vijh, U.; Leitherer, C.; Volk, K.; Points, S.; Reach, W.; Hora, J. L.; Bernard, J. -P.; Boulanger, F.; Bracker, S.; Cohen, M.; Fukui, Y.; Gallagher, J.; Gorjian, V.; Harris, J.; Kelly, D.; Kawamura, A.; Latter, W. B.; Madden, S.; Mizuno, A.; Mizuno, N.; Oey, M. S.; Onishi, T.; Paladini, R.; Panagia, N.; Perez-Gonzalez, P.; Shibai, H.; Sato, S.; Smith, L.; Staveley-Smith, L.; Tielens, A.G.G.M; Ueta, T.; Van Dyk, S.; Zaritsky, D.; Werner, M.J.

Color-magnitude diagrams (CMDs) are presented for the Spitzer SAGE (Surveying the Agents of a Galaxy's Evolution) survey of the Large Magellanic Cloud (LMC). IRAC and MIPS 24 mu m epoch 1 data are presented. These data represent the deepest, widest mid-infrared CMDs of their kind ever produced in

Calibration of the Herschel SPIRE Fourier Transform Spectrometer

OpenAIRE

Swinyard, Bruce; Polehampton, E. T.; Hopwood, R.; Valtchanov, I.; Lu, N.; Fulton, T.; Benielli, D.; Imhof, P.; Marchili, N.; Baluteau, J.- P.; Bendo, G. J.; Ferlet, M.; Griffin, Matthew Jason; Lim, T. L.; Makiwa, G.

2014-01-01

The Herschel Spectral and Photometric REceiver (SPIRE) instrument consists of an imaging photometric camera and an imaging Fourier Transform Spectrometer (FTS), both operating over a frequency range of ∼450–1550 GHz. In this paper, we briefly review the FTS design, operation, and data reduction, and describe in detail the approach taken to relative calibration (removal of instrument signatures) and absolute calibration against standard astronomical sources. The calibration scheme assumes a sp...

Discovery of three z > 6.5 quasars in the VISTA kilo-degree infrared galaxy (VIKING) survey

Energy Technology Data Exchange (ETDEWEB)

Venemans, B. P. [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Findlay, J. R. [Department of Physics, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Sutherland, W. J. [Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, London, E1 4NS (United Kingdom); De Rosa, G. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); McMahon, R. G.; González-Solares, E. A.; Lewis, J. R. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Simcoe, R. [MIT-Kavli Center for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Kuijken, K., E-mail: venemans@mpia.de [Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands)

2013-12-10

Studying quasars at the highest redshifts can constrain models of galaxy and black hole formation, and it also probes the intergalactic medium in the early universe. Optical surveys have to date discovered more than 60 quasars up to z ≅ 6.4, a limit set by the use of the z-band and CCD detectors. Only one z ≳ 6.4 quasar has been discovered, namely the z = 7.08 quasar ULAS J1120+0641, using near-infrared imaging. Here we report the discovery of three new z ≳ 6.4 quasars in 332 deg{sup 2} of the Visible and Infrared Survey Telescope for Astronomy Kilo-degree Infrared Galaxy (VIKING) survey, thus extending the number from 1 to 4. The newly discovered quasars have redshifts of z = 6.60, 6.75, and 6.89. The absolute magnitudes are between –26.0 and –25.5, 0.6-1.1 mag fainter than ULAS J1120+0641. Near-infrared spectroscopy revealed the Mg II emission line in all three objects. The quasars are powered by black holes with masses of ∼(1-2) × 10{sup 9} M {sub ☉}. In our probed redshift range of 6.44 < z < 7.44 we can set a lower limit on the space density of supermassive black holes of ρ(M {sub BH} > 10{sup 9} M {sub ☉}) > 1.1 × 10{sup –9} Mpc{sup –3}. The discovery of three quasars in our survey area is consistent with the z = 6 quasar luminosity function when extrapolated to z ∼ 7. We do not find evidence for a steeper decline in the space density of quasars with increasing redshift from z = 6 to z = 7.

IPHAS A-TYPE STARS WITH MID-INFRARED EXCESSES IN SPITZER SURVEYS

International Nuclear Information System (INIS)

Hales, Antonio S.; Barlow, Michael J.; Drew, Janet E.; Unruh, Yvonne C.; Greimel, Robert; Irwin, Michael J.; Gonzalez-Solares, Eduardo

2009-01-01

We have identified 17 A-type stars in the Galactic Plane that have mid-infrared (mid-IR) excesses at 8 μm. From observed colors in the (r' - Hα) - (r' - i') plane, we first identified 23,050 early A-type main-sequence (MS) star candidates in the Isaac Newton Photometric H-Alpha Survey (IPHAS) point source database that are located in Spitzer Galactic Legacy Mid-Plane Survey Extraordinaire Galactic plane fields. Imposing the requirement that they be detected in all seven Two Micron All Sky Survey and Infrared Astronomical Satellite bands led to a sample of 2692 candidate A-type stars with fully sampled 0.6 to 8 μm spectral energy distributions (SEDs). Optical classification spectra of 18 of the IPHAS candidate A-type MS stars showed that all but one could be well fitted using MS A-type templates, with the other being an A-type supergiant. Out of the 2692 A-type candidates 17 (0.6%) were found to have 8 μm excesses above the expected photospheric values. Taking into account non-A-Type contamination estimates, the 8 μm excess fraction is adjusted to ∼0.7%. The distances to these sources range from 0.7 to 2.5 kpc. Only 10 out of the 17 excess stars had been covered by Spitzer MIPSGAL survey fields, of which five had detectable excesses at 24 μm. For sources with excesses detected in at least two mid-IR wavelength bands, blackbody fits to the excess SEDs yielded temperatures ranging from 270 to 650 K, and bolometric luminosity ratios L IR /L * from 2.2 x 10 -3 - 1.9 x 10 -2 , with a mean value of 7.9 x 10 -3 (these bolometric luminosities are lower limits as cold dust is not detectable by this survey). Both the presence of mid-IR excesses and the derived bolometric luminosity ratios are consistent with many of these systems being in the planet-building transition phase between the early protoplanetary disk phase and the later debris disk phase.

Spray Formation of Herschel-Bulkley Fluids using Impinging Jets

Science.gov (United States)

Rodrigues, Neil; Gao, Jian; Chen, Jun; Sojka, Paul E.

2015-11-01

The impinging jet spray formation of two non-Newtonian, shear-thinning, Herschel-Bulkley fluids was investigated in this work. The water-based gelled solutions used were 1.0 wt.-% agar and 1.0 wt.-% kappa carrageenan. A rotational rheometer and a capillary viscometer were used to measure the strain-rate dependency of viscosity and the Herschel-Bulkley Extended (HBE) rheological model was used to characterize the shear-thinning behavior. A generalized HBE jet Reynolds number Rej , gen - HBE was used as the primary parameter to characterize the spray formation. A like-on-like impinging jet doublet was used to produce atomization. Shadowgraphs were captured in the plane of the sheet formed by the two jets using a CCD camera with an Nd:YAG laser beam providing the back-illumination. Typical behavior for impinging jet atomization using Newtonian liquids was not generally observed due to the non-Newtonian, viscous properties of the agar and kappa carrageenan gels. Instead various spray patterns were observed depending on Rej , gen - HBE. Spray characteristics of maximum instability wavelength and sheet breakup length were extracted from the shadowgraphs. Multi-University Research Initiative Grant Number W911NF-08-1-0171.

HERSCHEL MEASUREMENTS OF MOLECULAR OXYGEN IN ORION

International Nuclear Information System (INIS)

Goldsmith, Paul F.; Chen, Jo-Hsin; Li Di; Liseau, Rene; Black, John H.; Bell, Tom A.; Hollenbach, David; Kaufman, Michael J.; Lis, Dariusz C.; Melnick, Gary; Neufeld, David; Pagani, Laurent; Encrenaz, Pierre; Snell, Ronald; Benz, Arnold O.; Bruderer, Simon; Bergin, Edwin; Caselli, Paola; Caux, Emmanuel; Falgarone, Edith

2011-01-01

We report observations of three rotational transitions of molecular oxygen (O 2 ) in emission from the H 2 Peak 1 position of vibrationally excited molecular hydrogen in Orion. We observed the 487 GHz, 774 GHz, and 1121 GHz lines using the Heterodyne Instrument for the Far Infrared on the Herschel Space Observatory, having velocities of 11 km s -1 to 12 km s -1 and widths of 3 km s -1 . The beam-averaged column density is N(O 2 ) = 6.5 x 10 16 cm -2 , and assuming that the source has an equal beam-filling factor for all transitions (beam widths 44, 28, and 19''), the relative line intensities imply a kinetic temperature between 65 K and 120 K. The fractional abundance of O 2 relative to H 2 is (0.3-7.3) x 10 -6 . The unusual velocity suggests an association with a ∼5'' diameter source, denoted Peak A, the Western Clump, or MF4. The mass of this source is ∼10 M sun and the dust temperature is ≥150 K. Our preferred explanation of the enhanced O 2 abundance is that dust grains in this region are sufficiently warm (T ≥ 100 K) to desorb water ice and thus keep a significant fraction of elemental oxygen in the gas phase, with a significant fraction as O 2 . For this small source, the line ratios require a temperature ≥180 K. The inferred O 2 column density ≅5 x 10 18 cm -2 can be produced in Peak A, having N(H 2 ) ≅ 4 x 10 24 cm -2 . An alternative mechanism is a low-velocity (10-15 km s -1 ) C-shock, which can produce N(O 2 ) up to 10 17 cm -2 .

GNIRS-DQS: A Gemini Near Infrared Spectrograph Distant Quasar Survey

Science.gov (United States)

Matthews, Brandon; Shemmer, Ohad; Brotherton, Michael S.; Andruchow, Ileana; Boroson, Todd A.; Brandt, W. Niel; Cellone, Sergio; Ferrero, Gabriel; Gallagher, Sarah; Green, Richard F.; Hennawi, Joseph F.; Lira, Paulina; Myers, Adam D.; Plotkin, Richard; Richards, Gordon T.; Runnoe, Jessie; Schneider, Donald P.; Shen, Yue; Strauss, Michael A.; Willott, Chris J.; Wills, Beverley J.

2018-06-01

We describe an ongoing three-year Gemini survey, launched in 2017, that will obtain near-infrared spectroscopy of 416 Sloan Digital Sky Survey (SDSS) quasars between redshifts of 1.5 and 3.5 in the ~1.0-2.5 μm band. These spectra will cover critical diagnostic emission lines, such as Mg II, Hβ, and [O III], in each source. This project will more than double the existing inventory of near-infrared spectra of luminous quasars at these redshifts, including the era of fast quasar growth. Additional rest frame ultraviolet coverage of at least the C IV emission line is provided by the SDSS spectrum of each source. We will utilize the spectroscopic inventory to determine the most accurate and precise quasar black hole masses, accretion rates, and redshifts, and use the results to derive improved prescriptions for UV-based proxies for these parameters. The improved redshifts will establish velocities of quasar outflows that interact with the host galaxies, and will help constrain how imprecise distance estimates bias quasar clustering measurements. Furthermore, our measurements will facilitate a more complete understanding of how the rest-frame UV-optical spectral properties depend on redshift and luminosity, and test whether the physical properties of the quasar central engine evolve over cosmic time. We will make our data immediately available to the public, provide reduced spectra via a dedicated website, and produce a catalog of measurements and fundamental quasar properties.

WARM MOLECULAR GAS IN LUMINOUS INFRARED GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Lu, N.; Zhao, Y.; Xu, C. K.; Mazzarella, J. M.; Howell, J.; Appleton, P.; Lord, S.; Schulz, B. [Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Armus, L.; Díaz-Santos, T.; Surace, J. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Isaak, K. G. [ESA Astrophysics Missions Division, ESTEC, P.O. Box 299, 2200-AG Noordwijk (Netherlands); Petric, A. O. [Gemini Observatory, 670 N. A' ohoku Place, Hilo, HI 96720 (United States); Charmandaris, V. [Department of Physics, University of Crete, GR-71003 Heraklion (Greece); Evans, A. S. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Inami, H. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Iwasawa, K. [ICREA and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Martí i Franquès 1, E-08028 Barcelona (Spain); Leech, J. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Sanders, D. B., E-mail: lu@ipac.caltech.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); and others

2014-06-01

We present our initial results on the CO rotational spectral line energy distribution (SLED) of the J to J–1 transitions from J = 4 up to 13 from Herschel SPIRE spectroscopic observations of 65 luminous infrared galaxies (LIRGs) in the Great Observatories All-Sky LIRG Survey. The observed SLEDs change on average from one peaking at J ≤ 4 to a broad distribution peaking around J ∼ 6 to 7 as the IRAS 60-to-100 μm color, C(60/100), increases. However, the ratios of a CO line luminosity to the total infrared luminosity, L {sub IR}, show the smallest variation for J around 6 or 7. This suggests that, for most LIRGs, ongoing star formation (SF) is also responsible for a warm gas component that emits CO lines primarily in the mid-J regime (5 ≲ J ≲ 10). As a result, the logarithmic ratios of the CO line luminosity summed over CO (5–4), (6–5), (7–6), (8–7) and (10–9) transitions to L {sub IR}, log R {sub midCO}, remain largely independent of C(60/100), and show a mean value of –4.13 (≡log R{sub midCO}{sup SF}) and a sample standard deviation of only 0.10 for the SF-dominated galaxies. Including additional galaxies from the literature, we show, albeit with a small number of cases, the possibility that galaxies, which bear powerful interstellar shocks unrelated to the current SF, and galaxies, in which an energetic active galactic nucleus contributes significantly to the bolometric luminosity, have their R {sub midCO} higher and lower than R{sub midCO}{sup SF}, respectively.

Computer-aided discovery of debris disk candidates: A case study using the Wide-Field Infrared Survey Explorer (WISE) catalog

Science.gov (United States)

Nguyen, T.; Pankratius, V.; Eckman, L.; Seager, S.

2018-04-01

Debris disks around stars other than the Sun have received significant attention in studies of exoplanets, specifically exoplanetary system formation. Since debris disks are major sources of infrared emissions, infrared survey data such as the Wide-Field Infrared Survey (WISE) catalog potentially harbors numerous debris disk candidates. However, it is currently challenging to perform disk candidate searches for over 747 million sources in the WISE catalog due to the high probability of false positives caused by interstellar matter, galaxies, and other background artifacts. Crowdsourcing techniques have thus started to harness citizen scientists for debris disk identification since humans can be easily trained to distinguish between desired artifacts and irrelevant noises. With a limited number of citizen scientists, however, increasing data volumes from large surveys will inevitably lead to analysis bottlenecks. To overcome this scalability problem and push the current limits of automated debris disk candidate identification, we present a novel approach that uses citizen science results as a seed to train machine learning based classification. In this paper, we detail a case study with a computer-aided discovery pipeline demonstrating such feasibility based on WISE catalog data and NASA's Disk Detective project. Our approach of debris disk candidates classification was shown to be robust under a wide range of image quality and features. Our hybrid approach of citizen science with algorithmic scalability can facilitate big data processing for future detections as envisioned in future missions such as the Transiting Exoplanet Survey Satellite (TESS) and the Wide-Field Infrared Survey Telescope (WFIRST).

Introductory survey for wireless infrared communications

Directory of Open Access Journals (Sweden)

Munsif Ali Jatoi

2014-08-01

Full Text Available Wireless infrared communications can be defined as the propagation of light waves in free space using infrared radiation whose range is 400–700 nm. This range corresponds to frequencies of hundreds of terahertz, which is high for higher data rate applications. Wireless infrared is applied for higher data rates applications such as wireless computing, wireless video and wireless multimedia communication applications. Introduced by Gfeller, this field has grown with different link configurations, improved transmitter efficiency, increased receiver responsivity and various multiple access techniques for improved quality. Errors are caused because of background light, which causes degradation overall system performance. Error correction techniques are used to remove the errors caused during transmission. This study provides a brief account on field theory used for error correction in wireless infrared systems. The results are produced in terms of bit error rate and signal-to-noise ratio for various bit lengths to show the ability of encoding and decoding algorithms.

Herschel/SPIRE observations of the dusty disk of NGC 4244

NARCIS (Netherlands)

Holwerda, B. W.; Bianchi, S.; Boker, T.; Radburn-Smith, D.; de Jong, R. S.; Baes, M.; van der Kruit, P. C.; Xilouris, M.; Gordon, K. D.; Dalcanton, J. J.

We present Herschel/SPIRE images at 250, 350, and 500 mu m of NGC 4244, a typical low-mass, disk-only and edge-on spiral galaxy. The dust disk is clumpy and shows signs of truncation at the break radius of the stellar disk. This disk coincides with the densest part of the Hi disk. We compare the

White Dwarfs in the UKIRT Infrared Deep Sky Survey Data Release 9

Science.gov (United States)

Tremblay, P.-E.; Leggett, S. K.; Lodieu, N.; Freytag, B.; Bergeron, P.; Kalirai, J. S.; Ludwig, H.-G.

2014-06-01

We have identified 8 to 10 new cool white dwarfs from the Large Area Survey (LAS) Data Release 9 of the United Kingdom InfraRed Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS). The data set was paired with the Sloan Digital Sky Survey to obtain proper motions and a broad ugrizYJHK wavelength coverage. Optical spectroscopic observations were secured at Gemini Observatory and confirm the degenerate status for eight of our targets. The final sample includes two additional white dwarf candidates with no spectroscopic observations. We rely on improved one-dimensional model atmospheres and new multi-dimensional simulations with CO5BOLD to review the stellar parameters of the published LAS white dwarf sample along with our additional discoveries. Most of the new objects possess very cool atmospheres with effective temperatures below 5000 K, including two pure-hydrogen remnants with a cooling age between 8.5 and 9.0 Gyr, and tangential velocities in the range 40 km s-1 3.0 and 5.0 Gyr. These white dwarfs could be disk remnants with a very high velocity or former halo G stars. We also compare the LAS sample with earlier studies of very cool degenerates and observe a similar deficit of helium-dominated atmospheres in the range 5000 < T eff (K) < 6000. We review the possible explanations for the spectral evolution from helium-dominated toward hydrogen-rich atmospheres at low temperatures.

High resolution far-infrared survey of A section of the galactic plane. I. The nature of the sources

International Nuclear Information System (INIS)

Jaffe, D.T.; Stier, M.T.; Fazio, G.G.

1982-01-01

We have surveyed a 7.5 deg 2 portion of the galactic plane between l/sup II/ = 10 0 and l/sup II/ = 16 0 at 70 μm with a 1' beam. We present far-infrared, radio continuum, and 12 CO and 13 CO line observations of the 42 far-infrared sources in the survey region. The sources range in luminosity from 4 x 10 3 to 3 x 10 6 L/sub sun/. Most are associated with 12 CO peaks. More than half of the sources have associated H 2 O maser emission. Half have associated radio continuum emission at a limit of 100 mJy. Eight sources have radio emission at weaker levels. In a number of cases, the far-infrared source is smaller than its associated radio source. This difference can be explained in the context of the ''blister'' picture of H II regions. One group of sources emits many fewer Lyman continuum photons than expected, given the far-infrared luminosities. We examine a number of possible reasons for this and conclude that the most reasonable explanation is that clusters of early type stars rather than single stars excite the far-infrared sources. We examine the energetics in the molecular clouds surrounding the infrared sources and conclude that the sources could supply the energy to explain the observed temperature structure and velocity field in the molecular gas

White dwarfs in the UKIRT infrared deep sky survey data release

International Nuclear Information System (INIS)

Tremblay, P.-E.; Kalirai, J. S.; Leggett, S. K.; Lodieu, N.; Freytag, B.; Bergeron, P.; Ludwig, H.-G.

2014-01-01

We have identified 8 to 10 new cool white dwarfs from the Large Area Survey (LAS) Data Release 9 of the United Kingdom InfraRed Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS). The data set was paired with the Sloan Digital Sky Survey to obtain proper motions and a broad ugrizYJHK wavelength coverage. Optical spectroscopic observations were secured at Gemini Observatory and confirm the degenerate status for eight of our targets. The final sample includes two additional white dwarf candidates with no spectroscopic observations. We rely on improved one-dimensional model atmospheres and new multi-dimensional simulations with CO5BOLD to review the stellar parameters of the published LAS white dwarf sample along with our additional discoveries. Most of the new objects possess very cool atmospheres with effective temperatures below 5000 K, including two pure-hydrogen remnants with a cooling age between 8.5 and 9.0 Gyr, and tangential velocities in the range 40 km s –1 ≤v tan ≤ 60 km s –1 . They are likely thick disk 10-11 Gyr old objects. In addition, we find a resolved double degenerate system with v tan ∼ 155 km s –1 and a cooling age between 3.0 and 5.0 Gyr. These white dwarfs could be disk remnants with a very high velocity or former halo G stars. We also compare the LAS sample with earlier studies of very cool degenerates and observe a similar deficit of helium-dominated atmospheres in the range 5000 < T eff (K) < 6000. We review the possible explanations for the spectral evolution from helium-dominated toward hydrogen-rich atmospheres at low temperatures.

WINGS: WFIRST Infrared Nearby Galaxy Survey

Science.gov (United States)

Williams, Benjamin

WFIRST's combination of wide field and high resolution will revolutionize the study of nearby galaxies. We propose to produce and analyze simulated WFIRST data of nearby galaxies and their halos to maximize the scientific yield in the limited observing time available, ensuring the legacy value of WFIRST's eventual archive. We will model both halo structure and resolved stellar populations to optimize WFIRST's constraints on both dark matter and galaxy formation models in the local universe. WFIRST can map galaxy structure down to ~35 mag/square arcsecond using individual stars. The resulting maps of stellar halos and accreting dwarf companions will provide stringent tests of galaxy formation and dark matter models on galactic (and even sub-galactic) scales, which is where the most theoretical tension exists with the Lambda-CDM model. With a careful, coordinated plan, WFIRST can be expected to improve current sample sizes by 2 orders of magnitude, down to surface brightness limits comparable to those currently reached only in the Local Group, and that are >4 magnitudes fainter than achievable from the ground due to limitations in star-galaxy separation. WFIRST's maps of galaxy halos will simultaneously produce photometry for billions of stars in the main bodies of galaxies within 10 Mpc. These data will transform studies of star formation histories that track stellar mass growth as a function of time and position within a galaxy. They also will constrain critical stellar evolution models of the near-infrared bright, rapidly evolving stars that can contribute significantly to the integrated light of galaxies in the near-infrared. Thus, with WFIRST we can derive the detailed evolution of individual galaxies, reconstruct the complete history of star formation in the nearby universe, and put crucial constraints on the theoretical models used to interpret near-infrared extragalactic observations. We propose a three-component work plan that will ensure these gains by

THE SPITZER INFRARED NEARBY GALAXIES SURVEY: A HIGH-RESOLUTION SPECTROSCOPY ANTHOLOGY

International Nuclear Information System (INIS)

Dale, D. A.; Schlawin, E. A.; Cohen, S. A.; Johnson, L. C.; Staudaher, S.; Smith, J. D. T.; Armus, L.; Helou, G.; Jarrett, T. H.; Murphy, E. J.; Sheth, K.; Buckalew, B. A.; Moustakas, J.; Roussel, H.; Bot, C.; Calzetti, D.; Engelbracht, C. W.; Gordon, K. D.; Hollenbach, D. J.; Kennicutt, R. C.

2009-01-01

High-resolution mid-infrared spectra are presented for 155 nuclear and extranuclear regions from the Spitzer Infrared Nearby Galaxies Survey (SINGS). The fluxes for nine atomic forbidden and three molecular hydrogen mid-infrared emission lines are also provided, along with upper limits in key lines for infrared-faint targets. The SINGS sample shows a wide range in the ratio of [S III] 18.71 μm/[S III] 33.48 μm, but the average ratio of the ensemble indicates a typical interstellar electron density of 300-400 cm -3 on ∼23'' x 15'' scales and 500-600 cm -3 using ∼11'' x 9'' apertures, independent of whether the region probed is a star-forming nuclear, a star-forming extranuclear, or an active galactic nuclei (AGN) environment. Evidence is provided that variations in gas-phase metallicity play an important role in driving variations in radiation field hardness, as indicated by [Ne III] 15.56 μm/[Ne II] 12.81 μm, for regions powered by star formation. Conversely, the radiation hardness for galaxy nuclei powered by accretion around a massive black hole is independent of metal abundance. Furthermore, for metal-rich environments AGN are distinguishable from star-forming regions by significantly larger [Ne III] 15.56 μm/[Ne II] 12.81 μm ratios. Finally, [Fe II] 25.99 μm/[Ne II] 12.81 μm versus [Si II] 34.82 μm/[S III] 33.48 μm also provides an empirical method for discerning AGN from normal star-forming sources. However, similar to [Ne III] 15.56 μm/[Ne II] 12.81 μm, these mid-infrared line ratios lose their AGN/star-formation diagnostic powers for very low metallicity star-forming systems with hard radiation fields.

Comparison of star formation rates from Hα and infrared luminosity as seen by Herschel

NARCIS (Netherlands)

Domínguez Sánchez, H.; Mignoli, M.; Pozzi, F.; Calura, F.; Cimatti, A.; Gruppioni, C.; Cepa, J.; Sánchez Portal, M.; Zamorani, G.; Berta, S.; Elbaz, D.; Le Floc'h, E.; Granato, G. L.; Lutz, D.; Maiolino, R.; Matteucci, F.; Nair, P.; Nordon, R.; Pozzetti, L.; Silva, L.; Silverman, J.; Wuyts, S.; Carollo, C. M.; Contini, T.; Kneib, J. -P; Le Fèvre, O.; Lilly, S. J.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Bardelli, S.; Bolzonella, M.; Bongiorno, A.; Caputi, K.; Coppa, G.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovač, K.; Lamareille, F.; Le Borgne, J. -F; Le Brun, V.; Maier, C.; Magnelli, B.; Pelló, R.; Peng, Y.; Perez-Montero, E.; Ricciardelli, E.; Riguccini, L.; Tanaka, M.; Tasca, L. A. M.; Tresse, L.; Vergani, D.; Zucca, E.

2012-01-01

We empirically MD test the relation between the SFR(LIR) derived from the infrared luminosity, LIR, and the SFR(Ha) derived from the Ha emission line luminosity using simple conversion relations. We use a sample of 474 galaxies at z = 0.060.46 with both Ha detection [from 20k redshift Cosmological

Enabling Velocity-Resolved Science with Advanced Processing of Herschel/HIFI Observations

Science.gov (United States)

Morris, Patrick

an effort lead at the NASA Herschel Science Center, and delivered in November 2016 to the NASA InfraRed Science Archive (IRSA) and the HSA where they are available to the community. Due to limited resources, this effort could not cover the full list of observations in need of interactive treatments. We are proposing to cover that final set observations (spectral maps and a selection of spectral scans and point observations) in a project spread over 2 years with 0.5 FTE funding, for a guaranteed set of phased deliverables produced with optimized quality at high efficiency using expert processing and delivery procedures already in place. This effort will tackle the quality-degrading artifacts which could not be corrected in the automatic pipeline -- and becoming more and more remote for potential users to correct on their own even with scripted guidance. The expectation is that the huge investments by the funding agencies, and the successful operations of the observatory meeting and often exceeding performance requirements, can be returned to the maximum scientific extent possible. We can guarantee some of that scientific return, in a study of fundamental carbon chemistry in energetic star forming regions, using the proposed HPDPs from unpublished and partially unexploited HIFI data to probe UV- and shockdriven chemistries to explain an unexpected deficiency of C+ in the Orion KL eruptive outflow. We will test a hypothesis that C+ is depleted by production of CO rather than CH+, through a chain of reactions involving intermediate products suited to the molecular environment.

Herschel OBSERVATIONS OF DUST AROUND THE HIGH-MASS X-RAY BINARY GX 301-2

Energy Technology Data Exchange (ETDEWEB)

Servillat, M. [Laboratoire Univers et Théories (CNRS/INSU, Observatoire de Paris, Université Paris Diderot), 5 place Jules Janssen, F-92190 Meudon (France); Coleiro, A.; Chaty, S. [Laboratoire AIM (CEA/Irfu/SAp, CNRS/INSU, Universit Paris Diderot), CEA Saclay, Bat. 709, F-91191 Gif-sur-Yvette (France); Rahoui, F. [Harvard University, Department of Astronomy, 60 Garden Street, Cambridge, MA 02138 (United States); Zurita Heras, J. A., E-mail: mathieu.servillat@obspm.fr [AstroParticule et Cosmologie (Université Paris Diderot, CNRS/IN2P3, CEA/DSM, Observatoire de Paris, Sorbonne Paris Cité), 10 rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13 (France)

2014-12-20

We aim at characterizing the structure of the gas and dust around the high-mass X-ray binary GX 301-2, a highly obscured X-ray binary hosting a hypergiant (HG) star and a neutron star, in order to better constrain its evolution. We used Herschel PACS to observe GX 301-2 in the far infrared and completed the spectral energy distribution of the source using published data or catalogs from the optical to the radio range (0.4 to 4 × 10{sup 4} μm). GX 301-2 is detected for the first time at 70 and 100 μm. We fitted different models of circumstellar (CS) environments to the data. All tested models are statistically acceptable, and consistent with an HG star at ∼3 kpc. We found that the addition of a free-free emission component from the strong stellar wind is required and could dominate the far-infrared flux. Through comparisons with similar systems and discussion on the estimated model parameters, we favor a disk-like CS environment of ∼8 AU that would enshroud the binary system. The temperature goes down to ∼200 K at the edge of the disk, allowing for dust formation. This disk is probably a rimmed viscous disk with an inner rim at the temperature of the dust sublimation temperature (∼1500 K). The similarities between the HG GX 301-2, B[e] supergiants, and the highly obscured X-ray binaries (particularly IGR J16318-4848) are strengthened. GX 301-2 might represent a transition stage in the evolution of massive stars in binary systems, connecting supergiant B[e] systems to luminous blue variables.

MODELS OF THE η CORVI DEBRIS DISK FROM THE KECK INTERFEROMETER, SPITZER, AND HERSCHEL

Energy Technology Data Exchange (ETDEWEB)

Lebreton, J.; Beichman, C.; Millan-Gabet, R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Bryden, G.; Mennesson, B. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91107 (United States); Defrère, D. [Department of Astronomy, University of Arizona, 993 N. Cherry Avenue, Tucson, AZ, 85721 (United States); Boccaletti, A., E-mail: lebretoj@gmail.com [LESIA, Observatoire de Paris, CNRS, University Pierre et Marie Curie Paris 6 and University Denis Diderot Paris 7, 5 place Jules Janssen, F-92195 Meudon (France)

2016-02-01

Debris disks are signposts of analogs to small-body populations of the solar system, often, however, with much higher masses and dust production rates. The disk associated with the nearby star η Crv is especially striking, as it shows strong mid- and far-infrared excesses despite an age of ∼1.4 Gyr. We undertake constructing a consistent model of the system that can explain a diverse collection of spatial and spectral data. We analyze Keck Interferometer Nuller measurements and revisit Spitzer and additional spectrophotometric data, as well as resolved Herschel images, to determine the dust spatial distribution in the inner exozodi and in the outer belt. We model in detail the two-component disk and the dust properties from the sub-AU scale to the outermost regions by fitting simultaneously all measurements against a large parameter space. The properties of the cold belt are consistent with a collisional cascade in a reservoir of ice-free planetesimals at 133 AU. It shows marginal evidence for asymmetries along the major axis. KIN enables us to establish that the warm dust consists of a ring that peaks between 0.2 and 0.8 AU. To reconcile this location with the ∼400 K dust temperature, very high albedo dust must be invoked, and a distribution of forsterite grains starting from micron sizes satisfies this criterion, while providing an excellent fit to the spectrum. We discuss additional constraints from the LBTI and near-infrared spectra, and we present predictions of what James Webb Space Telescope can unveil about this unusual object and whether it can detect unseen planets.

Discoverers of the universe William and Caroline Herschel

CERN Document Server

Hoskin, Michael

2011-01-01

Discoverers of the Universe tells the gripping story of William Herschel, the brilliant, fiercely ambitious, emotionally complex musician and composer who became court astronomer to Britain's King George III, and of William's sister, Caroline, who assisted him in his observations of the night sky and became an accomplished astronomer in her own right. Together, they transformed our view of the universe from the unchanging, mechanical creation of Newton's clockmaker god to the ever-evolving, incredibly dynamic cosmos that it truly is. William was in his forties when his amateur observations usi

THE 31 DEG{sup 2} RELEASE OF THE STRIPE 82 X-RAY SURVEY: THE POINT SOURCE CATALOG

Energy Technology Data Exchange (ETDEWEB)

LaMassa, Stephanie M.; Urry, C. Megan; Ananna, Tonima; Civano, Francesca; Marchesi, Stefano; Pecoraro, Robert [Yale Center for Astronomy and Astrophysics, Physics Department, P.O. Box 208120, New Haven, CT 06520 (United States); Cappelluti, Nico; Comastri, Andrea; Brusa, Marcella [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Böhringer, Hans; Chon, Gayoung [Max-Planck-Institut für extraterrestrische Physik, D-85748 Garching (Germany); Glikman, Eilat [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States); Richards, Gordon [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Cardamone, Carie [Department of Math and Science, Wheelock College, 200 Riverway, Boston, MA 02215 (United States); Farrah, Duncan [Department of Physics MC 0435, Virginia Polytechnic Institute and State University, 850 West Campus Drive, Blacksburg, VA 24061 (United States); Gilfanov, Marat [Max-Planck Institut für Astrophysik, Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741 Garching (Germany); Green, Paul [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Komossa, S. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Lira, Paulina [Departamento de Astronomia, Universidad de Chile, Camino del Observatorio 1515, Santiago (Chile); Makler, Martin [Centro Brasileiro de Pesquisas Fisicas, Rua Dr Xavier Sigaud 150, Rio de Janeiro, RJ 22290-180 (Brazil); and others

2016-02-01

We release the next installment of the Stripe 82 X-ray survey point-source catalog, which currently covers 31.3 deg{sup 2} of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are significantly detected with XMM-Newton (>5σ) and Chandra (>4.5σ). This catalog release includes data from XMM-Newton cycle AO 13, which approximately doubled the Stripe 82X survey area. The flux limits of the Stripe 82X survey are 8.7 × 10{sup −16} erg s{sup −1} cm{sup −2}, 4.7 × 10{sup −15} erg s{sup −1} cm{sup −2}, and 2.1 × 10{sup −15} erg s{sup −1} cm{sup −2} in the soft (0.5–2 keV), hard (2–10 keV), and full bands (0.5–10 keV), respectively, with approximate half-area survey flux limits of 5.4 × 10{sup −15} erg s{sup −1} cm{sup −2}, 2.9 × 10{sup −14} erg s{sup −1} cm{sup −2}, and 1.7 × 10{sup −14} erg s{sup −1} cm{sup −2}. We matched the X-ray source lists to available multi-wavelength catalogs, including updated matches to the previous release of the Stripe 82X survey; 88% of the sample is matched to a multi-wavelength counterpart. Due to the wide area of Stripe 82X and rich ancillary multi-wavelength data, including coadded SDSS photometry, mid-infrared WISE coverage, near-infrared coverage from UKIDSS and VISTA Hemisphere Survey, ultraviolet coverage from GALEX, radio coverage from FIRST, and far-infrared coverage from Herschel, as well as existing ∼30% optical spectroscopic completeness, we are beginning to uncover rare objects, such as obscured high-luminosity active galactic nuclei at high-redshift. The Stripe 82X point source catalog is a valuable data set for constraining how this population grows and evolves, as well as for studying how they interact with the galaxies in which they live.

William Herschel during the 1780-1810 era: A natural historian studies "maturation" of stars over immeasurable time

Science.gov (United States)

Sullivan, Woody

2015-01-01

(A) William Herschel (1738-1822) considered himself a natural historian, different only from the usual natural historians in that his focus was on stars and nebulae rather than plants, animals, and minerals. In this regard, he developed ideas concerning changes over very long times, inferred from his catalogues of 2500 star clusters and nebulae. By assuming that all the observed types of star clusters and morphologies of nebulae represented different stages in the formation of stars and clusters under the action of gravity, Herschel argued for a sequence of "maturation," or evolution as we would call it. He could put no definite time scale on these dynamic processes, but inspired by contemporary geologists such as James Hutton and John Michell (yes, he was a geologist, too!), he felt that the time scales must be very long. In further support, he photometrically estimated that the very faintest stars that he could see in his giant 40-ft telescope were about two million light-years distant. Herschel's findings on the structure and age of the Milky Way system, his "construction of the heavens," were also influenced by geological notions of the formation and subsequent warping of strata over long times, and the geologists' attempts to uncover the interior and distant past of the Earth. (B) Herschel was a very successful professional musician for two decades, primarily in the fashionable resort city of Bath, England. And then he discovered Uranus in 1781 at age 43, an event that catapulted him into celebrity and allowed him immediately to transform himself into a full-time astronomer. He composed over twenty symphonies, many concertos, and a large number of organ and choral works. During this session, a chorus of University of Washington students will present a short concert featuring Herschel's most popular composition, a novelty number called "The Eccho Catch," as well as contemporary pieces with astronomical themes by other composers.

THE EXTENDED HIGH A ( V ) QUASAR SURVEY: SEARCHING FOR DUSTY ABSORBERS TOWARD MID-INFRARED-SELECTED QUASARS

Energy Technology Data Exchange (ETDEWEB)

Krogager, J.-K.; Noterdaeme, P. [Institut d’Astrophysique de Paris, CNRS-UPMC, UMR7095, 98bis bd Arago, F-75014 Paris (France); Fynbo, J. P. U.; Heintz, K. E.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Geier, S. [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Ledoux, C. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Møller, P. [European Southern Observatory, Karl-Schwarzschildstrasse 2, D-85748 Garching bei München (Germany); Venemans, B. P. [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

2016-11-20

We present the results of a new spectroscopic survey for dusty intervening absorption systems, particularly damped Ly α absorbers (DLAs), toward reddened quasars. The candidate quasars are selected from mid-infrared photometry from the Wide-field Infrared Survey Explorer combined with optical and near-infrared photometry. Out of 1073 candidates, we secure low-resolution spectra for 108 using the Nordic Optical Telescope on La Palma, Spain. Based on the spectra, we are able to classify 100 of the 108 targets as quasars. A large fraction (50%) is observed to have broad absorption lines (BALs). Moreover, we find six quasars with strange breaks in their spectra, which are not consistent with regular dust reddening. Using template fitting, we infer the amount of reddening along each line of sight ranging from A ( V ) ≈ 0.1 to 1.2 mag (assuming a Small Magellanic Cloud extinction curve). In four cases, the reddening is consistent with dust exhibiting the 2175 Å feature caused by an intervening absorber, and for two of these, an Mg ii absorption system is observed at the best-fit absorption redshift. In the rest of the cases, the reddening is most likely intrinsic to the quasar. We observe no evidence for dusty DLAs in this survey. However, the large fraction of BAL quasars hampers the detection of absorption systems. Out of the 50 non-BAL quasars, only 28 have sufficiently high redshift to detect Ly α in absorption.

THE FMOS-COSMOS SURVEY OF STAR-FORMING GALAXIES AT z ∼ 1.6. III. SURVEY DESIGN, PERFORMANCE, AND SAMPLE CHARACTERISTICS

Energy Technology Data Exchange (ETDEWEB)

Silverman, J. D.; Sugiyama, N. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, 277-8583 (Japan); Kashino, D. [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya, 464-8602 (Japan); Sanders, D.; Zahid, J.; Kewley, L. J.; Chu, J.; Hasinger, G. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI, 96822 (United States); Kartaltepe, J. S. [National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson, AZ, 85719 (United States); Arimoto, N. [Subaru Telescope, 650 North A’ohoku Place, Hilo, Hawaii, 96720 (United States); Renzini, A. [Instituto Nazionale de Astrofisica, Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, I-35122, Padova, Italy, EU (Italy); Rodighiero, G.; Baronchelli, I. [Dipartimento di Fisica e Astronomia, Universita di Padova, vicolo Osservatorio, 3, I-35122, Padova (Italy); Daddi, E.; Juneau, S. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d’Astrophysique, CEA Saclay (France); Nagao, T. [Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Lilly, S. J.; Carollo, C. M. [Institute of Astronomy, ETH Zürich, CH-8093, Zürich (Switzerland); Capak, P. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Ilbert, O., E-mail: john.silverman@ipmu.jp [Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France); and others

2015-09-15

We present a spectroscopic survey of galaxies in the COSMOS field using the Fiber Multi-object Spectrograph (FMOS), a near-infrared instrument on the Subaru Telescope. Our survey is specifically designed to detect the Hα emission line that falls within the H-band (1.6–1.8 μm) spectroscopic window from star-forming galaxies with 1.4 < z < 1.7 and M{sub stellar} ≳ 10{sup 10} M{sub ⊙}. With the high multiplex capability of FMOS, it is now feasible to construct samples of over 1000 galaxies having spectroscopic redshifts at epochs that were previously challenging. The high-resolution mode (R ∼ 2600) effectively separates Hα and [N ii]λ6585, thus enabling studies of the gas-phase metallicity and photoionization state of the interstellar medium. The primary aim of our program is to establish how star formation depends on stellar mass and environment, both recognized as drivers of galaxy evolution at lower redshifts. In addition to the main galaxy sample, our target selection places priority on those detected in the far-infrared by Herschel/PACS to assess the level of obscured star formation and investigate, in detail, outliers from the star formation rate (SFR)—stellar mass relation. Galaxies with Hα detections are followed up with FMOS observations at shorter wavelengths using the J-long (1.11–1.35 μm) grating to detect Hβ and [O iii]λ5008 which provides an assessment of the extinction required to measure SFRs not hampered by dust, and an indication of embedded active galactic nuclei. With 460 redshifts measured from 1153 spectra, we assess the performance of the instrument with respect to achieving our goals, discuss inherent biases in the sample, and detail the emission-line properties. Our higher-level data products, including catalogs and spectra, are available to the community.

Blind decomposition of Herschel-HIFI spectral maps of the NGC 7023 nebula

Science.gov (United States)

Berné, O.; Joblin, C.; Deville, Y.; Pilleri, P.; Pety, J.; Teyssier, D.; Gerin, M.; Fuente, A.

2012-12-01

Large spatial-spectral surveys are more and more common in astronomy. This calls for the need of new methods to analyze such mega- to giga-pixel data-cubes. In this paper we present a method to decompose such observations into a limited and comprehensive set of components. The original data can then be interpreted in terms of linear combinations of these components. The method uses non-negative matrix factorization (NMF) to extract latent spectral end-members in the data. The number of needed end-members is estimated based on the level of noise in the data. A Monte-Carlo scheme is adopted to estimate the optimal end-members, and their standard deviations. Finally, the maps of linear coefficients are reconstructed using non-negative least squares. We apply this method to a set of hyperspectral data of the NGC 7023 nebula, obtained recently with the HIFI instrument onboard the Herschel space observatory, and provide a first interpretation of the results in terms of 3-dimensional dynamical structure of the region.

HERSCHEL/HIFI DISCOVERY OF HCL+ IN THE INTERSTELLAR MEDIUM

International Nuclear Information System (INIS)

De Luca, M.; Gerin, M.; Falgarone, E.; Gupta, H.; Drouin, B. J.; Pearson, J. C.; Neufeld, D.; Teyssier, D.; Lis, D. C.; Monje, R.; Phillips, T. G.; Goicoechea, J. R.; Godard, B.; Bell, T. A.; Coutens, A.

2012-01-01

The radical ion HCl + , a key intermediate in the chlorine chemistry of the interstellar gas, has been identified for the first time in the interstellar medium with the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared. The ground-state rotational transition of H 35 Cl + , 2 Π 3/2 J = 5/2-3/2, showing Λ-doubling and hyperfine structure, is detected in absorption toward the Galactic star-forming regions W31C (G10.6-0.4) and W49N. The complex interstellar absorption features are modeled by convolving in velocity space the opacity profiles of other molecular tracers toward the same sources with the fine and hyperfine structure of HCl + . This structure is derived from a combined analysis of optical data from the literature and new laboratory measurements of pure rotational transitions, reported in the accompanying Letter by Gupta et al. The models reproduce well the interstellar absorption, and the frequencies inferred from the astronomical observations are in exact agreement with those calculated using spectroscopic constants derived from the laboratory data. The detection of H 37 Cl + toward W31C, with a column density consistent with the expected 35 Cl/ 37 Cl isotopic ratio, provides additional evidence for the identification. A comparison with the chemically related molecules HCl and H 2 Cl + yields an abundance ratio of unity with both species (HCl + : H 2 Cl + : HCl ∼ 1). These observations also yield the unexpected result that HCl + accounts for 3%-5% of the gas-phase chlorine toward W49N and W31C, values several times larger than the maximum fraction (∼1%) predicted by chemical models.

Using CO as a Physical Probe of the SF Activity in the Planck-Herschel Selected Hyper Luminous Infrared Galaxies

Science.gov (United States)

Harrington, Kevin

2018-01-01

Multi-J CO line studies are essential for quantifying the physical properties of the star-forming ISM, yet it is observationally expensive to detect those faint CO emission lines at high redshift. Our eight Planck-Herschel selected galaxies, with apparent LIR > 1013‑14 L⊙, serve as the best laboratories to conduct such a CO spectral line energy distribution analysis at high-z. Using our GBT and LMT (Jup = 1-3) measurements, we trace the bulk molecular gas mass, finding relatively large star formation efficiencies (as traced by the LIR-to-L’CO(1‑0) ratio) consistent with a starburst mode of activity. With our mid-J (Jup = 4-8) CO line measurements, obtained with the IRAM 30m telescope, we find gas excitation conditions ranging from sub-thermal SMGs to highly excited local starbursts out to Jup = 5-8. The consistently high velocity-integrated line intensities at Jup = 5-8 indicates the presence a warm/dense component responsible for exciting the higher-J CO lines, therefore we use coupled non-LTE large velocity gradient and dust radiative transfer models to begin characterising the two-component molecular ISM in these strongly lensed systems.

The SOFIA Massive (SOMA) Star Formation Survey. I. Overview and First Results

Energy Technology Data Exchange (ETDEWEB)

De Buizer, James M.; Shuping, Ralph [SOFIA-USRA, NASA Ames Research Center, MS 232-12, Moffett Field, CA 94035 (United States); Liu, Mengyao; Tan, Jonathan C.; Staff, Jan E.; Tanaka, Kei E. I. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Zhang, Yichen [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Beltrán, Maria T. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Whitney, Barbara [Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter St, Madison, WI 53706 (United States)

2017-07-01

We present an overview and first results of the Stratospheric Observatory For Infrared Astronomy Massive (SOMA) Star Formation Survey, which is using the FORCAST instrument to image massive protostars from ∼10 to 40 μ m. These wavelengths trace thermal emission from warm dust, which in Core Accretion models mainly emerges from the inner regions of protostellar outflow cavities. Dust in dense core envelopes also imprints characteristic extinction patterns at these wavelengths, causing intensity peaks to shift along the outflow axis and profiles to become more symmetric at longer wavelengths. We present observational results for the first eight protostars in the survey, i.e., multiwavelength images, including some ancillary ground-based mid-infrared (MIR) observations and archival Spitzer and Herschel data. These images generally show extended MIR/FIR emission along directions consistent with those of known outflows and with shorter wavelength peak flux positions displaced from the protostar along the blueshifted, near-facing sides, thus confirming qualitative predictions of Core Accretion models. We then compile spectral energy distributions and use these to derive protostellar properties by fitting theoretical radiative transfer models. Zhang and Tan models, based on the Turbulent Core Model of McKee and Tan, imply the sources have protostellar masses m {sub *} ∼ 10–50 M {sub ⊙} accreting at ∼10{sup −4}–10{sup −3} M {sub ⊙} yr{sup −1} inside cores of initial masses M {sub c} ∼ 30–500 M {sub ⊙} embedded in clumps with mass surface densities Σ{sub cl} ∼ 0.1–3 g cm{sup −2}. Fitting the Robitaille et al. models typically leads to slightly higher protostellar masses, but with disk accretion rates ∼100× smaller. We discuss reasons for these differences and overall implications of these first survey results for massive star formation theories.

THE HIGH A{sub V} Quasar Survey: Reddened Quasi-Stellar Objects selected from optical/near-infrared photometry. II

Energy Technology Data Exchange (ETDEWEB)

Krogager, J.-K.; Fynbo, J. P. U.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Geier, S. [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Venemans, B. P. [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Ledoux, C. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Møller, P. [European Southern Observatory, Karl-Schwarzschildstrasse 2, D-85748 Garching bei München (Germany); Noterdaeme, P. [Institut d’Astrophysique de Paris, CNRS-UPMC, UMR7095, 98bis bd Arago, F-75014 Paris (France); Kangas, T.; Pursimo, T.; Smirnova, O. [Nordic Optical Telescope, Apartado 474, E-38700 Santa Cruz de La Palma (Spain); Saturni, F. G. [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500 Piikkiö (Finland)

2015-03-15

Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the ones used by the Sloan Digital Sky Survey (SDSS). To overcome this bias against red QSOs, we employ a combined optical and near-infrared (near-IR) color selection. In this paper, we present a spectroscopic follow-up campaign of a sample of red candidate QSOs which were selected from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS photometry are supplemented by mid-infrared photometry from the Wide-field Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are confirmed to be QSOs. We use a statistical algorithm to identify sightlines with plausible intervening absorption systems and identify nine such cases assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We find absorption systems toward 30 QSOs, 2 of which are consistent with the best-fit absorber redshift from the statistical modeling. Furthermore, we observe a broad range in SED properties of the QSOs as probed by the rest-frame 2 μm flux. We find QSOs with a strong excess as well as QSOs with a large deficit at rest-frame 2 μm relative to a QSO template. Potential solutions to these discrepancies are discussed. Overall, our study demonstrates the high efficiency of the optical/near-IR selection of red QSOs.

The PEP survey: clustering of infrared-selected galaxies and structure formation at z ˜ 2 in GOODS-South

Science.gov (United States)

Magliocchetti, M.; Santini, P.; Rodighiero, G.; Grazian, A.; Aussel, H.; Altieri, B.; Andreani, P.; Berta, S.; Cepa, J.; Castañeda, H.; Cimatti, A.; Daddi, E.; Elbaz, D.; Genzel, R.; Gruppioni, C.; Lutz, D.; Magnelli, B.; Maiolino, R.; Popesso, P.; Poglitsch, A.; Pozzi, F.; Sanchez-Portal, M.; Förster Schreiber, N. M.; Sturm, E.; Tacconi, L.; Valtchanov, I.

2011-09-01

This paper presents the first direct estimate of the 3D clustering properties of far-infrared sources up to z˜ 3. This has been possible thanks to the PACS Evolutionary Probe (PEP) survey of the GOODS-South field performed with the PACS instrument on board the Herschel satellite. 550 and 502 sources were detected respectively in the 100- and 160-μm channels down to fluxes ? mJy and ? mJy, cuts that ensure >80 per cent completeness of the two catalogues. More than 65 per cent of these sources have an (either photometric or spectroscopic) redshift determination from the MUSIC catalogue; this percentage rises to ˜95 per cent in the inner portion of GOODS-South which is covered by data at other wavelengths. An analysis of the deprojected two-point correlation function w(θ) over the whole redshift range spanned by the data reports for the (comoving) correlation length, r0˜ 6.3 and ˜6.7 Mpc, respectively at 100 and 160 μm, corresponding to dark matter halo masses M≳ 1012.4 M⊙, in an excellent agreement with previous estimates obtained for mid-IR selected sources in the same field. Objects at z˜ 2 instead seem to be more strongly clustered, with r0˜ 19 and ˜17 Mpc in the two considered PACS channels. This dramatic increase of the correlation length between z˜ 1 and ˜2 is connected with the presence, more visible at 100 μm than in the other band, of a wide (at least 4 Mpc across in projection), M≳ 1014 M⊙, filamentary structure which includes more than 50 per cent of the sources detected at z˜ 2. An investigation of the properties of such sources indicates the possibility of a boosted star-forming activity in those which reside within the overdense environment with respect to more isolated galaxies found in the same redshift range. If confirmed by larger data sets, this result can be explained as due to the combined effect of large reservoirs of gas available at high redshifts in deep potential wells such as those associated with large overdensities

Remnant radio-loud AGN in the Herschel-ATLAS field

Science.gov (United States)

Mahatma, V. H.; Hardcastle, M. J.; Williams, W. L.; Brienza, M.; Brüggen, M.; Croston, J. H.; Gurkan, G.; Harwood, J. J.; Kunert-Bajraszewska, M.; Morganti, R.; Röttgering, H. J. A.; Shimwell, T. W.; Tasse, C.

2018-04-01

Only a small fraction of observed active galactic nuclei (AGN) display large-scale radio emission associated with jets, yet these radio-loud AGN have become increasingly important in models of galaxy evolution. In determining the dynamics and energetics of the radio sources over cosmic time, a key question concerns what happens when their jets switch off. The resulting `remnant' radio-loud AGN have been surprisingly evasive in past radio surveys, and therefore statistical information on the population of radio-loud AGN in their dying phase is limited. In this paper, with the recent developments of Low-Frequency Array (LOFAR) and the Very Large Array, we are able to provide a systematically selected sample of remnant radio-loud AGN in the Herschel-ATLAS field. Using a simple core-detection method, we constrain the upper limit on the fraction of remnants in our radio-loud AGN sample to 9 per cent, implying that the extended lobe emission fades rapidly once the core/jets turn off. We also find that our remnant sample has a wide range of spectral indices (-1.5≤slant α ^{1400}_{150}≤slant -0.5), confirming that the lobes of some remnants may possess flat spectra at low frequencies just as active sources do. We suggest that, even with the unprecedented sensitivity of LOFAR, our sample may still only contain the youngest of the remnant population.

CMB Polarization B-mode Delensing with SPTpol and Herschel

Energy Technology Data Exchange (ETDEWEB)

Manzotti, A.; et al.

2017-01-16

We present a demonstration of delensing the observed cosmic microwave background (CMB) B-mode polarization anisotropy. This process of reducing the gravitational-lensing generated B-mode component will become increasingly important for improving searches for the B modes produced by primordial gravitational waves. In this work, we delens B-mode maps constructed from multi-frequency SPTpol observations of a 90 deg$^2$ patch of sky by subtracting a B-mode template constructed from two inputs: SPTpol E-mode maps and a lensing potential map estimated from the $\\textit{Herschel}$ $500\\,\\mu m$ map of the CIB. We find that our delensing procedure reduces the measured B-mode power spectrum by 28% in the multipole range $300 < \\ell < 2300$; this is shown to be consistent with expectations from theory and simulations and to be robust against systematics. The null hypothesis of no delensing is rejected at $6.9 \\sigma$. Furthermore, we build and use a suite of realistic simulations to study the general properties of the delensing process and find that the delensing efficiency achieved in this work is limited primarily by the noise in the lensing potential map. We demonstrate the importance of including realistic experimental non-idealities in the delensing forecasts used to inform instrument and survey-strategy planning of upcoming lower-noise experiments, such as CMB-S4.

Neutral and Ionized Hydrides in Star-forming Regions. Observations with Herschel/HIFI

DEFF Research Database (Denmark)

O. Benz, Arnold; Bruderer, Simon; F. van Dishoeck, Ewine

2013-01-01

of OH, CH, NH, SH and their ions OH+, CH+, NH+, SH+, H2O+, and H3O+ were observed in star-forming regions by the HIFI spectrometer onboard the Herschel Space Observatory. Molecular column densities are derived from observed ground-state lines, models, or rotational diagrams. We report here on two...

Deep far infrared ISOPHOT survey in "Selected Area 57" - I. Observations and source counts

DEFF Research Database (Denmark)

Linden-Vornle, M.J.D.; Nørgaard-Nielsen, Hans Ulrik; Jørgensen, H.E.

2000-01-01

We present here the results of a deep survey in a 0.4 deg(2) blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO1) at both 60 mu m and 90 mu m. The resulting sky maps have a spatial resolution of 15 x 23 arcsrc(2) per pixel which is much...

A DETAILED GRAVITATIONAL LENS MODEL BASED ON SUBMILLIMETER ARRAY AND KECK ADAPTIVE OPTICS IMAGING OF A HERSCHEL-ATLAS SUBMILLIMETER GALAXY AT z = 4.243 {sup ,} {sup ,}

Energy Technology Data Exchange (ETDEWEB)

Bussmann, R. S.; Gurwell, M. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fu Hai; Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Smith, D. J. B.; Bonfield, D.; Dunne, L. [Centre for Astrophysics, Science and Technology Research Institute, University of Hertfordshire, Hatfield, Herts AL10 9AB (United Kingdom); Dye, S.; Eales, S. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Auld, R. [Cardiff University, School of Physics and Astronomy, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Baes, M.; Fritz, J. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Baker, A. J. [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States); Cava, A. [Departamento de Astrofisica, Facultad de CC. Fisicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Clements, D. L.; Dariush, A. [Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Coppin, K. [Department of Physics, McGill University, Ernest Rutherford Building, 3600 Rue University, Montreal, Quebec, H3A 2T8 (Canada); Dannerbauer, H. [Universitaet Wien, Institut fuer Astronomie, Tuerkenschanzstrasse 17, 1180 Wien, Oesterreich (Austria); De Zotti, G. [Universita di Padova, Dipto di Astronomia, Vicolo dell' Osservatorio 2, IT 35122, Padova (Italy); Hopwood, R., E-mail: rbussmann@cfa.harvard.edu [Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom); and others

2012-09-10

We present high-spatial resolution imaging obtained with the Submillimeter Array (SMA) at 880 {mu}m and the Keck adaptive optics (AO) system at the K{sub S}-band of a gravitationally lensed submillimeter galaxy (SMG) at z = 4.243 discovered in the Herschel Astrophysical Terahertz Large Area Survey. The SMA data (angular resolution Almost-Equal-To 0.''6) resolve the dust emission into multiple lensed images, while the Keck AO K{sub S}-band data (angular resolution Almost-Equal-To 0.''1) resolve the lens into a pair of galaxies separated by 0.''3. We present an optical spectrum of the foreground lens obtained with the Gemini-South telescope that provides a lens redshift of z{sub lens} = 0.595 {+-} 0.005. We develop and apply a new lens modeling technique in the visibility plane that shows that the SMG is magnified by a factor of {mu} = 4.1 {+-} 0.2 and has an intrinsic infrared (IR) luminosity of L{sub IR} = (2.1 {+-} 0.2) Multiplication-Sign 10{sup 13} L{sub Sun }. We measure a half-light radius of the background source of r{sub s} = 4.4 {+-} 0.5 kpc which implies an IR luminosity surface density of {Sigma}{sub IR} (3.4 {+-} 0.9) Multiplication-Sign 10{sup 11} L{sub Sun} kpc{sup -2}, a value that is typical of z > 2 SMGs but significantly lower than IR luminous galaxies at z {approx} 0. The two lens galaxies are compact (r{sub lens} Almost-Equal-To 0.9 kpc) early-types with Einstein radii of {theta}{sub E1} 0.57 {+-} 0.01 and {theta}{sub E2} = 0.40 {+-} 0.01 that imply masses of M{sub lens1} = (7.4 {+-} 0.5) Multiplication-Sign 10{sup 10} M{sub Sun} and M{sub lens2} = (3.7 {+-} 0.3) Multiplication-Sign 10{sup 10} M{sub Sun }. The two lensing galaxies are likely about to undergo a dissipationless merger, and the mass and size of the resultant system should be similar to other early-type galaxies at z {approx} 0.6. This work highlights the importance of high spatial resolution imaging in developing models of strongly lensed galaxies

An Occupation for an Independent Gentleman - Astronomy in the Life of Herschel, John

Science.gov (United States)

Chapman, Allan

Sir John Frederick William Herschel occupies a pivotal position in the history of British astronomy (1). He formed the living link between two styles or traditions of science by being the last major specimen of one breed, and the inspiration and intellectual role model for the generation that would follow. For John Herschel was perhaps the last significant figure to devote himself wholly and full-time to fundamental research in astronomy and its related sciences on the strength of a private fortune. And while the stature that he enjoyed did much to stimulate the concept of the 'professional' astronomer in Britain, so many of these men of the rising generation who admired his thorough-going dedication to science were themselves more obviously professional in the respect that they earned their livings through academic science. One sees in him, therefore, an eclectic blend of attitudes towards what science was, how it should be pursued, and how it should be paid for.

NEW M, L, AND T DWARF COMPANIONS TO NEARBY STARS FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

Energy Technology Data Exchange (ETDEWEB)

Luhman, Kevin L.; Loutrel, Nicholas P.; McCurdy, Nicholas S.; Melso, Nicole D.; Star, Kimberly M.; Terrien, Ryan C. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Mace, Gregory N.; McLean, Ian S. [UCLA Division of Astronomy and Astrophysics, Los Angeles, CA 90095 (United States); Young, Michael D.; Rhode, Katherine L. [Department of Astronomy, Indiana University, Swain West 319, 727 East Third Street, Bloomington, IN 47405 (United States); Davy Kirkpatrick, J., E-mail: kluhman@astro.psu.edu [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-12-01

We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar.

NEW M, L, AND T DWARF COMPANIONS TO NEARBY STARS FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

International Nuclear Information System (INIS)

Luhman, Kevin L.; Loutrel, Nicholas P.; McCurdy, Nicholas S.; Melso, Nicole D.; Star, Kimberly M.; Terrien, Ryan C.; Mace, Gregory N.; McLean, Ian S.; Young, Michael D.; Rhode, Katherine L.; Davy Kirkpatrick, J.

2012-01-01

We present 11 candidate late-type companions to nearby stars identified with data from the Wide-field Infrared Survey Explorer (WISE) and the Two Micron All Sky Survey (2MASS). Eight of the candidates are likely to be companions based on their common proper motions with the primaries. The remaining three objects are rejected as companions, one of which is a free-floating T7 dwarf. Spectral types are available for five of the companions, which consist of M2V, M8.5V, L5, T8, and T8. Based on their photometry, the unclassified companions are probably two mid-M dwarfs and one late-M/early-L dwarf. One of the T8 companions, WISE J142320.84+011638.0, has already been reported by Pinfield and coworkers. The other T8 companion, ULAS J095047.28+011734.3, was discovered by Burningham and coworkers through the United Kingdom Infrared Telescope Infrared Deep Sky Survey, but its companionship has not been previously recognized in the literature. The L5 companion, 2MASS J17430860+8526594, is a new member of a class of L dwarfs that exhibit unusually blue near-IR colors. Among the possible mechanisms that have been previously proposed for the peculiar colors of these L dwarfs, low metallicity does not appear to be a viable explanation for 2MASS J17430860+8526594 since our spectrum of the primary suggests that its metallicity is not significantly subsolar.

Wide-Field Infrared Survey Explorer Observations of the Evolution of Massive Star-Forming Regions

Science.gov (United States)

Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Rebull, L. M.; Padgett, D. L.; Asslef, R. J.

2012-01-01

We present the results of a mid-infrared survey of II outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the "fireworks hypothesis" since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF THE EVOLUTION OF MASSIVE STAR-FORMING REGIONS

International Nuclear Information System (INIS)

Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Padgett, D. L.; Rebull, L. M.; Assef, R. J.

2012-01-01

We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the 'fireworks hypothesis' since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars.

Report of Some Comets: The Discovery of Uranus and Comets by William, Caroline, and John Herschel

Science.gov (United States)

Pasachoff, Jay M.; Olson, R. J. M.

2011-01-01

We report on the discovery and drawings of comets by William, Caroline, and John Herschel. The first discovery, by William Herschel, in 1781 from Bath, published in the Philosophical Transactions of the Royal Society with the title "Report of a Comet," turned out to be Uranus, the first planet ever discovered, Mercury through Saturn having been known since antiquity. William's sister Caroline was given duties of sweeping the skies and turned out to be a discoverer of 8 comets in her own right, in addition to keeping William's notes. Caroline's comets were discovered from Slough between 1786 and 1797. In the process, we also discuss original documents from the archives of the Royal Society and of the Royal Astronomical Society. We conclude by showing comet drawings that we have recently attributed to John Herschel, including Halley's Comet from 1836, recently located in the Ransom Center of the University of Texas at Austin. Acknowledgments: Planetary astronomy at Williams College is supported in part by grant NNX08AO50G from NASA Planetary Astronomy. We thank Peter Hingley of the Royal Astronomical Society and Richard Oram of the Harry Ransom Center of The University of Texas at Austin for their assistance.

A STUDY OF HEATING AND COOLING OF THE ISM IN NGC 1097 WITH HERSCHEL-PACS AND SPITZER-IRS

International Nuclear Information System (INIS)

Beirão, P.; Armus, L.; Helou, G.; Appleton, P. N.; Smith, J.-D. T.; Croxall, K. V.; Murphy, E. J.; Dale, D. A.; Draine, B. T.; Aniano, G.; Wolfire, M. G.; Bolatto, A. D.; Sandstrom, K. M.; Groves, B.; Schinnerer, E.; Rix, H.-W.; Brandl, B. R.; Crocker, A. F.; Hinz, J. L.; Kennicutt, R. C.

2012-01-01

NGC 1097 is a nearby Seyfert 1 galaxy with a bright circumnuclear starburst ring, a strong large-scale bar, and an active nucleus. We present a detailed study of the spatial variation of the far-infrared (FIR) [C II]158 μm and [O I]63 μm lines and mid-infrared H 2 emission lines as tracers of gas cooling, and of the polycyclic aromatic hydrocarbon (PAH) bands as tracers of the photoelectric heating, using Herschel-PACS and Spitzer-IRS infrared spectral maps. We focus on the nucleus and the ring, and two star-forming regions (Enuc N and Enuc S). We estimated a photoelectric gas heating efficiency ([C II]158 μm+[O I]63 μm)/PAH in the ring about 50% lower than in Enuc N and S. The average 11.3/7.7 μm PAH ratio is also lower in the ring, which may suggest a larger fraction of ionized PAHs, but no clear correlation with [C II]158 μm/PAH(5.5-14 μm) is found. PAHs in the ring are responsible for a factor of two more [C II]158 μm and [O I]63 μm emission per unit mass than PAHs in the Enuc S. spectral energy distribution (SED) modeling indicates that at most 25% of the FIR power in the ring and Enuc S can come from high-intensity photodissociation regions (PDRs), in which case G 0 ∼ 10 2.3 and n H ∼ 10 3.5 cm –3 in the ring. For these values of G 0 and n H , PDR models cannot reproduce the observed H 2 emission. Much of the H 2 emission in the starburst ring could come from warm regions in the diffuse interstellar medium that are heated by turbulent dissipation or shocks.

Warm gas towards young stellar objects in Corona Australis. Herschel/PACS observations from the DIGIT key programme

Science.gov (United States)

Lindberg, Johan E.; Jørgensen, Jes K.; Green, Joel D.; Herczeg, Gregory J.; Dionatos, Odysseas; Evans, Neal J.; Karska, Agata; Wampfler, Susanne F.

2014-05-01

Context. The effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood. The Corona Australis star-forming region contains the R CrA dark cloud, comprising several low-mass protostellar cores irradiated by an intermediate-mass young star. Aims: We study the effects of the irradiation coming from the young luminous Herbig Be star R CrA on the warm gas and dust in a group of low-mass young stellar objects. Methods: Herschel/PACS far-infrared datacubes of two low-mass star-forming regions in the R CrA dark cloud are presented. The distributions of CO, OH, H2O, [C ii], [O i], and continuum emission are investigated. We have developed a deconvolution algorithm which we use to deconvolve the maps, separating the point-source emission from the extended emission. We also construct rotational diagrams of the molecular species. Results: By deconvolution of the Herschel data, we find large-scale (several thousand AU) dust continuum and spectral line emission not associated with the point sources. Similar rotational temperatures are found for the warm CO (282 ± 4 K), hot CO (890 ± 84 K), OH (79 ± 4 K), and H2O (197 ± 7 K) emission in the point sources and the extended emission. The rotational temperatures are also similar to those found in other more isolated cores. The extended dust continuum emission is found in two ridges similar in extent and temperature to molecular millimetre emission, indicative of external heating from the Herbig Be star R CrA. Conclusions: Our results show that nearby luminous stars do not increase the molecular excitation temperatures of the warm gas around young stellar objects (YSOs). However, the emission from photodissociation products of H2O, such as OH and O, is enhanced in the warm gas associated with these protostars and their surroundings compared to similar objects not subjected to external irradiation. Table 9 and appendices are available in

First extragalactic detection of submillimeter CH rotational lines from the Herschel space observatory

Energy Technology Data Exchange (ETDEWEB)

Rangwala, Naseem; Maloney, Philip R.; Glenn, Jason; Kamenetzky, Julia [Center for Astrophysics and Space Astronomy, University of Colorado, 1255 38th street, Boulder, CO 80303 (United States); Wilson, Christine D.; Schirm, Maximilien R. P. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Spinoglio, Luigi; Pereira Santaella, Miguel [Istituto di Fisica dello Spazio Interplanetario, INAF, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy)

2014-06-20

We present the first extragalactic detections of several CH rotational transitions in the far-infrared in four nearby galaxies, NGC 1068, Arp 220, M82, and NGC 253, using the Herschel Space Observatory. The CH lines in all four galaxies are a factor of 2-4 brighter than the adjacent HCN and HCO{sup +} J = 6-5 lines (also detected in the same spectra). In the star-formation-dominated galaxies, M82, NGC 253, and Arp 220, the CH/CO abundance ratio is low (∼10{sup –5}), implying that the CH is primarily arising in diffuse and translucent gas where the chemistry is driven by UV radiation as found in the Milky Way interstellar matter. In NGC 1068, which has a luminous active galactic nucleus (AGN), the CH/CO ratio is an order of magnitude higher, suggesting that CH formation is driven by an X-ray-dominated region (XDR). Our XDR models show that both the CH and CO abundances in NGC 1068 can be explained by an XDR-driven chemistry for gas densities and molecular hydrogen column densities that are well constrained by the CO observations. We conclude that the CH/CO ratio may a good indicator of the presence of AGN in galaxies. We also discuss the feasibility of detecting CH in intermediate- to high-z galaxies with ALMA.

HERSCHEL/SPIRE SUBMILLIMETER SPECTRA OF LOCAL ACTIVE GALAXIES {sup ,}

Energy Technology Data Exchange (ETDEWEB)

Pereira-Santaella, Miguel; Spinoglio, Luigi; Busquet, Gemma [Istituto di Astrofisica e Planetologia Spaziali, INAF, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Wilson, Christine D.; Schirm, Maximilien R. P. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Glenn, Jason; Kamenetzky, Julia; Rangwala, Naseem [Center for Astrophysics and Space Astronomy, 389-UCB, University of Colorado, Boulder, CO 80303 (United States); Isaak, Kate G. [ESA Astrophysics Missions Division, ESTEC, P.O. Box 299, 2200 AG Noordwijk (Netherlands); Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Barlow, Michael J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Boselli, Alessandro [Laboratoire d' Astrophysique de Marseille (LAM), Universite d' Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Cooray, Asantha [Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Cormier, Diane, E-mail: miguel.pereira@ifsi-roma.inaf.it [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, Irfu/Service d' Astrophysique, CEA Saclay, F-91191 Gif-sur-Yvette (France)

2013-05-01

We present the submillimeter spectra from 450 to 1550 GHz of 11 nearby active galaxies observed with the SPIRE Fourier Transform Spectrometer (SPIRE/FTS) on board Herschel. We detect CO transitions from J{sub up} = 4 to 12, as well as the two [C I] fine structure lines at 492 and 809 GHz and the [N II]1461 GHz line. We used radiative transfer models to analyze the observed CO spectral line energy distributions. The FTS CO data were complemented with ground-based observations of the low-J CO lines. We found that the warm molecular gas traced by the mid-J CO transitions has similar physical conditions (n{sub H{sub 2}}{approx} 10{sup 3.2}-10{sup 3.9} cm{sup -3} and T{sub kin} {approx} 300-800 K) in most of our galaxies. Furthermore, we found that this warm gas is likely producing the mid-IR rotational H{sub 2} emission. We could not determine the specific heating mechanism of the warm gas, however, it is possibly related to the star formation activity in these galaxies. Our modeling of the [C I] emission suggests that it is produced in cold (T{sub kin} < 30 K) and dense (n{sub H{sub 2}}>10{sup 3} cm{sup -3}) molecular gas. Transitions of other molecules are often detected in our SPIRE/FTS spectra. The HF J = 1-0 transition at 1232 GHz is detected in absorption in UGC 05101 and in emission in NGC 7130. In the latter, near-infrared pumping, chemical pumping, or collisional excitation with electrons are plausible excitation mechanisms likely related to the active galactic nucleus of this galaxy. In some galaxies, few H{sub 2}O emission lines are present. Additionally, three OH{sup +} lines at 909, 971, and 1033 GHz are identified in NGC 7130.

Surveying the elements of successful infrared predictive maintenance programs

Science.gov (United States)

Snell, John R., Jr.; Spring, Robert W.

1991-03-01

This paper summarizes the results of a survey of over three hundred maintenance personnel who use imaging equipment within their company or organization. All had previously participated in one or more of our training programs. The companies took in a broad range of industry, including, among other, power generation, pulp and paper, metals, mining, petrochemical, automotive and general manufacturing. The organizations were mainly quite large, either commercial or public, and included governmental agencies, military, colleges and universities, municipalities, and utilities. Although we had a very tight time line for the survey, we were pleased to have a 15% response rate. The results show that some of the causes of success and failure in infrared programs are not unlike those associated with any type of program in an organizational structure, i.e. the need for accurate and timely communications; justification requirements; etc. Another set of problems was shared more closely with other startup maintenance technologies (for example, vibration monitoring), such as the need for trending data; providing appropriate technical training; achieving reproducible results; etc. Finally, some of the driving mechanisms are more specific to this technology, such as re-designing equipment so that it can be thermally inspected; establishing effective documentation strategies; etc.

Infrared survey of 50 buildings constructed during 100 years: thermal performances and damage conditions

Science.gov (United States)

Ljungberg, Sven-Ake

1995-03-01

Different building constructions and craftsmanship give rise to different thermal performance and damage conditions. The building stock of most industrial countries consists of buildings of various age, and constructions, from old historic buildings with heavy stone or wooden construction, to new buildings with heavy or light concrete construction, or modern steel or wooden construction. In this paper the result from a detailed infrared survey of 50 buildings from six Swedish military camps is presented. The presentation is limited to a comparison of thermal performance and damage conditions of buildings of various ages, functions, and constructions, of a building period of more than 100 years. The result is expected to be relevant even to civilian buildings. Infrared surveys were performed during 1992-1993, with airborne, and mobile short- and longwave infrared systems, out- and indoor thermography. Interpretation and analysis of infrared data was performed with interactive image and analyzing systems. Field inspections were carried out with fiber optics system, and by ocular inspections. Air-exchange rate was measured in order to quantify air leakages through the building envelope, indicated in thermograms. The objects studied were single-family houses, barracks, office-, service-, school- and exercise buildings, military hotels and restaurants, aircraft hangars, and ship factory buildings. The main conclusions from this study are that most buildings from 1880 - 1940 have a solid construction with a high quality of craftsmanship, relatively good thermal performance, due to extremely thick walls, and adding insulation at the attic floor. From about 1940 - 1960 the quality of construction, thermal performance and craftsmanship seem to vary a lot. Buildings constructed during the period of 1960 - 1990 have in general the best thermal performance due to a better insulation capacity, however, also one finds here the greatest variety of problems. The result from this

THE GREAT OBSERVATORIES ALL-SKY LIRG SURVEY: COMPARISON OF ULTRAVIOLET AND FAR-INFRARED PROPERTIES

International Nuclear Information System (INIS)

Howell, Justin H.; Armus, Lee; Surace, Jason A.; Petric, Andreea; Bridge, Carrie; Haan, Sebastian; Inami, Hanae; Mazzarella, Joseph M.; Chan, Ben H. P.; Madore, Barry F.; Evans, Aaron S.; Kim, Dong-Chan; Sanders, David B.; Appleton, Phil; Frayer, David T.; Lord, Steven; Schulz, Bernhard; Bothun, Greg; Charmandaris, Vassilis; Melbourne, Jason

2010-01-01

The Great Observatories All-sky LIRG Survey (GOALS) consists of a complete sample of 202 luminous infrared galaxies (LIRGs) selected from the IRAS Revised Bright Galaxy Sample (RBGS). The galaxies span the full range of interaction stages, from isolated galaxies to interacting pairs to late stage mergers. We present a comparison of the UV and infrared properties of 135 galaxies in GOALS observed by GALEX and Spitzer. For interacting galaxies with separations greater than the resolution of GALEX and Spitzer (∼2''-6''), we assess the UV and IR properties of each galaxy individually. The contribution of the FUV to the measured star formation rate (SFR) ranges from 0.2% to 17.9%, with a median of 2.8% and a mean of 4.0% ± 0.4%. The specific star formation rate (SSFR) of the GOALS sample is extremely high, with a median value (3.9 x 10 -10 yr -1 ) that is comparable to the highest SSFRs seen in the Spitzer Infrared Nearby Galaxies Survey sample. We examine the position of each galaxy on the IR excess-UV slope (IRX-β) diagram as a function of galaxy properties, including IR luminosity and interaction stage. The LIRGs on average have greater IR excesses than would be expected based on their UV colors if they obeyed the same relations as starbursts with L IR 11 L sun or normal late-type galaxies. The ratio of L IR to the value one would estimate from the IRX-β relation published for lower luminosity starburst galaxies ranges from 0.2 to 68, with a median value of 2.7. A minimum of 19% of the total IR luminosity in the RBGS is produced in LIRGs and ultraluminous infrared galaxies with red UV colors (β>0). Among resolved interacting systems, 32% contain one galaxy which dominates the IR emission while the companion dominates the UV emission. Only 21% of the resolved systems contain a single galaxy which dominates both wavelengths.

AKARI NEAR-INFRARED SPECTROSCOPIC SURVEY FOR CO2 IN 18 COMETS

International Nuclear Information System (INIS)

Ootsubo, Takafumi; Kawakita, Hideyo; Hamada, Saki; Kobayashi, Hitomi; Yamaguchi, Mitsuru; Usui, Fumihiko; Nakagawa, Takao; Ueno, Munetaka; Ishiguro, Masateru; Sekiguchi, Tomohiko; Watanabe, Jun-ichi; Sakon, Itsuki; Shimonishi, Takashi; Onaka, Takashi

2012-01-01

We conducted a spectroscopic survey of cometary volatiles with the Infrared Camera on board the Japanese infrared satellite AKARI in the wavelength range from 2.5 to 5 μm. In our survey, 18 comets, including both the Oort cloud comets and the Jupiter-family comets, were observed in the period from 2008 June to 2010 January, most of which were observed at least twice. The prominent emission bands in the observed spectra are the fundamental vibrational bands of water (H 2 O) at 2.7 μm and carbon dioxide (CO 2 ) at 4.3 μm. The fundamental vibrational band of carbon monoxide (CO) around 4.7 μm and the broad emission feature, probably related to carbon-hydrogen-bearing molecules, can also be recognized around the 3.3-3.5-μm region in some of the comets. With respect to H 2 O, gas production rate ratios of CO 2 have been derived in 17 comets, except for the comet 29P/Schwassmann-Wachmann 1. Our data set provides the largest homogeneous database of CO 2 /H 2 O production rate ratios in comets obtained so far. The CO 2 /H 2 O production rate ratios are considered to reflect the composition of cometary ice when a comet is observed at a heliocentric distance within ∼2.5 AU, since H 2 O ice fully sublimates there. The CO 2 /H 2 O ratio in cometary ice spans from several to ∼30% among the comets observed at 2 in the comets seems to be smaller than unity based on our observations, although we only obtain upper limits for CO in most of the comets.

CANDELS : THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY-THE HUBBLE SPACE TELESCOPE OBSERVATIONS, IMAGING DATA PRODUCTS, AND MOSAICS

NARCIS (Netherlands)

Koekemoer, Anton M.; Faber, S. M.; Ferguson, Henry C.; Grogin, Norman A.; Kocevski, Dale D.; Koo, David C.; Lai, Kamson; Lotz, Jennifer M.; Lucas, Ray A.; McGrath, Elizabeth J.; Ogaz, Sara; Rajan, Abhijith; Riess, Adam G.; Rodney, Steve A.; Strolger, Louis; Casertano, Stefano; Castellano, Marco; Dahlen, Tomas; Dickinson, Mark; Dolch, Timothy; Fontana, Adriano; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Huang, Kuang-Han; van der Wel, Arjen; Yan, Hao-Jing; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Brown, Thomas M.; Caputi, Karina I.; Cassata, Paolo; Challis, Peter J.; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Cooray, Asantha Roshan; Croton, Darren J.; Daddi, Emanuele; Dave, Romeel; de Mello, Duilia F.; de Ravel, Loic; Dekel, Avishai; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Frazer, Chris; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Gruetzbauch, Ruth; Hartley, Will G.; Haeussler, Boris; Herrington, Jessica; Hopkins, Philip F.; Huang, Jia-Sheng; Jha, Saurabh W.; Johnson, Andrew; Kartaltepe, Jeyhan S.; Khostovan, Ali A.; Kirshner, Robert P.; Lani, Caterina; Lee, Kyoung-Soo; Li, Weidong; Madau, Piero; McCarthy, Patrick J.; McIntosh, Daniel H.; McLure, Ross J.; McPartland, Conor; Mobasher, Bahram; Moreira, Heidi; Mortlock, Alice; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Nielsen, Jennifer L.; Niemi, Sami; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Snyder, Diana; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; Vargas, Carlos; Villforth, Carolin; Wagner, Cory R.; Wandro, Pat; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yun, Min S.

2011-01-01

This paper describes the Hubble Space Telescope imaging data products and data reduction procedures for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). This survey is designed to document the evolution of galaxies and black holes at z approximate to 1.5-8, and to study

Water in star-forming regions with Herschel (WISH)

DEFF Research Database (Denmark)

E. Kristensen, L.; F. van Dishoeck, E.; A. Bergin, E.

2012-01-01

was observed in the ground-state transition at 557 GHz with HIFI on Herschel in 29 embedded Class 0 and I protostars. Complementary far-IR and sub-mm continuum data (including PACS data from our program) are used to constrain the spectral energy distribution of each source. H2O intensities are compared...... sources, increasing from 10^-3 at 10^-1 at >10 km/s. The H2O abundance in the outer envelope is low, ~10^-10. The different H2O profile components show a clear evolutionary trend: in the Class 0 sources, emission is dominated by outflow components originating inside an infalling envelope. When the infall...

A HERSCHEL STUDY OF D/H IN WATER IN THE JUPITER-FAMILY COMET 45P/HONDA-MRKOS-PAJDUŠÁKOVÁ AND PROSPECTS FOR D/H MEASUREMENTS WITH CCAT

International Nuclear Information System (INIS)

Lis, D. C.; Blake, G. A.; Biver, N.; Bockelée-Morvan, D.; Crovisier, J.; Moreno, R.

2013-01-01

We present Herschel observations of water isotopologues in the atmosphere of the Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková. No HDO emission is detected, with a 3σ upper limit of 2.0 × 10 –4 for the D/H ratio. This value is consistent with the earlier Herschel measurement in the Jupiter-family comet 103P/Hartley 2. The canonical value of 3 × 10 –4 measured pre-Herschel in a sample of Oort-cloud comets can be excluded at a 4.5σ level. The observations presented here further confirm that a diversity of D/H ratios exists in the comet population and emphasize the need for additional measurements with future ground-based facilities, such as CCAT, in the post-Herschel era

A HERSCHEL AND APEX CENSUS OF THE REDDEST SOURCES IN ORION: SEARCHING FOR THE YOUNGEST PROTOSTARS

Energy Technology Data Exchange (ETDEWEB)

Stutz, Amelia M.; Robitaille, Thomas; Henning, Thomas; Krause, Oliver [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Tobin, John J. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Stanke, Thomas [ESO, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Muenchen (Germany); Megeath, S. Thomas; Fischer, William J. [Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606 (United States); Ali, Babar; Furlan, Elise [NHSC/IPAC/Caltech, 770 S. Wilson Avenue, Pasadena, CA 91125 (United States); Di Francesco, James [National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Hartmann, Lee [Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States); Osorio, Mayra [Instituto de Astrofisica de Andalucia, CSIC, Camino Bajo de Huetor 50, E-18008 Granada (Spain); Wilson, Thomas L. [Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Allen, Lori [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Manoj, P., E-mail: stutz@mpia.de [Department of Physics and Astronomy, 500 Wilson Boulevard, University of Rochester, Rochester, NY 14627 (United States)

2013-04-10

We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using data obtained with the PACS instrument on board the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar candidates are detected at 70 {mu}m and 160 {mu}m that are either too faint (m{sub 24} > 7 mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS 24 {mu}m band. We find that the 11 reddest protostar candidates with log {lambda}F{sub {lambda}}70/{lambda}F{sub {lambda}}24 > 1.65 are free of contamination and can thus be reliably explained as protostars. The remaining 44 sources have less extreme 70/24 colors, fainter 70 {mu}m fluxes, and higher levels of contamination. Taking the previously known sample of Spitzer protostars and the new sample together, we find 18 sources that have log {lambda}F{sub {lambda}}70/{lambda}F{sub {lambda}}24 > 1.65; we name these sources 'PACS Bright Red sources', or PBRs. Our analysis reveals that the PBR sample is composed of Class 0 like sources characterized by very red spectral energy distributions (SEDs; T{sub bol} < 45 K) and large values of sub-millimeter fluxes (L{sub smm}/L{sub bol} > 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2-2 M{sub Sun} and luminosities of 0.7-10 L{sub Sun }. Based on these properties, and a comparison of the SEDs with radiative transfer models of protostars, we conclude that the PBRs are most likely extreme Class 0 objects distinguished by higher than typical envelope densities and hence, high mass infall rates.

THE TYPE Ia SUPERNOVA RATE IN RADIO AND INFRARED GALAXIES FROM THE CANADA-FRANCE-HAWAII TELESCOPE SUPERNOVA LEGACY SURVEY

International Nuclear Information System (INIS)

Graham, M. L.; Pritchet, C. J.; Balam, D.; Fabbro, S.; Sullivan, M.; Hook, I. M.; Howell, D. A.; Gwyn, S. D. J.; Astier, P.; Balland, C.; Guy, J.; Hardin, D.; Pain, R.; Regnault, N.; Basa, S.; Carlberg, R. G.; Perrett, K.; Conley, A.; Fouchez, D.; Rich, J.

2010-01-01

We have combined the large SN Ia database of the Canada-France-Hawaii Telescope Supernova Legacy Survey and catalogs of galaxies with photometric redshifts, Very Large Array 1.4 GHz radio sources, and Spitzer infrared sources. We present eight SNe Ia in early-type host galaxies which have counterparts in the radio and infrared source catalogs. We find the SN Ia rate in subsets of radio and infrared early-type galaxies is ∼1-5 times the rate in all early-type galaxies, and that any enhancement is always ∼<2σ. Rates in these subsets are consistent with predictions of the two-component 'A+B' SN Ia rate model. Since infrared properties of radio SN Ia hosts indicate dust-obscured star formation, we incorporate infrared star formation rates into the 'A+B' model. We also show the properties of SNe Ia in radio and infrared galaxies suggest the hosts contain dust and support a continuum of delay time distributions (DTDs) for SNe Ia, although other DTDs cannot be ruled out based on our data.

Herschel Observations of Gas and Dust in the Unusual 49 Ceti Debris Disk

NARCIS (Netherlands)

Roberge, A.; Kamp, I.; Montesinos, B.; Dent, W. R. F.; Meeus, G.; Donaldson, J. K.; Olofsson, J.; Moor, A.; Augereau, J. -C.; Howard, C.; Eiroa, C.; Thi, W. -F.; Ardila, D. R.; Sandell, G.; Woitke, P.

2013-01-01

We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space

Examining the infrared variable star population discovered in the Small Magellanic Cloud using the SAGE-SMC survey

International Nuclear Information System (INIS)

Polsdofer, Elizabeth; Marengo, M.; Seale, J.; Sewiło, M.; Vijh, U. P.; Terrazas, M.; Meixner, M.

2015-01-01

We present our study on the infrared variability of point sources in the Small Magellanic Cloud (SMC). We use the data from the Spitzer Space Telescope Legacy Program “Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud” (SAGE-SMC) and the “Spitzer Survey of the Small Magellanic Cloud” (S 3 MC) survey, over three different epochs, separated by several months to 3 years. Variability in the thermal infrared is identified using a combination of Spitzer’s InfraRed Array Camera 3.6, 4.5, 5.8, and 8.0 μm bands, and the Multiband Imaging Photometer for Spitzer 24 μm band. An error-weighted flux difference between each pair of three epochs (“variability index”) is used to assess the variability of each source. A visual source inspection is used to validate the photometry and image quality. Out of ∼2 million sources in the SAGE-SMC catalog, 814 meet our variability criteria. We matched the list of variable star candidates to the catalogs of SMC sources classified with other methods, available in the literature. Carbon-rich Asymptotic Giant Branch (AGB) stars make up the majority (61%) of our variable sources, with about a third of all of our sources being classified as extreme AGB stars. We find a small, but significant population of oxygen-rich (O-rich) AGB (8.6%), Red Supergiant (2.8%), and Red Giant Branch (<1%) stars. Other matches to the literature include Cepheid variable stars (8.6%), early type stars (2.8%), Young-stellar objects (5.8%), and background galaxies (1.2%). We found a candidate OH maser star, SSTISAGE1C J005212.88-730852.8, which is a variable O-rich AGB star, and would be the first OH/IR star in the SMC, if confirmed. We measured the infrared variability of a rare RV Tau variable (a post-AGB star) that has recently left the AGB phase. 59 variable stars from our list remain unclassified.

Examining the infrared variable star population discovered in the Small Magellanic Cloud using the SAGE-SMC survey

Energy Technology Data Exchange (ETDEWEB)

Polsdofer, Elizabeth; Marengo, M. [Iowa State University, Department of Physics and Astronomy, 12 Physics Hall, Ames, Iowa 50011 (United States); Seale, J.; Sewiło, M. [The Johns Hopkins University, Department of Physics and Astronomy, 366 Bloomberg Center, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Vijh, U. P.; Terrazas, M. [Ritter Astrophysical Research Center, University of Toledo, Toledo, OH 43606 (United States); Meixner, M., E-mail: empolsdofer@gmail.com [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)

2015-02-01

We present our study on the infrared variability of point sources in the Small Magellanic Cloud (SMC). We use the data from the Spitzer Space Telescope Legacy Program “Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud” (SAGE-SMC) and the “Spitzer Survey of the Small Magellanic Cloud” (S{sup 3}MC) survey, over three different epochs, separated by several months to 3 years. Variability in the thermal infrared is identified using a combination of Spitzer’s InfraRed Array Camera 3.6, 4.5, 5.8, and 8.0 μm bands, and the Multiband Imaging Photometer for Spitzer 24 μm band. An error-weighted flux difference between each pair of three epochs (“variability index”) is used to assess the variability of each source. A visual source inspection is used to validate the photometry and image quality. Out of ∼2 million sources in the SAGE-SMC catalog, 814 meet our variability criteria. We matched the list of variable star candidates to the catalogs of SMC sources classified with other methods, available in the literature. Carbon-rich Asymptotic Giant Branch (AGB) stars make up the majority (61%) of our variable sources, with about a third of all of our sources being classified as extreme AGB stars. We find a small, but significant population of oxygen-rich (O-rich) AGB (8.6%), Red Supergiant (2.8%), and Red Giant Branch (<1%) stars. Other matches to the literature include Cepheid variable stars (8.6%), early type stars (2.8%), Young-stellar objects (5.8%), and background galaxies (1.2%). We found a candidate OH maser star, SSTISAGE1C J005212.88-730852.8, which is a variable O-rich AGB star, and would be the first OH/IR star in the SMC, if confirmed. We measured the infrared variability of a rare RV Tau variable (a post-AGB star) that has recently left the AGB phase. 59 variable stars from our list remain unclassified.

Extending pure luminosity evolution models into the mid-infrared, far-infrared and submillimetre

Science.gov (United States)

Hill, Michael D.; Shanks, Tom

2011-07-01

Simple pure luminosity evolution (PLE) models, in which galaxies brighten at high redshift due to increased star formation rates (SFRs), are known to provide a good fit to the colours and number counts of galaxies throughout the optical and near-infrared. We show that optically defined PLE models, where dust reradiates absorbed optical light into infrared spectra composed of local galaxy templates, fit galaxy counts and colours out to 8 μm and to at least z≈ 2.5. At 24-70 μm, the model is able to reproduce the observed source counts with reasonable success if 16 per cent of spiral galaxies show an excess in mid-IR flux due to a warmer dust component and a higher SFR, in line with observations of local starburst galaxies. There remains an underprediction of the number of faint-flux, high-z sources at 24 μm, so we explore how the evolution may be altered to correct this. At 160 μm and longer wavelengths, the model fails, with our model of normal galaxies accounting for only a few percent of sources in these bands. However, we show that a PLE model of obscured AGN, which we have previously shown to give a good fit to observations at 850 μm, also provides a reasonable fit to the Herschel/BLAST number counts and redshift distributions at 250-500 μm. In the context of a ΛCDM cosmology, an AGN contribution at 250-870 μm would remove the need to invoke a top-heavy IMF for high-redshift starburst galaxies.

NEW YOUNG STAR CANDIDATES IN THE TAURUS-AURIGA REGION AS SELECTED FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

International Nuclear Information System (INIS)

Rebull, L. M.; Padgett, D. L.; Noriega-Crespo, A.

2011-01-01

The Taurus Molecular Cloud subtends a large solid angle on the sky, in excess of 250 deg 2 . The search for legitimate Taurus members to date has been limited by sky coverage as well as the challenge of distinguishing members from field interlopers. The Wide-field Infrared Survey Explorer has recently observed the entire sky, and we take advantage of the opportunity to search for young stellar object (YSO) candidate Taurus members from a ∼260 deg 2 region designed to encompass previously identified Taurus members. We use near- and mid-infrared colors to select objects with apparent infrared excesses and incorporate other catalogs of ancillary data to present a list of rediscovered Taurus YSOs with infrared excesses (taken to be due to circumstellar disks), a list of rejected YSO candidates (largely galaxies), and a list of 94 surviving candidate new YSO-like Taurus members. There is likely to be contamination lingering in this candidate list, and follow-up spectra are warranted.

Developments in fiber-positioning technology for the WEAVE instrument at the William Herschel Telescope

NARCIS (Netherlands)

Schallig, Ellen; Lewis, Ian J.; Gilbert, James; Dalton, Gavin; Brock, Matthew; Abrams, Don Carlos; Middleton, Kevin; Aguerri, J. Alfonso L.; Bonifacio, Piercarlo; Carrasco, Esperanza; Trager, Scott C.; Vallenari, Antonella

2016-01-01

WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) on La Palma in the Canary Islands, Spain. It is a multi-object "pick-and-place" fibre-fed spectrograph with a 1000 fibre multiplex behind a new dedicated 2° prime focus corrector. The WEAVE

A MID-INFRARED CENSUS OF STAR FORMATION ACTIVITY IN BOLOCAM GALACTIC PLANE SURVEY SOURCES

International Nuclear Information System (INIS)

Dunham, Miranda K.; Robitaille, Thomas P.; Evans, Neal J. II; Schlingman, Wayne M.; Cyganowski, Claudia J.; Urquhart, James

2011-01-01

We present the results of a search for mid-infrared signs of star formation activity in the 1.1 mm sources in the Bolocam Galactic Plane Survey (BGPS). We have correlated the BGPS catalog with available mid-IR Galactic plane catalogs based on the Spitzer Space Telescope GLIMPSE legacy survey and the Midcourse Space Experiment (MSX) Galactic plane survey. We find that 44% (3712 of 8358) of the BGPS sources contain at least one mid-IR source, including 2457 of 5067 (49%) within the area where all surveys overlap (10 deg. s tarlessBGPS sources which were not matched to any mid-IR sources. The mean 1.1 mm flux of each group increases with increasing probability of active star formation. We also find that the 'starless' BGPS sources are the most compact, while the sources with the highest probability of star formation activity are on average more extended with large skirts of emission. A subsample of 280 BGPS sources with known distances demonstrates that mass and mean H 2 column density also increase with probability of star formation activity.

EXTREME CONDITIONS IN A CLOSE ANALOG TO THE YOUNG SOLAR SYSTEM: HERSCHEL OBSERVATIONS OF ε ERIDANI

Energy Technology Data Exchange (ETDEWEB)

Greaves, J. S. [SUPA, Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Sibthorpe, B.; Holland, W. S. [UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Acke, B.; Vandenbussche, B.; Blommaert, J. A. D. L. [Instituut voor Sterrenkunde, K. U. Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Pantin, E. E. [Laboratoire AIM, CEA/DSM-CNRS-Universit Paris Diderot, IRFU/Service dAstrophysique, Bat.709, CEA-Saclay, F-91191 Gif- sur-Yvette Cedex (France); Olofsson, G.; Brandeker, A.; De Vries, B. L. [Stockholm University Astrobiology Centre, SE-106 91 Stockholm (Sweden); Dominik, C. [Astronomical Institute Anton Pannekoek, University of Amsterdam, P.O. Box 94249, 1090-GE Amsterdam (Netherlands); Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Bendo, G. J. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Dent, W. R. F. [ALMA SCO, Alonso de Cordova 3107, Vitacura, Casilla 763 0355, Santiago (Chile); Di Francesco, J. [Herzberg Astronomy and Astrophysics Programs, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Fridlund, M. [ESA, SRE-SA, Keplerlaan 1, NL-2201 AZ Noordwijk (Netherlands); Gear, W. K. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Harvey, P. M. [Astronomy Department, University of Texas, Austin, TX 78712 (United States); Hogerheijde, M. R. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Ivison, R. J., E-mail: jsg5@st-andrews.ac.uk [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); and others

2014-08-10

Far-infrared Herschel images of the ε Eridani system, seen at a fifth of the Sun's present age, resolve two belts of debris emission. Fits to the 160 μm PACS image yield radial spans for these belts of 12-16 and 54-68 AU. The south end of the outer belt is ≈10% brighter than the north end in the PACS+SPIRE images at 160, 250, and 350 μm, indicating a pericenter glow attributable to a planet ''c''. From this asymmetry and an upper bound on the offset of the belt center, this second planet should be mildly eccentric (e{sub c} ≈ 0.03-0.3). Compared to the asteroid and Kuiper Belts of the young Sun, the ε Eri belts are intermediate in brightness and more similar to each other, with up to 20 km sized collisional fragments in the inner belt totaling ≈5% of an Earth mass. This reservoir may feed the hot dust close to the star and could send many impactors through the Habitable Zone, especially if it is being perturbed by the suspected planet ε Eri b, at semi-major axis ≈3 AU.

THE PHYSICAL ENVIRONMENT AROUND IRAS 17599–2148: INFRARED DARK CLOUD AND BIPOLAR NEBULA

Energy Technology Data Exchange (ETDEWEB)

Dewangan, L. K.; Janardhan, P. [Physical Research Laboratory, Navrangpura, Ahmedabad 380 009 (India); Ojha, D. K. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Zinchenko, I. [Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov st., Nizhny Novgorod 603950 (Russian Federation); Ghosh, S. K. [National Centre for Radio Astrophysics, Ganeshkhind, Pune 411 007 (India); Luna, A., E-mail: lokeshd@prl.res.in [Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro # 1, Tonantzintla, Puebla, C.P. 72840 (Mexico)

2016-12-20

We present a multiscale and multiwavelength study to investigate the star formation process around IRAS 17599–2148, which is part of an elongated filamentary structure (EFS) (extension ∼21 pc) seen in the Herschel maps. Using the Herschel data analysis, at least six massive clumps (M {sub clump} ∼ 777–7024 M {sub ⊙}) are found in the EFS with a range of temperature and column density of ∼16–39 K and ∼(0.6–11) × 10{sup 22} cm{sup −2} (A {sub V}  ∼ 7–117 mag), respectively. The EFS hosts cold gas regions (i.e., infrared dark cloud) without any radio detection and a bipolar nebula (BN) linked with the H ii region IRAS 17599–2148, tracing two distinct environments inferred through the temperature distribution and ionized emission. Based on virial analysis and higher values of self-gravitating pressure, the clumps are found unstable against gravitational collapse. We find 474 young stellar objects (YSOs) in the selected region, and ∼72% of these YSOs are found in the clusters distributed mainly toward the clumps in the EFS. These YSOs might have spontaneously formed due to processes not related to the expanding H ii region. At the edges of BN, four additional clumps are also associated with YSO clusters, which appear to be influenced by the expanding H ii region. The most massive clump in the EFS contains two compact radio sources traced in the Giant Metre-wave Radio Telescope 1.28 GHz map and a massive protostar candidate, IRS 1, prior to an ultracompact H ii phase. Using the Very Large Telescope/NACO near-infrared images, IRS 1 is resolved with a jet-like feature within a 4200 au scale.

HERSCHEL/HIFI DISCOVERY OF HCL{sup +} IN THE INTERSTELLAR MEDIUM

Energy Technology Data Exchange (ETDEWEB)

De Luca, M.; Gerin, M.; Falgarone, E. [LERMA-LRA, UMR 8112 du CNRS, Observatoire de Paris, Ecole Normale Superieure, UPMC and UCP, 24 rue Lhomond, 75231 Paris Cedex 05 (France); Gupta, H.; Drouin, B. J.; Pearson, J. C. [Jet Propulsion Laboratory, Caltech, Pasadena, CA 91109 (United States); Neufeld, D. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Teyssier, D. [European Space Astronomy Centre, ESA, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Lis, D. C.; Monje, R.; Phillips, T. G. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Goicoechea, J. R.; Godard, B.; Bell, T. A. [Centro de Astrobiologia (CSIC/INTA), Ctra. de Torrejon a Ajalvir, km 4, 28850 Torrejon de Ardoz, Madrid (Spain); Coutens, A. [Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France)

2012-06-01

The radical ion HCl{sup +}, a key intermediate in the chlorine chemistry of the interstellar gas, has been identified for the first time in the interstellar medium with the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared. The ground-state rotational transition of H{sup 35}Cl{sup +}, {sup 2}{Pi}{sub 3/2} J = 5/2-3/2, showing {Lambda}-doubling and hyperfine structure, is detected in absorption toward the Galactic star-forming regions W31C (G10.6-0.4) and W49N. The complex interstellar absorption features are modeled by convolving in velocity space the opacity profiles of other molecular tracers toward the same sources with the fine and hyperfine structure of HCl{sup +}. This structure is derived from a combined analysis of optical data from the literature and new laboratory measurements of pure rotational transitions, reported in the accompanying Letter by Gupta et al. The models reproduce well the interstellar absorption, and the frequencies inferred from the astronomical observations are in exact agreement with those calculated using spectroscopic constants derived from the laboratory data. The detection of H{sup 37}Cl{sup +} toward W31C, with a column density consistent with the expected {sup 35}Cl/{sup 37}Cl isotopic ratio, provides additional evidence for the identification. A comparison with the chemically related molecules HCl and H{sub 2}Cl{sup +} yields an abundance ratio of unity with both species (HCl{sup +} : H{sub 2}Cl{sup +} : HCl {approx} 1). These observations also yield the unexpected result that HCl{sup +} accounts for 3%-5% of the gas-phase chlorine toward W49N and W31C, values several times larger than the maximum fraction ({approx}1%) predicted by chemical models.

A Herschel Study of D/H in Water in the Jupiter-family Comet 45P/Honda-Mrkos-Pajdušáková and Prospects for D/H Measurements with CCAT

Science.gov (United States)

Lis, D. C.; Biver, N.; Bockelée-Morvan, D.; Hartogh, P.; Bergin, E. A.; Blake, G. A.; Crovisier, J.; de Val-Borro, M.; Jehin, E.; Küppers, M.; Manfroid, J.; Moreno, R.; Rengel, M.; Szutowicz, S.

2013-09-01

We present Herschel observations of water isotopologues in the atmosphere of the Jupiter-family comet 45P/Honda-Mrkos-Pajdušáková. No HDO emission is detected, with a 3σ upper limit of 2.0 × 10-4 for the D/H ratio. This value is consistent with the earlier Herschel measurement in the Jupiter-family comet 103P/Hartley 2. The canonical value of 3 × 10-4 measured pre-Herschel in a sample of Oort-cloud comets can be excluded at a 4.5σ level. The observations presented here further confirm that a diversity of D/H ratios exists in the comet population and emphasize the need for additional measurements with future ground-based facilities, such as CCAT, in the post-Herschel era.

Recent advances in infrared astronomy

International Nuclear Information System (INIS)

Robson, E.I.

1980-01-01

A background survey is given of developments in infrared astronomy during the last decade. Advantages obtained in using infrared wavelengths to penetrate the Earth's atmosphere and the detectors used for this work are considered. Infrared studies of, among other subjects, the stars, dust clouds, the centre of our galaxy and the 3k cosmic background radiation, are discussed. (UK)

EXTENDED [C II] EMISSION IN LOCAL LUMINOUS INFRARED GALAXIES

International Nuclear Information System (INIS)

Díaz-Santos, T.; Armus, L.; Surace, J. A.; Charmandaris, V.; Stacey, G.; Murphy, E. J.; Haan, S.; Stierwalt, S.; Evans, A. S.; Malhotra, S.; Appleton, P.; Inami, H.; Magdis, G. E.; Elbaz, D.; Mazzarella, J. M.; Xu, C. K.; Lu, N.; Howell, J. H.; Van der Werf, P. P.; Meijerink, R.

2014-01-01

We present Herschel/PACS observations of extended [C II] 157.7 μm line emission detected on ∼1-10 kpc scales in 60 local luminous infrared galaxies (LIRGs) from the Great Observatories All-sky LIRG Survey. We find that most of the extra-nuclear emission show [C II]/FIR ratios ≥4 × 10 –3 , larger than the mean ratio seen in the nuclei, and similar to those found in the extended disks of normal star-forming galaxies and the diffuse interstellar medium of our Galaxy. The [C II] ''deficits'' found in the most luminous local LIRGs are therefore restricted to their nuclei. There is a trend for LIRGs with warmer nuclei to show larger differences between their nuclear and extra-nuclear [C II]/FIR ratios. We find an anti-correlation between [C II]/FIR and the luminosity surface density, Σ IR , for the extended emission in the spatially resolved galaxies. However, there is an offset between this trend and that found for the LIRG nuclei. We use this offset to derive a beam filling-factor for the star-forming regions within the LIRG disks of ∼6% relative to their nuclei. We confront the observed trend to photo-dissociation region models and find that the slope of the correlation is much shallower than the model predictions. Finally, we compare the correlation found between [C II]/FIR and Σ IR with measurements of high-redshift starbursting IR-luminous galaxies

THE SCUBA-2 COSMOLOGY LEGACY SURVEY: MULTIWAVELENGTH COUNTERPARTS TO 10{sup 3} SUBMILLIMETER GALAXIES IN THE UKIDSS-UDS FIELD

Energy Technology Data Exchange (ETDEWEB)

Chen, Chian-Chou; Smail, Ian; Ma, Cheng-Jiun; Simpson, James M.; Swinbank, A. Mark [Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Ivison, Rob J.; Arumugam, Vinodiran; Mortlock, Alice; Dunlop, James S.; Michałowski, Michał J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Almaini, Omar; Conselice, Christopher J.; Hartley, Will G. [University of Nottingham, School of Physics and Astronomy, Nottingham, NG7 2RD (United Kingdom); Geach, James E. [Center for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Simpson, Chris [Astrophysics Research Institute, Liverpool John Moores University, Liverpool Science Park, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Aretxaga, Itziar [Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Luis Enrique Erro 1, Sta. Ma. Tonantzintla, Puebla (Mexico); Blain, Andrew [Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom); Chapman, Scott C. [Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, NS B3H 4R2 (Canada); Farrah, Duncan [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Halpern, Mark [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); and others

2016-04-01

We present multiwavelength identifications for the counterparts of 1088 submillimeter sources detected at 850 μm in the SCUBA-2 Cosmology Legacy Survey study of the UKIRT Infrared Deep Sky Survey-Ultra-Deep Survey (UDS) field. By utilizing an Atacama Large Millimeter Array (ALMA) pilot study on a subset of our bright SCUBA-2 sample as a training set, along with the deep optical–near-infrared (OIR) data available in this field, we develop a novel technique, Optical–IR Triple Color (OIRTC), using z − K, K − [3.6], [3.6] − [4.5] colors to select the candidate submillimeter galaxy (SMG) counterparts. By combining radio identification and the OIRTC technique, we find counterpart candidates for 80% of the Class = 1 ≥ 4σ SCUBA-2 sample, defined as those that are covered by both radio and OIR imaging and the base sample for our scientific analyses. Based on the ALMA training set, we expect the accuracy of these identifications to be 82% ± 20%, with a completeness of 69% ± 16%, essentially as accurate as the traditional p-value technique but with higher completeness. We find that the fraction of SCUBA-2 sources having candidate counterparts is lower for fainter 850 μm sources, and we argue that for follow-up observations sensitive to SMGs with S{sub 850} ≳ 1 mJy across the whole ALMA beam, the fraction with multiple counterparts is likely to be >40% for SCUBA-2 sources at S{sub 850} ≳ 4 mJy. We find that the photometric redshift distribution for the SMGs is well fit by a lognormal distribution, with a median redshift of z = 2.3 ± 0.1. After accounting for the sources without any radio and/or OIRTC counterpart, we estimate the median redshift to be z = 2.6 ± 0.1 for SMGs with S{sub 850} > 1 mJy. We also use this new large sample to study the clustering of SMGs and the far-infrared properties of the unidentified submillimeter sources by stacking their Herschel SPIRE far-infrared emission.

The Munich Near-Infrared Cluster Survey - IX. Galaxy evolution to z ~ 2 from optically selected catalogues†‡

Science.gov (United States)

Feulner, Georg; Goranova, Yuliana; Hopp, Ulrich; Gabasch, Armin; Bender, Ralf; Botzler, Christine S.; Drory, Niv

2007-06-01

We present B-, R- and I-band-selected galaxy catalogues based on the Munich Near-Infrared Cluster Survey (MUNICS) which, together with the previously used K-selected sample, serve as an important probe of galaxy evolution in the redshift range 0 Karl-Schwarzschild Strasse 2, D-85748, Garching bei München, Germany.

TNOs are Cool: Thermophysical modeling of a sample of 20 classical KBOs using Herschel/PACS

NARCIS (Netherlands)

Vilenius, E.; Müller, T.; Pal, A.; Santos-Sanz, P.; Rengel, M.; Hartogh, P.; Protopapa, S.; Mueller, M.; Mommert, M.; Stansberry, J.; Lellouch, E.; Böhnhardt, H.; Ortiz, J. L.; Thirouin, A.; Henry, F.; Delsanti, A.; Fornasier, S.; Hestroffer, D.; Dotto, E.

2011-01-01

We determine the sizes and albedos of 20 classical Kuiper belt objects. Our observations with the PACS instrument on-board Herschel Space Observatory cover the wavelength range where the thermal emission from trans-Neptunian objects has its maximum. We use a consistent method for data reduction and

The Kepler and K2 Near-Infrared Transit Survey (KNITS)

Science.gov (United States)

Colon, Knicole; Rodriguez, Joseph E.; Barentsen, Geert; Cardoso, Jose Vinicius de Miranda; Vanderburg, Andrew

2018-01-01

NASA's Kepler mission discovered a plethora of transiting exoplanets after observing a single region of the Galaxy for four years. After a second reaction wheel failed, NASA's Kepler spacecraft was repurposed as K2 to observe different fields along the ecliptic in ~80 day campaigns. To date, K2 has discovered ~130 exoplanets along with another ~400 candidates. The exoplanets that have been confirmed or validated from Kepler and K2 have been primarily subject to spectroscopic observations, high-resolution imaging, or statistical methods. However, most of these, along with all the remaining candidate exoplanets, have had no follow-up transit photometry. In addition, recent studies have shown that for single-planet systems, statistical validation alone can be unreliable and additional follow-up observations are required to reveal the true nature of the system. I will present the latest results from an ongoing program to use the 3.5-meter WIYN telescope at Kitt Peak National Observatory for near-infrared transit photometry of Kepler and K2 exoplanets and candidates. Our program of high-precision, high-cadence, high-spatial-resolution near-infrared transit photometry is providing new measurements of the transit ephemerides and planetary radii as well as weeding out false positives lurking within the candidate lists. To date, 25 K2 and 5 Kepler targets have been observed with WIYN. I will also describe upcoming observations with WIYN that will take place in January 2018 as part of a campaign to observe exoplanet transits in the near-infrared simultaneously with the Kepler spacecraft during K2 Campaign 16. Our program ultimately provides a vetted sample of exoplanets that could be targeted in the future by NASA’s James Webb Space Telescope (JWST) and also demonstrates WIYN’s capabilities for observations of exoplanets to be discovered by NASA's all-sky Transiting Exoplanet Survey Satellite (TESS).Data presented herein were obtained at the WIYN Observatory from

The infrared medium-deep survey. II. How to trigger radio AGNs? Hints from their environments

Energy Technology Data Exchange (ETDEWEB)

Karouzos, Marios; Im, Myungshin; Kim, Jae-Woo; Lee, Seong-Kook; Jeon, Yiseul; Choi, Changsu; Hong, Jueun; Hyun, Minhee; Jun, Hyunsung David; Kim, Dohyeong; Kim, Yongjung; Kim, Ji Hoon; Kim, Duho; Park, Won-Kee; Taak, Yoon Chan; Yoon, Yongmin [CEOU—Astronomy Program, Department of Physics and Astronomy, Seoul National University, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Chapman, Scott [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia (Canada); Pak, Soojong [School of Space Research, Kyung Hee University, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Edge, Alastair, E-mail: mkarouzos@astro.snu.ac.kr [Department of Physics, University of Durham, South Road, Durham, DH1 3LE (United Kingdom)

2014-12-10

Activity at the centers of galaxies, during which the central supermassive black hole is accreting material, is nowadays accepted to be rather ubiquitous and most probably a phase of every galaxy's evolution. It has been suggested that galactic mergers and interactions may be the culprits behind the triggering of nuclear activity. We use near-infrared data from the new Infrared Medium-Deep Survey and the Deep eXtragalactic Survey of the VIMOS-SA22 field and radio data at 1.4 GHz from the FIRST survey and a deep Very Large Array survey to study the environments of radio active galactic nuclei (AGNs) over an area of ∼25 deg{sup 2} and down to a radio flux limit of 0.1 mJy and a J-band magnitude of 23 mag AB. Radio AGNs are predominantly found in environments similar to those of control galaxies at similar redshift, J-band magnitude, and (M{sub u} – M{sub r} ) rest-frame color. However, a subpopulation of radio AGNs is found in environments up to 100 times denser than their control sources. We thus preclude merging as the dominant triggering mechanism of radio AGNs. By fitting the broadband spectral energy distribution of radio AGNs in the least and most dense environments, we find that those in the least dense environments show higher radio-loudness, higher star formation efficiencies, and higher accretion rates, typical of the so-called high-excitation radio AGNs. These differences tend to disappear at z > 1. We interpret our results in terms of a different triggering mechanism for these sources that is driven by mass loss through winds of young stars created during the observed ongoing star formation.

A deep near-infrared spectroscopic survey of the Scutum-Crux arm for Wolf-Rayet stars

Science.gov (United States)

Rosslowe, C. K.; Crowther, Paul A.

2018-01-01

We present a New Technology Telescope/Son-of-Isaac spectroscopic survey of infrared selected Wolf-Rayet (WR) candidates in the Scutum-Crux spiral arm (298° ≤ l ≤ 340°, |b| ≤ 0.5°. We obtained near-IR spectra of 127 candidates, revealing 17 WR stars - a ∼13 per cent success rate - of which 16 are newly identified here. The majority of the new WR stars are classified as narrow-lined WN5-7 stars, with two broad-lined WN4-6 stars and three WC6-8 stars. The new stars, with distances estimated from previous absolute magnitude calibrations, have no obvious association with the Scutum-Crux arm. Refined near-infrared (YHJK) classification criteria based on over a hundred Galactic and Magellanic Cloud WR stars, providing diagnostics for hydrogen in WN stars, plus the identification of WO stars and intermediate WN/C stars. Finally, we find that only a quarter of WR stars in the survey region are associated with star clusters and/or H II regions, with similar statistics found for luminous blue variables (LBVs) in the Milky Way. The relative isolation of evolved massive stars is discussed, together with the significance of the co-location of LBVs and WR stars in young star clusters.

A STUDY OF HEATING AND COOLING OF THE ISM IN NGC 1097 WITH HERSCHEL-PACS AND SPITZER-IRS

Energy Technology Data Exchange (ETDEWEB)

Beirao, P.; Armus, L. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Helou, G. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Appleton, P. N. [NASA Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Smith, J.-D. T.; Croxall, K. V. [Department of Physics and Astronomy, Mail Drop 111, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Murphy, E. J. [Carnegie Observatories, Pasadena, CA 91101 (United States); Dale, D. A. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Draine, B. T.; Aniano, G. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Wolfire, M. G.; Bolatto, A. D. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Sandstrom, K. M.; Groves, B.; Schinnerer, E.; Rix, H.-W. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg (Germany); Brandl, B. R. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Crocker, A. F. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Hinz, J. L. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Kennicutt, R. C., E-mail: pedro@ipac.caltech.edu [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); and others

2012-06-01

NGC 1097 is a nearby Seyfert 1 galaxy with a bright circumnuclear starburst ring, a strong large-scale bar, and an active nucleus. We present a detailed study of the spatial variation of the far-infrared (FIR) [C II]158 {mu}m and [O I]63 {mu}m lines and mid-infrared H{sub 2} emission lines as tracers of gas cooling, and of the polycyclic aromatic hydrocarbon (PAH) bands as tracers of the photoelectric heating, using Herschel-PACS and Spitzer-IRS infrared spectral maps. We focus on the nucleus and the ring, and two star-forming regions (Enuc N and Enuc S). We estimated a photoelectric gas heating efficiency ([C II]158 {mu}m+[O I]63 {mu}m)/PAH in the ring about 50% lower than in Enuc N and S. The average 11.3/7.7 {mu}m PAH ratio is also lower in the ring, which may suggest a larger fraction of ionized PAHs, but no clear correlation with [C II]158 {mu}m/PAH(5.5-14 {mu}m) is found. PAHs in the ring are responsible for a factor of two more [C II]158 {mu}m and [O I]63 {mu}m emission per unit mass than PAHs in the Enuc S. spectral energy distribution (SED) modeling indicates that at most 25% of the FIR power in the ring and Enuc S can come from high-intensity photodissociation regions (PDRs), in which case G{sub 0} {approx} 10{sup 2.3} and n{sub H} {approx} 10{sup 3.5} cm{sup -3} in the ring. For these values of G{sub 0} and n{sub H}, PDR models cannot reproduce the observed H{sub 2} emission. Much of the H{sub 2} emission in the starburst ring could come from warm regions in the diffuse interstellar medium that are heated by turbulent dissipation or shocks.

WISE: The Wide-field Infrared Survey Explorer

Science.gov (United States)

Eisenhardt, Peter R.; Wright, E. L.; Benford, D.; Blain, A.; Cohen, M.; Cutri, R.; Gautier, T. N.; Jarrett, T.; Kirkpatrick, J. D.; Leisawitz, D.; Lonsdale, C.; Mainzer, A.; Mather, J.; McLean, I.; McMillan, R.; Mendez, B.; Padgett, D.; Ressler, M.; Skrutskie, M.; Stanford, S. A.; Walker, R.

2009-01-01

WISE will map the entire sky at 3.3, 4.7, 12 and 23 microns with sensitivities of 0.12, 0.16. 0.65, and 2.6 mJy. WISE will find the most luminous galaxies in the universe, the closest stars to the Sun, and detect most main belt asteroids larger than 3 km. WISE will be placed into a Sun-synchronous polar orbit on a Delta 7320-10 rocket, rotating at a constant rate while a scan mirror freezes the line of sight during each exposure, covering the sky in 6 months following a one month checkout. Orbit to orbit overlap provides 8 or more exposures at each location. The instrument, provided by the Space Dynamics Laboratory, includes an all-reflective aluminum telescope with a 40 cm primary built by SSG-Tinsley, a solid hydrogen cryostat built by Lockheed-Martin's Advanced Technology Center, and 1024x1024 pixel Si:As and HgCdTe arrays built by DRS and Teledyne. Dichroic beamsplitters allow simultaneous images in the four bands over a 47'x47' field of view with 5" resolution to be obtained every 11 seconds. Ball Aerospace is providing the spacecraft, including a 500W fixed solar array, Li-ion battery, two star trackers, reaction wheels, and torque rods. The 50 GB per day of images are losslessly compressed, stored in flash memory, and downlinked at 100 Mbps four times per day using a fixed antenna and TDRSS satellites. The Infrared Processing and Analysis Center will process the data and deliver the image atlas and source catalog, with a preliminary release 6 months after the survey, and a final release 2 years after the survey. JPL manages the project for UCLA PI Ned Wright, and conducts mission operations. Education and Public Outreach is provided by UC Berkeley's Space Science Laboratory. WISE hardware is presently being integrated and tested, with launch scheduled in November 2009.

Herschel HIFI GOT C+ Survey: CII, HI, and CO Emissions in a Sample of Transition Clouds and Star-Forming regions in the Inner Galaxy

Science.gov (United States)

Pineda, Jorge; Velusamy, Thangasamy; Langer, William D.; Goldsmith, Paul; Li, Di; Yorke, Harold

The GOT C+ a HIFI Herschel Key Project, studies the diffuse ISM throughout the Galactic Plane, using C+ as cloud tracer. The C+ line at 1.9 THz traces a so-far poorly studied stage in ISM cloud evolution -the transitional clouds going from atomic HI to molecular H2. This transition cloud phase, which is difficult to observe in HI and CO alone, may be best characterized via CII emission or absorption. The C+ line is also an excellent tracer of the warm diffuse gas and the warm, dense gas in the Photon Dominated Regions (PDRs). We can, therefore, use the CII emission as a probe to understand the effects of star formation on their interstellar environment. We present our first results on the transition between dense and hot gas (traced by CII) and dense and cold gas (traced by 12CO and 13CO) along a few representative lines of sight in the inner Galaxy from longitude 325 degrees to 25 degrees, taken during the HIFI Priority Science Phase. Comparisons of the high spectral resolution ( 1 km/s) HIFI data on C+ with HI, 12CO, and 13CO spectra allow us to separate out the different ISM components along each line of sight. Our results provide detailed information about the transition of diffuse atomic to molecular gas clouds needed to understand star formation and the lifecycle of the interstellar gas. These observations are being carried out with the Herschel Space Observatory, which is an ESA cornerstone mission, with contributions from NASA. This research was conducted at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space Administration. JLP was supported under the NASA Postdoctoral Program at JPL, Caltech, administered by Oak Ridge Associated Universities through a contract with NASA, and is currently supported as a Caltech-JPL Postdoctoral associate.

THE FOURSTAR GALAXY EVOLUTION SURVEY (ZFOURGE): ULTRAVIOLET TO FAR-INFRARED CATALOGS, MEDIUM-BANDWIDTH PHOTOMETRIC REDSHIFTS WITH IMPROVED ACCURACY, STELLAR MASSES, AND CONFIRMATION OF QUIESCENT GALAXIES TO z ∼ 3.5

International Nuclear Information System (INIS)

Straatman, Caroline M. S.; Labbé, Ivo; Van Houdt, Josha; Spitler, Lee R.; Cowley, Michael; Quadri, Ryan F.; Papovich, Casey; Tran, Kim-Vy H.; Tomczak, Adam; Alcorn, Leo; Broussard, Adam; Forrest, Ben; Kawinwanichakij, Lalitwadee; Glazebrook, Karl; Nanayakkara, Themiya; Allen, Rebecca; Kacprzak, Glenn G.; Persson, S. Eric; Brammer, Gabriel B.; Van Dokkum, Pieter

2016-01-01

The FourStar galaxy evolution survey (ZFOURGE) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date. ZFOURGE covers a total of 400 arcmin 2 in cosmic fields CDFS, COSMOS and UDS, overlapping CANDELS. We present photometric catalogs comprising >70,000 galaxies, selected from ultradeep K s -band detection images (25.5–26.5 AB mag, 5 σ , total), and >80% complete to K s < 25.3–25.9 AB. We use 5 near-IR medium-bandwidth filters ( J 1 , J 2 , J 3 , H s , H l ) as well as broad-band K s at 1.05–2.16 μ m to 25–26 AB at a seeing of ∼0.″5. Each field has ancillary imaging in 26–40 filters at 0.3–8 μ m. We derive photometric redshifts and stellar population properties. Comparing with spectroscopic redshifts indicates a photometric redshift uncertainty σ z = 0.010, 0.009, and 0.011 in CDFS, COSMOS, and UDS. As spectroscopic samples are often biased toward bright and blue sources, we also inspect the photometric redshift differences between close pairs of galaxies, finding σ z ,pairs = 0.01–0.02 at 1 < z < 2.5. We quantify how σ z ,pairs depends on redshift, magnitude, spectral energy distribution type, and the inclusion of FourStar medium bands. σ z ,pairs is smallest for bright, blue star-forming samples, while red star-forming galaxies have the worst σ z ,pairs . Including FourStar medium bands reduces σ z ,pairs by 50% at 1.5 < z < 2.5. We calculate star formation rates (SFRs) based on ultraviolet and ultradeep far-IR Spitzer /MIPS and Herschel /PACS data. We derive rest-frame U − V and V − J colors, and illustrate how these correlate with specific SFR and dust emission to z = 3.5. We confirm the existence of quiescent galaxies at z ∼ 3, demonstrating their SFRs are suppressed by > ×15.

AKARI NEAR-INFRARED SPECTROSCOPIC SURVEY FOR CO{sub 2} IN 18 COMETS

Energy Technology Data Exchange (ETDEWEB)

Ootsubo, Takafumi [Astronomical Institute, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Kawakita, Hideyo; Hamada, Saki; Kobayashi, Hitomi; Yamaguchi, Mitsuru [Koyama Astronomical Observatory, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555 (Japan); Usui, Fumihiko; Nakagawa, Takao; Ueno, Munetaka [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Ishiguro, Masateru [Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Sekiguchi, Tomohiko [Department of Teacher Training, Hokkaido University of Education, Asahikawa Campus, Hokumon 9, Asahikawa, Hokkaido 070-8621 (Japan); Watanabe, Jun-ichi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Sakon, Itsuki; Shimonishi, Takashi; Onaka, Takashi, E-mail: ootsubo@astr.tohoku.ac.jp [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2012-06-10

We conducted a spectroscopic survey of cometary volatiles with the Infrared Camera on board the Japanese infrared satellite AKARI in the wavelength range from 2.5 to 5 {mu}m. In our survey, 18 comets, including both the Oort cloud comets and the Jupiter-family comets, were observed in the period from 2008 June to 2010 January, most of which were observed at least twice. The prominent emission bands in the observed spectra are the fundamental vibrational bands of water (H{sub 2}O) at 2.7 {mu}m and carbon dioxide (CO{sub 2}) at 4.3 {mu}m. The fundamental vibrational band of carbon monoxide (CO) around 4.7 {mu}m and the broad emission feature, probably related to carbon-hydrogen-bearing molecules, can also be recognized around the 3.3-3.5-{mu}m region in some of the comets. With respect to H{sub 2}O, gas production rate ratios of CO{sub 2} have been derived in 17 comets, except for the comet 29P/Schwassmann-Wachmann 1. Our data set provides the largest homogeneous database of CO{sub 2}/H{sub 2}O production rate ratios in comets obtained so far. The CO{sub 2}/H{sub 2}O production rate ratios are considered to reflect the composition of cometary ice when a comet is observed at a heliocentric distance within {approx}2.5 AU, since H{sub 2}O ice fully sublimates there. The CO{sub 2}/H{sub 2}O ratio in cometary ice spans from several to {approx}30% among the comets observed at <2.5 AU (13 out of the 17 comets). Alternatively, the ratio of CO/CO{sub 2} in the comets seems to be smaller than unity based on our observations, although we only obtain upper limits for CO in most of the comets.

Herschel/HIFI observations of CO, H2O and NH3 in Monoceros R2

NARCIS (Netherlands)

Pilleri, P.; Fuente, A.; Cernicharo, J.; Ossenkopf, V.; Berne, O.; Gerin, M.; Pety, J.; Goicoechea, J. R.; Rizzo, J. R.; Montillaud, J.; Gonzalez-Garcia, M.; Joblin, C.; Le Bourlot, J.; Le Petit, F.; Kramer, C.

Context. Mon R2, at a distance of 830 pc, is the only ultracompact H II region (UCH II) where the associated photon-dominated region (PDR) can be resolved with Herschel. Owing to its brightness and proximity, it is one of the best-suited sources for investigating the chemistry and physics of highly

LUMINOUS AND HIGH STELLAR MASS CANDIDATE GALAXIES AT z ≈ 8 DISCOVERED IN THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

International Nuclear Information System (INIS)

Yan Haojing; Finkelstein, Steven L.; Huang, Kuang-Han; Ryan, Russell E.; Ferguson, Henry C.; Koekemoer, Anton M.; Grogin, Norman A.; Dickinson, Mark; Newman, Jeffrey A.; Somerville, Rachel S.; Davé, Romeel; Faber, S. M.; Papovich, Casey; Guo Yicheng; Giavalisco, Mauro; Lee, Kyoung-soo; Reddy, Naveen; Siana, Brian D.; Cooray, Asantha R.; Hathi, Nimish P.

2012-01-01

One key goal of the Hubble Space Telescope Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey is to track galaxy evolution back to z ≈ 8. Its two-tiered ''wide and deep'' strategy bridges significant gaps in existing near-infrared surveys. Here we report on z ≈ 8 galaxy candidates selected as F105W-band dropouts in one of its deep fields, which covers 50.1 arcmin 2 to 4 ks depth in each of three near-infrared bands in the Great Observatories Origins Deep Survey southern field. Two of our candidates have J 1 mag brighter than any previously known F105W-dropouts. We derive constraints on the bright end of the rest-frame ultraviolet luminosity function of galaxies at z ≈ 8, and show that the number density of such very bright objects is higher than expected from the previous Schechter luminosity function estimates at this redshift. Another two candidates are securely detected in Spitzer Infrared Array Camera images, which are the first such individual detections at z ≈ 8. Their derived stellar masses are on the order of a few × 10 9 M ☉ , from which we obtain the first measurement of the high-mass end of the galaxy stellar mass function at z ≈ 8. The high number density of very luminous and very massive galaxies at z ≈ 8, if real, could imply a large stellar-to-halo mass ratio and an efficient conversion of baryons to stars at such an early time.

VizieR Online Data Catalog: Stellar mass of brightest cluster galaxies (Bellstedt+, 2016)

Science.gov (United States)

Bellstedt, S.; Lidman, C.; Muzzin, A.; Franx, M.; Guatelli, S.; Hill, A. R.; Hoekstra, H.; Kurinsky, N.; Labbe, I.; Marchesini, D.; Marsan, Z. C.; Safavi-Naeini, M.; Sifon, C.; Stefanon, M.; van de Sande, J.; van Dokkum, P.; Weigel, C.

2017-11-01

We utilize a sample of 98 newly imaged galaxy clusters from the RELICS (REd Lens Infrared Cluster Survey) survey within this study. The data were collected during six observing runs on three instruments over a period spanning from 2013 October to 2015 March. The instruments utilized were the SofI2 camera on the New Technology Telescope at the European Southern Observatory (ESO) La Silla Observatory in Chile, WHIRC3 on the WIYN telescope at the Kitt Peak National Observatory and LIRIS4 on the William Herschel Telescope (WHT) in La Palma, Spain. (2 data files).

A survey of infrared continuum versus line radiation from metal halide lamps

International Nuclear Information System (INIS)

Kato, M; Herd, M T; Lawler, J E

2008-01-01

Near-infrared radiation (near-IR) losses from the arcs of six commercial metal halide high intensity discharge (MH-HID) lamps with various power levels and with both Na/Sc and rare earth doses were surveyed in this paper. A radiometrically calibrated Fourier transform infrared spectrometer was used. Lamps with rare earth doses have appreciably better color rendering indices (CRIs) than lamps with Na/Sc doses. The ratios of near-IR continuum emission over near-IR line emission from these six lamps were compared. The near-IR continuum dominates near-IR losses from lamps with rare earth doses and the continuum is significant, but not dominant, from lamps with Na/Sc doses. There was no strong dependence of this ratio on input power or color temperature (T c ). Total near-IR losses were estimated using absolutely calibrated, horizontal irradiance measurements. Estimated total near-IR losses were correlated with CRI. The lamps with rare earth doses yield the best CRIs, but have appreciably higher near-IR losses due primarily to continuum processes. One of these rare earth MH-HID lamps was used in a more detailed study of the microscopic physics of the continuum mechanism (Herd M T and Lawler E 2007 J. Phys. D: Appl. Phys. 40 3386)

THE TAIWAN ECDFS NEAR-INFRARED SURVEY: VERY BRIGHT END OF THE LUMINOSITY FUNCTION AT z > 7

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Bau-Ching; Wang, Wei-Hao; Lin, Lihwai; Lim, Jeremy; Ho, Paul T. P. [Institute of Astrophysics and Astronomy, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China); Yan, Haojing [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Karoji, Hiroshi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Tsai, Chao-Wei [Infrared Processing and Analysis Center, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States)

2012-04-10

The primary goal of the Taiwan ECDFS Near-Infrared Survey (TENIS) is to find well-screened galaxy candidates at z > 7 (z' dropout) in the Extended Chandra Deep Field-South (ECDFS). To this end, TENIS provides relatively deep J and K{sub s} data ({approx}25.3 ABmag, 5{sigma}) for an area of 0.5 Multiplication-Sign 0.5 deg. Leveraged with existing data at mid-infrared to optical wavelengths, this allows us to screen for the most luminous high-z objects, which are rare and thus require a survey over a large field to be found. We introduce new color selection criteria to select a z > 7 sample with minimal contaminations from low-z galaxies and Galactic cool stars; to reduce confusion in the relatively low angular resolution Infrared Array Camera (IRAC) images, we introduce a novel deconvolution method to measure the IRAC fluxes of individual sources. Illustrating perhaps the effectiveness at which we screen out interlopers, we find only one z > 7 candidate, TENIS-ZD1. The candidate has a weighted z{sub phot} of 7.8, and its colors and luminosity indicate a young (45M years old) starburst galaxy with a stellar mass of 3.2 Multiplication-Sign 10{sup 10} M{sub Sun }. The result matches with the observational luminosity function analysis and the semianalytic simulation result based on the Millennium Simulations, which may over predict the volume density for high-z massive galaxies. The existence of TENIS-ZD1, if confirmed spectroscopically to be at z > 7, therefore poses a challenge to current theoretical models for how so much mass can accumulate in a galaxy at such a high redshift.

A Nonlinear Model for Designing Herschel-Quincke Waveguide Arrays to Attenuate Shock Waves from Transonic Turbofan Engines, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Techsburg is teaming with the Vibration and Acoustics Laboratory of Virginia Tech to propose a non-linear analytical tool for designing Herschel-Quincke (HQ)...

Discovery of water vapour in the carbon star V Cygni from observations with Herschel/HIFI

NARCIS (Netherlands)

Neufeld, D. A.; Gonzalez-Alfonso, E.; Melnick, G.; Pulecka, M.; Schmidt, M.; Szczerba, R.; Bujarrabal, V.; Alcolea, J.; Cernicharo, J.; Decin, L.; Dominik, C.; Justtanont, K.; de Koter, A.; Marston, A. P.; Menten, K.; Olofsson, H.; Planesas, P.; Schoier, F. L.; Teyssier, D.; Waters, L. B. F. M.; Edwards, K.; McCoey, C.; Shipman, R.; Jellema, W.; de Graauw, T.; Ossenkopf, V.; Schieder, R.; Philipp, S.

2010-01-01

We report the discovery of water vapour toward the carbon star V Cygni. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 1(11)-0(00) para-water transition at 1113.3430 GHz in the upper sideband of the Band 4b receiver. The observed spectral line profile is nearly

Shockingly low water abundances in Herschel/PACS observations of low-mass protostars in Perseus

DEFF Research Database (Denmark)

Karska, A.; Kristensen, L. E.; Dishoeck, E. F. van

2014-01-01

Protostars interact with their surroundings through jets and winds impacting on the envelope and creating shocks, but the nature of these shocks is still poorly understood. Our aim is to survey far-infrared molecular line emission from a uniform and significant sample of deeply-embedded low...

Analysis of the Herschel DEBRIS Sun-like star sample

Science.gov (United States)

Sibthorpe, B.; Kennedy, G. M.; Wyatt, M. C.; Lestrade, J.-F.; Greaves, J. S.; Matthews, B. C.; Duchêne, G.

2018-04-01

This paper presents a study of circumstellar debris around Sun-like stars using data from the Herschel DEBRIS Key Programme. DEBRIS is an unbiased survey comprising the nearest ˜90 stars of each spectral type A-M. Analysis of the 275 F-K stars shows that excess emission from a debris disc was detected around 47 stars, giving a detection rate of 17.1^{+2.6}_{-2.3} per cent, with lower rates for later spectral types. For each target a blackbody spectrum was fitted to the dust emission to determine its fractional luminosity and temperature. The derived underlying distribution of fractional luminosity versus blackbody radius in the population showed that most detected discs are concentrated at f ˜ 10-5 and at temperatures corresponding to blackbody radii 7-40 au, which scales to ˜40 au for realistic dust properties (similar to the current Kuiper belt). Two outlying populations are also evident; five stars have exceptionally bright emission ( f > 5 × 10-5), and one has unusually hot dust <4 au. The excess emission distributions at all wavelengths were fitted with a steady-state evolution model, showing that these are compatible with all stars being born with a narrow belt that then undergoes collisional grinding. However, the model cannot explain the hot dust systems - likely originating in transient events - and bright emission systems - arising potentially from atypically massive discs or recent stirring. The emission from the present-day Kuiper belt is predicted to be close to the median of the population, suggesting that half of stars have either depleted their Kuiper belts (similar to the Solar system) or had a lower planetesimal formation efficiency.

THE ORION H ii REGION AND THE ORION BAR IN THE MID-INFRARED

International Nuclear Information System (INIS)

Salgado, F.; Tielens, A. G. G. M.; Berné, O.; Adams, J. D.; Herter, T. L.; Keller, L. D.

2016-01-01

We present mid-infrared photometry of the Orion bar obtained with the Faint Object infraRed Camera for the SOFIA Telescope (FORCAST) on board SOFIA at 6.4, 6.6, 7.7, 19.7, 31.5, and 37.1 μ m. By complementing this observation with archival FORCAST and Herschel /PACS images, we are able to construct a complete infrared spectral energy distribution of the Huygens region in the Orion nebula. Comparing the infrared images with gas tracers, we find that PACS maps trace the molecular cloud, while the FORCAST data trace the photodissociation region (PDR) and the H ii region. Analysis of the energetics of the region reveal that the PDR extends for 0.28 pc along the line of sight and that the bar is inclined at an angle of 4°. The infrared and submillimeter images reveal that the Orion bar represents a swept-up shell with a thickness of 0.1 pc. The mass of the shell implies a shock velocity of ≃3 km s −1 and an age of ≃10 5 years for the H ii region. Our analysis shows that the UV and infrared dust opacities in the H ii region and the PDR are a factor 5 to 10 lower than in the diffuse interstellar medium. In the ionized gas, Ly α photons are a major source of dust heating at distances larger than ≃0.06 pc from θ 1 Ori C. Dust temperatures can be explained if the size of the grains is between 0.1 and 1 μ m. We derive the photoelectric heating efficiency of the atomic gas in the Orion bar. The results are in good qualitative agreement with models and the quantitative differences indicate a decreased polycyclic aromatic hydrocarbon abundance in this region.

THE ORION H ii REGION AND THE ORION BAR IN THE MID-INFRARED

Energy Technology Data Exchange (ETDEWEB)

Salgado, F.; Tielens, A. G. G. M. [Leiden Observatory, University of Leiden, P.O. Box 9513, 2300 RA Leiden (Netherlands); Berné, O. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Adams, J. D.; Herter, T. L. [Astronomy Department, 202 Space Sciences Building, Cornell University, Ithaca, NY 14853-6801 (United States); Keller, L. D. [Department of Physics and Astronomy, Ithaca College, Ithaca, NY 14850 (United States)

2016-10-20

We present mid-infrared photometry of the Orion bar obtained with the Faint Object infraRed Camera for the SOFIA Telescope (FORCAST) on board SOFIA at 6.4, 6.6, 7.7, 19.7, 31.5, and 37.1 μ m. By complementing this observation with archival FORCAST and Herschel /PACS images, we are able to construct a complete infrared spectral energy distribution of the Huygens region in the Orion nebula. Comparing the infrared images with gas tracers, we find that PACS maps trace the molecular cloud, while the FORCAST data trace the photodissociation region (PDR) and the H ii region. Analysis of the energetics of the region reveal that the PDR extends for 0.28 pc along the line of sight and that the bar is inclined at an angle of 4°. The infrared and submillimeter images reveal that the Orion bar represents a swept-up shell with a thickness of 0.1 pc. The mass of the shell implies a shock velocity of ≃3 km s{sup −1} and an age of ≃10{sup 5} years for the H ii region. Our analysis shows that the UV and infrared dust opacities in the H ii region and the PDR are a factor 5 to 10 lower than in the diffuse interstellar medium. In the ionized gas, Ly α photons are a major source of dust heating at distances larger than ≃0.06 pc from θ {sup 1} Ori C. Dust temperatures can be explained if the size of the grains is between 0.1 and 1 μ m. We derive the photoelectric heating efficiency of the atomic gas in the Orion bar. The results are in good qualitative agreement with models and the quantitative differences indicate a decreased polycyclic aromatic hydrocarbon abundance in this region.

EMBEDDED PROTOSTARS IN THE DUST, ICE, AND GAS IN TIME (DIGIT) HERSCHEL KEY PROGRAM: CONTINUUM SEDs, AND AN INVENTORY OF CHARACTERISTIC FAR-INFRARED LINES FROM PACS SPECTROSCOPY

Energy Technology Data Exchange (ETDEWEB)

Green, Joel D.; Evans, Neal J. II; Rascati, Michelle R. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Jorgensen, Jes K.; Dionatos, Odysseas; Lindberg, Johan E. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Herczeg, Gregory J. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Kristensen, Lars E.; Yildiz, Umut A.; Van Kempen, Tim A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300-RA Leiden (Netherlands); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Gyeonggi 446-701 (Korea, Republic of); Salyk, Colette [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Meeus, Gwendolyn [Dpt. Fisica Teorica, Universidad Autonoma de Madrid, Campus Cantoblanco, E-28049 Madrid (Spain); Bouwman, Jeroen [Max Planck Institute for Astronomy, D-69117 Heidelberg (Germany); Visser, Ruud; Bergin, Edwin A. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Van Dishoeck, Ewine F.; Karska, Agata; Fedele, Davide [Max-Planck Institute for Extraterrestrial Physics, Postfach 1312, D-85741 Garching (Germany); Dunham, Michael M., E-mail: joel@astro.as.utexas.edu [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Collaboration: DIGIT Team1

2013-06-20

We present 50-210 {mu}m spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 {mu}m spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H{sub 2}O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rotational lines ranging from J = 14 {yields} 13 up to J = 40 {yields} 39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two very low luminosity objects. The mean 63/145 {mu}m [O I] flux ratio is 17.2 {+-} 9.2. The [O I] 63 {mu}m line correlates with L{sub bol}, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample L{sub bol} increased by 1.25 (1.06) and T{sub bol} decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ( = (0.70 {+-} 1.12) x 10{sup 49} total particles). N{sub CO} correlates strongly with L{sub bol}, but neither T{sub rot} nor N{sub CO}(warm)/N{sub CO}(hot) correlates with L{sub bol}, suggesting that the total excited gas is related to the current source luminosity, but that the excitation is primarily determined by the physics of the interaction (e.g., UV-heating/shocks). Rotational temperatures for H{sub 2}O ( = 194 +/- 85 K) and OH ( = 183 +/- 117 K) are generally lower than for CO, and much of the scatter in the observations about the best fit is attributed to differences in excitation conditions and optical depths among the detected lines.

HERSCHEL* FAR-INFRARED SPECTROSCOPY OF THE GALACTIC CENTER. HOT MOLECULAR GAS: SHOCKS VERSUS RADIATION NEAR Sgr A

Energy Technology Data Exchange (ETDEWEB)

Goicoechea, Javier R.; Etxaluze, M.; Cernicharo, J.; Bell, T. A. [Departamento de Astrofisica, Centro de Astrobiologia, CSIC-INTA, Carretera de Ajalvir, Km 4, Torrejon de Ardoz, E-28850 Madrid (Spain); Gerin, M.; De Luca, M.; Encrenaz, P. [LERMA, UMR 8112 du CNRS, Observatoire de Paris, Ecole Normale Superieure (France); Neufeld, D. A.; Indriolo, N. [Johns Hopkins University, Baltimore, MD 21218 (United States); Contursi, A. [Max-Planck-Institut fuer extraterrestrische Physik (MPE), Postfach 1312, D-85741 Garching (Germany); Lis, D. C. [California Institute of Technology, Pasadena, CA 91125 (United States); Polehampton, E. T. [RAL Space, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Sonnentrucker, P., E-mail: jr.goicoechea@cab.inta-csic.es [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

2013-05-20

We present a {approx}52-671 {mu}m spectral scan toward Sgr A* taken with the PACS and SPIRE spectrometers on board Herschel. The achieved angular resolution allows us to separate, for the first time at far-IR wavelengths, the emission toward the central cavity (gas in the inner central parsec of the galaxy) from that of the surrounding circumnuclear disk. The spectrum toward Sgr A* is dominated by strong [O III], [O I], [C II], [N III], [N II], and [C I] fine-structure lines (in decreasing order of luminosity) arising in gas irradiated by UV photons from the central stellar cluster. In addition, rotationally excited lines of {sup 12}CO (from J = 4-3 to 24-23), {sup 13}CO, H{sub 2}O, OH, H{sub 3}O{sup +}, HCO{sup +}, and HCN, as well as ground-state absorption lines of OH{sup +}, H{sub 2}O{sup +}, H{sub 3}O{sup +}, CH{sup +}, H{sub 2}O, OH, HF, CH, and NH are detected. The excitation of the {sup 12}CO ladder is consistent with a hot isothermal component at T{sub k} {approx_equal} 10{sup 3.1} K and n(H{sub 2}) {approx}< 10{sup 4} cm{sup -3}. It is also consistent with a distribution of temperature components at higher density with most CO at T{sub k} {approx}< 300 K. The detected molecular features suggest that, at present, neither very enhanced X-ray nor cosmic-ray fluxes play a dominant role in the heating of the hot molecular gas. The hot CO component (either the bulk of the CO column or just a small fraction depending on the above scenario) results from a combination of UV- and shock-driven heating. If irradiated dense clumps/clouds do not exist, shocks likely dominate the heating of the hot molecular gas. This is consistent with the high-velocity gas detected toward Sgr A*.

Herschel CHESS discovery of the fossil cloud that gave birth to the Trapezium and Orion KL

NARCIS (Netherlands)

López-Sepulcre, A.; Kama, M.; Ceccarelli, C.; Dominik, C.; Caux, E.; Fuente, A.; Alonso-Albi, T.

2013-01-01

Context. The Orion A molecular complex is a nearby (420 pc), very well studied stellar nursery that is believed to contain examples of triggered star formation. Aims. As part of the Herschel guaranteed time key programme CHESS, we present the discovery of a diffuse gas component in the foreground of

Infrared Photometric Study of Wolf–Rayet Galaxies

Science.gov (United States)

Chen, P. S.; Yang, X. H.; Liu, J. Y.; Shan, H. G.

2018-01-01

We collected observational data on 781 Wolf–Rayet (WR) galaxies from the literature to photometrically study their infrared properties measured by the 2MASS, WISE, IRAS, AKARI, and Herschel missions. It is found that in the 1–5 μm range the radiations of WR galaxies are dominated by the free–free emissions from the stellar winds and the circumstellar dust from the late-type stars in the host galaxy. In the 5–22 μm range, the radiation of WR galaxies is dominated by the free–free emissions and the synchrotron radiation from the central active galactic nucleus (AGN; but not always present). In the 22–140 μm range, the radiations of WR galaxies are dominated by the free–free emissions and the star formation/starburst activities. In the 250–500 μm range, the radiation of WR galaxies is dominated by the free–free emissions. In addition, the comparison with the non-WR galaxies is made. It is shown that some star formation WR galaxies have redder near-infrared colors than non-WR star-forming galaxies probably due to the gas emission in the near-infrared. In the 2–5 μm region WR galaxies have redder colors due to the thermal emission from circumstellar dust of late-type stars and the enhanced gas emission. In the 5–22 μm region, both WR galaxies and non-WR galaxies have similar behavior, indicative of having similar free–free emission as the dominant radiation. In the 25–140 μm region, both types of galaxies also have similar behavior, indicative of having free–free emission from the stellar winds or the thermal radiation from the starburst/star formation as the dominant radiation.

Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15

DEFF Research Database (Denmark)

Kristensen, Lars Egstrøm; Van Dishoeck, E. F.; Mottram, J. C.

2017-01-01

Context. Through spectrally unresolved observations of high-J CO transitions, Herschel Photodetector Array Camera and Spectrometer (PACS) has revealed large reservoirs of warm (300 K) and hot (700 K) molecular gas around low-mass protostars. The excitation and physical origin of this gas is still...... in cooling molecular H2-poor gas just prior to the onset of H2 formation. High spectral resolution observations of highly excited CO transitions uniquely shed light on the origin of warm and hot gas in low-mass protostellar objects....... not understood. Aims. We aim to shed light on the excitation and origin of the CO ladder observed toward protostars, and on the water abundance in different physical components within protostellar systems using spectrally resolved Herschel-HIFI data. Methods. Observations are presented of the highly excited CO...

THE UNIFICATION OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Podigachoski, Pece; Barthel, Peter [Kapteyn Astronomical Institute, University of Groningen, 9747 AD Groningen (Netherlands); Haas, Martin [Astronomisches Institut, Ruhr Universität, D-44801 Bochum (Germany); Leipski, Christian [Max-Planck Institut für Astronomie (MPIA), D-69117 Heidelberg (Germany); Wilkes, Belinda, E-mail: podigachoski@astro.rug.nl [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2015-06-10

The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the unification model. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies.

THE UNIFICATION OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES

International Nuclear Information System (INIS)

Podigachoski, Pece; Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda

2015-01-01

The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the unification model. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies

GLOBAL STAR FORMATION RATES AND DUST EMISSION OVER THE GALAXY INTERACTION SEQUENCE

Energy Technology Data Exchange (ETDEWEB)

Lanz, Lauranne; Zezas, Andreas; Smith, Howard A.; Ashby, Matthew L. N.; Fazio, Giovanni G.; Hernquist, Lars [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Brassington, Nicola [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield, AL10 9AB (United Kingdom); Da Cunha, Elisabete [Max Planck Institute for Astronomy (MPIA), Koenigstuhl 17, D-69117, Heidelberg (Germany); Hayward, Christopher C. [Heidelberger Institut fuer Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118, Heidelberg (Germany); Jonsson, Patrik, E-mail: llanz@head.cfa.harvard.edu [Space Exploration Technologies, 1 Rocket Road, Hawthorne, CA 90250 (United States)

2013-05-01

We measured and modeled spectral energy distributions (SEDs) in 28 bands from the ultraviolet to the far-infrared (FIR) for 31 interacting galaxies in 14 systems. The sample is drawn from the Spitzer Interacting Galaxy Survey, which probes a range of galaxy interaction parameters at multiple wavelengths with an emphasis on the infrared bands. The subset presented in this paper consists of all galaxies for which FIR Herschel SPIRE observations are publicly available. Our SEDs combine the Herschel photometry with multi-wavelength data from Spitzer, GALEX, Swift UVOT, and 2MASS. While the shapes of the SEDs are broadly similar across our sample, strongly interacting galaxies typically have more mid-infrared emission relative to their near-infrared and FIR emission than weakly or moderately interacting galaxies. We modeled the full SEDs to derive host galaxy star formation rates (SFRs), specific star formation rates (sSFRs), stellar masses, dust temperatures, dust luminosities, and dust masses. We find increases in the dust luminosity and mass, SFR, and cold (15-25 K) dust temperature as the interaction progresses from moderately to strongly interacting and between non-interacting and strongly interacting galaxies. We also find increases in the SFR between weakly and strongly interacting galaxies. In contrast, the sSFR remains unchanged across all the interaction stages. The ultraviolet photometry is crucial for constraining the age of the stellar population and the SFR, while dust mass is primarily determined by SPIRE photometry. The SFR derived from the SED modeling agrees well with rates estimated by proportionality relations that depend on infrared emission.

QUANTIFYING THE HEATING SOURCES FOR MID-INFRARED DUST EMISSIONS IN GALAXIES: THE CASE OF M 81

Energy Technology Data Exchange (ETDEWEB)

Lu, N.; Zhao, Y. [Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States); Bendo, G. J. [Jordrell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Boselli, A. [Laboratoire d' Astrophysique de Marseille-LAM, Université d' Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Baes, M.; De Looze, I. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Wu, H.; Lam, M. I. [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Beijing 100012 (China); Madden, S. C.; Rémy-Ruyer, A. [Laboratoire AIM, CEA, Université Paris VII, IRFU/Service d' Ástrophysique, Bat. 709, F-91191 Gif-sur-Yvette (France); Boquien, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Wilson, C. D. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Galametz, M. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching-bei-Mnchen (Germany); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Spinoglio, L., E-mail: lu@ipac.caltech.edu [Istituto di Astrofisica e Planetologia Spaziali, INAF, Via Fosso del Cavaliere 100, I-00133 Roma (Italy)

2014-12-20

With the newly available photometric images at 250 and 500 μm from the Herschel Space Observatory, we study quantitative correlations over a sub-kiloparsec scale among three distinct emission components in the interstellar medium of the nearby spiral galaxy M 81 (NGC 3031): (1) I {sub 8} or I {sub 24}, the surface brightness of the mid-infrared emission observed in the Spitzer Space Telescope 8 or 24 μm band, with I {sub 8} and I {sub 24} being dominated by the emissions from polycyclic aromatic hydrocarbons (PAHs) and very small grains (VSGs) of dust, respectively; (2) I {sub 500}, that of the cold dust continuum emission in the Herschel Space Observatory 500 μm band, dominated by the emission from large dust grains heated by evolved stars; and (3) I {sub Hα}, a nominal surface brightness of the Hα line emission, from gas ionized by newly formed massive stars. The results from our correlation study, free from any assumption on or modeling of dust emissivity law or dust temperatures, present solid evidence for significant heating of PAHs and VSGs by evolved stars. In the case of M 81, about 67% (48%) of the 8 μm (24 μm ) emission derives its heating from evolved stars, with the remainder attributed to radiation heating associated with ionizing stars.

Herschel-PACS photometry of faint stars for sensitivity performance assessment and establishment of faint FIR primary photometric standards

Science.gov (United States)

Klaas, U.; Balog, Z.; Nielbock, M.; Müller, T. G.; Linz, H.; Kiss, Cs.

2018-05-01

Aims: Our aims are to determine flux densities and their photometric accuracy for a set of seventeen stars that range in flux from intermediately bright (≲2.5 Jy) to faint (≳5 mJy) in the far-infrared (FIR). We also aim to derive signal-to-noise dependence with flux and time, and compare the results with predictions from the Herschel exposure-time calculation tool. Methods: We obtain aperture photometry from Herschel-PACS high-pass-filtered scan maps and chop/nod observations of the faint stars. The issues of detection limits and sky confusion noise are addressed by comparison of the field-of-view at different wavelengths, by multi-aperture photometry, by special processing of the maps to preserve extended emission, and with the help of large-scale absolute sky brightness maps from AKARI. This photometry is compared with flux-density predictions based on photospheric models for these stars. We obtain a robust noise estimate by fitting the flux distribution per map pixel histogram for the area around the stars, scaling it for the applied aperture size and correcting for noise correlation. Results: For 15 stars we obtain reliable photometry in at least one PACS filter, and for 11 stars we achieve this in all three PACS filters (70, 100, 160 μm). Faintest fluxes, for which the photometry still has good quality, are about 10-20 mJy with scan map photometry. The photometry of seven stars is consistent with models or flux predictions for pure photospheric emission, making them good primary standard candidates. Two stars exhibit source-intrinsic far-infrared excess: β Gem (Pollux), being the host star of a confirmed Jupiter-size exoplanet, due to emission of an associated dust disk, and η Dra due to dust emission in a binary system with a K1 dwarf. The investigation of the 160 μm sky background and environment of four sources reveals significant sky confusion prohibiting the determination of an accurate stellar flux at this wavelength. As a good model

HIGH-MASS STAR FORMATION TOWARD SOUTHERN INFRARED BUBBLE S10

Energy Technology Data Exchange (ETDEWEB)

Das, Swagat Ranjan; Tej, Anandmayee; Vig, Sarita [Indian Institute of Space Science and Technology, Trivandrum 695547 (India); Ghosh, Swarna K.; Ishwara Chandra, C. H., E-mail: swagat.12@iist.ac.in [National Centre For Radio Astrophysics, Pune 411007 (India)

2016-11-01

An investigation in radio and infrared wavelengths of two high-mass star-forming regions toward the southern Galactic bubble S10 is presented here. The two regions under study are associated with the broken bubble S10 and Extended Green Object, G345.99-0.02, respectively. Radio continuum emission mapped at 610 and 1280 MHz using the Giant Metrewave Radio Telescope, India, is detected toward both of the regions. These regions are estimated to be ionized by early-B- to late-O-type stars. Spitzer GLIMPSE mid-infrared data is used to identify young stellar objects (YSOs) associated with these regions. A Class-I/II-type source, with an estimated mass of 6.2  M {sub ⊙}, lies ∼7″ from the radio peak. Pixel-wise, modified blackbody fits to the thermal dust emission using Herschel far-infrared data is performed to construct dust temperature and column density maps. Eight clumps are detected in the two regions using the 250 μ m image. The masses and linear diameter of these range between ∼300–1600  M {sub ⊙} and 0.2–1.1 pc, respectively, which qualifies them as high-mass star-forming clumps. Modeling of the spectral energy distribution of these clumps indicates the presence of high luminosity, high accretion rate, massive YSOs possibly in the accelerating accretion phase. Furthermore, based on the radio and MIR morphology, the occurrence of a possible bow wave toward the likely ionizing star is explored.

Exploring the Dust Content, Metallicity, Star Formation and AGN Activity in Distant Dusty, Star-Forming Galaxies Using Cosmic Telescope

Science.gov (United States)

Walth, Gregory; Egami, Eiichi; Clément, Benjamin; Rujopakarn, Wiphu; Rawle, Tim; Richard, Johan; Dessauges, Miroslava; Perez-Gonzalez, Pablo; Ebeling, Harald; Vayner, Andrey; Wright, Shelley; Cosens, Maren; Herschel Lensing Survey

2018-01-01

We present our recent ALMA observations of Herschel-detected gravitationally lensed dusty, star-forming galaxies (DSFGs) and how they compliment our near-infrared spectroscopic observations of their rest-frame optical nebular emission. This provides the complete picture of star formation; from the molecular gas that fuels star formation, to the dust emission which are the sites of star formation, and the nebular emission which is the gas excited by the young stars. DSFGs undergo the largest starbursts in the Universe, contributing to the bulk of the cosmic star formation rate density between redshifts z = 1 - 4. Internal processes within high-redshift DSFGs remains largely unexplored; such as feedback from star formation, the role of turbulence, gas surface density of molecular gas, AGN activity, and the rates of metal production. Much that is known about DSFGs star formation properties comes from their CO and dust emission. In order to fully understand the star formation history of DSFGs, it is necessary to observe their optical nebular emission. Unfortunately, UV/optical emission is severely attenuated by dust, making it challenging to detect. With the Herschel Lensing Survey, a survey of the cores of almost 600 massive galaxy clusters, we are able to probe faint dust-attenuated nebular emission. We are currently conducting a new survey using Keck/OSIRIS to resolve a sample of gravitationally lensed DSFGs from the Herschel Lensing Survey (>100 mJy, with SFRs >100 Msun/yr) at redshifts z=1-4 with magnifications >10x all with previously detected nebular emission lines. We present the physical and resolved properties of gravitationally lensed DSFGs at unprecedented spatial scales; such as ionization, metallicity, AGN activity, and dust attenuation.

Gas morphology and energetics at the surface of PDRs : New insights with Herschel observations of NGC 7023

NARCIS (Netherlands)

Joblin, C.; Pilleri, P.; Montillaud, J.; Fuente, A.; Gerin, M.; Berne, O.; Ossenkopf, V.; Le Bourlot, J.; Teyssier, D.; Goicoechea, J. R.; Le Petit, F.; Roellig, M.; Akyilmaz, M.; Benz, A. O.; Boulanger, F.; Bruderer, S.; Dedes, C.; France, K.; Guesten, R.; Harris, A.; Klein, T.; Kramer, C.; Lord, S. D.; Martin, P. G.; Martin-Pintado, J.; Mookerjea, B.; Okada, Y.; Phillips, T. G.; Rizzo, J. R.; Simon, R.; Stutzki, J.; van der Tak, F.; Yorke, H. W.; Steinmetz, E.; Jarchow, C.; Hartogh, P.; Honingh, C. E.; Siebertz, O.; Caux, E.; Colin, B.

2010-01-01

Context. We investigate the physics and chemistry of the gas and dust in dense photon-dominated regions (PDRs), along with their dependence on the illuminating UV field. Aims: Using Herschel/HIFI observations, we study the gas energetics in NGC 7023 in relation to the morphology of this nebula. NGC

A Search for O2 in CO-Depleted Molecular Cloud Cores With Herschel

Science.gov (United States)

Wirstroem, Eva S.; Charnley, Steven B.; Cordiner, Martin; Ceccarelli, Cecilia

2016-01-01

The general lack of molecular oxygen in molecular clouds is an outstanding problem in astrochemistry. Extensive searches with the Submillimeter Astronomical Satellite, Odin, and Herschel have only produced two detections; upper limits to the O2 abundance in the remaining sources observed are about 1000 times lower than predicted by chemical models. Previous atomic oxygen observations and inferences from observations of other molecules indicated that high abundances of O atoms might be present in dense cores exhibiting large amounts of CO depletion. Theoretical arguments concerning the oxygen gas-grain interaction in cold dense cores suggested that, if O atoms could survive in the gas after most of the rest of the heavy molecular material has frozen out onto dust, then O2 could be formed efficiently in the gas. Using Herschel HIFI, we searched a small sample of four depletion cores-L1544, L694-2, L429, and Oph D-for emission in the low excitation O2 N(sub J)?=?3(sub 3)-1(sub 2) line at 487.249 GHz. Molecular oxygen was not detected and we derive upper limits to its abundance in the range of N(O2)/N (H2) approx. = (0.6-1.6) x10(exp -7). We discuss the absence of O2 in the light of recent laboratory and observational studies.

EVIDENCE FOR CO SHOCK EXCITATION IN NGC 6240 FROM HERSCHEL SPIRE SPECTROSCOPY

Energy Technology Data Exchange (ETDEWEB)

Meijerink, R.; Spaans, M. [Kapteyn Astronomical Institute, P.O. Box 800, NL-9700 AV Groningen (Netherlands); Kristensen, L. E.; Van der Werf, P. P.; Loenen, A. F.; Israel, F. P. [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Weiss, A.; Papadopoulos, P. P.; Guesten, R. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 16, Bonn, D-53121 (Germany); Walter, F. [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, Heidelberg, D-69117 (Germany); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, Washington, DC 20375 (United States); Isaak, K. [ESA Astrophysics Missions Division, ESTEC, P.O. Box 299, NL-2200 AG Noordwijk (Netherlands); Aalto, S. [Department of Radio and Space Science, Onsala Observatory, Chalmers University of Technology, SE-43992 Onsala (Sweden); Armus, L.; Diaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Charmandaris, V. [University of Crete, Department of Physics, GR-71003 Heraklion (Greece); Dasyra, K. M. [Observatoire de Paris, LERMA (CNRS:UMR8112), 61 Av. de l' Observatoire, F-75014, Paris (France); Evans, A. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); Gonzalez-Alfonso, E. [Universidad de Alcala Henares, Departamente de Fisica, Campus Universitario, E-28871 Alcala de Henares, Madrid (Spain); and others

2013-01-10

We present Herschel SPIRE FTS spectroscopy of the nearby luminous infrared galaxy NGC 6240. In total 20 lines are detected, including CO J = 4 - 3 through J = 13 - 12, 6 H{sub 2}O rotational lines, and [C I] and [N II] fine-structure lines. The CO to continuum luminosity ratio is 10 times higher in NGC 6240 than Mrk 231. Although the CO ladders of NGC 6240 and Mrk 231 are very similar, UV and/or X-ray irradiation are unlikely to be responsible for the excitation of the gas in NGC 6240. We applied both C and J shock models to the H{sub 2} v = 1-0 S(1) and v = 2-1 S(1) lines and the CO rotational ladder. The CO ladder is best reproduced by a model with shock velocity v{sub s} = 10 km s{sup -1} and a pre-shock density n{sub H} = 5 Multiplication-Sign 10{sup 4} cm{sup -3}. We find that the solution best fitting the H{sub 2} lines is degenerate. The shock velocities and number densities range between v{sub s} = 17-47 km s{sup -1} and n{sub H} = 10{sup 7}-5 Multiplication-Sign 10{sup 4} cm{sup -3}, respectively. The H{sub 2} lines thus need a much more powerful shock than the CO lines. We deduce that most of the gas is currently moderately stirred up by slow (10 km s{sup -1}) shocks while only a small fraction ({approx}< 1%) of the interstellar medium is exposed to the high-velocity shocks. This implies that the gas is rapidly losing its highly turbulent motions. We argue that a high CO line-to-continuum ratio is a key diagnostic for the presence of shocks.

Fast Molecular Outflows in Luminous Galaxy Mergers: Evidence for Quasar Feedback from Herschel

Science.gov (United States)

Veilleux, S.; Melendez, M.; Sturm, E.; Garcia-Carpio, J.; Fischer, J.; Gonzalez-Alfonso, E.; Contursi, A.; Lutz, D.; Poglitsch, A.; Davies, R.;

SAGE-VAR: AN INFRARED SURVEY OF VARIABILITY IN THE MAGELLANIC CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Riebel, D. [Department of Physics, United States Naval Academy, 572 C Holloway Road, Annapolis, MD 21402 (United States); Boyer, M. L. [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Srinivasan, S. [Academia Sinica, Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Whitelock, P.; Feast, M. [Astrophysics, Cosmology and Gravity Centre, Astronomy Department, University of Cape Town, Rondebosch 7701 (South Africa); Meixner, M.; Shiao, B. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Babler, B.; Meade, M.; Whitney, B. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States); Groenewegen, M. A. T. [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels (Belgium); Ita, Y., E-mail: riebel.d@gmail.com [Astronomical Institute, Graduate School of Science, Tohoku University, 6-3 Aramaki Aoba, Aoba-ku, Sendai, Miyagi 980-8578 (Japan)

2015-07-01

We present the first results from the Surveying the Agents of Galaxy Evolution (SAGE)-Var program, a follow up to the Spitzer legacy program SAGE (Meixner et al.). We obtained four epochs of photometry at 3.6 and 4.5 μm covering the bar of the LMC and the central region of the SMC in order to probe the variability of extremely red sources missed by variability surveys conducted at shorter wavelengths, and to provide additional epochs of observation for known variables. Our six total epochs of observations allow us to probe infrared (IR) variability on 15 different timescales ranging from ∼20 days to ∼5 yr. Out of a full catalog of 1 717 554 (LMC) and 457 760 (SMC) objects, we find 10 (LMC) and 6 (SMC) large amplitude Asymptotic Giant Branch (AGB) variables without optically measured variability owing to circumstellar dust obscuration. The catalog also contains multiple observations of known AGB variables, type I and II Cepheids, eclipsing variables, R CrB stars, and young stellar objects, which will be discussed in following papers. Here we present IR Period–Luminosity (PL) relations for classical Cepheids in the Magellanic Clouds, as well as improved PL relationships for AGB stars pulsating in the fundamental mode using mean magnitudes constructed from six epochs of observations.

SAGE-VAR: AN INFRARED SURVEY OF VARIABILITY IN THE MAGELLANIC CLOUDS

International Nuclear Information System (INIS)

Riebel, D.; Boyer, M. L.; Srinivasan, S.; Whitelock, P.; Feast, M.; Meixner, M.; Shiao, B.; Babler, B.; Meade, M.; Whitney, B.; Groenewegen, M. A. T.; Ita, Y.

2015-01-01

We present the first results from the Surveying the Agents of Galaxy Evolution (SAGE)-Var program, a follow up to the Spitzer legacy program SAGE (Meixner et al.). We obtained four epochs of photometry at 3.6 and 4.5 μm covering the bar of the LMC and the central region of the SMC in order to probe the variability of extremely red sources missed by variability surveys conducted at shorter wavelengths, and to provide additional epochs of observation for known variables. Our six total epochs of observations allow us to probe infrared (IR) variability on 15 different timescales ranging from ∼20 days to ∼5 yr. Out of a full catalog of 1 717 554 (LMC) and 457 760 (SMC) objects, we find 10 (LMC) and 6 (SMC) large amplitude Asymptotic Giant Branch (AGB) variables without optically measured variability owing to circumstellar dust obscuration. The catalog also contains multiple observations of known AGB variables, type I and II Cepheids, eclipsing variables, R CrB stars, and young stellar objects, which will be discussed in following papers. Here we present IR Period–Luminosity (PL) relations for classical Cepheids in the Magellanic Clouds, as well as improved PL relationships for AGB stars pulsating in the fundamental mode using mean magnitudes constructed from six epochs of observations

Microscopic processes controlling the Herschel-Bulkley exponent

Science.gov (United States)

Lin, Jie; Wyart, Matthieu

2018-01-01

The flow curve of various yield stress materials is singular as the strain rate vanishes and can be characterized by the so-called Herschel-Bulkley exponent n =1 /β . A mean-field approximation due to Hebraud and Lequeux (HL) assumes mechanical noise to be Gaussian and leads to β =2 in rather good agreement with observations. Here we prove that the improved mean-field model where the mechanical noise has fat tails instead leads to β =1 with logarithmic correction. This result supports that HL is not a suitable explanation for the value of β , which is instead significantly affected by finite-dimensional effects. From considerations on elastoplastic models and on the limitation of speed at which avalanches of plasticity can propagate, we argue that β =1 +1 /(d -df) , where df is the fractal dimension of avalanches and d the spatial dimension. Measurements of df then supports that β ≈2.1 and β ≈1.7 in two and three dimensions, respectively. We discuss theoretical arguments leading to approximations of β in finite dimensions.

THE SPATIAL EXTENT OF (U)LIRGs IN THE MID-INFRARED. I. THE CONTINUUM EMISSION

International Nuclear Information System (INIS)

DIaz-Santos, T.; Charmandaris, V.; Armus, L.; Petric, A. O.; Howell, J. H.; Murphy, E. J.; Inami, H.; Haan, S.; Marshall, J. A.; Stierwalt, S.; Surace, J. A.; Mazzarella, J. M.; Veilleux, S.; Bothun, G.; Appleton, P. N.; Evans, A. S.; Sanders, D. B.

2010-01-01

We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey sample based on 5-15 μm low-resolution spectra obtained with the Infrared Spectrograph on Spitzer. We calculate the fraction of extended emission (FEE) as a function of wavelength for the galaxies in the sample, FEE λ , defined as the fraction of the emission which originates outside of the unresolved component of a source at a given distance. We find that the FEE λ varies from one galaxy to another, but we can identify three general types of FEE λ : one where FEE λ is constant, one where features due to emission lines and polycyclic aromatic hydrocarbons appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7 μm. More than 30% of the galaxies have a median FEE λ larger than 0.5, implying that at least half of their MIR emission is extended. Luminous Infrared Galaxies (LIRGs) display a wide range of FEE in their warm dust continuum (0 ∼ 13.2 μ m ∼ 13.2 μ m that we find in many LIRGs suggest that the extended component of their MIR continuum emission originates in scales up to 10 kpc and may contribute as much as the nuclear region to their total MIR luminosity. The mean size of the LIRG cores at 13.2 μm is 2.6 kpc. However, once the IR luminosity of the systems reaches the threshold of L IR ∼ 10 11.8 L sun , slightly below the regime of Ultra-luminous Infrared Galaxies (ULIRGs), all sources become clearly more compact, with FEE 13.2 μ m ∼ IR ∼> 10 11.25 L sun strongly increases in those classified as mergers in their final stage of interaction. The FEE 13.2 μ m is also related to the contribution of an active galactic nucleus (AGN) to the MIR emission. Galaxies which are more AGN dominated are less extended, independently of their L IR . We finally find that the extent of the MIR continuum emission is correlated with the far-IR IRAS log(f 60 μ m /f 100 μ m

DUST SPECTRAL ENERGY DISTRIBUTIONS IN THE ERA OF HERSCHEL AND PLANCK: A HIERARCHICAL BAYESIAN-FITTING TECHNIQUE

International Nuclear Information System (INIS)

Kelly, Brandon C.; Goodman, Alyssa A.; Shetty, Rahul; Stutz, Amelia M.; Launhardt, Ralf; Kauffmann, Jens

2012-01-01

We present a hierarchical Bayesian method for fitting infrared spectral energy distributions (SEDs) of dust emission to observed fluxes. Under the standard assumption of optically thin single temperature (T) sources, the dust SED as represented by a power-law-modified blackbody is subject to a strong degeneracy between T and the spectral index β. The traditional non-hierarchical approaches, typically based on χ 2 minimization, are severely limited by this degeneracy, as it produces an artificial anti-correlation between T and β even with modest levels of observational noise. The hierarchical Bayesian method rigorously and self-consistently treats measurement uncertainties, including calibration and noise, resulting in more precise SED fits. As a result, the Bayesian fits do not produce any spurious anti-correlations between the SED parameters due to measurement uncertainty. We demonstrate that the Bayesian method is substantially more accurate than the χ 2 fit in recovering the SED parameters, as well as the correlations between them. As an illustration, we apply our method to Herschel and submillimeter ground-based observations of the star-forming Bok globule CB244. This source is a small, nearby molecular cloud containing a single low-mass protostar and a starless core. We find that T and β are weakly positively correlated—in contradiction with the χ 2 fits, which indicate a T-β anti-correlation from the same data set. Additionally, in comparison to the χ 2 fits the Bayesian SED parameter estimates exhibit a reduced range in values.

OBSERVATIONS OF Arp 220 USING HERSCHEL-SPIRE: AN UNPRECEDENTED VIEW OF THE MOLECULAR GAS IN AN EXTREME STAR FORMATION ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

Rangwala, Naseem; Maloney, Philip R.; Glenn, Jason; Kamenetzky, Julia [Center for Astrophysics and Space Astronomy, University of Colorado, 1255 38th street, Boulder, CO 80303 (United States); Wilson, Christine D.; Mentuch, Erin; Schirm, Maximilien R. P. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Rykala, Adam [School of Physics and Astronomy, Cardiff University, Queens Buildings The Parade, Cardiff CF24 3AA (United Kingdom); Isaak, Kate [ESA Astrophysics Missions Division, ESTEC, PO Box 299, 2200 AG Noordwijk (Netherlands); Baes, Maarten [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, George J. [UK ALMA Regional Centre Node, Jordell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Boselli, Alessandro [Laboratoire d' Astrophysique de Marseille, UMR6110 CNRS, 38 rue F. Joliot-Curie, F-13388 Marseille (France); Bradford, Charles M. [JPL, Pasadena, CA 91109 (United States); Clements, D. L. [Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Fulton, Trevor; Imhof, Peter [Blue Sky Spectroscopy Inc, Suite 9-740 4th Avenue South, Lethbridge, Alberta T1J 0N9 (Canada); Madden, Suzanne C.; Sauvage, Marc [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Sacchi, Nicola [Istituto di Fisica dello Spazio Interplanetario, INAF, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); and others

2011-12-10

We present Herschel Spectral and Photometric Imaging Receiver Fourier Transform Spectrometer (Herschel SPIRE-FTS) observations of Arp 220, a nearby ultra-luminous infrared galaxy. The FTS provides continuous spectral coverage from 190 to 670 {mu}m, a wavelength region that is either very difficult to observe or completely inaccessible from the ground. The spectrum provides a good measurement of the continuum and detection of several molecular and atomic species. We detect luminous CO (J = 4-3 to 13-12) and water rotational transitions with comparable total luminosity {approx}2 Multiplication-Sign 10{sup 8} L{sub Sun }; very high-J transitions of HCN (J = 12-11 to 17-16) in absorption; strong absorption features of rare species such as OH{sup +}, H{sub 2}O{sup +}, and HF; and atomic lines of [C I] and [N II]. The modeling of the continuum shows that the dust is warm, with T = 66 K, and has an unusually large optical depth, with {tau}{sub dust} {approx} 5 at 100 {mu}m. The total far-infrared luminosity of Arp 220 is L{sub FIR} {approx} 2 Multiplication-Sign 10{sup 12} L{sub Sun }. Non-LTE modeling of the extinction corrected CO rotational transitions shows that the spectral line energy distribution of CO is fit well by two temperature components: cold molecular gas at T {approx} 50 K and warm molecular gas at T {approx} 1350{sup +280}{sub -100} K (the inferred temperatures are much lower if CO line fluxes are not corrected for dust extinction). These two components are not in pressure equilibrium. The mass of the warm gas is 10% of the cold gas, but it dominates the CO luminosity. The ratio of total CO luminosity to the total FIR luminosity is L{sub CO}/L{sub FIR} {approx} 10{sup -4} (the most luminous lines, such as J = 6-5, have L{sub CO,J=6-5}/L{sub FIR} {approx} 10{sup -5}). The temperature of the warm gas is in excellent agreement with the observations of H{sub 2} rotational lines. At 1350 K, H{sub 2} dominates the cooling ({approx}20 L{sub Sun} M{sup -1}{sub

Final design and progress of WEAVE : the next generation wide-field spectroscopy facility for the William Herschel Telescope

NARCIS (Netherlands)

Dalton, Gavin; Trager, Scott; Abrams, Don Carlos; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; Middleton, Kevin; Benn, Chris; Dee, Kevin; Sayède, Frédéric; Lewis, Ian; Pragt, Johannes; Pico, Sergio; Walton, Nic; Rey, Jeurg; Allende Prieto, Carlos; Peñate, José; Lhome, Emilie; Agócs, Tibor; Alonso, José; Terrett, David; Brock, Matthew; Gilbert, James; Schallig, Ellen; Ridings, Andy; Guinouard, Isabelle; Verheijen, Marc; Tosh, Ian; Rogers, Kevin; Lee, Martin; Steele, Iain; Stuik, Remko; Tromp, Niels; Jaskó, Attila; Carrasco, Esperanza; Farcas, Szigfrid; Kragt, Jan; Lesman, Dirk; Kroes, Gabby; Mottram, Chris; Bates, Stuart; Rodriguez, Luis Fernando; Gribbin, Frank; Delgado, José Miguel; Herreros, José Miguel; Martin, Carlos; Cano, Diego; Navarro, Ramon; Irwin, Mike; Lewis, Jim; Gonzalez Solares, Eduardo; Murphy, David; Worley, Clare; Bassom, Richard; O'Mahoney, Neil; Bianco, Andrea; Zurita, Christina; ter Horst, Rik; Molinari, Emilio; Lodi, Marcello; Guerra, José; Martin, Adrian; Vallenari, Antonella; Salasnich, Bernardo; Baruffolo, Andrea; Jin, Shoko; Hill, Vanessa; Smith, Dan; Drew, Janet; Poggianti, Bianca; Pieri, Mat; Dominquez Palmero, Lillian; Farina, Cecilia

2016-01-01

We present the Final Design of the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT), together with a status update on the details of manufacturing, integration and the overall project schedule now that all the major fabrication contracts are in place. We also

Final design and progress of WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope

NARCIS (Netherlands)

Dalton, Gavin; Trager, Scott; Abrams, Don Carlos; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; Middleton, Kevin; Benn, Chris; Dee, Kevin; Sayède, Frédéric; Lewis, Ian; Pragt, Johannes; Pico, Sergio; Walton, Nic; Rey, Jeurg; Allende Prieto, Carlos; Peñate, José; Lhome, Emilie; Agócs, Tibor; Alonso, José; Terrett, David; Brock, Matthew; Gilbert, James; Schallig, Ellen; Ridings, Andy; Guinouard, Isabelle; Verheijen, Marc; Tosh, Ian; Rogers, Kevin; Lee, Martin; Steele, Iain; Stuik, Remko; Tromp, Niels; Jaskó, Attila; Carrasco, Esperanza; Farcas, Szigfrid; Kragt, Jan; Lesman, Dirk; Kroes, Gabby; Mottram, Chris; Bates, Stuart; Rodriguez, Luis Fernando; Gribbin, Frank; Delgado, José Miguel; Herreros, José Miguel; Martin, Carlos; Cano, Diego; Navarro, Ramon; Irwin, Mike; Lewis, Jim; Gonzalez Solares, Eduardo; Murphy, David; Worley, Clare; Bassom, Richard; O'Mahoney, Neil; Bianco, Andrea; Zurita, Christina; ter Horst, Rik; Molinari, Emilio; Lodi, Marcello; Guerra, José; Martin, Adrian; Vallenari, Antonella; Salasnich, Bernardo; Baruffolo, Andrea; Jin, Shoko; Hill, Vanessa; Smith, Dan; Drew, Janet; Poggianti, Bianca; Pieri, Mat; Dominquez Palmero, Lillian; Farina, Cecilia

2016-01-01

We present the Final Design of the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT), together with a status update on the details of manufacturing, integration and the overall project schedule now that all the major fabrication contracts are in place. We also

Herschel observations in the ultracompact HII region Mon R2 : Water in dense photon-dominated regions (PDRs)

NARCIS (Netherlands)

Fuente, A.; Berne, O.; Cernicharo, J.; Rizzo, J. R.; Gonzalez-Garcia, M.; Goicoechea, J. R.; Pilleri, P.; Ossenkopf, V.; Gerin, M.; Guesten, R.; Akyilmaz, M.; Benz, A. O.; Boulanger, F.; Bruderer, S.; Dedes, C.; France, K.; Garcia-Burillo, S.; Harris, A.; Joblin, C.; Klein, T.; Kramer, C.; Le Petit, F.; Lord, S. D.; Martin, P. G.; Martin-Pintado, J.; Mookerjea, B.; Neufeld, D. A.; Okada, Y.; Pety, J.; Phillips, T. G.; Roellig, M.; Simon, R.; Stutzki, J.; van der Tak, F.; Teyssier, D.; Usero, A.; Yorke, H.; Schuster, K.; Melchior, M.; Lorenzani, A.; Szczerba, R.; Fich, M.; McCoey, C.; Pearson, J.; Dieleman, P.

2010-01-01

Context. Monoceros R2, at a distance of 830 pc, is the only ultracompact Hii region (UC Hii) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. Therefore, it is an excellent laboratory to study the chemistry in extreme PDRs (G0 >

Can reliable sage-grouse lek counts be obtained using aerial infrared technology

Science.gov (United States)

Gillette, Gifford L.; Coates, Peter S.; Petersen, Steven; Romero, John P.

2013-01-01

More effective methods for counting greater sage-grouse (Centrocercus urophasianus) are needed to better assess population trends through enumeration or location of new leks. We describe an aerial infrared technique for conducting sage-grouse lek counts and compare this method with conventional ground-based lek count methods. During the breeding period in 2010 and 2011, we surveyed leks from fixed-winged aircraft using cryogenically cooled mid-wave infrared cameras and surveyed the same leks on the same day from the ground following a standard lek count protocol. We did not detect significant differences in lek counts between surveying techniques. These findings suggest that using a cryogenically cooled mid-wave infrared camera from an aerial platform to conduct lek surveys is an effective alternative technique to conventional ground-based methods, but further research is needed. We discuss multiple advantages to aerial infrared surveys, including counting in remote areas, representing greater spatial variation, and increasing the number of counted leks per season. Aerial infrared lek counts may be a valuable wildlife management tool that releases time and resources for other conservation efforts. Opportunities exist for wildlife professionals to refine and apply aerial infrared techniques to wildlife monitoring programs because of the increasing reliability and affordability of this technology.

LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies

Science.gov (United States)

Rosario, D. J.; Burtscher, L.; Davies, R. I.; Koss, M.; Ricci, C.; Lutz, D.; Riffel, R.; Alexander, D. M.; Genzel, R.; Hicks, E. H.; Lin, M.-Y.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry, G.; Riffel, R. A.; Schartmann, M.; Schawinski, K.; Schnorr-Müller, A.; Saintonge, A.; Shimizu, T.; Sternberg, A.; Storchi-Bergmann, T.; Sturm, E.; Tacconi, L.; Treister, E.; Veilleux, S.

2018-02-01

Using new Atacama Pathfinder Experiment and James Clerk Maxwell Telescope spectroscopy of the CO 2→1 line, we undertake a controlled study of cold molecular gas in moderately luminous (Lbol = 1043-44.5 erg s-1) active galactic nuclei (AGN) and inactive galaxies from the Luminous Local AGN with Matched Analogs (LLAMA) survey. We use spatially resolved infrared photometry of the LLAMA galaxies from 2MASS, the Wide-field Infrared Survey Explorer the Infrared Astronomical Satellite and the Herschel Space Observatory (Herschel), corrected for nuclear emission using multicomponent spectral energy distribution fits, to examine the dust-reprocessed star formation rates, molecular gas fractions and star formation efficiencies (SFEs) over their central 1-3 kpc. We find that the gas fractions and central SFEs of both active and inactive galaxies are similar when controlling for host stellar mass and morphology (Hubble type). The equivalent central molecular gas depletion times are consistent with the discs of normal spiral galaxies in the local Universe. Despite energetic arguments that the AGN in LLAMA should be capable of disrupting the observable cold molecular gas in their central environments, our results indicate that nuclear radiation only couples weakly with this phase. We find a mild preference for obscured AGN to contain higher amounts of central molecular gas, which suggests connection between AGN obscuration and the gaseous environment of the nucleus. Systems with depressed SFEs are not found among the LLAMA AGN. We speculate that the processes that sustain the collapse of molecular gas into dense pre-stellar cores may also be a prerequisite for the inflow of material on to AGN accretion discs.

HerMES: The contribution to the cosmic infrared background from galaxies selected by mass and redshift

Energy Technology Data Exchange (ETDEWEB)

Viero, M. P.; Moncelsi, L.; Bock, J.; Bridge, C.; Cooray, A. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Quadri, R. F. [Carnegie Observatories, Pasadena, CA 91101 (United States); Arumugam, V.; Ivison, R. J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Assef, R. J. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Béthermin, M. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Université Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France); Casey, C. M. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Conley, A.; Glenn, J. [Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Heinis, S. [Laboratoire d' Astrophysique de Marseille-LAM, Université d' Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Ibar, E. [Departamento de Astronomía y Astrofísica, Pontificia Universidad Catolica de Chile, Vicuña Mackenna 4860, Casilla 306, Santiago 22 (Chile); Ikarashi, S.; Kohno, K. [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Marsden, G. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Oliver, S. J., E-mail: marco.viero@caltech.edu [Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom); and others

2013-12-10

We quantify the fraction of the cosmic infrared background (CIB) that originates from galaxies identified in the UV/optical/near-infrared by stacking 81,250 (∼35.7 arcmin{sup –2}) K-selected sources (K {sub AB} < 24.0) split according to their rest-frame U – V versus V – J colors into 72,216 star-forming and 9034 quiescent galaxies, on maps from Spitzer/MIPS (24 μm), Herschel/PACS (100, 160 μm), Herschel/SPIRE (250, 350, 500 μm), and AzTEC (1100 μm). The fraction of the CIB resolved by our catalog is (69% ± 15%) at 24 μm, (78% ± 17%) at 70 μm, (58% ± 13%) at 100 μm, (78% ± 18%) at 160 μm, (80% ± 17%) at 250 μm, (69% ± 14%) at 350 μm, (65% ± 12%) at 500 μm, and (45% ± 8%) at 1100 μm. Of that total, about 95% originates from star-forming galaxies, while the remaining 5% is from apparently quiescent galaxies. The CIB at λ ≲ 200 μm appears to be sourced predominantly from galaxies at z ≲ 1, while at λ ≳ 200 μm the bulk originates from 1 ≲ z ≲ 2. Galaxies with stellar masses log(M/M {sub ☉}) = 9.5-11 are responsible for the majority of the CIB, with those in the log(M/M {sub ☉}) = 9.5-10 bin contributing mostly at λ < 250 μm, and those in the log(M/M {sub ☉}) = 10-11 bin dominating at λ > 350 μm. The contribution from galaxies in the log(M/M {sub ☉}) = 9.0-9.5 (lowest) and log(M/M {sub ☉}) = 11.0-12.0 (highest) stellar-mass bins contribute the least—both of order 5%—although the highest stellar-mass bin is a significant contributor to the luminosity density at z ≳ 2. The luminosities of the galaxies responsible for the CIB shifts from combinations of 'normal' and luminous infrared galaxies (LIRGs) at λ ≲ 160 μm, to LIRGs at 160 ≲ λ ≲ 500 μm, to finally LIRGs and ultra-luminous infrared galaxies at λ ≳ 500 μm. Stacking analyses were performed using SIMSTACK, a novel algorithm designed to account for possible biases in the stacked flux density due to clustering. It is made available to

Embedded protostars in the dust, ice, and gas in time (DIGIT) Herschel key program

DEFF Research Database (Denmark)

Green, Joel D.; Evans II, Neal J.; Jørgensen, Jes Kristian

2013-01-01

We present 50-210 um spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 um SEDs, as part of the Dust, Ice, and Gas in Time (DIGIT) Key Program. Some sources exhibit up to 75 H2O lines ranging in excitation energy from 100-2000 K, 12 transitions of OH, a...

HERUS: the far-IR/submm spectral energy distributions of local ULIRGs and photometric atlas

Science.gov (United States)

Clements, D. L.; Pearson, C.; Farrah, D.; Greenslade, J.; Bernard-Salas, Jeronimo; González-Alfonso, E.; Afonso, J.; Efstathiou, A.; Rigopoulou, D.; Lebouteiller, V.; Hurley, P. D.; Spoon, H.

2018-04-01

We present the Herschel-SPIRE photometric atlas for a complete flux limited sample of 43 local ultraluminous infrared galaxies (ULIRGs), selected at 60 μm by IRAS, as part of the HERschel ULIRG Survey (HERUS). Photometry observations were obtained using the SPIRE instrument at 250, 350, and 500 μm. We describe these observations, present the results, and combine the new observations with data from IRAS to examine the far-infrared spectral energy distributions (SEDs) of these sources. We fit the observed SEDs of HERUS objects with a simple parametrized modified blackbody model, where temperature and emissivity β are free parameters. We compare the fitted values to those of non-ULIRG local galaxies, and find, in agreement with earlier results, that HERUS ULIRGs have warmer dust (median temperature T = 37.9 ± 4.7 K compared to 21.3 ± 3.4 K) but a similar β distribution (median β = 1.7 compared to 1.8) to the Herschel reference sample (HRS, Cortese et al. 2014) galaxies. Dust masses are found to be in the range of 107.5-109 M⊙, significantly higher than that of HRS sources. We compare our results for local ULIRGs with higher redshift samples selected at 250 and 850 μm. These latter sources generally have cooler dust and/or redder 100-to-250 μm colours than our 60 μm-selected ULIRGs. We show that this difference may in part be the result of the sources being selected at different wavelengths rather than being a simple indication of rapid evolution in the properties of the population.

THE CIRCUMGALACTIC MEDIUM OF SUBMILLIMETER GALAXIES. I. FIRST RESULTS FROM A RADIO-IDENTIFIED SAMPLE

Energy Technology Data Exchange (ETDEWEB)

Fu, Hai; Mutel, R.; Isbell, J.; Lang, C.; McGinnis, D. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Hennawi, J. F. [Max-Planck-Institut fur Astronomie, Heidelberg (Germany); Prochaska, J. X. [Department of Astronomy and Astrophysics, UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Casey, C. [Department of Astronomy, the University of Texas at Austin, 2515 Speedway Blvd, Stop C1400, Austin, TX 78712 (United States); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Kereš, D. [Department of Physics, Center for Astrophysics and Space Sciences, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Zhang, Z.-Y.; Michałowski, M. J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Clements, D. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Mooley, K. [Oxford Centre For Astrophysical Surveys, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United States); Perley, D. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 København Ø (Denmark); Stockton, A. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Thompson, D. [Large Binocular Telescope Observatory, University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721 (United States)

2016-11-20

We present the first results from an ongoing survey to characterize the circumgalactic medium (CGM) of massive high-redshift galaxies detected as submillimeter galaxies (SMGs). We constructed a parent sample of 163 SMG–QSO pairs with separations less than ∼36″ by cross-matching far-infrared-selected galaxies from Herschel with spectroscopically confirmed QSOs. The Herschel sources were selected to match the properties of the SMGs. We determined the sub-arcsecond positions of six Herschel sources with the Very Large Array and obtained secure redshift identification for three of those with near-infrared spectroscopy. The QSO sightlines probe transverse proper distances of 112, 157, and 198 kpc at foreground redshifts of 2.043, 2.515, and 2.184, respectively, which are comparable to the virial radius of the ∼10{sup 13} M {sub ⊙} halos expected to host SMGs. High-quality absorption-line spectroscopy of the QSOs reveals systematically strong H i Ly α absorption around all three SMGs, with rest-frame equivalent widths of ∼2–3 Å. However, none of the three absorbers exhibit compelling evidence for optically thick H i gas or metal absorption, in contrast to the dominance of strong neutral absorbers in the CGM of luminous z ∼ 2 QSOs. The low covering factor of optically thick H i gas around SMGs tentatively indicates that SMGs may not have as prominent cool gas reservoirs in their halos as the coeval QSOs and that they may inhabit less massive halos than previously thought.

Wide Field Infra-Red Survey Telescope (WFIRST) 2.4-Meter Mission Study

Science.gov (United States)

Content, D.; Aaron, K.; Alplanalp, L.; Anderson, K.; Capps, R.; Chang, Z.; Dooley, J.; Egerman, R.; Goullioud, R.; Klein, D.;

HERSCHEL's ''COLD DEBRIS DISKS'': BACKGROUND GALAXIES OR QUIESCENT RIMS OF PLANETARY SYSTEMS?

Energy Technology Data Exchange (ETDEWEB)

Krivov, A. V.; Loehne, T.; Mutschke, H.; Neuhaeuser, R. [Astrophysikalisches Institut und Universitaetssternwarte, Friedrich-Schiller-Universitaet Jena, Schillergaesschen 2-3, D-07745 Jena (Germany); Eiroa, C.; Marshall, J. P.; Mustill, A. J. [Departamento de Fisica Teorica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Montesinos, B. [Departamento de Astrofisica, Centro de Astrobiologia (CAB, CSIC-INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Del Burgo, C. [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), Apartado Postal 51 y 216, 72000 Puebla, Pue. (Mexico); Absil, O. [Institut d' Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout 17, B-4000 Liege (Belgium); Ardila, D. [NASA Herschel Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Augereau, J.-C.; Ertel, S.; Lebreton, J. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG), UMR 5274, F-38041 Grenoble (France); Bayo, A. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Bryden, G. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Danchi, W. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Liseau, R. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992, Onsala (Sweden); Mora, A. [ESA-ESAC Gaia SOC, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Pilbratt, G. L., E-mail: krivov@astro.uni-jena.de [ESA Astrophysics and Fundamental Physics Missions Division, ESTEC/SRE-SA, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); and others

2013-07-20

Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around {approx}100 {mu}m or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant-and in some cases extended-excess emission at 160 {mu}m, which is larger than the 100 {mu}m excess. This excess emission has been attributed to circumstellar dust and has been suggested to stem from debris disks colder than those known previously. Since the excess emission of the cold disk candidates is extremely weak, challenging even the unrivaled sensitivity of Herschel, it is prudent to carefully consider whether some or even all of them may represent unrelated galactic or extragalactic emission, or even instrumental noise. We re-address these issues using several distinct methods and conclude that it is highly unlikely that none of the candidates represents a true circumstellar disk. For true disks, both the dust temperatures inferred from the spectral energy distributions and the disk radii estimated from the images suggest that the dust is nearly as cold as a blackbody. This requires the grains to be larger than {approx}100 {mu}m, even if they are rich in ices or are composed of any other material with a low absorption in the visible. The dearth of small grains is puzzling, since collisional models of debris disks predict that grains of all sizes down to several times the radiation pressure blowout limit should be present. We explore several conceivable scenarios: transport-dominated disks, disks of low dynamical excitation, and disks of unstirred primordial macroscopic grains. Our qualitative analysis and collisional simulations rule out the first two of these scenarios, but show the feasibility of the third one. We show that such disks can indeed survive for gigayears, largely preserving the primordial size distribution. They should be composed of macroscopic solids larger than millimeters, but smaller

THE FOURSTAR GALAXY EVOLUTION SURVEY (ZFOURGE): ULTRAVIOLET TO FAR-INFRARED CATALOGS, MEDIUM-BANDWIDTH PHOTOMETRIC REDSHIFTS WITH IMPROVED ACCURACY, STELLAR MASSES, AND CONFIRMATION OF QUIESCENT GALAXIES TO z ∼ 3.5

Energy Technology Data Exchange (ETDEWEB)

Straatman, Caroline M. S.; Labbé, Ivo; Van Houdt, Josha [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Spitler, Lee R.; Cowley, Michael [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Quadri, Ryan F.; Papovich, Casey; Tran, Kim-Vy H.; Tomczak, Adam; Alcorn, Leo; Broussard, Adam; Forrest, Ben; Kawinwanichakij, Lalitwadee [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Glazebrook, Karl; Nanayakkara, Themiya; Allen, Rebecca; Kacprzak, Glenn G. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Persson, S. Eric [Carnegie Observatories, Pasadena, CA 91101 (United States); Brammer, Gabriel B. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Van Dokkum, Pieter, E-mail: straatman@mpia.de [Department of Astronomy, Yale University, New Haven, CT 06520 (United States); and others

2016-10-10

The FourStar galaxy evolution survey (ZFOURGE) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date. ZFOURGE covers a total of 400 arcmin{sup 2} in cosmic fields CDFS, COSMOS and UDS, overlapping CANDELS. We present photometric catalogs comprising >70,000 galaxies, selected from ultradeep K {sub s} -band detection images (25.5–26.5 AB mag, 5 σ , total), and >80% complete to K {sub s} < 25.3–25.9 AB. We use 5 near-IR medium-bandwidth filters ( J {sub 1}, J {sub 2}, J {sub 3}, H {sub s} , H {sub l} ) as well as broad-band K {sub s} at 1.05–2.16 μ m to 25–26 AB at a seeing of ∼0.″5. Each field has ancillary imaging in 26–40 filters at 0.3–8 μ m. We derive photometric redshifts and stellar population properties. Comparing with spectroscopic redshifts indicates a photometric redshift uncertainty σ {sub z} = 0.010, 0.009, and 0.011 in CDFS, COSMOS, and UDS. As spectroscopic samples are often biased toward bright and blue sources, we also inspect the photometric redshift differences between close pairs of galaxies, finding σ {sub z} {sub ,pairs} = 0.01–0.02 at 1 < z < 2.5. We quantify how σ {sub z} {sub ,pairs} depends on redshift, magnitude, spectral energy distribution type, and the inclusion of FourStar medium bands. σ {sub z} {sub ,pairs} is smallest for bright, blue star-forming samples, while red star-forming galaxies have the worst σ {sub z} {sub ,pairs}. Including FourStar medium bands reduces σ {sub z} {sub ,pairs} by 50% at 1.5 < z < 2.5. We calculate star formation rates (SFRs) based on ultraviolet and ultradeep far-IR Spitzer /MIPS and Herschel /PACS data. We derive rest-frame U − V and V − J colors, and illustrate how these correlate with specific SFR and dust emission to z = 3.5. We confirm the existence of quiescent galaxies at z ∼ 3, demonstrating their SFRs are suppressed by > ×15.

A Cross-Sectional Survey of Near-Infrared Spectroscopy Use in Pediatric Cardiac ICUs in the United Kingdom, Ireland, Italy, and Germany.

Science.gov (United States)

Hoskote, Aparna U; Tume, Lyvonne N; Trieschmann, Uwe; Menzel, Christoph; Cogo, Paola; Brown, Katherine L; Broadhead, Michael W

2016-01-01

Despite the increasing use of near-infrared spectroscopy across pediatric cardiac ICUs, there is significant variability and equipoise with no universally accepted management algorithms. We aimed to explore the use of near-infrared spectroscopy in pediatric cardiac ICUs in the United Kingdom, Ireland, Italy, and Germany. A cross-sectional multicenter, multinational electronic survey of one consultant in each pediatric cardiac ICU. Pediatric cardiac ICUs in the United Kingdom and Ireland (n = 13), Italy (n = 12), and Germany (n = 33). Questionnaire targeted to establish use, targets, protocols/thresholds for intervention, and perceived usefulness of near-infrared spectroscopy monitoring. Overall, 42 of 58 pediatric cardiac ICUs (72%) responded: United Kingdom and Ireland, 11 of 13 (84.6%); Italy, 12 of 12 (100%); and Germany, 19 of 33 (57%, included all major centers). Near-infrared spectroscopy usage varied with 35% (15/42) reporting that near-infrared spectroscopy was not used at all (7/42) or occasionally (8/42); near-infrared spectroscopy use was much less common in the United Kingdom (46%) when compared with 78% in Germany and all (100%) in Italy. Only four units had a near-infrared spectroscopy protocol, and 18 specifically used near-infrared spectroscopy in high-risk patients; 37 respondents believed that near-infrared spectroscopy added value to standard monitoring and 23 believed that it gave an earlier indication of deterioration, but only 19 would respond based on near-infrared spectroscopy data alone. Targets for absolute values and critical thresholds for intervention varied widely between units. The reasons cited for not or occasionally using near-infrared spectroscopy were expense (n = 6), limited evidence and uncertainty on how it guides management (n = 4), difficulty in interpretation, and unreliability of data (n = 3). Amongst the regular or occasional near-infrared spectroscopy users (n = 35), 28 (66%) agreed that a multicenter study is warranted

How Dusty Is Alpha Centauri? Excess or Non-excess over the Infrared Photospheres of Main-sequence Stars

Science.gov (United States)

Wiegert, J.; Liseau, R.; Thebault, P.; Olofsson, G.; Mora, A.; Bryden, G.; Marshall, J. P.; Eiroa, C.; Montesinos, B.; Ardila, D.;

ESPRIT: a study concept for a far-infrared interferometer in space

Science.gov (United States)

Wild, W.; de Graauw, Th.; Helmich, F.; Baryshev, A.; Cernicharo, J.; Gao, J. R.; Gunst, A.; Bos, A.; den Herder, J.-W.; Jackson, B.; Koshelets, V.; Langevelde, H.-J.; Maat, P.; Martin-Pintado, J.; Noordam, J.; Roelfsema, P.; Venema, L.; Wesselius, P.; Yagoubov, P.

2008-07-01

In the far-infrared (FIR) / THz regime the angular (and often spectral) resolution of observing facilities is still very restricted despite the fact that this frequency range has become of prime importance for modern astrophysics. ALMA (Atacama Large Millimeter Array) with its superb sensitivity and angular resolution will only cover frequencies up to about 1 THz, while the HIFI instrument for ESA'a Herschel Space Observatory will provide limited angular resolution (10 to 30 arcsec) up to 2 THz. Observations of regions with star and planet formation require extremely high angular resolution as well as frequency resolution in the full THz regime. In order to open these regions for high-resolution astrophysics we present a study concept for a heterodyne space interferometer, ESPRIT (Exploratory Submm Space Radio-Interferometric Telescope). This mission will cover the Terahertz regime inaccessible from the ground and outside the operating range of the James Webb Space Telescope (JWST).

HERSCHEL OBSERVATIONS OF THE T CHA TRANSITION DISK: CONSTRAINING THE OUTER DISK PROPERTIES

OpenAIRE

Cieza, Lucas A.; Olofsson, Johan; Harvey, Paul M.; Pinte, Christophe; Merin, Bruno; Augereau, Jean-Charles; Evans, Neal J., II; Najita, Joan; Henning, Thomas; Menard, Francois

2011-01-01

T Cha is a nearby (d = 100 pc) transition disk known to have an optically thin gap separating optically thick inner and outer disk components. Huelamo et al. (2011) recently reported the presence of a low-mass object candidate within the gap of the T Cha disk, giving credence to the suspected planetary origin of this gap. Here we present the Herschel photometry (70, 160, 250, 350, and 500 micron) of T Cha from the "Dust, Ice, and Gas in Time" (DIGIT) Key Program, which bridges the wavelength ...

DISCOVERY OF THREE DISTANT, COLD BROWN DWARFS IN THE WFC3 INFRARED SPECTROSCOPIC PARALLELS SURVEY

International Nuclear Information System (INIS)

Masters, D.; Siana, B.; McCarthy, P.; Hathi, N. P.; Dressler, A.; Burgasser, A. J.; Malkan, M.; Ross, N. R.; Scarlata, C.; Henry, A.; Colbert, J.; Atek, H.; Rafelski, M.; Teplitz, H.; Bunker, A.

2012-01-01

We present the discovery of three late-type (≥T4.5) brown dwarfs, including a probable Y dwarf, in the WFC3 Infrared Spectroscopic Parallels (WISP) survey. We use the G141 grism spectra to determine the spectral types of the dwarfs and derive distance estimates based on a comparison with nearby T dwarfs with known parallaxes. These are the most distant spectroscopically confirmed T/Y dwarfs, with the farthest at an estimated distance of ∼400 pc. We compare the number of cold dwarfs found in the WISP survey with simulations of the brown dwarf mass function. The number found is generally consistent with an initial stellar mass function dN/dM∝M –α with α = 0.0-0.5, although the identification of a Y dwarf is somewhat surprising and may be indicative of either a flatter absolute magnitude/spectral-type relation than previously reported or an upturn in the number of very-late-type brown dwarfs in the observed volume.

DISCOVERY OF TIME VARIATION OF THE INTENSITY OF MOLECULAR LINES IN IRC+10216 IN THE SUBMILLIMETER AND FAR-INFRARED DOMAINS

Energy Technology Data Exchange (ETDEWEB)

Cernicharo, J.; Quintana-Lacaci, G.; Agúndez, M.; Velilla-Prieto, L. [Group of Molecular Astrophysics, ICMM, CSIC, C/Sor Juana Inés de La Cruz N3, E-28049 Madrid (Spain); Teyssier, D.; García-Lario, P. [ESA, ESAC, P.O. Box 78, Villanueva de la Cañada, E-28691 Madrid (Spain); Daniel, F. [Univ. Grenoble Alpes, IPAG, F-38000 Grenoble (France); Decin, L. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Guélin, M. [Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, F-38406 St-Martin d' Hères (France); Encrenaz, P. [LERMA, Observatoire de Paris, 61 Av. de l' Observatoire, F-75014 Paris (France); De Beck, E. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE 439 92 Onsala (Sweden); Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Groenewegen, M. A. T. [Koninklijke Sterrenwacht van België, Ringlaan 3, B-1180 Brussels (Belgium); Neufeld, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Pearson, J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

2014-11-20

We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species toward the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on board Herschel and with the IRAM30 m telescope. They cover several observing periods spreading over three years. The line intensity variations for molecules produced in the external layers of the envelope most likely result from time variations in the infrared pumping rates. We analyze the main implications this discovery has on the interpretation of molecular line emission in the envelopes of Mira-type stars. Radiative transfer calculations must take into account both the time variability of infrared pumping and the possible variation of the dust and gas temperatures with stellar phase in order to reproduce the observation of molecular lines at different epochs. The effect of gas temperature variations with stellar phase could be particularly important for lines produced in the innermost regions of the envelope. Each layer of the circumstellar envelope sees the stellar light radiation with a different lag time (phase). Our results show that this effect must be included in the models. The submillimeter and far infrared lines of asymptotic giant branch stars can no longer be considered as safe intensity calibrators.

Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z 2-4 as probed by multi-J CO lines

Science.gov (United States)

Yang, C.; Omont, A.; Beelen, A.; Gao, Y.; van der Werf, P.; Gavazzi, R.; Zhang, Z.-Y.; Ivison, R.; Lehnert, M.; Liu, D.; Oteo, I.; González-Alfonso, E.; Dannerbauer, H.; Cox, P.; Krips, M.; Neri, R.; Riechers, D.; Baker, A. J.; Michałowski, M. J.; Cooray, A.; Smail, I.

2017-12-01

We present the IRAM-30 m observations of multiple-J CO (Jup mostly from 3 up to 8) and [C I](3P2 → 3P1) ([C I](2-1) hereafter) line emission in a sample of redshift 2-4 submillimeter galaxies (SMGs). These SMGs are selected among the brightest-lensed galaxies discovered in the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS). Forty-seven CO lines and 7 [C I](2-1) lines have been detected in 15 lensed SMGs. A non-negligible effect of differential lensing is found for the CO emission lines, which could have caused significant underestimations of the linewidths, and hence of the dynamical masses. The CO spectral line energy distributions (SLEDs), peaking around Jup 5-7, are found to be similar to those of the local starburst-dominated ultra-luminous infrared galaxies and of the previously studied SMGs. After correcting for lensing amplification, we derived the global properties of the bulk of molecular gas in the SMGs using non-LTE radiative transfer modelling, such as the molecular gas density nH2 102.5-104.1 cm-3 and the kinetic temperature Tk 20-750 K. The gas thermal pressure Pth ranging from 105 K cm-3 to 106 K cm-3 is found to be correlated with star formation efficiency. Further decomposing the CO SLEDs into two excitation components, we find a low-excitation component with nH2 102.8-104.6 cm-3 and Tk 20-30 K, which is less correlated with star formation, and a high-excitation one (nH2 102.7-104.2 cm-3, Tk 60-400 K) which is tightly related to the on-going star-forming activity. Additionally, tight linear correlations between the far-infrared and CO line luminosities have been confirmed for the Jup ≥ 5 CO lines of these SMGs, implying that these CO lines are good tracers of star formation. The [C I](2-1) lines follow the tight linear correlation between the luminosities of the [C I](2-1) and the CO(1-0) line found in local starbursts, indicating that [C I] lines could serve as good total molecular gas mass tracers for high-redshift SMGs as well

The optical, infrared and radio properties of extragalactic sources observed by SDSS, 2mass and first surveys

International Nuclear Information System (INIS)

Z. Ivezic et al.

2002-01-01

We positionally match sources observed by the Sloan Digital Sky Survey (SDSS), the Two Micron All Sky Survey (2MASS), and the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. Practically all 2MASS sources are matched to an SDSS source within 2 arcsec; ∼ 11% of them are optically resolved galaxies and the rest are dominated by stars. About 1/3 of FIRST sources are matched to an SDSS source within 2 arcsec; ∼ 80% of these are galaxies and the rest are dominated by quasars. Based on these results, we project that by the completion of these surveys the matched samples will include about 10 7 and 10 6 galaxies observed by both SDSS and 2MASS, and about 250,000 galaxies and 50,000 quasars observed by both SDSS and FIRST. Here we present a preliminary analysis of the optical, infrared and radio properties for the extragalactic sources from the matched samples. In particular, we find that the fraction of quasars with stellar colors missed by the SDSS spectroscopic survey is probably not larger than ∼ 10%, and that the optical colors of radio-loud quasars are ∼ 0.05 mag. redder (with 4σ significance) than the colors of radio-quiet quasars

Infrared studies of two dark clouds

International Nuclear Information System (INIS)

Elias, J.H.

1978-01-01

The IC5146 dark cloud complex was surveyed in the infrared in order to identify and study associated young stellar objects. Most of the objects detected in the survey appears to be field stars, predominantly late-type giants. Three young objects were detected in the survey: the BO star BD + 46 x 3474, the Ae star BD + 46 x 3471, and a previously unidentified object which appear to be a heavily obscured FU Ori star. The properties of the last two objects are examined in detail, and an attempt is made to produce reasonable models for them. It is suggested that FU Ori stars are binaries, and some consequences of this model are described. Photometry of the brighter stars in the IC5146 cluster was used to establish a distance to the cluster of 900 +- 100 pc. A near-infrared survey was also conducted of nearly 18 square degrees of the Ophiuchus dark cloud complex. Additional observations were made of selected objects found in this region, in order to identify and study the young stars associated with the cloud. These observations show that very recent star formation has been largely restricted to a small region no more than a few parsecs in extent at the center of the dark cloud complex. Most of the young stars do not appear to be main sequence stars. At least three of these objects appear to be surrounded by infrared reflection nebulae. Many of the objects studies are background K and M giants which can be used to determine the near-infrared extinction due to the dark cloud

NEAR-INFRARED SPECTROSCOPY OF POST-AGB STARS

NARCIS (Netherlands)

OUDMAIJER, RD; WATERS, LBFM; VANDERVEEN, WECJ; GEBALLE, TR

The results of a medium resolution near-infrared spectral survey of 18 post-AGB candidate stars are presented. Most of the stars have near-infrared hydrogen lines in absorption, which is normal for their spectral types. Three stars, HD 101584, HD 179821 and HD 170756 have the CO first overtone bands

Origins Space Telescope: Breaking the Confusion Limit

Science.gov (United States)

Wright, Edward L.; Origins Space Telescope Science and Technology Definition Team

2018-01-01

The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s.OST will have a background-limited sensitivity for a background 27,000 times lower than the Herschel background caused by thermal emission from Herschel's warm telescope. For continuum observations the confusion limit in a diffraction-limited survey can be reached in very short integration times at longer far-infrared wavelengths. But the confusion limit can be pierced for both the nearest and the farthest objects to be observed by OST. For outer the Solar System the targets' motion across the sky will provide a clear signature in surveys repeated after an interval of days to months. This will provide a size-frequency distribution of TNOs that is not biased toward high albedo objects.For the distant Universe the first galaxies and the first metals will provide a third dimension of spectral information that can be measured with a long-slit, medium resolution spectrograph. This will allow 3Dmapping to measure source densities as a function of redshift. The continuum shape associated with sourcesat different redshifts can be derived from correlation analyses of these 3D maps.Fairly large sky areas can be scanned by moving the spacecraft at a constant angular rate perpendicular to the orientation of the long slit of the spectrograph, avoiding the high overhead of step-and-stare surveying with a large space observatory.We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at ost_info@lists.ipac.caltech.edu

Reversal of infall in SgrB2(M) revealed by Herschel/HIFI observations of HCN lines at THz frequencies

NARCIS (Netherlands)

Rolffs, R.; Schilke, P.; Comito, C.; Bergin, E. A.; van der Tak, F. F. S.; Lis, D. C.; Qin, S.-L.; Menten, K. M.; Guesten, R.; Bell, T. A.; Blake, G.A.; Caux, E.; Ceccarelli, C.; Cernicharo, J.; Crockett, N. R.; Daniel, F.; Dubernet, M. -L.; Emprechtinger, M.; Encrenaz, P.; Gerin, M.; Giesen, T. F.; Goicoechea, J. R.; Goldsmith, P. F.; Gupta, H.; Herbst, E.; Joblin, C.; Johnstone, D.; Langer, W. D.; Latter, W. D.; Lord, S. D.; Maret, S.; Martin, P. G.; Melnick, G. J.; Morris, P.; Mueller, H. S. P.; Murphy, J. A.; Ossenkopf, V.; Pearson, J. C.; Perault, M.; Phillips, T. G.; Plume, R.; Schlemmer, S.; Stutzki, J.; Trappe, N.; Vastel, C.; Wang, S.; Yorke, H. W.; Yu, S.; Zmuidzinas, J.; Diez-Gonzalez, M. C.; Bachiller, R.; Martin-Pintado, J.; Baechtold, W.; Olberg, M.; Nordh, L. H.; Gill, J. J.; Chattopadhyay, G.

2010-01-01

Aims. To investigate the accretion and feedback processes in massive star formation, we analyze the shapes of emission lines from hot molecular cores, whose asymmetries trace infall and expansion motions. Methods. The high-mass star forming region SgrB2(M) was observed with Herschel/HIFI (HEXOS key

Four faint T dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS) Southern Stripe

Science.gov (United States)

Chiu, Kuenley; Liu, Michael C.; Jiang, Linhua; Allers, Katelyn N.; Stark, Daniel P.; Bunker, Andrew; Fan, Xiaohui; Glazebrook, Karl; Dupuy, Trent J.

2008-03-01

We present the optical and near-infrared photometry and spectroscopy of four faint T dwarfs newly discovered from the UKIDSS first data release. The sample, drawn from an imaged area of ~136 deg2 to a depth of Y = 19.9 (5σ, Vega), is located in the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, a region of significant future deep imaging potential. We detail the selection and followup of these objects, three of which are spectroscopically confirmed brown dwarfs ranging from type T2.5 to T7.5, and one is photometrically identified as early T. Their magnitudes range from Y = 19.01 to 19.88 with derived distances from 34 to 98 pc, making these among the coldest and faintest brown dwarfs known. The T7.5 dwarf appears to be single based on 0.05-arcsec images from Keck laser guide star adaptive optics. The sample brings the total number of T dwarfs found or confirmed by UKIDSS data in this region to nine, and we discuss the projected numbers of dwarfs in the future survey data. We estimate that ~240 early and late T dwarfs are discoverable in the UKIDSS Large Area Survey (LAS) data, falling significantly short of published model projections and suggesting that initial mass functions and/or birth rates may be at the low end of possible models. Thus, deeper optical data have good potential to exploit the UKIDSS survey depth more fully, but may still find the potential Y dwarf sample to be extremely rare.

Infrared

Science.gov (United States)

Vollmer, M.

2013-11-01

'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

THE HERSCHEL EXPLOITATION OF LOCAL GALAXY ANDROMEDA (HELGA). VI. THE DISTRIBUTION AND PROPERTIES OF MOLECULAR CLOUD ASSOCIATIONS IN M31

Energy Technology Data Exchange (ETDEWEB)

Kirk, J. M. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Gear, W. K.; Smith, M. W. L.; Ford, G.; Eales, S. A.; Gomez, H. L. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, Wales CF24 3AA (United Kingdom); Fritz, J.; Baes, M.; De Looze, I.; Gentile, G.; Gordon, K.; Verstappen, J.; Viaene, S. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Bendo, G. J. [UK ALMA Regional Centre Node, Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); O' Halloran, B. [Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Madden, S. C.; Lebouteiller, V. [Laboratoire AIM, CEA/DSM-CNRS-Université Paris Diderot, Irfu/Service, Paris, F-91190 Gif-sur-Yvette (France); Roman-Duval, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Boselli, A. [Laboratoire d' Astrophysique de Marseille, UMR 7326 CNRS, 38 rue F. Joliot-Curie, F-13388 Marseille (France); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); and others

2015-01-01

In this paper we present a catalog of giant molecular clouds (GMCs) in the Andromeda (M31) galaxy extracted from the Herschel Exploitation of Local Galaxy Andromeda (HELGA) data set. GMCs are identified from the Herschel maps using a hierarchical source extraction algorithm. We present the results of this new catalog and characterize the spatial distribution and spectral energy properties of its clouds based on the radial dust/gas properties found by Smith et al. A total of 326 GMCs in the mass range 10{sup 4}-10{sup 7} M {sub ☉} are identified; their cumulative mass distribution is found to be proportional to M {sup –2.34}, in agreement with earlier studies. The GMCs appear to follow the same correlation of cloud mass to L {sub CO} observed in the Milky Way. However, comparison between this catalog and interferometry studies also shows that the GMCs are substructured below the Herschel resolution limit, suggesting that we are observing associations of GMCs. Following Gordon et al., we study the spatial structure of M31 by splitting the observed structure into a set of spiral arms and offset rings. We fit radii of 10.3 and 15.5 kpc to the two most prominent rings. We then fit a logarithmic spiral with a pitch angle of 8.°9 to the GMCs not associated with either ring. Last, we comment on the effects of deprojection on our results and investigate the effect different models for M31's inclination will have on the projection of an unperturbed spiral arm system.

Infrared galaxies evolution. From cosmological observations with ISO to a mid-infrared to sub-millimetric modeling

International Nuclear Information System (INIS)

Dole, Herve

2000-01-01

This thesis deals with the analysis of the FIRBACK deep survey performed in the far infrared at λ=170 μm with the Infrared Space Observatory whose aim is the study of the galaxies contributing to the Cosmic Infrared Background, and with the modelling of galaxy evolution in the mid-infrared to submillimeter range. The FIRBACK survey covers 3. 89 Sq. Deg. in 3 high galactic latitude and low foreground emission fields (2 of which are in the northern sky). I first present the techniques of reduction, processing and calibration of the ISOPHOT cosmological data. I show that there is a good agreement between PHOT and DIRBE on extended emission, thanks to the derivation of the PHOT footprint. Final maps are created, and the survey is confusion limited at σc=45 mJy. I present then the techniques of source extraction and the simulations for photometry needed to build the final catalog of 106 sources between 180 mJy (4σ) and 2.4 Jy. The complementary catalog is made of 90 sources between 135 and 180 mJy. Galaxy counts show a large excess with respect to local counts or models (with and without evolution), only compatible with strong evolution scenarios. The Cosmic Infrared Background (CIB) is resolved at 4 % at 170 μm. The identifications of the sources at other wavelengths suggest that most of the sources are local, but a non-negligible part lies above redshift 1. I have developed a phenomenological model of galaxy evolution in order to constrain galaxy evolution in the infrared and to have a better understanding of what the FIRBACK sources are. Using the local Luminosity Function (LF), and template spectra of starburst galaxies, it is possible to constrain the evolution of the LF using all the available data: deep source counts at 15, 170 and 850 μm and the CIB spectrum. I show that galaxy evolution is dominated by a high infrared luminosity population, peaking at L=2.0*10"1"1 Redshift distributions are in agreement with available observations. Predictions are

A-type Stellar Abundances: A Corollary to Herschel Observations of Debris Disks

Science.gov (United States)

Draper, Zachary H.; Matthews, Brenda; Venn, Kim; Lambert, David; Kennedy, Grant; Sitnova, Tatyana

2018-04-01

In order to assess the relationship between metallicity and exoplanetary systems, we compare the abundances of AF-type main-sequence stars with debris disk properties assessed using Herschel observations of an unbiased survey of nearby stars. Hot stars are not as commonly observed, given their unique constraints in data reduction, lack of metal lines, and “astrophysical noise” from rotation speed. Here, we address that deficiency using new and archival spectra of 83 AF-type stars. We measure the abundances of a few species in addition to Fe in order to classify the stars with Ap/Am or Lambda Boo signatures. Lambda Boo stars have a chemical signature of solar-abundant volatile species and sub-solar refractory abundances that is hypothesized to be altered by the pollution of volatiles. Overall, we see no correlation between debris disks and metallicity, primarily because the sample size is cut significantly when using only reliable fits to the spectroscopic data. The abundance measured from the Mg II 4481 blend is a useful diagnostic because it can be reliably measured at large v·sin(i) and is found to be lower around stars with bright debris disks. We find that Lambda Boo stars have brighter debris disks compared to a bias-free sample of AF stars. The trend with disk brightness and Mg abundances suggests pollution effects can be significant and used as a marker for the stability of planetary systems. We explore trends with other species, such as with the C/O ratios, but are significantly limited by the low number of reliable detections.

NASA/IPAC Infrared Science Archive

Data.gov (United States)

National Aeronautics and Space Administration — IRSA is chartered to curate the calibrated science products from NASAs infrared and sub-millimeter missions, including five major large-area/all-sky surveys. IRSA...

FIRE SPECTROSCOPY OF FIVE LATE-TYPE T DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

International Nuclear Information System (INIS)

Burgasser, Adam J.; Cushing, Michael C.; Mainzer, A.; Bauer, James M.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Griffith, Roger L.; Marsh, Kenneth A.; Looper, Dagny L.; Tinney, Christopher; Simcoe, Robert A.; Bochanski, John J.; Skrutskie, Michael F.; Thompson, Maggie A.; Wright, Edward L.

2011-01-01

We present the discovery of five late-type T dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Low-resolution near-infrared spectroscopy obtained with the Magellan Folded-port InfraRed Echellette reveal strong H 2 O and CH 4 absorption in all five sources, and spectral indices and comparison to spectral templates indicate classifications ranging from T5.5 to T8.5:. The spectrum of the latest-type source, WISE J1812+2721, is an excellent match to that of the T8.5 companion brown dwarf Wolf 940B. WISE-based spectrophotometric distance estimates place these T dwarfs at 12-13 pc from the Sun, assuming they are single. Preliminary fits of the spectral data to the atmosphere models of Saumon and Marley indicate effective temperatures ranging from 600 K to 930 K, both cloudy and cloud-free atmospheres, and a broad range of ages and masses. In particular, two sources show evidence of both low surface gravity and cloudy atmospheres, tentatively supporting a trend noted in other young brown dwarfs and exoplanets. In contrast, the high proper motion T dwarf WISE J2018-7423 exhibits a suppressed K-band peak and blue spectrophotometric J - K colors indicative of an old, massive brown dwarf; however, it lacks the broadened Y-band peak seen in metal-poor counterparts. These results illustrate the broad diversity of low-temperature brown dwarfs that will be uncovered with WISE.

The debris disc of solar analogue τ Ceti: Herschel observations and dynamical simulations of the proposed multiplanet system

NARCIS (Netherlands)

Lawler, S.M.; Di Francesco, J.; Kennedy, G.M.; Sibthorpe, B.; Booth, M.; Vandenbussche, B.; Matthews, B.C.; Holland, W.S.; Greaves, J.; Wilner, D.J.; Tuomi, M.; Blommaert, J.A.D.L.; de Vries, B.L.; Dominik, C.; Fridlund, M.; Gear, W.; Heras, A.M.; Ivison, R.; Olofsson, G.

2014-01-01

τ Ceti is a nearby, mature G-type star very similar to our Sun, with a massive Kuiper Belt analogue and possible multiplanet system that has been compared to our Solar system. We present Herschel Space Observatory images of the debris disc, finding the disc is resolved at 70 μm and 160 μm, and

INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

Energy Technology Data Exchange (ETDEWEB)

Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

2016-02-10

The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

Herschel/HIFI Observations of IRC+10216: Water Vapor in the Inner Envelope of a Carbon-rich Asymptotic Giant Branch Star

NARCIS (Netherlands)

Neufeld, D. A.; González-Alfonso, E.; Melnick, G.; Szczerba, R.; Schmidt, M.; Decin, L.; de Koter, A.; Schöier, F. L.; Cernicharo, J.

2011-01-01

We report the results of observations of 10 rotational transitions of water vapor toward the carbon-rich asymptotic giant branch (AGB) star IRC+10216 (CW Leonis), carried out with Herschel's HIFI instrument. Each transition was securely detected by means of observations using the dual beam switch

Discovery of two new Galactic candidate luminous blue variables with Wide-field Infrared Survey Explorer

Science.gov (United States)

Gvaramadze, V. V.; Kniazev, A. Y.; Miroshnichenko, A. S.; Berdnikov, L. N.; Langer, N.; Stringfellow, G. S.; Todt, H.; Hamann, W.-R.; Grebel, E. K.; Buckley, D.; Crause, L.; Crawford, S.; Gulbis, A.; Hettlage, C.; Hooper, E.; Husser, T.-O.; Kotze, P.; Loaring, N.; Nordsieck, K. H.; O'Donoghue, D.; Pickering, T.; Potter, S.; Romero Colmenero, E.; Vaisanen, P.; Williams, T.; Wolf, M.; Reichart, D. E.; Ivarsen, K. M.; Haislip, J. B.; Nysewander, M. C.; LaCluyze, A. P.

2012-04-01

We report the discovery of two new Galactic candidate luminous blue variable (LBV) stars via detection of circular shells (typical of confirmed and candidate LBVs) and follow-up spectroscopy of their central stars. The shells were detected at 22 μm in the archival data of the Mid-Infrared All Sky Survey carried out with the Wide-field Infrared Survey Explorer (WISE). Follow-up optical spectroscopy of the central stars of the shells conducted with the renewed Southern African Large Telescope (SALT) showed that their spectra are very similar to those of the well-known LBVs P Cygni and AG Car, and the recently discovered candidate LBV MN112, which implies the LBV classification for these stars as well. The LBV classification of both stars is supported by detection of their significant photometric variability: one of them brightened in the R and I bands by 0.68 ± 0.10 and 0.61 ± 0.04 mag, respectively, during the last 13-18 years, while the second one (known as Hen 3-1383) varies its B, V, R, I and Ks brightnesses by ≃0.5-0.9 mag on time-scales from 10 d to decades. We also found significant changes in the spectrum of Hen 3-1383 on a time-scale of ≃3 months, which provides additional support for the LBV classification of this star. Further spectrophotometric monitoring of both stars is required to firmly prove their LBV status. We discuss a connection between the location of massive stars in the field and their fast rotation, and suggest that the LBV activity of the newly discovered candidate LBVs might be directly related to their possible runaway status. a USNO B-1 (Monet et al. 2003); bDENIS; c2MASS; dSALT; ePROMPT.

Mid infrared lasers for remote sensing applications

Energy Technology Data Exchange (ETDEWEB)

Walsh, Brian M., E-mail: brian.m.walsh@nasa.gov [NASA Langley Research Center, Hampton, VA 23681 (United States); Lee, Hyung R. [National Institute of Aerospace, Hampton, VA 23666 (United States); Barnes, Norman P. [Science Systems and Applications, Inc., Hampton, VA 23666 (United States)

2016-01-15

To accurately measure the concentrations of atmospheric gasses, especially the gasses with low concentrations, strong absorption features must be accessed. Each molecular species or constituent has characteristic mid-infrared absorption features by which either column content or range resolved concentrations can be measured. Because of these characteristic absorption features the mid infrared spectral region is known as the fingerprint region. However, as noted by the Decadal Survey, mid-infrared solid-state lasers needed for DIAL systems are not available. The primary reason is associated with short upper laser level lifetimes of mid infrared transitions. Energy gaps between the energy levels that produce mid-infrared laser transitions are small, promoting rapid nonradiative quenching. Nonradiative quenching is a multiphonon process, the more phonons needed, the smaller the effect. More low energy phonons are required to span an energy gap than high energy phonons. Thus, low energy phonon materials have less nonradiative quenching compared to high energy phonon materials. Common laser materials, such as oxides like YAG, are high phonon energy materials, while fluorides, chlorides and bromides are low phonon materials. Work at NASA Langley is focused on a systematic search for novel lanthanide-doped mid-infrared solid-state lasers using both quantum mechanical models (theoretical) and spectroscopy (experimental) techniques. Only the best candidates are chosen for laser studies. The capabilities of modeling materials, experimental challenges, material properties, spectroscopy, and prospects for lanthanide-doped mid-infrared solid-state laser devices will be presented. - Highlights: • We discuss mid infrared lasers and laser materials. • We discuss applications to remote sensing. • We survey the lanthanide ions in low phonon materials for potential. • We present examples of praseodymium mid infrared spectroscopy and laser design.

CHEMICAL EVOLUTION IN HIGH-MASS STAR-FORMING REGIONS: RESULTS FROM THE MALT90 SURVEY

Energy Technology Data Exchange (ETDEWEB)

Hoq, Sadia; Jackson, James M.; Foster, Jonathan B.; Sanhueza, Patricio; Claysmith, Christopher [Institute for Astrophysical Research, Boston University, Boston, MA 02215 (United States); Guzmán, Andrés [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Whitaker, J. Scott [Physics Department, Boston University, Boston, MA 02215 (United States); Rathborne, Jill M. [Australia Telescope National Facility, CSIRO Astronomy and Space Science, Epping, NSW (Australia); Vasyunina, Tatiana; Vasyunin, Anton, E-mail: shoq@bu.edu, E-mail: jackson@bu.edu, E-mail: patricio@bu.edu, E-mail: claysmit@bu.edu, E-mail: jonathan.b.foster@yale.edu, E-mail: aguzmanf@cfa.harvard.edu, E-mail: scott@bu.edu, E-mail: rathborne@csiro.au, E-mail: tv3h@virginia.edu, E-mail: aiv3f@virginia.edu [Department of Chemistry, University of Virginia, Charlottesville, VA 22904 (United States)

2013-11-10

The chemical changes of high-mass star-forming regions provide a potential method for classifying their evolutionary stages and, ultimately, ages. In this study, we search for correlations between molecular abundances and the evolutionary stages of dense molecular clumps associated with high-mass star formation. We use the molecular line maps from Year 1 of the Millimetre Astronomy Legacy Team 90 GHz (MALT90) Survey. The survey mapped several hundred individual star-forming clumps chosen from the ATLASGAL survey to span the complete range of evolution, from prestellar to protostellar to H II regions. The evolutionary stage of each clump is classified using the Spitzer GLIMPSE/MIPSGAL mid-IR surveys. Where possible, we determine the dust temperatures and H{sub 2} column densities for each clump from Herschel/Hi-GAL continuum data. From MALT90 data, we measure the integrated intensities of the N{sub 2}H{sup +}, HCO{sup +}, HCN and HNC (1-0) lines, and derive the column densities and abundances of N{sub 2}H{sup +} and HCO{sup +}. The Herschel dust temperatures increase as a function of the IR-based Spitzer evolutionary classification scheme, with the youngest clumps being the coldest, which gives confidence that this classification method provides a reliable way to assign evolutionary stages to clumps. Both N{sub 2}H{sup +} and HCO{sup +} abundances increase as a function of evolutionary stage, whereas the N{sub 2}H{sup +} (1-0) to HCO{sup +} (1-0) integrated intensity ratios show no discernable trend. The HCN (1-0) to HNC(1-0) integrated intensity ratios show marginal evidence of an increase as the clumps evolve.

THE DISCOVERY OF Y DWARFS USING DATA FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE)

International Nuclear Information System (INIS)

Cushing, Michael C.; Mainzer, A.; Eisenhardt, Peter R.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Griffith, Roger L.; Marsh, Kenneth A.; Beichman, Charles A.; Skrutskie, Michael F.; Burgasser, Adam J.; Prato, Lisa A.; Simcoe, Robert A.; Marley, Mark S.; Freedman, Richard S.; Saumon, D.; Wright, Edward L.

2011-01-01

We present the discovery of seven ultracool brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Near-infrared spectroscopy reveals deep absorption bands of H 2 O and CH 4 that indicate all seven of the brown dwarfs have spectral types later than UGPS J072227.51–054031.2, the latest-type T dwarf currently known. The spectrum of WISEP J182831.08+265037.8 is distinct in that the heights of the J- and H-band peaks are approximately equal in units of f λ , so we identify it as the archetypal member of the Y spectral class. The spectra of at least two of the other brown dwarfs exhibit absorption on the blue wing of the H-band peak that we tentatively ascribe to NH 3 . These spectral morphological changes provide a clear transition between the T dwarfs and the Y dwarfs. In order to produce a smooth near-infrared spectral sequence across the T/Y dwarf transition, we have reclassified UGPS 0722–05 as the T9 spectral standard and tentatively assign WISEP J173835.52+273258.9 as the Y0 spectral standard. In total, six of the seven new brown dwarfs are classified as Y dwarfs: four are classified as Y0, one is classified as Y0 (pec?), and WISEP J1828+2650 is classified as >Y0. We have also compared the spectra to the model atmospheres of Marley and Saumon and infer that the brown dwarfs have effective temperatures ranging from 300 K to 500 K, making them the coldest spectroscopically confirmed brown dwarfs known to date.

GALACTICNUCLEUS: A high angular resolution JHKs imaging survey of the Galactic centre. I. Methodology, performance, and near-infrared extinction towards the Galactic centre

Science.gov (United States)

Nogueras-Lara, F.; Gallego-Calvente, A. T.; Dong, H.; Gallego-Cano, E.; Girard, J. H. V.; Hilker, M.; de Zeeuw, P. T.; Feldmeier-Krause, A.; Nishiyama, S.; Najarro, F.; Neumayer, N.; Schödel, R.

2018-03-01

Context. The Galactic centre (GC) is of fundamental astrophysical interest, but existing near-infrared surveys fall short covering it adequately, either in terms of angular resolution, multi-wavelength coverage, or both. Here we introduce the GALACTICNUCLEUS survey, a JHKs imaging survey of the centre of the Milky Way with a 0.2″ angular resolution. Aim. The purpose of this paper is to present the observations of Field 1 of our survey, centred approximately on SgrA* with an approximate size of 7.95' × 3.43'. We describe the observational set-up and data reduction pipeline and discuss the quality of the data. Finally, we present the analysis of the data. Methods: The data were acquired with the near-infrared camera High Acuity Wide field K-band Imager (HAWK-I) at the ESO Very Large Telescope (VLT). Short readout times in combination with the speckle holography algorithm allowed us to produce final images with a stable, Gaussian PSF (point spread function) of 0.2″ FWHM (full width at half maximum). Astrometric calibration is achieved via the VISTA Variables in the Via Lactea (VVV) survey and photometric calibration is based on the SIRIUS/Infrared Survey Facility telescope (IRSF) survey. The quality of the data is assessed by comparison between observations of the same field with different detectors of HAWK-I and at different times. Results: We reach 5σ detection limits of approximately J = 22, H = 21, and Ks = 20. The photometric uncertainties are less than 0.05 at J ≲ 20, H ≲ 17, and Ks ≲ 16. We can distinguish five stellar populations in the colour-magnitude diagrams; three of them appear to belong to foreground spiral arms, and the other two correspond to high- and low-extinction star groups at the GC. We use our data to analyse the near-infrared extinction curve and find some evidence for a possible difference between the extinction index between J - H and H - Ks. However, we conclude that it can be described very well by a power law with an index of

Water deuteration in star-forming regions: Contribution of Herschel/HIFI spectroscopic data

International Nuclear Information System (INIS)

Coutens, Audrey

2012-01-01

Water (H_2O) is one of the most abundant molecules in the interstellar medium. In addition to being a primordial ingredient in the emergence of life, this species plays an essential role in the process of star formation through the cooling of warm gas. It also controls the chemistry for many species, either in the gas phase or on the grain surfaces. Studying its deuterated form HDO is a unique opportunity, through the estimation of the HDO/H_2O ratio, to constrain the mechanisms of water formation and to better understand the origin of water contained in terrestrial oceans. Indeed, recent results obtained with the Herschel satellite show that the HDO/H_2O ratio observed in comets is similar to the value measured in oceans (∼1.5 10"-"4), which suggests that comets could have brought a large fraction to Earth to form the oceans during heavy bombardments (Hartogh et al. 2011). In this thesis, I was interested in the study of deuterated water in the first stages of star formation, the Class 0 stage, which precede the formation of the protoplanetary disk leading to the birth of comets and planets. Through a 1D non-Local Thermodynamic Equilibrium radiative transfer modeling of the line profiles of the numerous HDO and H_2"1"8O transitions detected with the HIFI (Heterodyne Instrument for Far-Infrared) instrument onboard the Herschel Space Observatory and ground-based telescopes (IRAM, JCMT), I determined that the HDO/H_2O ratios of the solar-type protostar IRAS 16293-2422 was about 2% in the hot corino, the inner part of the protostellar envelope sufficiently warm (T ≥ 100 K) to desorb in gas phase the water molecules trapped in the icy grain mantles, and about 0.5% in the colder part of the envelope. This study (Coutens et al. 2012) also allowed me to show that an absorbing layer rich in water surrounds the protostar. This layer could be produced by the photo-desorption through the UV field of the water molecules frozen on the grains, on the edges of the molecular

Combining Dark Energy Survey Science Verification data with near-infrared data from the ESO VISTA Hemisphere Survey

Energy Technology Data Exchange (ETDEWEB)

Banerji, M.; Jouvel, S.; Lin, H.; McMahon, R. G.; Lahav, O.; Castander, F. J.; Abdalla, F. B.; Bertin, E.; Bosman, S. E.; Carnero, A.; Kind, M. C.; da Costa, L. N.; Gerdes, D.; Gschwend, J.; Lima, M.; Maia, M. A. G.; Merson, A.; Miller, C.; Ogando, R.; Pellegrini, P.; Reed, S.; Saglia, R.; Sanchez, C.; Allam, S.; Annis, J.; Bernstein, G.; Bernstein, J.; Bernstein, R.; Capozzi, D.; Childress, M.; Cunha, C. E.; Davis, T. M.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Doel, P.; Findlay, J.; Finley, D. A.; Flaugher, B.; Frieman, J.; Gaztanaga, E.; Glazebrook, K.; Gonzalez-Fernandez, C.; Gonzalez-Solares, E.; Honscheid, K.; Irwin, M. J.; Jarvis, M. J.; Kim, A.; Koposov, S.; Kuehn, K.; Kupcu-Yoldas, A.; Lagattuta, D.; Lewis, J. R.; Lidman, C.; Makler, M.; Marriner, J.; Marshall, J. L.; Miquel, R.; Mohr, J. J.; Neilsen, E.; Peoples, J.; Sako, M.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla, I.; Sharp, R.; Soares-Santos, M.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Tucker, D.; Uddin, S. A.; Wechsler, R.; Wester, W.; Yuan, F.; Zuntz, J.

2014-11-25

We present the combination of optical data from the Science Verification phase of the Dark Energy Survey (DES) with near-infrared (NIR) data from the European Southern Observatory VISTA Hemisphere Survey (VHS). The deep optical detections from DES are used to extract fluxes and associated errors from the shallower VHS data. Joint seven-band (grizYJK) photometric catalogues are produced in a single 3 sq-deg dedicated camera field centred at 02h26m-04d36m where the availability of ancillary multiwavelength photometry and spectroscopy allows us to test the data quality. Dual photometry increases the number of DES galaxies with measured VHS fluxes by a factor of ~4.5 relative to a simple catalogue level matching and results in a ~1.5 mag increase in the 80 per cent completeness limit of the NIR data. Almost 70 per cent of DES sources have useful NIR flux measurements in this initial catalogue. Photometric redshifts are estimated for a subset of galaxies with spectroscopic redshifts and initial results, although currently limited by small number statistics, indicate that the VHS data can help reduce the photometric redshift scatter at both z < 0.5 and z > 1. We present example DES+VHS colour selection criteria for high-redshift luminous red galaxies (LRGs) at z ~ 0.7 as well as luminous quasars. Using spectroscopic observations in this field we show that the additional VHS fluxes enable a cleaner selection of both populations with <10 per cent contamination from galactic stars in the case of spectroscopically confirmed quasars and <0.5 per cent contamination from galactic stars in the case of spectroscopically confirmed LRGs. The combined DES+VHS data set, which will eventually cover almost 5000 sq-deg, will therefore enable a range of new science and be ideally suited for target selection for future wide-field spectroscopic surveys.

The Bright and Dark Sides of High-redshift Starburst Galaxies from Herschel and Subaru Observations

Energy Technology Data Exchange (ETDEWEB)

Puglisi, A.; Rodighiero, G.; Rodríguez-Muñoz, L.; Mancini, C.; Franceschini, A. [Dipartimento di Fisica e Astronomia, Università di Padova, vicolo dell’Osservatorio 2, I-35122 Padova (Italy); Daddi, E.; Valentino, F.; Calabrò, A.; Jin, S. [Laboratoire AIM-Paris-Saclay, CEA/DSM-CNRS-Université Paris Diderot, IRFU/Service d’Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Renzini, A. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio, 5, I-35122 Padova (Italy); Silverman, J. D. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for for Advanced Study, The University of Tokyo, Kashiwanoha, Kashiwa 277-8583 (Japan); Kashino, D. [Institute for Astronomy, Department of Physics, ETH Zürich, Wolfgang-Pauli-strasse 27, CH-8093 Zürich (Switzerland); Mainieri, V.; Man, A. [ESO, Karl-Schwarschild-Straße 2, D-85748 Garching bei München (Germany); Darvish, B. [Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Pasadena, CA 91125 (United States); Maier, C. [University of Vienna, Department of Astrophysics, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria); Kartaltepe, J. S. [National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Sanders, D. B. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

2017-04-01

We present rest-frame optical spectra from the FMOS-COSMOS survey of 12 z ∼ 1.6 Herschel starburst galaxies, with star formation rate (SFR) elevated by ×8, on average, above the star-forming main sequence (MS). Comparing the H α to IR luminosity ratio and the Balmer decrement, we find that the optically thin regions of the sources contain on average only ∼10% of the total SFR, whereas ∼90% come from an extremely obscured component that is revealed only by far-IR observations and is optically thick even in H α . We measure the [N ii]{sub 6583}/H α ratio, suggesting that the less obscured regions have a metal content similar to that of the MS population at the same stellar masses and redshifts. However, our objects appear to be metal-rich outliers from the metallicity–SFR anticorrelation observed at fixed stellar mass for the MS population. The [S ii]{sub 6732}/[S ii]{sub 6717} ratio from the average spectrum indicates an electron density n {sub e} ∼ 1100 cm{sup −3} , larger than what was estimated for MS galaxies but only at the 1.5 σ level. Our results provide supporting evidence that high- z MS outliers are analogous of local ULIRGs and are consistent with a major-merger origin for the starburst event.

Do the Herschel cold clouds in the Galactic halo embody its dark matter?

International Nuclear Information System (INIS)

Nieuwenhuizen, Theo M; Heusden, Erik F G van; Liska, Matthew T P

2012-01-01

Recent Herschel/SPIRE (Spectral and Photometric Imaging Receiver) maps of the Small and Large Magellanic Clouds (SMC, LMC) exhibit, in each, thousands of clouds. Observed at 250 μm, they must be cold, T ∼ 15 K, hence the name ‘Herschel cold clouds’ (HCCs). From the observed rotational velocity profile of the Galaxy and the assumption of spherical symmetry, its mass density is modeled in a form close to that of an isothermal sphere. If the HCCs constitute a certain fraction of it, their angular size distribution has a specified shape. A fit to the data deduced from the SMC/LMC maps supports this and yields 1.7 pc for their average radius. There are so many HCCs that they will make up all the missing Halo mass density if there is spherical symmetry and their average mass is of the order of 10 000M ⊙ . This compares with the Jeans mass of about 40 000M ⊙ and puts forward that the HCCs are, in fact, Jeans clusters, constituting all the Galactic dark matter and many of its missing baryons, a conclusion deduced before from a different field of the sky (Nieuwenhuizen et al 2011 J. Cosmol. 15 6017-29). A preliminary analysis of the intensities yields that the Jeans clusters themselves may consist of some billion MACHOs of a few dozen Earth masses. With a size of dozens of solar radii, they would mostly not lens, but cause occultation of stars in the LMC, SMC and toward the Galactic center, and may thus have been overlooked in microlensing.

Herschel/HIFI measurements of the ortho/para ratio in water towards Sagittarius B2(M) and W31C

NARCIS (Netherlands)

Lis, D. C.; Phillips, T. G.; Goldsmith, P. F.; Neufeld, D. A.; Herbst, E.; Comito, C.; Schilke, P.; Mueller, H. S. P.; Bergin, E. A.; Gerin, M.; Bell, T. A.; Emprechtinger, M.; Black, J. H.; Blake, G. A.; Boulanger, F.; Caux, E.; Ceccarelli, C.; Cernicharo, J.; Coutens, A.; Crockett, N. R.; Daniel, F.; Dartois, E.; De Luca, M.; Dubernet, M. -L.; Encrenaz, P.; Falgarone, E.; Geballe, T. R.; Godard, B.; Giesen, T. F.; Goicoechea, J. R.; Gry, C.; Gupta, H.; Hennebelle, P.; Hily-Blant, P.; Kolos, R.; Krelowski, J.; Joblin, C.; Johnstone, D.; Kazmierczak, M.; Lord, S. D.; Maret, S.; Martin, P. G.; Martin-Pintado, J.; Melnick, G. J.; Menten, K. M.; Monje, R.; Mookerjea, B.; Morris, P.; Murphy, J. A.; Ossenkopf, V.; Pearson, J. C.; Perault, M.; Persson, C.; Plume, R.; Qin, S. -L.; Salez, M.; Schlemmer, S.; Schmidt, M.; Sonnentrucker, P.; Stutzki, J.; Teyssier, D.; Trappe, N.; van der Tak, F. F. S.; Vastel, C.; Wang, S.; Yorke, H. W.; Yu, S.; Zmuidzinas, J.; Boogert, A.; Erickson, N.; Karpov, A.; Kooi, J.; Maiwald, F. W.; Schieder, R.; Zaal, P.

2010-01-01

We present Herschel/HIFI observations of the fundamental rotational transitions of ortho- and para-(H2O)-O-16 and (H2O)-O-18 in absorption towards Sagittarius B2(M) and W31C. The ortho/para ratio in water in the foreground clouds on the line of sight towards these bright continuum sources is

Andromeda (M31) optical and infrared disk survey. I. Insights in wide-field near-IR surface photometry

International Nuclear Information System (INIS)

Sick, Jonathan; Courteau, Stéphane; Cuillandre, Jean-Charles; McDonald, Michael; De Jong, Roelof; Tully, R. Brent

2014-01-01

We present wide-field near-infrared J and K s images of the Andromeda Galaxy (M31) taken with WIRCam at the Canada-France-Hawaii Telescope as part of the Andromeda Optical and Infrared Disk Survey. This data set allows simultaneous observations of resolved stars and near-infrared (NIR) surface brightness across M31's entire bulge and disk (within R = 22 kpc), permitting a direct test of the stellar composition of near-infrared light in a nearby galaxy. Here we develop NIR observation and reduction methods to recover a uniform surface brightness map across the 3° × 1° disk of M31 with 27 WIRCam fields. Two sky-target nodding strategies are tested, and we find that strictly minimizing sky sampling latency cannot improve background subtraction accuracy to better than 2% of the background level due to spatio-temporal variations in the NIR skyglow. We fully describe our WIRCam reduction pipeline and advocate using flats built from night-sky images over a single night, rather than dome flats that do not capture the WIRCam illumination field. Contamination from scattered light and thermal background in sky flats has a negligible effect on the surface brightness shape compared to the stochastic differences in background shape between sky and galaxy disk fields, which are ∼0.3% of the background level. The most dramatic calibration step is the introduction of scalar sky offsets to each image that optimizes surface brightness continuity. Sky offsets reduce the mean surface brightness difference between observation blocks from 1% to <0.1% of the background level, though the absolute background level remains statistically uncertain to 0.15% of the background level. We present our WIRCam reduction pipeline and performance analysis to give specific recommendations for the improvement of NIR wide-field imaging methods.

Thermographic survey of two rural buildings in Spain

Energy Technology Data Exchange (ETDEWEB)

Martin Ocana, S.; Canas Guerrero, I. [Departamento de Construccion y Vias Rurales, Escuela Tecnica Superior de Ingenieros Agronomos, Universidad Politecnica de Madrid, Madrid (Spain); Gonzalez Requena, I. [Departamento de Materiales y Produccion Aeroespacial, Escuela Tecnica Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Madrid (Spain)

2004-07-01

Two common housing prototypes of existing buildings in Spanish rural areas were surveyed by infrared inspection. The aim of the study is to assess the usefulness of infrared thermography as a technique for the detection of the thermal performance of rural buildings. For the traditional house the best results were obtained in the thermographic survey carried out in the evening. Contrarily, for the modern house the thermographic survey at daybreak provided more information. Infrared thermography allowed the comparison of the thermal performance of two buildings. (author)

Progress Towards a High-Precision Infrared Spectroscopic Survey of the H_3^+ Ion

Science.gov (United States)

Perry, Adam J.; Hodges, James N.; Markus, Charles R.; Kocheril, G. Stephen; Jenkins, Paul A., II; McCall, Benjamin J.

2015-06-01

The trihydrogen cation, H_3^+, represents one of the most important and fundamental molecular systems. Having only two electrons and three nuclei, H_3^+ is the simplest polyatomic system and is a key testing ground for the development of new techniques for calculating potential energy surfaces and predicting molecular spectra. Corrections that go beyond the Born-Oppenheimer approximation, including adiabatic, non-adiabatic, relativistic, and quantum electrodynamic corrections are becoming more feasible to calculate. As a result, experimental measurements performed on the H_3^+ ion serve as important benchmarks which are used to test the predictive power of new computational methods. By measuring many infrared transitions with precision at the sub-MHz level it is possible to construct a list of the most highly precise experimental rovibrational energy levels for this molecule. Until recently, only a select handful of infrared transitions of this molecule have been measured with high precision (˜ 1 MHz). Using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy, we are aiming to produce the largest high-precision spectroscopic dataset for this molecule to date. Presented here are the current results from our survey along with a discussion of the combination differences analysis used to extract the experimentally determined rovibrational energy levels. O. Polyansky, et al., Phil. Trans. R. Soc. A (2012), 370, 5014. M. Pavanello, et al., J. Chem. Phys. (2012), 136, 184303. L. Diniz, et al., Phys. Rev. A (2013), 88, 032506. L. Lodi, et al., Phys. Rev. A (2014), 89, 032505. J. Hodges, et al., J. Chem. Phys (2013), 139, 164201.

INFRARED COLOR-COLOR DIAGRAMS FOR AGB STARS

Directory of Open Access Journals (Sweden)

Kyung-Won Suh

2007-09-01

Full Text Available We present infrared color-color diagrams of AGB stars from the observations at near and mid infrared bands. We compile the observations for hundreds of OH/IR stars and carbon stars using the data from the Midcourse Space Experiment (MSX, the two micron sky survey (2MASS, and the IRAS point source catalog (PSC. We compare the observations with the theoretical evolutionary tracks of AGB stars. From the new observational data base and the theoretical evolution tracks, we discuss the meaning of the infrared color-color diagrams at different wavelengths.

Cryogenic implications of orbit selection of the Space Infrared Telescope Facility (SIRTF)

International Nuclear Information System (INIS)

Lee, J.H.; Brooke, W.F.; Maa, S.

1986-01-01

The Infrared Astronomical Satellite (IRAS) which completed the first all sky survey in the infrared demonstrated the tremendous advantage of space-based infrared astronomy. The ability to cool the telescope optics and focal plane to liquid helium temperatures and the absence of atmospheric disturbances which cause ''seeing'' effects resulted in the discovery of 250,000 IR sources and many interesting phenomena including dust clouds around Vega and the infrared ''cirrus'' at 100 μm. To realize the true benefit of space infrared astronomy, NASA is now studying the Space Infrared Telescope Facility, a long-life space-based observatory, to follow up on the survey results of IRAS. The choice of orbits is a critical program decision. The objective of this paper is to compare the performance of an all superfluid helium SIRTF system in the two possible orbit inclinations, polar orbit (99 0 ) and the low inclination orbit (28.5 0 )

Herschel and SCUBA-2 observations of dust emission in a sample of Planck cold clumps

Science.gov (United States)

Juvela, Mika; He, Jinhua; Pattle, Katherine; Liu, Tie; Bendo, George; Eden, David J.; Fehér, Orsolya; Michel, Fich; Fuller, Gary; Hirano, Naomi; Kim, Kee-Tae; Li, Di; Liu, Sheng-Yuan; Malinen, Johanna; Marshall, Douglas J.; Paradis, Deborah; Parsons, Harriet; Pelkonen, Veli-Matti; Rawlings, Mark G.; Ristorcelli, Isabelle; Samal, Manash R.; Tatematsu, Ken'ichi; Thompson, Mark; Traficante, Alessio; Wang, Ke; Ward-Thompson, Derek; Wu, Yuefang; Yi, Hee-Weon; Yoo, Hyunju

2018-04-01

Context. Analysis of all-sky Planck submillimetre observations and the IRAS 100 μm data has led to the detection of a population of Galactic cold clumps. The clumps can be used to study star formation and dust properties in a wide range of Galactic environments. Aims: Our aim is to measure dust spectral energy distribution (SED) variations as a function of the spatial scale and the wavelength. Methods: We examined the SEDs at large scales using IRAS, Planck, and Herschel data. At smaller scales, we compared JCMT/SCUBA-2 850 μm maps with Herschel data that were filtered using the SCUBA-2 pipeline. Clumps were extracted using the Fellwalker method, and their spectra were modelled as modified blackbody functions. Results: According to IRAS and Planck data, most fields have dust colour temperatures TC 14-18 K and opacity spectral index values of β = 1.5-1.9. The clumps and cores identified in SCUBA-2 maps have T 13 K and similar β values. There are some indications of the dust emission spectrum becoming flatter at wavelengths longer than 500 μm. In fits involving Planck data, the significance is limited by the uncertainty of the corrections for CO line contamination. The fits to the SPIRE data give a median β value that is slightly above 1.8. In the joint SPIRE and SCUBA-2 850 μm fits, the value decreases to β 1.6. Most of the observed T-β anticorrelation can be explained by noise. Conclusions: The typical submillimetre opacity spectral index β of cold clumps is found to be 1.7. This is above the values of diffuse clouds, but lower than in some previous studies of dense clumps. There is only tentative evidence of a T-β anticorrelation and β decreasing at millimetre wavelengths. Planck (http://www.esa.int/Planck) is a project of the European Space Agency - ESA - with instruments provided by two scientific consortia funded by ESA member states (in particular the lead countries: France and Italy) with contributions from NASA (USA), and telescope reflectors

Physics and Chemistry of the Interstellar Medium. General Colloquium, 19-21 November 2012, Paris

International Nuclear Information System (INIS)

Aguillon, Francois; Alata, Ivan; Alcaraz, Christian; Alves, Marta; Andre, Philippe; Bachiller, Rafael; Bacmann, Aurore; Baklouti, Donia; Bernard, Jean-Philippe; Berne, Olivier; Beroff, Karine; Bertin, Mathieu; Biennier, Ludovic; Bocchio, Marco; Bonal, Lydie; Bontemps, Sylvain; Bouchez Giret, Aurelia; Boulanger, Francois; Bracco, Andrea; Bron, Emeric; Brunetto, Rosario; Cabrit, Sylvie; Canosa, Andre; Capron, Michael; Ceccarelli, Cecilia; Cernicharo, Jose; Chaabouni, Henda; Chabot, Marin; Chen, Hui-Chen; Chiavassa, Thierry; Cobut, Vincent; Commercon, Benoit; Congiu, Emanuele; Coutens, Audrey; Danger, Gregoire; Daniel, Fabien; Dartois, Emmanuel; Demyk, Karine; Denis, Alpizar; Despois, Didier; D'hendecourt, Louis; Dontot, Leo; Doronin, Mikhail; Dubernet, Marie-Lise; Dulieu, Francois; Dumouchel, Fabien; Duvernay, Fabrice; Ellinger, Yves; Falgarone, Edith; Falvo, Cyril; Faure, Alexandre; Fayolle, Edith; Feautrier, Nicole; Feraud, Geraldine; Fillion, Jean-Hugues; Gamboa, Antonio; Gardez, Aline; Gavilan, Lisseth; Gerin, Maryvonne; Ghesquiere, Pierre; Godard, Benjamin; Godard, Marie; Gounelle, Matthieu; Gratier, Pierre; Grenier, Isabelle; Gruet, Sebastien; Gry, Cecile; Guillemin, Jean-Claude; Guilloteau, Stephane; Gusdorf, Antoine; Guzman, Viviana; Habart, Emilie; Hennebelle, Patrick; Herrera, Cinthya; Hily-Blant, Pierre; Hincelin, Ugo; Hochlaf, Majdi; Huet, Therese; Iftner, Christophe; Jallat, Aurelie; Joblin, Christine; Kahane, Claudine; Kalugina, Yulia; Kleiner, Isabelle; Koehler, Melanie; Kokkin, Damian; Koutroumpa, Dimitra; Krim, Lahouari; Lallement, Rosine; Lanza, Mathieu; Lattelais, Marie; Le Bertre, Thibaut; Le Gal, Romane; Le Petit, Franck; Le Picard, Sebastien; Lefloch, Bertrand; Lemaire, Jean Louis; Lesaffre, Pierre; Lique, Francois; Loison, Jean-Christophe; Lopez Sepulcre, Ana; Maillard, Jean-Pierre; Margules, Laurent; Martin, Celine; Mascetti, Joelle; Michaut, Xavier; Minissale, Marco; Miville-Deschenes, Marc-Antoine; Mokrane, Hakima; Momferratos, Georgios; Montillaud, Julien; Montmerle, Thierry; Moret-Bailly, Jacques; Motiyenko, Roman; Moudens, Audrey; Noble, Jennifer; Padovani, Marco; Pagani, Laurent; Pardanaud, Cedric; Parisel, Olivier; Pauzat, Francoise; Pernet, Amelie; Pety, Jerome; Philippe, Laurent; Piergiorgio, Casavecchia; Pilme, Julien; Pinto, Cecilia; Pirali, Olivier; Pirim, Claire; Puspitarini, Lucky; Rist, Claire; Ristorcelli, Isabelle; Romanzin, Claire; Roueff, Evelyne; Rousseau, Patrick; Sabbah, Hassan; Saury, Eleonore; Schneider, Ioan; Schwell, Martin; Sims, Ian; Spielfiedel, Annie; Stoecklin, Thierry; Talbi, Dahbia; Taquet, Vianney; Teillet-Billy, Dominique; Theule, Patrice; Thi, Wing-Fai; Trolez, Yann; Valdivia, Valeska; Van Dishoeck, Ewine; Verstraete, Laurent; Vinogradoff, Vassilissa; Wiesenfeld, Laurent; Ysard, Nathalie; Yvart, Walter; Zicler Eleonore

2012-11-01

This document publishes the oral contributions and the 66 posters presented during a colloquium on physics and chemistry of interstellar medium. The following themes have been addressed: New views on the interstellar medium with Herschel, Planck and Alma, Cycle of interstellar dusts, Physics and Dynamics of the interstellar medium, Molecular complexifying and the link towards pre-biotic chemistry. More precisely, the oral contributions addressed the following topics: Interstellar medium with Herschel and Planck; The anomalous microwave emission: a new window on the physics of small grains; Sub-millimetre spectroscopy of complex molecules and of radicals for ALMA and Herschel missions; Analysing observations of molecules in the ISM: theoretical and experimental studies of energy transfer; Unravelling the labyrinth of star formation with Herschel; Star formation regions with Herschel and Alma: astro-chemistry in the Netherlands; Physical structure of gas and dust in photo-dissociation regions observed with Herschel; Photo-desorption of analogues of interstellar ices; Formation of structures in the interstellar medium: theoretical and numerical aspects; Towards a 3D mapping of the galactic ISM by inversion of absorption individual measurements; Low velocity shocks as signatures of turbulent dissipation in diffuse irradiated gas; Early phases of solar system formation: 3D physical and chemical modelling of the collapse of pre-stellar dense core; Cosmic-ray propagation in molecular clouds; Protostellar shocks in the time of Herschel; A new PDR model of the physics and chemistry of the interstellar gas; Molecular spectroscopy in the ALMA era and laboratory Astrophysics in Spain; Which molecules to be searched for in the interstellar medium; Physics and chemistry of UV illuminated neutral gas: the Horsehead case; Nitrogen fractionation in dark clouds; Molecular spectral surveys from millimetre range to far infrared; Mechanisms and synthesis at the surface of cold grains

THE FIRST HUNDRED BROWN DWARFS DISCOVERED BY THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE)

International Nuclear Information System (INIS)

Davy Kirkpatrick, J.; Gelino, Christopher R.; Griffith, Roger L.; Marsh, Kenneth A.; Tsai, Chao-Wei; Beichman, Charles A.; Cushing, Michael C.; Mainzer, A.; Eisenhardt, Peter R.; Bauer, James M.; Skrutskie, Michael F.; Wright, Edward L.; McLean, Ian S.; Lake, Sean E.; Petty, Sara M.; Thompson, Maggie A.; Benford, Dominic J.; Bridge, Carrie R.; Stanford, S. A.; Bailey, Vanessa

2011-01-01

We present ground-based spectroscopic verification of 6 Y dwarfs (see also Cushing et al.), 89 T dwarfs, 8 L dwarfs, and 1 M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types ≥T6, six of which have been announced earlier by Mainzer et al. and Burgasser et al. We present color-color and color-type diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. Near-infrared and, in a few cases, optical spectra are presented for these discoveries. Near-infrared classifications as late as early Y are presented and objects with peculiar spectra are discussed. Using these new discoveries, we are also able to extend the optical T dwarf classification scheme from T8 to T9. After deriving an absolute WISE 4.6 μm (W2) magnitude versus spectral type relation, we estimate spectrophotometric distances to our discoveries. We also use available astrometric measurements to provide preliminary trigonometric parallaxes to four of our discoveries, which have types of L9 pec (red), T8, T9, and Y0; all of these lie within 10 pc of the Sun. The Y0 dwarf, WISE 1541–2250, is the closest at 2.8 +1.3 –0.6 pc; if this 2.8 pc value persists after continued monitoring, WISE 1541–2250 will become the seventh closest stellar system to the Sun. Another 10 objects, with types between T6 and >Y0, have spectrophotometric distance estimates also placing them within 10 pc. The closest of these, the T6 dwarf WISE 1506+7027, is believed to fall at a distance of ∼4.9 pc. WISE multi-epoch positions supplemented with positional info primarily from the Spitzer/Infrared Array Camera allow us to calculate proper motions and tangential velocities for roughly one-half of the new discoveries. This work represents the first step by WISE to complete a full-sky, volume-limited census of late-T and Y dwarfs. Using early results from this census, we present preliminary, lower limits to the space density of these objects

Estimation of walrus populations on sea ice with infrared imagery and aerial photography

Science.gov (United States)

Udevitz, M.S.; Burn, D.M.; Webber, M.A.

2008-01-01

Population sizes of ice-associated pinnipeds have often been estimated with visual or photographic aerial surveys, but these methods require relatively slow speeds and low altitudes, limiting the area they can cover. Recent developments in infrared imagery and its integration with digital photography could allow substantially larger areas to be surveyed and more accurate enumeration of individuals, thereby solving major problems with previous survey methods. We conducted a trial survey in April 2003 to estimate the number of Pacific walruses (Odobenus rosmarus divergens) hauled out on sea ice around St. Lawrence Island, Alaska. The survey used high altitude infrared imagery to detect groups of walruses on strip transects. Low altitude digital photography was used to determine the number of walruses in a sample of detected groups and calibrate the infrared imagery for estimating the total number of walruses. We propose a survey design incorporating this approach with satellite radio telemetry to estimate the proportion of the population in the water and additional low-level flights to estimate the proportion of the hauled-out population in groups too small to be detected in the infrared imagery. We believe that this approach offers the potential for obtaining reliable population estimates for walruses and other ice-associated pinnipeds. ?? 2007 by the Society for Marine Mammalogy.

DETECTION OF AN ULTRA-BRIGHT SUBMILLIMETER GALAXY BEHIND THE SMALL MAGELLANIC CLOUD

Energy Technology Data Exchange (ETDEWEB)

Takekoshi, Tatsuya; Minamidani, Tetsuhiro; Sorai, Kazuo; Habe, Asao [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Tamura, Yoichi; Kohno, Kotaro [Institute of Astronomy, University of Tokyo, Osawa, Mitaka, Tokyo 181-0015 (Japan); Oogi, Taira [Department of Physics, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Ezawa, Hajime; Komugi, Shinya; Mizuno, Norikazu; Muller, Erik; Kawamura, Akiko [Chile Observatory, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Oshima, Tai [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Scott, Kimberly S. [North American ALMA Science Center, National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Austermann, Jason E. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Tosaki, Tomoka [Joetsu University of Education, Joetsu, Niigata 943-8512 (Japan); Onishi, Toshikazu [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, 599-8531 Osaka (Japan); Fukui, Yasuo [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Matsuo, Hiroshi [Advanced Technology Center, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Aretxaga, Itziar [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), 72000 Puebla (Mexico); and others

2013-09-10

We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3 {+-} 8.4 mJy point source (MM J01071-7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitzer MIPS 24 {mu}m, all IRAC bands, Wide-field Infrared Survey Explorer, and near-infrared (J, H, K{sub S} ). We find an optical (U, B, V) source, which might be the lensing object, at a distance of 1.''4 from near-infrared and IRAC sources. Photometric redshift estimates for the SMG using representative spectral energy distribution templates show the redshifts of 1.4-3.9. We estimate total far-infrared luminosity of (0.3-2.2) Multiplication-Sign 10{sup 14} {mu}{sup -1} L{sub Sun} and a star formation rate of 5600-39, 000 {mu}{sup -1} M{sub Sun} yr{sup -1}, where {mu} is the gravitational magnification factor. This apparent extreme star formation activity is likely explained by a highly magnified gravitational lens system.

THE GEOMETRY OF THE INFRARED AND X-RAY OBSCURER IN A DUSTY HYPERLUMINOUS QUASAR

Energy Technology Data Exchange (ETDEWEB)

Farrah, Duncan; Harris, Kathryn [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Baloković, Mislav; Brightman, Murray [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, Daniel; Walton, Dominic J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Kunimoto, Michelle; Clements, David L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Alexander, David M. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Arévalo, Patricia [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretana N 1111, Playa Ancha, Valparaíso (Chile); Ballantyne, David R. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30332-0430 (United States); Bauer, Franz E. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Boggs, Steven [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States); Brandt, William N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Christensen, Finn [DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Craig, William [EMBIGGEN Anillo, Concepción (Chile); Fabian, Andrew, E-mail: farrah@vt.edu [Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA (United Kingdom); and others

2016-11-01

We study the geometry of the active galactic nucleus (AGN) obscurer in IRAS 09104+4109, an IR-luminous, radio-intermediate FR-I source at z = 0.442, using infrared data from Spitzer and Herschel , X-ray data from NuSTAR , Swift , Suzaku , and Chandra , and an optical spectrum from Palomar. The infrared data imply a total rest-frame 1–1000 μ m luminosity of 5.5 × 10{sup 46} erg s{sup −1} and require both an AGN torus and a starburst model. The AGN torus has an anisotropy-corrected IR luminosity of 4.9 × 10{sup 46} erg s{sup −1} and a viewing angle and half-opening angle both of approximately 36° from pole-on. The starburst has a star formation rate of (110 ± 34) M {sub ⊙} yr{sup −1} and an age of <50 Myr. These results are consistent with two epochs of luminous activity in IRAS 09104+4109: one approximately 150 Myr ago, and one ongoing. The X-ray data suggest a photon index of Γ ≃ 1.8 and a line-of-sight column density of N {sub H} ≃ 5 × 10{sup 23} cm{sup −2}. This argues against a reflection-dominated hard X-ray spectrum, which would have implied a much higher N {sub H} and luminosity. The X-ray and infrared data are consistent with a bolometric AGN luminosity of L {sub bol} ∼ (0.5–2.5) × 10{sup 47} erg s{sup −1}. The X-ray and infrared data are further consistent with coaligned AGN obscurers in which the line of sight “skims” the torus. This is also consistent with the optical spectra, which show both coronal iron lines and broad lines in polarized but not direct light. Combining constraints from the X-ray, optical, and infrared data suggest that the AGN obscurer is within a vertical height of 20 pc, and a radius of 125 pc, of the nucleus.

The Geometry of the Infrared and X-Ray Obscurer in a Dusty Hyperluminous Quasar

Science.gov (United States)

Farrah, Duncan; Balokovic, Mislav; Stern, Daniel; Harris, Kathryn; Kunimoto, Michelle; Walton, Dominc J.; Alexander, David M.; Arevalo, Patricia; Ballantyne, David R.; Bauer, Franz E.;

HERSCHEL /HIFI OBSERVATIONS OF IRC+10216: WATER VAPOR IN THE INNER ENVELOPE OF A CARBON-RICH ASYMPTOTIC GIANT BRANCH STAR

International Nuclear Information System (INIS)

Neufeld, David A.; Gonzalez-Alfonso, Eduardo; Melnick, Gary J.; Szczerba, Ryszard; Schmidt, Miroslaw; Decin, Leen; De Koter, Alex; Schoeier, Fredrik; Cernicharo, Jose

2011-01-01

We report the results of observations of 10 rotational transitions of water vapor toward the carbon-rich asymptotic giant branch (AGB) star IRC+10216 (CW Leonis), carried out with Herschel's HIFI instrument. Each transition was securely detected by means of observations using the dual beam switch mode of HIFI. The measured line ratios imply that water vapor is present in the inner outflow at small distances (≤few x 10 14 cm) from the star, confirming recent results reported by Decin et al. from observations with Herschel's PACS and SPIRE instruments. This finding definitively rules out the hypothesis that the observed water results from the vaporization of small icy objects in circular orbits. The origin of water within the dense C-rich envelope of IRC+10216 remains poorly understood. We derive upper limits on the H 17 2 O/H 16 2 O and H 18 2 O/H 16 2 O isotopic abundance ratios of ∼5 x 10 -3 (3σ), providing additional constraints on models for the origin of the water vapor in IRC+10216.

VizieR Online Data Catalog: Dust properties of major-merger galaxy pairs (Domingue+, 2016)

Science.gov (United States)

Domingue, D. L.; Cao, C.; Xu, C. K.; Jarrett, T. H.; Ronca, J.; Hill, E.; Jacques, A.

2018-04-01

We present an analysis of dust properties of a sample of close major-merger galaxy pairs selected by Ks magnitude and redshift. The pairs represent the two populations of spiral-spiral (S+S) and mixed morphology spiral-elliptical (S+E). The Code Investigating GALaxy Emission (CIGALE) software is used to fit dust models to the Two Micron All Sky Survey, Wide-Field Infrared Survey Explorer, and Herschel flux density measurements, and to derive the parameters describing the polycyclic aromatic hydrocarbons contribution, interstellar radiation field, and photodissociation regions. Model fits verify our previous Spitzer Space Telescope analysis that S+S and S+E pairs do not have the same level of enhancement of star formation and differ in dust composition. (1 data file).

HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

International Nuclear Information System (INIS)

Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Wright, Edward L.; Eisenhardt, Peter R.; Skrutskie, M. F.; Griffith, Roger L.; Marsh, Kenneth A.

2015-01-01

We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments

HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

Energy Technology Data Exchange (ETDEWEB)

Schneider, Adam C.; Cushing, Michael C. [Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606 (United States); Kirkpatrick, J. Davy; Gelino, Christopher R. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Mace, Gregory N.; Wright, Edward L. [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Eisenhardt, Peter R. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Skrutskie, M. F. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Griffith, Roger L. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Marsh, Kenneth A., E-mail: Adam.Schneider@Utoledo.edu [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)

2015-05-10

We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.

HERSCHEL OBSERVATIONS OF GAS AND DUST IN THE UNUSUAL 49 Ceti DEBRIS DISK

Energy Technology Data Exchange (ETDEWEB)

Roberge, A. [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Kamp, I. [Kapteyn Astronomical Institute, University of Groningen, 9700 AV Groningen (Netherlands); Montesinos, B. [Departamento de Astrofisica, Centro de Astrobiologia (INTA-CSIC), ESAC Campus, PO Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Dent, W. R. F. [ALMA, Avda Apoquindo 3846, Piso 19, Edificio Alsacia, Las Condes, Santiago (Chile); Meeus, G.; Eiroa, C. [Departmento Fisica Teorica, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Donaldson, J. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Olofsson, J. [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117, Heidelberg (Germany); Moor, A. [Konkoly Observatory of the Hungarian Academy of Sciences, P.O. Box 67, H-1525 Budapest (Hungary); Augereau, J.-C.; Thi, W.-F. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble, UMR 5274, F-38041, Grenoble (France); Howard, C.; Sandell, G. [SOFIA-USRA, NASA Ames Research Center, Building N232, PO Box 1, Moffett Field, CA 94035 (United States); Ardila, D. R. [NASA Herschel Science Center, California Institute of Technology, 1200 E. California Blvd., Mail Stop 220-6, Pasadena, CA 91125 (United States); Woitke, P., E-mail: Aki.Roberge@nasa.gov [University of Vienna, Department of Astronomy, Tuerkenschanzstr. 17, A-1180, Vienna (Austria)

2013-07-01

We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space Observatory PACS and SPIRE instruments, largely as part of the ''Gas in Protoplanetary Systems'' (GASPS) Open Time Key Programme. Disk dust emission is detected in images at 70, 160, 250, 350, and 500 {mu}m; 49 Cet is significantly extended in the 70 {mu}m image, spatially resolving the outer dust disk for the first time. Spectra covering small wavelength ranges centered on eight atomic and molecular emission lines were obtained, including [O I] 63 {mu}m and [C II] 158 {mu}m. The C II line was detected at the 5{sigma} level-the first detection of atomic emission from the disk. No other emission lines were seen, despite the fact that the O I line is the brightest one observed in Herschel protoplanetary disk spectra. We present an estimate of the amount of circumstellar atomic gas implied by the C II emission. The new far-IR/sub-mm data fills in a large gap in the previous spectral energy distribution (SED) of 49 Cet. A simple model of the new SED confirms the two-component structure of the disk: warm inner dust and cold outer dust that produces most of the observed excess. Finally, we discuss preliminary thermochemical modeling of the 49 Cet gas/dust disk and our attempts to match several observational results simultaneously. Although we are not yet successful in doing so, our investigations shed light on the evolutionary status of the 49 Cet gas, which might not be primordial gas but rather secondary gas coming from comets.

Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background.

Science.gov (United States)

Ade, P A R; Akiba, Y; Anthony, A E; Arnold, K; Atlas, M; Barron, D; Boettger, D; Borrill, J; Borys, C; Chapman, S; Chinone, Y; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feng, C; Flanigan, D; Gilbert, A; Grainger, W; Halverson, N W; Hasegawa, M; Hattori, K; Hazumi, M; Holzapfel, W L; Hori, Y; Howard, J; Hyland, P; Inoue, Y; Jaehnig, G C; Jaffe, A; Keating, B; Kermish, Z; Keskitalo, R; Kisner, T; Le Jeune, M; Lee, A T; Leitch, E M; Linder, E; Lungu, M; Matsuda, F; Matsumura, T; Meng, X; Miller, N J; Morii, H; Moyerman, S; Myers, M J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Poletti, D; Quealy, E; Rebeiz, G; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K; Schanning, I; Schenck, D E; Sherwin, B D; Shimizu, A; Shimmin, C; Shimon, M; Siritanasak, P; Smecher, G; Spieler, H; Stebor, N; Steinbach, B; Stompor, R; Suzuki, A; Takakura, S; Tikhomirov, A; Tomaru, T; Wilson, B; Yadav, A; Zahn, O

2014-04-04

We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

Infrared Astronomy Satellite

Science.gov (United States)

Ferrera, G. A.

1981-09-01

In 1982, the Infrared Astronomy Satellite (IRAS) will be launched into a 900-km sun-synchronous (twilight) orbit to perform an unbiased, all-sky survey of the far-infrared spectrum from 8 to 120 microns. Observations telemetered to ground stations will be compiled into an IR astronomy catalog. Attention is given the cryogenically cooled, 60-cm Ritchey-Chretien telescope carried by the satellite, whose primary and secondary mirrors are fabricated from beryllium by means of 'Cryo-Null Figuring'. This technique anticipates the mirror distortions that will result from cryogenic cooling of the telescope and introduces dimensional compensations for them during machining and polishing. Consideration is also given to the interferometric characterization of telescope performance and Cryo/Thermal/Vacuum simulated space environment testing.

Far-infrared spectroscopy of neutral interstellar clouds

International Nuclear Information System (INIS)

Watson, D.M.

1984-01-01

A summary is presented of airborne observations of the far-infrared fine structure lines of neutral atomic oxygen and singly-ionized carbon, and of the far-infrared rotational lines of CO, OH, NH 3 and HD, together with a brief description of the analysis and interpretation of the spectra. The 'state of the art' in instrument performance and the prospects for improved sensitivity and resolution are also surveyed. (Auth.)

Comparison of visual-based helicopter and fixed-wing forward-looking infrared surveys for counting white-tailed deer Odocoileus virginianus

Science.gov (United States)

Storm, Daniel J.; Samuel, Michael D.; Van Deelen, Timothy R.; Malcolm, Karl D.; Rolley, Robert E.; Frost, Nancy A.; Bates, Donald P.; Richards, Bryan J.

2011-01-01

Aerial surveys using direct counts of animals are commonly used to estimate deer abundance. Forward-looking infrared (FLIR) technology is increasingly replacing traditional methods such as visual observation from helicopters. Our goals were to compare fixed-wing FLIR and visual, helicopter-based counts in terms of relative bias, influence of snow cover and cost. We surveyed five plots: four 41.4 km2 plots with free-ranging white-tailed deer Odocoileus virginianus populations in Wisconsin and a 5.3 km2 plot with a white-tailed deer population contained by a high fence in Michigan. We surveyed plots using both fixed-wing FLIR and helicopters, both with snow cover and without snow. None of the methods counted more deer than the other when snow was present. Helicopter counts were lower in the absence of snow, but lack of snow cover did not apparently affect FLIR. Group sizes of observed deer were similar regardless of survey method or season. We found that FLIR counts were generally precise (CV = 0.089) when two or three replicate surveys were conducted within a few hours. However, at the plot level, FLIR counts differed greatly between seasons, suggesting that detection rates vary over larger time scales. Fixed-wing FLIR was more costly than visual observers in helicopters and was more restrictive in terms of acceptable survey conditions. Further research is needed to understand what factors influence the detection of deer during FLIR surveys.

Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

Science.gov (United States)

Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

2010-02-01

Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

SPECTROSCOPIC INFRARED EXTINCTION MAPPING AS A PROBE OF GRAIN GROWTH IN IRDCs

Energy Technology Data Exchange (ETDEWEB)

Lim, Wanggi [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Carey, Sean J. [Infrared Processing Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Tan, Jonathan C. [Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611 (United States)

2015-11-20

We present spectroscopic tests of MIR to FIR extinction laws in IRDC G028.36+00.07, a potential site of massive star and star cluster formation. Lim and Tan developed methods of FIR extinction mapping of this source using Spitzer-MIPS 24 μm and Herschel-PACS 70 μm images, and by comparing to MIR Spitzer-IRAC 3–8 μm extinction maps, found tentative evidence for grain growth in the highest mass surface density regions. Here we present results of spectroscopic infrared extinction mapping using Spitzer-IRS (14–38 μm) data of the same Infrared dark cloud (IRDC). These methods allow us to first measure the SED of the diffuse Galactic interstellar medium that is in the foreground of the IRDC. We then carry out our primary investigation of measuring the MIR to FIR opacity law and searching for potential variations as a function of mass surface density within the IRDC. We find relatively flat, featureless MIR–FIR opacity laws that lack the ∼12 and ∼35 μm features associated with the thick water ice mantle models of Ossenkopf and Henning. Their thin ice mantle models and the coagulating aggregate dust models of Ormel et al. are a generally better match to the observed opacity laws. We also find evidence for generally flatter MIR to FIR extinction laws as mass surface density increases, strengthening the evidence for grain and ice mantle growth in higher density regions.

SPECTROSCOPIC INFRARED EXTINCTION MAPPING AS A PROBE OF GRAIN GROWTH IN IRDCs

International Nuclear Information System (INIS)

Lim, Wanggi; Carey, Sean J.; Tan, Jonathan C.

2015-01-01

We present spectroscopic tests of MIR to FIR extinction laws in IRDC G028.36+00.07, a potential site of massive star and star cluster formation. Lim and Tan developed methods of FIR extinction mapping of this source using Spitzer-MIPS 24 μm and Herschel-PACS 70 μm images, and by comparing to MIR Spitzer-IRAC 3–8 μm extinction maps, found tentative evidence for grain growth in the highest mass surface density regions. Here we present results of spectroscopic infrared extinction mapping using Spitzer-IRS (14–38 μm) data of the same Infrared dark cloud (IRDC). These methods allow us to first measure the SED of the diffuse Galactic interstellar medium that is in the foreground of the IRDC. We then carry out our primary investigation of measuring the MIR to FIR opacity law and searching for potential variations as a function of mass surface density within the IRDC. We find relatively flat, featureless MIR–FIR opacity laws that lack the ∼12 and ∼35 μm features associated with the thick water ice mantle models of Ossenkopf and Henning. Their thin ice mantle models and the coagulating aggregate dust models of Ormel et al. are a generally better match to the observed opacity laws. We also find evidence for generally flatter MIR to FIR extinction laws as mass surface density increases, strengthening the evidence for grain and ice mantle growth in higher density regions

THE DUSTIEST POST-MAIN SEQUENCE STARS IN THE MAGELLANIC CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Jones, Olivia C.; Meixner, Margaret; Roman-Duval, Julia [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Sargent, Benjamin A. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Boyer, Martha L. [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sewiło, Marta [The Johns Hopkins University, Department of Physics and Astronomy, 366 Bloomberg Center, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Hony, Sacha [Institut für Theoretische Astrophysik, Zentrum für Astronomie, Universitt Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany)

2015-10-01

Using observations from the Herschel Inventory of The Agents of Galaxy Evolution (HERITAGE) survey of the Magellanic Clouds (MC), we have found 35 evolved stars and stellar end products that are bright in the far-infrared. These 28 (LMC) and 7 (SMC) sources were selected from the 529 evolved star candidates in the HERITAGE far-infrared point source catalogs. Our source identification method is based on spectral confirmation, spectral energy distribution characteristics, careful examination of the multiwavelength images and includes constraints on the luminosity, resulting in a thoroughly vetted list of evolved stars. These sources span a wide range in luminosity and hence initial mass. We found 13 low- to intermediate-mass evolved stars, including asymptotic giant branch (AGB) stars, post-AGB stars, planetary nebulae, and a symbiotic star. We also identify 10 high mass stars, including 4 of the 15 known B[e] stars in the MC, 3 extreme red supergiants that are highly enshrouded by dust, a Luminous Blue Variable, a Wolf–Rayet star, and two supernova remnants. Further, we report the detection of 9 probable evolved objects which were previously undescribed in the literature. These sources are likely to be among the dustiest evolved objects in the MC. The Herschel emission may either be due to dust produced by the evolved star or it may arise from swept-up interstellar medium material.

Infrared Faint Radio Sources in the Extended Chandra Deep Field South

Science.gov (United States)

Huynh, Minh T.

2009-01-01

Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey (ATLAS) which have no observable counterpart in the Spitzer Wide-area Infrared Extragalactic Survey (SWIRE). The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6 to 70 micron) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the SED of these objects shows that they are consistent with high redshift AGN (z > 2).

A HIGH-PRECISION NEAR-INFRARED SURVEY FOR RADIAL VELOCITY VARIABLE LOW-MASS STARS USING CSHELL AND A METHANE GAS CELL

International Nuclear Information System (INIS)

Gagné, Jonathan; Plavchan, Peter; Gao, Peter; Anglada-Escude, Guillem; Furlan, Elise; Brinkworth, Carolyn; Ciardi, David R.; Davison, Cassy; Henry, Todd J.; White, Russel; Tanner, Angelle; Riedel, Adric R.; Latham, David; Johnson, John A.; Bottom, Michael; Mills, Sean; Beichman, Chas; Wallace, Kent; Mennesson, Bertrand; Von Braun, Kaspar

2016-01-01

We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2–M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25–150 Myr) moving groups, the young field star ε Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8–15 m s −1 with a long-term stability of 15–50 m s −1 over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25–50 m s −1 at ≈2.3125 μ m, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3 σ –5 σ . Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of ≲5 m s −1 in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.

Recent SPIRITS discoveries of Infrared Transients and Variables with Spitzer/IRAC

Science.gov (United States)

Jencson, J. E.; Kasliwal, M. M.; Adams, S.; Cook, D.; Tinyanont, S.; Kwan, S.; Prince, T.; Lau, R. M.; Perley, D.; Masci, F.; Helou, G.; Armus, L.; Surace, J.; Dyk, S. D. Van; Cody, A.; Boyer, M. L.; Bond, H. E.; Monson, A.; Bally, J.; Khan, R.; Levesque, E.; Fox, O.; Williams, R.; Whitelock, P. A.; Mohamed, S.; Gehrz, R. D.; Amodeo, S.; Shenoy, D.; Carlon, R.; Cass, A.; Corgan, D.; Dykhoff, D.; Faella, J.; Gburek, T.; Smith, N.; Cantiello, M.; Langer, N.; Ofek, E.; Johansson, J.; Parthasarathy, M.; Hsiao, E.; Phillips, M.; Morrell, N.; Gonzalez, C.; Contreras, C.

2018-04-01

We report the discoveries of mid-infrared transients/strong variables found in the course of the Spitzer InfraRed Intensive Transients Survey (SPIRITS) using Spitzer Early Release Data (ATel #6644, #7929, #8688, #8940, #9434, #10171, #10172, #10488, #10903).

SPIRITS: Uncovering Unusual Infrared Transients with Spitzer

International Nuclear Information System (INIS)

Kasliwal, Mansi M.; Jencson, Jacob E.; Tinyanont, Samaporn; Cao, Yi; Cook, David; Bally, John; Masci, Frank; Armus, Lee; Cody, Ann Marie; Bond, Howard E.; Contreras, Carlos; Dykhoff, Devin A.; Amodeo, Samuel; Carlon, Robert L.; Cass, Alexander C.; Corgan, David T.; Faella, Joseph; Boyer, Martha; Cantiello, Matteo; Fox, Ori D.

2017-01-01

We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS—SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer /IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between −11 and −14 (Vega-mag) and [3.6]–[4.5] colors between 0.3 mag and 1.6 mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1 mag yr −1 to >7 mag yr −1 . SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.

SPIRITS: Uncovering Unusual Infrared Transients with Spitzer

Energy Technology Data Exchange (ETDEWEB)

Kasliwal, Mansi M.; Jencson, Jacob E.; Tinyanont, Samaporn; Cao, Yi; Cook, David [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Bally, John [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Masci, Frank; Armus, Lee [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Cody, Ann Marie [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Bond, Howard E. [Dept. of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Contreras, Carlos [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Dykhoff, Devin A.; Amodeo, Samuel; Carlon, Robert L.; Cass, Alexander C.; Corgan, David T.; Faella, Joseph [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States); Boyer, Martha [NASA Goddard Space Flight Center, MC 665, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Cantiello, Matteo [Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Avenue, New York, NY 10010 (United States); Fox, Ori D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

2017-04-20

We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS—SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer /IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between −11 and −14 (Vega-mag) and [3.6]–[4.5] colors between 0.3 mag and 1.6 mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1 mag yr{sup −1} to >7 mag yr{sup −1}. SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.

X-ray Counterparts of Infrared Faint Radio Sources

Science.gov (United States)

Schartel, Norbert

2011-10-01

Infrared Faint Radio Sources (IFRS) are radio sources with extremely faint or even absent infrared emission in deep Spitzer Surveys. Models of their spectral energy distributions, the ratios of radio to infrared flux densities and their steep radio spectra strongly suggest that IFRS are AGN at high redshifts (2IFRS, but if confirmed, the increased AGN numbers at these redshifts will account for the unresolved part of the X-ray background. The identification of X-ray counterparts of IFRS is considered to be the smoking gun for this hypothesis. We propose to observe 8 IFRS using 30ks pointed observations. X-ray detections of IFRS with different ratios of radio-to-infrared fluxes, will constrain the class-specific SED.

A Resolved Debris Disk Around the Nearby G Star HIP 32480

Science.gov (United States)

Stapelfeldt, K. R.; Bryden, G. C.; Marshall, J.; Eiroa, C.; Absil, O.; Mora, A.; Krist, J. E.; Su, K. Y. L.

2012-01-01

The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a GO star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grain-size of 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

Infrared spectrophotometry and radiative transfer in optically thick circumstellar dust envelopes

International Nuclear Information System (INIS)

Merrill, K.M.

1976-01-01

The Two-Micron Sky Survey of Neugebauer and Leighton and, more recently, the AFCRL Infrared Sky Survey of Walker and Price have detected numerous compact, isolated, bright infrared sources which are not identified with previously cataloged stars. Observations of many such objects suggest that extensive circumstellar dust envelopes modify the flux from a central source. The present investigations employ broad bandpass photometry at lambda lambda 1.65 μm to 12.5 μm and narrow bandpass spectrophotometry (Δ lambda/lambda approximately 0.015) at lambda lambda 2-4 μm and lambda lambda 8-13 μm to determine the properties of a large sample of such infrared sources. Infrared spectrophotometry can clearly differentiate between normal stars of spectral types M(''oxygen-rich'') and C (''carbon-rich'') on the basis of characteristic absorption bands arising in cool stellar atmospheres. Most of the 2 μ Sky Survey and many of the AFCRL Sky Survey sources appear to be stars of spectral types M and C which are differentiated from normal cool comparison stars only by the presence of extensive circumstellar dust envelopes. Due to the large optical depth of the envelopes, the flux from the star and from the dust cannot be simply separated. Hence solutions of radiative transfer through spherically symmetric envelopes of arbitrary optical depth were generated by a generalized computer code which employed opacities of real dust

A survey of infrared technology for special nuclear materials control and accounting

International Nuclear Information System (INIS)

Stanbro, W.D.; Leonard, R.S.; Steverson, C.A.; Angerman, M.I.

1992-03-01

This report reviews some aspects of current infrared measurement technology and suggests two applications in which it may be used in nuclear safeguards. These applications include both materials control and materials accounting. In each case, the measurements rely on passive detection of infrared radiation generated from the heat produced by the radioactive decay of plutonium. Both imaging and non-imaging techniques are discussed

UNIVERSALITY OF THE NEAR-INFRARED EXTINCTION LAW BASED ON THE APOGEE SURVEY

Energy Technology Data Exchange (ETDEWEB)

Wang, Shu; Jiang, B. W., E-mail: shuwang@mail.bnu.edu.cn, E-mail: bjiang@bnu.edu.cn [Department of Astronomy, Beijing Normal University, Beijing 100875 (China)

2014-06-10

Whether the near-infrared (NIR) extinction law is universal has long been a debated topic. Based on the APOGEE H-band spectroscopic survey, a key project of SDSS-III, the intrinsic colors of a large number of giant stars are accurately determined from the stellar effective temperature. Taking advantage of this and using a sample of 5942 K-type giants, the NIR extinction law is carefully revisited. The color excess ratio E(J – H)/E(J – K {sub S}), representative of the NIR extinction law, shows no dependence on the color excess when E(J – K {sub S}) changes from ∼0.3 to ∼4.0, which implies a universal NIR extinction law from diffuse to dense regions. The constant value of E(J – H)/E(J – K {sub S}), 0.64, corresponds to a power law index of 1.95. The other two ratios, E(H – K {sub S})/E(J – K {sub S}) and E(J – H)/E(H – K {sub S}), are 0.36 and 1.78, respectively. The results are consistent with the MRN dust size distribution.

Dust, ice and gas in time (DIGIT): Herschel and Spitzer spectro-imaging of SMM3 and SMM4 in Serpens

Science.gov (United States)

Dionatos, O.; Jørgensen, J. K.; Green, J. D.; Herczeg, G. J.; Evans, N. J.; Kristensen, L. E.; Lindberg, J. E.; van Dishoeck, E. F.

2013-10-01

Context. Mid- and far-infrared observations of the environment around embedded protostars reveal a plethora of high excitation molecular and atomic emission lines. Different mechanisms for the origin of these lines have been proposed, including shocks induced by protostellar jets and radiation or heating by the embedded protostar of its immediate surroundings. Aims: By studying of the most important molecular and atomic coolants, we aim at constraining the physical conditions around the embedded protostars SMM3 and SMM4 in the Serpens molecular cloud core and measuring the CO/H2 ratio in warm gas. Methods: Spectro-imaging observations from the Spitzer Infrared Spectrograph (IRS) and the Herschel Photodetector Array Camera and Spectrometer (PACS) provide an almost complete wavelength coverage between 5 and 200 μm. Within this range, emission from all major molecular (H2, CO, H2O and OH) and many atomic ([OI], [CII], [FeII], [SiII] and [SI]) coolants of excited gas are detected. Emission line maps reveal the morphology of the observed emission and indicate associations between the different species. The excitation conditions for molecular species are assessed through rotational diagrams. Emission lines from major coolants are compared to the results of steady-state C- and J-type shock models. Results: Line emission tends to peak at distances of ~10-20″ from the protostellar sources with all but [CII] peaking at the positions of outflow shocks seen in near-IR and sub-millimeter interferometric observations. The [CII] emission pattern suggests that it is most likely excited from energetic UV radiation originating from the nearby flat-spectrum source SMM6. Excitation analysis indicates that H2 and CO originate in gas at two distinct rotational temperatures of ~300 K and 1000 K, while the excitation temperature for H2O and OH is ~100-200 K. The morphological and physical association between CO and H2 suggests a common excitation mechanism, which allows direct

Chasing Small Exoplanets with Ground-Based Near-Infrared Transit Photometry

Science.gov (United States)

Colon, K. D.; Barentsen, G.; Vinicius, Z.; Vanderburg, A.; Coughlin, J.; Thompson, S.; Mullally, F.; Barclay, T.; Quintana, E.

2017-11-01

I will present results from a ground-based survey to measure the infrared radius and other properties of small K2 exoplanets and candidates. The survey is preparation for upcoming discoveries from TESS and characterization with JWST.

The infrared astronomical mission AKARI

NARCIS (Netherlands)

Murakami, Hiroshi; Baba, Hajime; Barthel, Peter; Clements, David L.; Cohen, Martin; Doi, Yasuo; Enya, Keigo; Figueredo, Elysandra; Fujishiro, Naofumi; Fujiwara, Hideaki; Fujiwara, Mikio; Garcia-Lario, Pedro; Goto, Tomotsugu; Hasegawa, Sunao; Hibi, Yasunori; Hirao, Takanori; Hiromoto, Norihisa; Hong, Seung Soo; Imai, Koji; Ishigaki, Miho; Ishiguro, Masateru; Ishihara, Daisuke; Ita, Yoshifusa; Jeong, Woong-Seob; Jeong, Kyung Sook; Kaneda, Hidehiro; Kataza, Hirokazu; Kawada, Mitsunobu; Kawai, Toshihide; Kawamura, Akiko; Kessler, Martin F.; Kester, Do; Kii, Tsuneo; Kim, Dong Chan; Kim, Wjung; Kobayashi, Hisato; Koo, Bon Chul; Kwon, Suk Minn; Lee, Hyung Mok; Lorente, Rosario; Makiuti, Sin'itirou; Matsuhara, Hideo; Matsumoto, Toshio; Matsuo, Hiroshi; Matsuura, Shuji; Mueller, Thomas G.; Murakami, Noriko; Nagata, Hirohisa; Nakagawa, Takao; Naoi, Takahiro; Narita, Masanao; Noda, Manabu; Oh, Sang Hoon; Ohnishi, Akira; Ohyama, Youichi; Okada, Yoko; Okuda, Haruyuki; Oliver, Sebastian; Onaka, Takashi; Ootsubo, Takafumi; Oyabu, Shinki; Pak, Sojong; Park, Yong-Sun; Pearson, Chris P.; Rowan-Robinson, Michael; Saito, Toshinobu; Sakon, Itsuki; Salama, Alberto; Sato, Shinji; Savage, Richard S.; Serjeant, Stephen; Shibai, Hiroshi; Shirahata, Mai; Sohn, Jungjoo; Suzuki, Toyoaki; Takagi, Toshinobu; Takahashi, Hidenori; Tanabe, Toshihiko; Takeuchi, Tsutomu T.; Takita, Satoshi; Thomson, Matthew; Uemizu, Kazunori; Ueno, Munetaka; Usui, Fumihiko; Verdugo, Eva; Wada, Takehiko; Wang, Lingyu; Watabe, Toyoki; Watarai, Hidenori; White, Glenn J.; Yamamura, Issei; Yamauchi, Chisato; Yasuda, Akiko

2007-01-01

AKARI, the first Japanese satellite dedicated to infrared astronomy, was launched on 2006 February 21, and started observations in May of the same year. AKARI has a 68.5 cm cooled telescope, together with two focal-plane instruments, which survey the sky in six wavelength bands from mid- to

Factors affecting thermal infrared images at selected field sites

International Nuclear Information System (INIS)

Sisson, J.B.; Ferguson, J.S.

1993-07-01

A thermal infrared (TIR) survey was conducted to locate surface ordnance in and around the Naval Ordnance Disposal Area, and a thermal anomaly was found. This report documents studies conducted to identify the position of cause of the thermal anomaly. Also included are results of a long path Fourier transform infrared survey, soil sampling activities, soil gas surveys, and buried heater studies. The results of these studies indicated that the thermal anomaly was caused by a gravel pad, which had thermal properties different than those of the surrounding soil. Results from this investigation suggest that TIR is useful for locating surface objects having a high thermal inertia compared to the surrounding terrain, but TIR is of very limited use for characterizing buried waste or other similar buried objects at the INEL

VELOCITY-RESOLVED [C ii] EMISSION AND [C ii]/FIR MAPPING ALONG ORION WITH HERSCHEL *,**

Science.gov (United States)

Goicoechea, Javier R.; Teyssier, D.; Etxaluze, M.; Goldsmith, P.F.; Ossenkopf, V.; Gerin, M.; Bergin, E.A.; Black, J.H.; Cernicharo, J.; Cuadrado, S.; Encrenaz, P.; Falgarone, E.; Fuente, A.; Hacar, A.; Lis, D.C.; Marcelino, N.; Melnick, G.J.; Müller, H.S.P.; Persson, C.; Pety, J.; Röllig, M.; Schilke, P.; Simon, R.; Snell, R.L.; Stutzki, J.

2015-01-01

We present the first ~7.5′×11.5′ velocity-resolved (~0.2 km s−1) map of the [C ii] 158 μm line toward the Orion molecular cloud 1 (OMC 1) taken with the Herschel/HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41α hydrogen recombination and CO J=2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [C ii] luminosity (~85 %) is from the extended, FUV-illuminated face of the cloud (G0>500, nH>5×103 cm−3) and from dense PDRs (G≳104, nH≳105 cm−3) at the interface between OMC 1 and the H ii region surrounding the Trapezium cluster. Around ~15 % of the [C ii] emission arises from a different gas component without CO counterpart. The [C ii] excitation, PDR gas turbulence, line opacity (from [13C ii]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of the L[C ii]/LFIR and LFIR/MGas ratios and show that L[C ii]/LFIR decreases from the extended cloud component (~10−2–10−3) to the more opaque star-forming cores (~10−3–10−4). The lowest values are reminiscent of the “[C ii] deficit” seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasing L[C ii]/LFIR ratio correlates better with the column density of dust through the molecular cloud than with LFIR/MGas. We conclude that the [C ii] emitting column relative to the total dust column along each line of sight is responsible for the observed L[C ii]/LFIR variations through the cloud. PMID:26568638

VELOCITY-RESOLVED [C ii] EMISSION AND [C ii]/FIR MAPPING ALONG ORION WITH HERSCHEL.

Science.gov (United States)

Goicoechea, Javier R; Teyssier, D; Etxaluze, M; Goldsmith, P F; Ossenkopf, V; Gerin, M; Bergin, E A; Black, J H; Cernicharo, J; Cuadrado, S; Encrenaz, P; Falgarone, E; Fuente, A; Hacar, A; Lis, D C; Marcelino, N; Melnick, G J; Müller, H S P; Persson, C; Pety, J; Röllig, M; Schilke, P; Simon, R; Snell, R L; Stutzki, J

2015-10-10

We present the first ~7.5'×11.5' velocity-resolved (~0.2 km s -1 ) map of the [C ii] 158 μ m line toward the Orion molecular cloud 1 (OMC 1) taken with the Herschel /HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41 α hydrogen recombination and CO J =2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [C ii] luminosity (~85 %) is from the extended, FUV-illuminated face of the cloud ( G 0 >500, n H >5×10 3 cm -3 ) and from dense PDRs ( G ≳10 4 , n H ≳10 5 cm -3 ) at the interface between OMC 1 and the H ii region surrounding the Trapezium cluster. Around ~15 % of the [C ii] emission arises from a different gas component without CO counterpart. The [C ii] excitation, PDR gas turbulence, line opacity (from [ 13 C ii]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of the L [C ii]/ L FIR and L FIR / M Gas ratios and show that L [C ii]/ L FIR decreases from the extended cloud component (~10 -2 -10 -3 ) to the more opaque star-forming cores (~10 -3 -10 -4 ). The lowest values are reminiscent of the "[C ii] deficit" seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasing L [C ii]/ L FIR ratio correlates better with the column density of dust through the molecular cloud than with L FIR / M Gas . We conclude that the [C ii] emitting column relative to the total dust column along each line of sight is responsible for the observed L [C ii]/ L FIR variations through the cloud.

Herschel Spectroscopy of Early-type Galaxies

Energy Technology Data Exchange (ETDEWEB)

Lapham, Ryen Carl; Young, Lisa M. [Physics Department, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 (United States); Crocker, Alison, E-mail: ryen.lapham@student.nmt.edu, E-mail: lyoung@physics.nmt.edu, E-mail: crockera@reed.edu [Physics Department, Reed College, Portland, OR 97202 (United States)

2017-05-01

We present Herschel spectroscopy of atomic lines arising in photodissociation regions as well as ionization regions of nearby early-type galaxies (ETGs), focusing on the volume-limited Atlas3D sample. Our data include the [C ii], [O i], and [N ii] 122 and 205 μ m lines, along with ancillary data including CO and H i maps. We find that ETGs have [C ii]/FIR ratios slightly lower than spiral galaxies in the KINGFISH sample, and several ETGs have unusually large [N ii] 122/[C ii] ratios. The [N ii] 122/[C ii] ratio is correlated with UV colors and there is a strong anti-correlation of [C ii]/FIR with NUV-K seen in both spirals and ETGs, likely due to a softer radiation field with fewer photons available to ionize carbon and heat the gas. The correlation thus makes a [C ii] deficit in galaxies with redder stellar populations. The high [N ii] 122/[C ii] (and low [C ii]/FIR) line ratios could also be affected by the removal of much of the diffuse, low-density gas, which is consistent with the low H i/H{sub 2} ratios. [C ii] is now being used as a star-formation indicator, and we find that it is just as good for ETGs as in spirals. The [C ii]/CO ratios found are also similar to those found in spiral galaxies. Through the use of the [N ii] 205 μ m line, estimates of the percentage of [C ii] emission arising from ionized gas indicate that a significant portion could arise in ionized regions.

A HIGH-PRECISION NEAR-INFRARED SURVEY FOR RADIAL VELOCITY VARIABLE LOW-MASS STARS USING CSHELL AND A METHANE GAS CELL

Energy Technology Data Exchange (ETDEWEB)

Gagné, Jonathan [Carnegie Institution of Washington DTM, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Plavchan, Peter [Department of Physics, Missouri State University, 901 S National Ave, Springfield, MO 65897 (United States); Gao, Peter [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Anglada-Escude, Guillem [School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Rd, E1 4NS, London (United Kingdom); Furlan, Elise; Brinkworth, Carolyn; Ciardi, David R. [NASA Exoplanet Science Institute, California Institute of Technology, 770 S. Wilson Ave., Pasadena, CA 91125 (United States); Davison, Cassy; Henry, Todd J.; White, Russel [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Tanner, Angelle [Mississippi State University, Department of Physics and Astronomy, Hilbun Hall, Starkville, MS 39762 (United States); Riedel, Adric R. [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Latham, David; Johnson, John A. [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Bottom, Michael [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Mills, Sean [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Ave, Chicago, IL 60637 (United States); Beichman, Chas [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States); Wallace, Kent; Mennesson, Bertrand [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91125 (United States); Von Braun, Kaspar, E-mail: jgagne@carnegiescience.edu [Lowell Observatory, West Mars Hill Road, Flagstaff, AZ 86001 (United States); and others

2016-05-01

We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2–M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25–150 Myr) moving groups, the young field star ε Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8–15 m s{sup −1}with a long-term stability of 15–50 m s{sup −1} over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25–50 m s{sup −1} at ≈2.3125 μ m, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3 σ –5 σ . Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of ≲5 m s{sup −1} in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.

Large Magellanic Cloud Near-infrared Synoptic Survey. V. Period–Luminosity Relations of Miras

International Nuclear Information System (INIS)

Yuan, Wenlong; Macri, Lucas M.; He, Shiyuan; Huang, Jianhua Z.; Kanbur, Shashi M.; Ngeow, Chow-Choong

2017-01-01

We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK s . We use densely sampled I -band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period–Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K s . We study the Period–Luminosity–Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.

Early results from the Infrared Astronomical Satellite

International Nuclear Information System (INIS)

Neugebauer, G.; Beichman, C.A.; Soifer, B.T.

1984-01-01

For 10 months the Infrared Astronomical Satellite (IRAS) provided astronomers with what might be termed their first view of the infrared sky on a clear, dark night. Without IRAS, atmospheric absorption and the thermal emission from both the atmosphere and Earthbound telescopes make the task of the infrared astronomer comparable to what an optical astronomer would face if required to work only on cloudy afternoons. IRAS observations are serving astronomers in the same manner as the photographic plates of the Palomar Observatory Sky Survey; just as the optical survey has been used by all astronomers for over three decades, as a source of quantitative information about the sky and as a roadmap for future observations, the results of IRAS will be studied for years to come. IRAS has demonstrated the power of infrared astronomy from space. Already, from a brief look at a miniscule fraction of the data available, we have learned much about the solar system, about nearby stars, about the Galaxy as a whole and about distant extragalactic systems. Comets are much dustier than previously thought. Solid particles, presumably the remnants of the star-formation process, orbit around Vega and other stars and may provide the raw material for planetary systems. Emission from cool interstellar material has been traced throughout the Galaxy all the way to the galactic poles. Both the clumpiness and breadth of the distribution of this material were previously unsuspected. The far-infrared sky away from the galactic plane has been found to be dominate by spiral galaxies, some of which emit more than 50% and as much as 98% of their energy in the infrared - an exciting and surprising revelation. The IRAS mission is clearly the pathfinder for future mission that, to a large extent, will be devoted to the discoveries revealed by IRAS. 8 figures

An infrared view of (candidate accretion) disks around massive young stars

NARCIS (Netherlands)

Bik, A.; Lenorzer, A.; Thi, W.F.; Puga Antolín, E.; Waters, L.B.F.M.; Kaper, L.; Martín-Hernández, L.N.

2008-01-01

Near-infrared surveys of high-mass star-forming regions start to shed light onto their stellar content. A particular class of objects found in these regions, the so-called massive Young Stellar Objects (YSOs) are surrounded by dense circumstellar material. Several near- and mid-infrared diagnostic

Near-Infrared Spectroscopic Study of Chlorite Minerals

OpenAIRE

Min Yang; Meifang Ye; Haihui Han; Guangli Ren; Ling Han; Zhuan Zhang

2018-01-01

The mineral chemistry of twenty chlorite samples from the United States Geological Survey (USGS) spectral library and two other regions, having a wide range of Fe and Mg contents and relatively constant Al and Si contents, was studied via infrared (IR) spectroscopy, near-infrared (NIR) spectroscopy, and X-ray fluorescence (XRF) analysis. Five absorption features of the twenty samples near 4525, 4440, 4361, 4270, and 4182 cm−1 were observed, and two diagnostic features at 4440 and 4280 cm−1 we...

A wide deep infrared look at the Pleiades with UKIDSS: new constraints on the substellar binary fraction and the low-mass initial mass function

NARCIS (Netherlands)

Lodieu, N.; Dobbie, P.D.; Deacon, N.R.; Hodgkin, S.T.; Hambly, N.C.; Jameson, R.F.

2007-01-01

We present the results of a deep wide-field near-infrared survey of 12 deg² of the Pleiades conducted as part of the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) Galactic Cluster Survey (GCS). We have extracted over 340 high-probability proper motion (PM)

A search for a distant companion to the sun with the wide-field infrared survey explorer

International Nuclear Information System (INIS)

Luhman, K. L.

2014-01-01

I have used multi-epoch astrometry from the Wide-field Infrared Survey Explorer to perform a search for a distant companion to the Sun via its parallactic motion. I have not found an object of this kind down to W2 = 14.5. This limit corresponds to analogs of Saturn and Jupiter at 28,000 and 82,000 AU, respectively, according to models of the Jovian planets by Fortney and coworkers. Models of brown dwarfs by Burrows and coworkers predict fainter fluxes at a given mass for the age of the solar system, producing a closer distance limit of 26,000 AU for a Jupiter-mass brown dwarf. These constraints exclude most combinations of mass and separation at which a solar companion has been suggested to exist by various studies over the years.

Large Magellanic Cloud Near-infrared Synoptic Survey. V. Period–Luminosity Relations of Miras

Energy Technology Data Exchange (ETDEWEB)

Yuan, Wenlong; Macri, Lucas M. [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); He, Shiyuan; Huang, Jianhua Z. [Department of Statistics, Texas A and M University, College Station, TX 77843 (United States); Kanbur, Shashi M. [Department of Physics, The State University of New York at Oswego, Oswego, NY 13126 (United States); Ngeow, Chow-Choong, E-mail: lmacri@tamu.edu [Graduate Institute of Astronomy, National Central University, Jhongli 32001, Taiwan (China)

2017-10-01

We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK{sub s}. We use densely sampled I -band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period–Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K{sub s}. We study the Period–Luminosity–Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.

Thermal-Infrared Surveys of Near-Earth Object Diameters and Albedos with Spitzer and IRTF/MIRSI

Science.gov (United States)

Mommert, Michael; Trilling, David; Hora, Joseph L.; Chesley, Steven; Emery, Josh; Fazio, Giovanni; Harris, Alan W.; Moskovitz, Nick; Mueller, Michael; Smith, Howard

2015-08-01

More than 12000 Near-Earth Objects (NEOs) have been discovered over the past few decades and current discovery surveys find on average 4 new NEOs every night. In comparison to asteroid discovery, the physical characterization of NEOs lags far behind: measured diameters and albedos exist only for roughly 10% of all known NEOs. We describe a current and a future observing program that provide diameter and albedo measurements of a large number of NEOs.In our Spitzer Space Telescope Exploration Science program 'NEOSurvey', we are performing a fast and efficient flux-limited survey in which we measure the diameters and albedos of ~600 NEOs in a total of 710 hrs of observing time. We measure the thermal emission of our targets at 4.5 micron and combine these measurements with optical data in a thermal model. Our diameters and albedos come with highly realistic uncertainties that account for a wide range of potential asteroid properties. Our primary goal is to create a large and uniform catalog of NEO properties, including diameters, albedos, and flux density data. This catalog is publicly accessible and provides the latest results usually within 2 weeks after the observation.Starting in 2016, we will also make use of the refurbished and recommissioned MIRSI mid-infrared imaging camera on NASA's InfraRed Telescope Facility (IRTF) to derive the diameters and albedos of up to 750 NEOs over a period of 3 yrs. MIRSI will be equipped with an optical camera that will allow for simultaneous optical imaging, which will improve our thermal modeling results. With MIRSI, we will focus on newly discovered NEOs that are close to Earth and hence relatively bright.The results from both programs, together with already exisiting diameter and albedo results from the literature, will form the largest database of NEO physical properties available to date. With this data set, we will be able to refine the size distribution of small NEOs and the corresponding impact frequency, and compare the

Infrared astronomical satellite (IRAS) catalogs and atlases. Volume 1: Explanatory supplement

Science.gov (United States)

Beichman, C. A. (Editor); Neugebauer, G. (Editor); Habing, H. J. (Editor); Clegg, P. E. (Editor); Chester, Thomas J. (Editor)

1988-01-01

The Infrared Astronomical Satellite (IRAS) was launched on January 26, 1983. During its 300-day mission, IRAS surveyed over 96 pct of the celestial sphere at four infrared wavelengths, centered approximately at 12, 25, 60, and 100 microns. Volume 1 describes the instrument, the mission, and data reduction.

THE SPITZER INFRARED SPECTROGRAPH SURVEY OF T TAURI STARS IN TAURUS

International Nuclear Information System (INIS)

Furlan, E.; Luhman, K. L.; Espaillat, C.

2011-01-01

We present 161 Spitzer Infrared Spectrograph (IRS) spectra of T Tauri stars and young brown dwarfs in the Taurus star-forming region. All of the targets were selected based on their infrared excess and are therefore surrounded by protoplanetary disks; they form the complete sample of all available IRS spectra of T Tauri stars with infrared excesses in Taurus. We also present the IRS spectra of seven Class 0/I objects in Taurus to complete the sample of available IRS spectra of protostars in Taurus. We use spectral indices that are not significantly affected by extinction to distinguish between envelope- and disk-dominated objects. Together with data from the literature, we construct spectral energy distributions for all objects in our sample. With spectral indices derived from the IRS spectra we infer disk properties such as dust settling and the presence of inner disk holes and gaps. We find a transitional disk frequency, which is based on objects with unusually large 13-31 μm spectral indices indicative of a wall surrounding an inner disk hole, of about 3%, and a frequency of about 20% for objects with unusually large 10 μm features, which could indicate disk gaps. The shape and strength of the 10 μm silicate emission feature suggests weaker 10 μm emission and more processed dust for very low mass objects and brown dwarfs (spectral types M6-M9). These objects also display weaker infrared excess emission from their disks, but do not appear to have more settled disks than their higher-mass counterparts. We find no difference for the spectral indices and properties of the dust between single and multiple systems.

Obscured asymptotic giant branch stars in the Magellanic Clouds .2. Near-infrared and mid-infrared counterparts

NARCIS (Netherlands)

Zijlstra, AA; Loup, C; Waters, LBFM; Whitelock, PA; vanLoon, JT; Guglielmo, F

1996-01-01

We have carried out an infrared search for obscured asymptotic giant branch (AGB) stars in the Magellanic Clouds. Fields were observed in the vicinity of IRAS sources with colours and flux densities consistent with such a classification. The survey uncovered a number of obscured AGE stars as well as

The Herschel Virgo Cluster Survey. XIX. Physical properties of low luminosity FIR sources at z < 0.5

Science.gov (United States)

Pappalardo, Ciro; Bizzocchi, Luca; Fritz, Jacopo; Boselli, Alessandro; Boquien, Mederic; Boissier, Samuel; Baes, Maarten; Ciesla, Laure; Bianchi, Simone; Clemens, Marcel; Viaene, Sebastien; Bendo, George J.; De Looze, Ilse; Smith, Matthew W. L.; Davies, Jonathan

2016-05-01

Context. The star formation rate is a crucial parameter for the investigation galaxy evolution. At low redshift the cosmic star formation rate density declines smoothly, and massive active galaxies become passive, reducing their star formation activity. This implies that the bulk of the star formation rate density at low redshift is mainly driven by low mass objects. Aims: We investigate the properties of a sample of low luminosity far-infrared sources selected at 250 μm. We have collected data from ultraviolet to far-infrared in order to perform a multiwavelengths analysis. The main goal is to investigate the correlation between star formation rate, stellar mass, and dust mass for a galaxy population with a wide range in dust content and stellar mass, including the low mass regime that most probably dominates the star formation rate density at low redshift. Methods: We define a main sample of ~800 sources with full spectral energy distribution coverage between 0.15 libraries and dust emission templates. Results: In the star formation rate versus stellar mass plane our samples occupy a region included between local spirals and higher redshift star forming galaxies. These galaxies represent the population that at z 3 × 1010 M⊙) do not lie on the main sequence, but show a small offset as a consequence of the decreased star formation. Low mass galaxies (M∗consortia and with an important participation from NASA.

Properties of the Variation of the Infrared Emission of OH/IR Stars I. The K Band Light Curves

Directory of Open Access Journals (Sweden)

Kyung-Won Suh

2009-09-01

Full Text Available To study properties of the variation of the infrared emission of OH/IR stars, we collect and analyze the infrared observational data in K band for nine OH/IR stars. We use the observational data obtained for about three decades including recent data from the two micron all sky survey (2MASS and the deep near infrared survey of the southern sky (DENIS. We use Marquardt-Levenberg algorithm to determine the pulsation period and amplitude for each star and compare them with previous results of infrared and radio investigations.

MID- AND FAR-INFRARED PROPERTIES OF A COMPLETE SAMPLE OF LOCAL ACTIVE GALACTIC NUCLEI

International Nuclear Information System (INIS)

Ichikawa, Kohei; Ueda, Yoshihiro; Terashima, Yuichi; Oyabu, Shinki; Gandhi, Poshak; Nakagawa, Takao; Matsuta, Keiko

2012-01-01

We investigate the mid- (MIR) to far-infrared (FIR) properties of a nearly complete sample of local active galactic nuclei (AGNs) detected in the Swift/Burst Alert Telescope (BAT) all-sky hard X-ray (14-195 keV) survey, based on the cross correlation with the AKARI infrared survey catalogs complemented by those with Infrared Astronomical Satellite and Wide-field Infrared Survey Explorer. Out of 135 non-blazer AGNs in the Swift/BAT nine-month catalog, we obtain the MIR photometric data for 128 sources either in the 9, 12, 18, 22, and/or 25 μm band. We find good correlation between their hard X-ray and MIR luminosities over three orders of magnitude (42 λ (9, 18 μm) < 45), which is tighter than that with the FIR luminosities at 90 μm. This suggests that thermal emission from hot dusts irradiated by the AGN emission dominate the MIR fluxes. Both X-ray unabsorbed and absorbed AGNs follow the same correlation, implying isotropic infrared emission, as expected in clumpy dust tori rather than homogeneous ones. We find excess signals around 9 μm in the averaged infrared spectral energy distribution from heavy obscured 'new type' AGNs with small scattering fractions in the X-ray spectra. This could be attributed to the polycyclic aromatic hydrocarbon emission feature, suggesting that their host galaxies have strong starburst activities.

ENSEMBLE VARIABILITY OF NEAR-INFRARED-SELECTED ACTIVE GALACTIC NUCLEI

International Nuclear Information System (INIS)

Kouzuma, S.; Yamaoka, H.

2012-01-01

We present the properties of the ensemble variability V for nearly 5000 near-infrared active galactic nuclei (AGNs) selected from the catalog of Quasars and Active Galactic Nuclei (13th Edition) and the SDSS-DR7 quasar catalog. From three near-infrared point source catalogs, namely, Two Micron All Sky Survey (2MASS), Deep Near Infrared Survey (DENIS), and UKIDSS/LAS catalogs, we extract 2MASS-DENIS and 2MASS-UKIDSS counterparts for cataloged AGNs by cross-identification between catalogs. We further select variable AGNs based on an optimal criterion for selecting the variable sources. The sample objects are divided into subsets according to whether near-infrared light originates by optical emission or by near-infrared emission in the rest frame; and we examine the correlations of the ensemble variability with the rest-frame wavelength, redshift, luminosity, and rest-frame time lag. In addition, we also examine the correlations of variability amplitude with optical variability, radio intensity, and radio-to-optical flux ratio. The rest-frame optical variability of our samples shows negative correlations with luminosity and positive correlations with rest-frame time lag (i.e., the structure function, SF), and this result is consistent with previous analyses. However, no well-known negative correlation exists between the rest-frame wavelength and optical variability. This inconsistency might be due to a biased sampling of high-redshift AGNs. Near-infrared variability in the rest frame is anticorrelated with the rest-frame wavelength, which is consistent with previous suggestions. However, correlations of near-infrared variability with luminosity and rest-frame time lag are the opposite of these correlations of the optical variability; that is, the near-infrared variability is positively correlated with luminosity but negatively correlated with the rest-frame time lag. Because these trends are qualitatively consistent with the properties of radio-loud quasars reported

SEDS: THE SPITZER EXTENDED DEEP SURVEY. SURVEY DESIGN, PHOTOMETRY, AND DEEP IRAC SOURCE COUNTS

International Nuclear Information System (INIS)

Ashby, M. L. N.; Willner, S. P.; Fazio, G. G.; Huang, J.-S.; Hernquist, L.; Hora, J. L.; Arendt, R.; Barmby, P.; Barro, G.; Faber, S.; Guhathakurta, P.; Bell, E. F.; Bouwens, R.; Cattaneo, A.; Croton, D.; Davé, R.; Dunlop, J. S.; Egami, E.; Finlator, K.; Grogin, N. A.

2013-01-01

The Spitzer Extended Deep Survey (SEDS) is a very deep infrared survey within five well-known extragalactic science fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the Hubble Deep Field North, and the Extended Groth Strip. SEDS covers a total area of 1.46 deg 2 to a depth of 26 AB mag (3σ) in both of the warm Infrared Array Camera (IRAC) bands at 3.6 and 4.5 μm. Because of its uniform depth of coverage in so many widely-separated fields, SEDS is subject to roughly 25% smaller errors due to cosmic variance than a single-field survey of the same size. SEDS was designed to detect and characterize galaxies from intermediate to high redshifts (z = 2-7) with a built-in means of assessing the impact of cosmic variance on the individual fields. Because the full SEDS depth was accumulated in at least three separate visits to each field, typically with six-month intervals between visits, SEDS also furnishes an opportunity to assess the infrared variability of faint objects. This paper describes the SEDS survey design, processing, and publicly-available data products. Deep IRAC counts for the more than 300,000 galaxies detected by SEDS are consistent with models based on known galaxy populations. Discrete IRAC sources contribute 5.6 ± 1.0 and 4.4 ± 0.8 nW m –2 sr –1 at 3.6 and 4.5 μm to the diffuse cosmic infrared background (CIB). IRAC sources cannot contribute more than half of the total CIB flux estimated from DIRBE data. Barring an unexpected error in the DIRBE flux estimates, half the CIB flux must therefore come from a diffuse component.

TWO MASS DISTRIBUTIONS IN THE L 1641 MOLECULAR CLOUDS: THE HERSCHEL CONNECTION OF DENSE CORES AND FILAMENTS IN ORION A

International Nuclear Information System (INIS)

Polychroni, D.; Schisano, E.; Elia, D.; Molinari, S.; Turrini, D.; Rygl, K. L. J.; Benedettini, M.; Busquet, G.; Di Giorgio, A. M.; Pestalozzi, M.; Pezzuto, S.; Roy, A.; André, Ph.; Hennemann, M.; Hill, T.; Könyves, V.; Martin, P.; Di Francesco, J.; Arzoumanian, D.; Bontemps, S.

2013-01-01

We present Herschel survey maps of the L 1641 molecular clouds in Orion A. We extracted both the filaments and dense cores in the region. We identified which of the dense sources are proto- or pre-stellar, and studied their association with the identified filaments. We find that although most (71%) of the pre-stellar sources are located on filaments there, is still a significant fraction of sources not associated with such structures. We find that these two populations (on and off the identified filaments) have distinctly different mass distributions. The mass distribution of the sources on the filaments is found to peak at 4 M ☉ and drives the shape of the core mass function (CMF) at higher masses, which we fit with a power law of the form dN/dlogM∝M –1.4±0.4 . The mass distribution of the sources off the filaments, on the other hand, peaks at 0.8 M ☉ and leads to a flattening of the CMF at masses lower than ∼4 M ☉ . We postulate that this difference between the mass distributions is due to the higher proportion of gas that is available in the filaments, rather than in the diffuse cloud

TWO MASS DISTRIBUTIONS IN THE L 1641 MOLECULAR CLOUDS: THE HERSCHEL CONNECTION OF DENSE CORES AND FILAMENTS IN ORION A

Energy Technology Data Exchange (ETDEWEB)

Polychroni, D. [Department of Astrophysics, University of Athens, Astronomy and Mechanics, Faculty of Physics, Panepistimiopolis, 15784 Zografos, Athens (Greece); Schisano, E.; Elia, D.; Molinari, S.; Turrini, D.; Rygl, K. L. J.; Benedettini, M.; Busquet, G.; Di Giorgio, A. M.; Pestalozzi, M.; Pezzuto, S. [Istituto di Astrofisica e Planetologia Spaziali (INAF-IAPS), via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Roy, A.; André, Ph.; Hennemann, M.; Hill, T.; Könyves, V. [Laboratoire AIM, CEA/IRFU CNRS/INSU Université Paris Diderot, Paris-Saclay, F-91191 Gif-sur-Yvette (France); Martin, P. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Di Francesco, J. [National Research Council Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Arzoumanian, D. [IAS, CNRS (UMR 8617), Université Paris-Sud, Bâtiment 121, F-91400 Orsay (France); Bontemps, S., E-mail: dpolychroni@phys.uoa.gr [Université de Bordeaux, Laboratoire d' Astrophysique de Bordeaux, CNRS/INSU, UMR 5804, BP 89, F-33271, Floirac Cedex (France); and others

2013-11-10

We present Herschel survey maps of the L 1641 molecular clouds in Orion A. We extracted both the filaments and dense cores in the region. We identified which of the dense sources are proto- or pre-stellar, and studied their association with the identified filaments. We find that although most (71%) of the pre-stellar sources are located on filaments there, is still a significant fraction of sources not associated with such structures. We find that these two populations (on and off the identified filaments) have distinctly different mass distributions. The mass distribution of the sources on the filaments is found to peak at 4 M {sub ☉} and drives the shape of the core mass function (CMF) at higher masses, which we fit with a power law of the form dN/dlogM∝M {sup –1.4±0.4}. The mass distribution of the sources off the filaments, on the other hand, peaks at 0.8 M {sub ☉} and leads to a flattening of the CMF at masses lower than ∼4 M {sub ☉}. We postulate that this difference between the mass distributions is due to the higher proportion of gas that is available in the filaments, rather than in the diffuse cloud.

Optical and infrared astronomy in the 21st century - the continuing revolution

Science.gov (United States)

Cesarsky, Catherine; West, Richard

2002-05-01

For some decades, astronomy and astrophysics have undergone a technological and conceptual revolution. Supported by ever more powerful telescopes and instruments on the ground and in space, the volume and quality of new insights is incredible, both in terms of physical understanding of individual celestial objects and the grand evolutionary scheme. New and powerful observational facilities such as the ESO Very Large Telescope (VLT) are opening new horizons, from the nearby solar system to the corners of the Milky Way galaxy in which we live and, not least, towards the vast expanses in time and space of the remote and early Universe. The next generation of ultra-sensitive optical-infrared telescopes such as Herschel and ALMA will be ready within this decade and concepts are being elaborated for the construction of super-giant telescopes like the 100 m optical/IR OWL, the ‘Overwhelmingly Large telescope’. With these impressive developments, and in a true spirit of exploration, astronomers can now look forward to great research opportunities, in a resounding manifestation of the continuous drive towards a better understanding of our cosmic surroundings and of our own origins, so characteristic for enlightened humankind of every age.

Prediction of the diffuse far-infrared flux from the galactic plane

International Nuclear Information System (INIS)

Fazio, G.G.; Stecker, F.W.

1976-01-01

A basic model and simple numerical relations useful for future far-infrared studies of the Galaxy are presented. Making use of recent CO and other galactic surveys, we then predict the diffuse far-infrared flux distribution from the galactic plane as a function of galactic longitude l for 4degree< or =l< or =90degree and the far-infrared emissivity as a function of galactocentric distance. Future measurements of the galactic far-infrared flux would yield valuable information on the physical properties and distribution of dust and molecular clouds in the Galaxy, particulary the inner region

Predictions of Planet Detections with Near-infrared Radial Velocities in the Upcoming SPIRou Legacy Survey-planet Search

Science.gov (United States)

Cloutier, Ryan; Artigau, Étienne; Delfosse, Xavier; Malo, Lison; Moutou, Claire; Doyon, René; Donati, Jean-Francois; Cumming, Andrew; Dumusque, Xavier; Hébrard, Élodie; Menou, Kristen

2018-02-01

The SPIRou near-infrared spectropolarimeter is destined to begin science operations at the Canada–France–Hawaii Telescope in mid-2018. One of the instrument’s primary science goals is to discover the closest exoplanets to the solar system by conducting a three- to five-year long radial velocity survey of nearby M dwarfs at an expected precision of ∼1 m s‑1, the SPIRou Legacy Survey-Planet Search (SLS-PS). In this study, we conduct a detailed Monte Carlo simulation of the SLS-PS using our current understanding of the occurrence rate of M dwarf planetary systems and physical models of stellar activity. From simultaneous modeling of planetary signals and activity, we predict the population of planets to be detected in the SLS-PS. With our fiducial survey strategy and expected instrument performance over a nominal survey length of ∼3 years, we expect SPIRou to detect {85.3}-12.4+29.3 planets including {20.0}-7.2+16.8 habitable-zone planets and {8.1}-3.2+7.6 Earth-like planets from a sample of 100 M1–M8.5 dwarfs out to 11 pc. By studying mid-to-late M dwarfs previously inaccessible to existing optical velocimeters, SPIRou will put meaningful constraints on the occurrence rate of planets around those stars including the value of {η }\\oplus at an expected level of precision of ≲ 45 % . We also predict that a subset of {46.7}-6.0+16.0 planets may be accessible with dedicated high-contrast imagers on the next generation of extremely large telescopes including {4.9}-2.0+4.7 potentially imagable Earth-like planets. Lastly, we compare the results of our fiducial survey strategy to other foreseeable survey versions to quantify which strategy is optimized to reach the SLS-PS science goals. The results of our simulations are made available to the community on GitHub (https://github.com/r-cloutier/SLSPS_Simulations).

Addressing Thermal Model Run Time Concerns of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA)

Science.gov (United States)

Peabody, Hume; Guerrero, Sergio; Hawk, John; Rodriguez, Juan; McDonald, Carson; Jackson, Cliff

2016-01-01

The Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) utilizes an existing 2.4 m diameter Hubble sized telescope donated from elsewhere in the federal government for near-infrared sky surveys and Exoplanet searches to answer crucial questions about the universe and dark energy. The WFIRST design continues to increase in maturity, detail, and complexity with each design cycle leading to a Mission Concept Review and entrance to the Mission Formulation Phase. Each cycle has required a Structural-Thermal-Optical-Performance (STOP) analysis to ensure the design can meet the stringent pointing and stability requirements. As such, the models have also grown in size and complexity leading to increased model run time. This paper addresses efforts to reduce the run time while still maintaining sufficient accuracy for STOP analyses. A technique was developed to identify slews between observing orientations that were sufficiently different to warrant recalculation of the environmental fluxes to reduce the total number of radiation calculation points. The inclusion of a cryocooler fluid loop in the model also forced smaller time-steps than desired, which greatly increases the overall run time. The analysis of this fluid model required mitigation to drive the run time down by solving portions of the model at different time scales. Lastly, investigations were made into the impact of the removal of small radiation couplings on run time and accuracy. Use of these techniques allowed the models to produce meaningful results within reasonable run times to meet project schedule deadlines.

THE TAIWAN ECDFS NEAR-INFRARED SURVEY: ULTRA-DEEP J AND K{sub S} IMAGING IN THE EXTENDED CHANDRA DEEP FIELD-SOUTH

Energy Technology Data Exchange (ETDEWEB)

Hsieh, Bau-Ching; Wang, Wei-Hao; Hsieh, Chih-Chiang; Lin, Lihwai; Lim, Jeremy; Ho, Paul T. P. [Institute of Astrophysics and Astronomy, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China); Yan Haojing [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

2012-12-15

We present ultra-deep J and K{sub S} imaging observations covering a 30' Multiplication-Sign 30' area of the Extended Chandra Deep Field-South (ECDFS) carried out by our Taiwan ECDFS Near-Infrared Survey (TENIS). The median 5{sigma} limiting magnitudes for all detected objects in the ECDFS reach 24.5 and 23.9 mag (AB) for J and K{sub S} , respectively. In the inner 400 arcmin{sup 2} region where the sensitivity is more uniform, objects as faint as 25.6 and 25.0 mag are detected at 5{sigma}. Thus, this is by far the deepest J and K{sub S} data sets available for the ECDFS. To combine TENIS with the Spitzer IRAC data for obtaining better spectral energy distributions of high-redshift objects, we developed a novel deconvolution technique (IRACLEAN) to accurately estimate the IRAC fluxes. IRACLEAN can minimize the effect of blending in the IRAC images caused by the large point-spread functions and reduce the confusion noise. We applied IRACLEAN to the images from the Spitzer IRAC/MUSYC Public Legacy in the ECDFS survey (SIMPLE) and generated a J+K{sub S} -selected multi-wavelength catalog including the photometry of both the TENIS near-infrared and the SIMPLE IRAC data. We publicly release the data products derived from this work, including the J and K{sub S} images and the J+K{sub S} -selected multi-wavelength catalog.

The WEAVE-LOFAR Survey

Science.gov (United States)

Smith, D. J. B.; Best, P. N.; Duncan, K. J.; Hatch, N. A.; Jarvis, M. J.; Röttgering, H. J. A.; Simpson, C. J.; Stott, J. P.; Cochrane, R. K.; Coppin, K. E.; Dannerbauer, H.; Davis, T. A.; Geach, J. E.; Hale, C. L.; Hardcastle, M. J.; Hatfield, P. W.; Houghton, R. C. W.; Maddox, N.; McGee, S. L.; Morabito, L.; Nisbet, D.; Pandey-Pommier, M.; Prandoni, I.; Saxena, A.; Shimwell, T. W.; Tarr, M.; van Bemmel, I.; Verma, A.; White, G. J.; Williams, W. L.

2016-12-01

In these proceedings we highlight the primary scientific goals and design of the WEAVE-LOFAR survey, which will use the new WEAVE spectrograph on the 4.2m William Herschel Telescope to provide the primary source of spectroscopic information for the LOFAR Surveys Key Science Project. Beginning in 2018, WEAVE-LOFAR will generate more than 10^6 R=5000 365-960nm spectra of low-frequency selected radio sources, across three tiers designed to efficiently sample the redshift-luminosity plane, and produce a data set of enormous legacy value. The radio frequency selection, combined with the high multiplex and throughput of the WEAVE spectrograph, make obtaining redshifts in this way very efficient, and we expect that the redshift success rate will approach 100 per cent at z < 1. This unprecedented spectroscopic sample - which will be complemented by an integral field component - will be transformational in key areas, including studying the star formation history of the Universe, the role of accretion and AGN-driven feedback, properties of the epoch of reionisation, cosmology, cluster haloes and relics, as well as the nature of radio galaxies and protoclusters. Each topic will be addressed in unprecedented detail, and with the most reliable source classifications and redshift information in existence.

Hier ist wahrhaftig ein Loch im Himmel. The NGC 1999 dark globule is not a globule

Science.gov (United States)

Stanke, T.; Stutz, A. M.; Tobin, J. J.; Ali, B.; Megeath, S. T.; Krause, O.; Linz, H.; Allen, L.; Bergin, E.; Calvet, N.; di Francesco, J.; Fischer, W. J.; Furlan, E.; Hartmann, L.; Henning, T.; Manoj, P.; Maret, S.; Muzerolle, J.; Myers, P. C.; Neufeld, D.; Osorio, M.; Pontoppidan, K.; Poteet, C. A.; Watson, D. M.; Wilson, T.

2010-07-01

The NGC 1999 reflection nebula features a dark patch with a size of 10 000 AU, which has been interpreted as a small, dense foreground globule and possible site of imminent star formation. We present Herschel PACS far-infrared 70 and 160 μm maps, which reveal a flux deficit at the location of the globule. We estimate the globule mass needed to produce such an absorption feature to be a few tenths to a few {M}⊙. Inspired by this Herschel observation, we obtained APEX LABOCA and SABOCA submillimeter continuum maps, and Magellan PANIC near-infrared images of the region. We do not detect a submillimer source at the location of the Herschel flux decrement; furthermore our observations place an upper limit on the mass of the globule of 2.4×10-2 {M}⊙. Indeed, the submillimeter maps appear to show a flux depression as well. Furthermore, the near-infrared images detect faint background stars that are less affected by extinction inside the dark patch than in its surroundings. We suggest that the dark patch is in fact a hole or cavity in the material producing the NGC 1999 reflection nebula, excavated by protostellar jets from the V 380 Ori multiple system. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASAThis publication includes data acquired with the Atacama Pathfinder Experiment (APEX; proposal E-082.F-9807 and E-284.C-5015). APEX is a collaboration between the Max-Planck-Institut für Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.Appendices A and B are only available in electronic form at http://www.aanda.org

Molecular spectroscopy in biodiagnostics (from Hippocrates to Herschel and beyond)

Science.gov (United States)

Mantsch, Henry; Jackson, Michael

1995-03-01

After two decades of intense research on the spectroscopic properties of biological molecules in isolated systems, infrared spectroscopy is now being applied to the study of human tissues. Extending this approach, it is possible to use the sensitivity of infrared spectroscopy to probe the biochemical events underlying transformation from normal to a diseased state within tissues, and so develop novel diagnostic methods. We highlight some of the areas of research within our group aimed at developing clinically useful methodologies based upon infrared spectroscopy.

MID-INFRARED SELECTION OF ACTIVE GALACTIC NUCLEI WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER. II. PROPERTIES OF WISE-SELECTED ACTIVE GALACTIC NUCLEI IN THE NDWFS BOÖTES FIELD

International Nuclear Information System (INIS)

Assef, R. J.; Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W.; Kochanek, C. S.; Blain, A. W.; Brodwin, M.; Brown, M. J. I.; Donoso, E.; Jarrett, T. H.; Yan, L.; Jannuzi, B. T.; Stanford, S. A.; Wu, J.

2013-01-01

Stern et al. presented a study of Wide-field Infrared Survey Explorer (WISE) selection of active galactic nuclei (AGNs) in the 2 deg 2 COSMOS field, finding that a simple criterion W1-W2 ≥ 0.8 provides a highly reliable and complete AGN sample for W2 2 NOAO Deep Wide-Field Survey Boötes field which also has considerably deeper WISE observations than the COSMOS field, and find that this simple color cut significantly loses reliability at fainter fluxes. We define a modified selection criterion combining the W1–W2 color and the W2 magnitude to provide highly reliable or highly complete AGN samples for fainter WISE sources. In particular, we define a color-magnitude cut that finds 130 ± 4 deg –2 AGN candidates for W2 AGN ∼ 3 × 10 44 erg s –1 , 29% ± 7% of AGNs are observed as Type 1, while at ∼4 × 10 45 erg s –1 the fraction is 64% ± 13%. The distribution of obscuration values suggests that dust in the torus is present as both a diffuse medium and in optically thick clouds

Hot-electron bolometer terahertz mixers for the Herschel Space Observatory.

Science.gov (United States)

Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Khosropanah, Pourya; Kollberg, Erik

2008-03-01

We report on low noise terahertz mixers (1.4-1.9 THz) developed for the heterodyne spectrometer onboard the Herschel Space Observatory. The mixers employ double slot antenna integrated superconducting hot-electron bolometers (HEBs) made of thin NbN films. The mixer performance was characterized in terms of detection sensitivity across the entire rf band by using a Fourier transform spectrometer (from 0.5 to 2.5 THz, with 30 GHz resolution) and also by measuring the mixer noise temperature at a limited number of discrete frequencies. The lowest mixer noise temperature recorded was 750 K [double sideband (DSB)] at 1.6 THz and 950 K DSB at 1.9 THz local oscillator (LO) frequencies. Averaged across the intermediate frequency band of 2.4-4.8 GHz, the mixer noise temperature was 1100 K DSB at 1.6 THz and 1450 K DSB at 1.9 THz LO frequencies. The HEB heterodyne receiver stability has been analyzed and compared to the HEB stability in the direct detection mode. The optimal local oscillator power was determined and found to be in a 200-500 nW range.

Near-infrared imaging of white dwarfs with candidate debris disks

International Nuclear Information System (INIS)

Wang, Zhongxiang; Tziamtzis, Anestis; Wang, Xuebing

2014-01-01

We have carried out JHK s imaging of 12 white dwarf debris disk candidates from the WIRED Sloan Digital Sky Survey Data Release 7 catalog, aiming to confirm or rule out disks among these sources. On the basis of positional identification and the flux density spectra, we find that seven white dwarfs have excess infrared emission, but mostly at Wide-field Infrared Survey Explorer W1 and W2 bands. Four are due to nearby red objects consistent with background galaxies or very low mass dwarfs, and one exhibits excess emission at JHK s consistent with an unresolved L0 companion at the correct distance. While our photometry is not inconsistent with all seven excesses arising from disks, the stellar properties are distinct from the known population of debris disk white dwarfs, making the possibility questionable. In order to further investigate the nature of these infrared sources, warm Spitzer imaging is needed, which may help resolve galaxies from the white dwarfs and provide more accurate flux measurements.

A primary study on finding hot groundwater using infrared remote sensing

Science.gov (United States)

Qiao, Y.; Wu, Q.

Hot groundwater is a kind of valuable natural resources to be explored utilized. Shanxi Province, located in the eastern Loess Plateau of China, is rich in geothermal resources, most of which was found in irrigation well drilling or geological survey. Basic study is weak. Now new developed Remote Sensing technique provides geothermal study with an advanced way. Air-RS information of thermal infrared and dada from thermal channel of Meteorological Landset AVHRR has been used widely. A thermal infrared channel (TM6) was installed in the U. S. second Landset, Its resolving power of space is as high as 120 m, 10 times more t an one ofh AVHRR. A Landset earth recourses launched by China and Brazil (CBERS-1) in 1999, including a spectrum of thermal infrared. It is paid a great interested and attention to survey geothermal resources using thermal infrared. This article is a brief introduction of finding hot groundwater with on the bases of differences of thermal radiation of objects reflected by thermal infrared in the Landset, and treated with HIS colors changes. This study provides an advanced way widely used to exploit hot groundwater and to promote the development of tourism and geothermal medical in China.

THE IMPACT OF EVOLVING INFRARED SPECTRAL ENERGY DISTRIBUTIONS OF GALAXIES ON STAR FORMATION RATE ESTIMATES

Energy Technology Data Exchange (ETDEWEB)

Nordon, R.; Lutz, D.; Genzel, R.; Berta, S.; Wuyts, S.; Magnelli, B.; Foerster Schreiber, N. M.; Poglitsch, A.; Popesso, P. [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, 85741 Garching (Germany); Altieri, B. [Herschel Science Centre, European Space Astronomy Centre, ESA, Villanueva de al Canada, 28691 Madrid (Spain); Andreani, P. [ESO, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Aussel, H.; Daddi, E. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/Service d' Astrophysique, Bat.709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France); Bongiovanni, A.; Cepa, J.; Perez Garcia, A. M. [Instituto de Astrofisica de Canarias, 38200 La Laguna, Tenerife (Spain); Cimatti, A. [Dipartimento di Astronomia, Universita di Bologna, Via Ranzani 1, 40127 Bologna (Italy); Fadda, D. [IPAC, California Institute of Technology, Pasadena, CA 91125 (United States); Lagache, G. [Institut d' Astrophysique Spatiale (IAS), Bat 121, Universite de Paris XI, 91450 Orsay Cedex (France); Maiolino, R., E-mail: nordon@mpe.mpg.de [INAF-Osservatorio Astronomico di Roma, via di Frascati 33, 00040 Monte Porzio Catone (Italy); and others

2012-02-01

We combine Herschel-Photodetector Array Camera and Spectrometer (PACS) data from the PACS Evolutionary Probe (PEP) program with Spitzer 24 {mu}m and 16 {mu}m photometry and ultra deep Infrared Spectrograph (IRS) mid-infrared spectra to measure the mid- to far-infrared spectral energy distribution (SED) of 0.7 < z < 2.5 normal star-forming galaxies (SFGs) around the main sequence (the redshift-dependent relation of star formation rate (SFR) and stellar mass). Our very deep data confirm from individual far-infrared detections that z {approx} 2 SFRs are overestimated if based on 24 {mu}m fluxes and SED templates that are calibrated via local trends with luminosity. Galaxies with similar ratios of rest-frame {nu}L{sub {nu}}(8) to 8-1000 {mu}m infrared luminosity (LIR) tend to lie along lines of constant offset from the main sequence. We explore the relation between SED shape and offset in specific star formation rate (SSFR) from the redshift-dependent main sequence. Main-sequence galaxies tend to have a similar {nu}L{sub {nu}}(8)/LIR regardless of LIR and redshift, up to z {approx} 2.5, and {nu}L{sub {nu}}(8)/LIR decreases with increasing offset above the main sequence in a consistent way at the studied redshifts. We provide a redshift-independent calibration of SED templates in the range of 8-60 {mu}m as a function of {Delta}log(SSFR) offset from the main sequence. Redshift dependency enters only through the evolution of the main sequence with time. Ultra deep IRS spectra match these SED trends well and verify that they are mostly due to a change in ratio of polycyclic aromatic hydrocarbon (PAH) to LIR rather than continua of hidden active galactic nuclei (AGNs). Alternatively, we discuss the dependence of {nu}L{sub {nu}}(8)/LIR on LIR. The same {nu}L{sub {nu}}(8)/LIR is reached at increasingly higher LIR at higher redshift, with shifts relative to local by 0.5 and 0.8 dex in log(LIR) at redshifts z {approx} 1 and z {approx} 2. Corresponding SED template calibrations

Structure formation in a colliding flow: The Herschel view of the Draco nebula

Science.gov (United States)

Miville-Deschênes, M.-A.; Salomé, Q.; Martin, P. G.; Joncas, G.; Blagrave, K.; Dassas, K.; Abergel, A.; Beelen, A.; Boulanger, F.; Lagache, G.; Lockman, F. J.; Marshall, D. J.

2017-03-01

Context. The Draco nebula is a high Galactic latitude interstellar cloud observed at velocities corresponding to the intermediate velocity cloud regime. This nebula shows unusually strong CO emission and remarkably high-contrast small-scale structures for such a diffuse high Galactic latitude cloud. The 21 cm emission of the Draco nebula reveals that it is likely to have been formed by the collision of a cloud entering the disk of the Milky Way. Such physical conditions are ideal to study the formation of cold and dense gas in colliding flows of diffuse and warm gas. Aims: The objective of this study is to better understand the process of structure formation in a colliding flow and to describe the effects of matter entering the disk on the interstellar medium. Methods: We conducted Herschel-SPIRE observations of the Draco nebula. The clumpfind algorithm was used to identify and characterize the small-scale structures of the cloud. Results: The high-resolution SPIRE map reveals the fragmented structure of the interface between the infalling cloud and the Galactic layer. This front is characterized by a Rayleigh-Taylor (RT) instability structure. From the determination of the typical length of the periodic structure (2.2 pc) we estimated the gas kinematic viscosity. This allowed us to estimate the dissipation scale of the warm neutral medium (0.1 pc), which was found to be compatible with that expected if ambipolar diffusion were the main mechanism of turbulent energy dissipation. The statistical properties of the small-scale structures identified with clumpfind are found to be typical of that seen in molecular clouds and hydrodynamical turbulence in general. The density of the gas has a log-normal distribution with an average value of 103 cm-3. The typical size of the structures is 0.1-0.2 pc, but this estimate is limited by the resolution of the observations. The mass of these structures ranges from 0.2 to 20 M⊙ and the distribution of the more massive structures

PROBING THE STAR FORMATION HISTORY AND INITIAL MASS FUNCTION OF THE z {approx} 2.5 LENSED GALAXY SMM J163554.2+661225 WITH HERSCHEL

Energy Technology Data Exchange (ETDEWEB)

Finkelstein, Keely D.; Papovich, Casey; Finkelstein, Steven L. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States); Willmer, Christopher N. A.; Egami, Eiichi; Rieke, Marcia [Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Rigby, Jane R. [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Rudnick, Gregory [Department of Physics and Astronomy, 1251 Wescoe Hall Dr., University of Kansas, Lawrence, KS 66045-7582 (United States); Smith, J.-D. T. [Ritter Observatory, Department of Physics and Astronomy, University of Toledo, MS 113, Toledo, OH 43606 (United States)

2011-12-01

We present the analysis of Herschel Spectral and Photometric Imaging Receiver far-infrared (FIR) observations of the z = 2.515 lensed galaxy SMM J163554.2+661225. Combining new 250, 350, and 500 {mu}m observations with existing data, we make an improved fit to the FIR spectral energy distribution of this galaxy. We find a total infrared (IR) luminosity of L(8-1000 {mu}m) = 6.9 {+-} 0.6 Multiplication-Sign 10{sup 11} L{sub Sun }, a factor of three more precise over previous L{sub IR} estimates for this galaxy, and one of the most accurate measurements for any galaxy at these redshifts. This FIR luminosity implies an unlensed star formation rate (SFR) for this galaxy of 119 {+-} 10 M{sub Sun} yr{sup -1}, which is a factor of 1.9 {+-} 0.35 lower than the SFR derived from the nebular Pa{alpha} emission line (a 2.5{sigma} discrepancy). Both SFR indicators assume an identical Salpeter initial mass function (IMF) with slope {Gamma} = 2.35 over a mass range of 0.1-100 M{sub Sun }; thus this discrepancy suggests that more ionizing photons may be necessary to account for the higher Pa{alpha}-derived SFR. We examine a number of scenarios and find that the observations can be explained with a varying star formation history (SFH) due to an increasing SFR, paired with a slight flattening of the IMF. If the SFR is constant in time, then larger changes need to be made to the IMF by either increasing the upper mass cutoff to {approx}200 M{sub Sun }, or a flattening of the IMF slope to 1.9 {+-} 0.15, or a combination of the two. These scenarios result in up to double the number of stars with masses above 20 M{sub Sun }, which produce the requisite increase in ionizing photons over a Salpeter IMF with a constant SFH.

The Green Bank Ammonia Survey: Observations of Hierarchical Dense Gas Structures in Cepheus-L1251

Science.gov (United States)

Keown, Jared; Di Francesco, James; Kirk, Helen; Friesen, Rachel K.; Pineda, Jaime E.; Rosolowsky, Erik; Ginsburg, Adam; Offner, Stella S. R.; Caselli, Paola; Alves, Felipe; Chacón-Tanarro, Ana; Punanova, Anna; Redaelli, Elena; Seo, Young Min; Matzner, Christopher D.; Chun-Yuan Chen, Michael; Goodman, Alyssa A.; Chen, How-Huan; Shirley, Yancy; Singh, Ayushi; Arce, Hector G.; Martin, Peter; Myers, Philip C.

2017-11-01

We use Green Bank Ammonia Survey observations of NH3 (1, 1) and (2, 2) emission with 32″ FWHM resolution from a ˜10 pc2 portion of the Cepheus-L1251 molecular cloud to identify hierarchical dense gas structures. Our dendrogram analysis of the NH3 data results in 22 top-level structures, which reside within 13 lower-level parent structures. The structures are compact (0.01 {pc}≲ {R}{eff}≲ 0.1 {pc}) and are spatially correlated with the highest H2 column density portions of the cloud. We also compare the ammonia data to a catalog of dense cores identified by higher-resolution (18.″2 FWHM) Herschel Space Observatory observations of dust continuum emission from Cepheus-L1251. Maps of kinetic gas temperature, velocity dispersion, and NH3 column density, derived from detailed modeling of the NH3 data, are used to investigate the stability and chemistry of the ammonia-identified and Herschel-identified structures. We show that the dust and dense gas in the structures have similar temperatures, with median T dust and T K measurements of 11.7 ± 1.1 K and 10.3 ± 2.0 K, respectively. Based on a virial analysis, we find that the ammonia-identified structures are gravitationally dominated, yet may be in or near a state of virial equilibrium. Meanwhile, the majority of the Herschel-identified dense cores appear to be not bound by their own gravity and instead confined by external pressure. CCS (20 - 10) and HC5N (9-8) emission from the region reveal broader line widths and centroid velocity offsets when compared to the NH3 (1, 1) emission in some cases, likely due to these carbon-based molecules tracing the turbulent outer layers of the dense cores.

The Herschel-ATLAS: magnifications and physical sizes of 500-μm-selected strongly lensed galaxies

Science.gov (United States)

Enia, A.; Negrello, M.; Gurwell, M.; Dye, S.; Rodighiero, G.; Massardi, M.; De Zotti, G.; Franceschini, A.; Cooray, A.; van der Werf, P.; Birkinshaw, M.; Michałowski, M. J.; Oteo, I.

2018-04-01

We perform lens modelling and source reconstruction of Sub-millimetre Array (SMA) data for a sample of 12 strongly lensed galaxies selected at 500μm in the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). A previous analysis of the same data set used a single Sérsic profile to model the light distribution of each background galaxy. Here we model the source brightness distribution with an adaptive pixel scale scheme, extended to work in the Fourier visibility space of interferometry. We also present new SMA observations for seven other candidate lensed galaxies from the H-ATLAS sample. Our derived lens model parameters are in general consistent with previous findings. However, our estimated magnification factors, ranging from 3 to 10, are lower. The discrepancies are observed in particular where the reconstructed source hints at the presence of multiple knots of emission. We define an effective radius of the reconstructed sources based on the area in the source plane where emission is detected above 5σ. We also fit the reconstructed source surface brightness with an elliptical Gaussian model. We derive a median value reff ˜ 1.77 kpc and a median Gaussian full width at half-maximum ˜1.47 kpc. After correction for magnification, our sources have intrinsic star formation rates (SFR) ˜ 900-3500 M⊙ yr-1, resulting in a median SFR surface density ΣSFR ˜ 132 M⊙ yr-1 kpc-2 (or ˜218 M⊙ yr-1 kpc-2 for the Gaussian fit). This is consistent with that observed for other star-forming galaxies at similar redshifts, and is significantly below the Eddington limit for a radiation pressure regulated starburst.

A COMPREHENSIVE CENSUS OF NEARBY INFRARED EXCESS STARS

Energy Technology Data Exchange (ETDEWEB)

Cotten, Tara H.; Song, Inseok, E-mail: tara@physast.uga.edu, E-mail: song@physast.uga.edu [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

2016-07-01

The conclusion of the Wide-Field Infrared Survey Explorer ( WISE ) mission presents an opportune time to summarize the history of using excess emission in the infrared as a tracer of circumstellar material and exploit all available data for future missions such as the James Webb Space Telescope . We have compiled a catalog of infrared excess stars from peer-reviewed articles and perform an extensive search for new infrared excess stars by cross-correlating the Tycho-2 and all-sky WISE (AllWISE) catalogs. We define a significance of excess in four spectral type divisions and select stars showing greater than either 3 σ or 5 σ significance of excess in the mid- and far-infrared. Through procedures including spectral energy distribution fitting and various image analyses, each potential excess source was rigorously vetted to eliminate false positives. The infrared excess stars from the literature and the new stars found through the Tycho-2 and AllWISE cross-correlation produced nearly 500 “Prime” infrared excess stars, of which 74 are new sources of excess, and >1200 are “Reserved” stars, of which 950 are new sources of excess. The main catalog of infrared excess stars are nearby, bright, and either demonstrate excess in more than one passband or have infrared spectroscopy confirming the infrared excess. This study identifies stars that display a spectral energy distribution suggestive of a secondary or post-protoplanetary generation of dust, and they are ideal targets for future optical and infrared imaging observations. The final catalogs of stars summarize the past work using infrared excess to detect dust disks, and with the most extensive compilation of infrared excess stars (∼1750) to date, we investigate various relationships among stellar and disk parameters.

Star Formation in M 33 (HerM33es)

Science.gov (United States)

Kramer, C.; Boquien, M.; Braine, J.; Buchbender, C.; Calzetti, D.; Gratier, P.; Mookerjea, B.; Relaño, M.; Verley, S.

2011-11-01

Within the key project "Herschel M 33 extended survey" (HerM33es), we are studying the physical and chemical processes driving star formation and galactic evolution in the nearby galaxy M 33, combining the study of local conditions affecting individual star formation with properties only becoming apparent on global scales. Here, we present recent results obtained by the HerM33es team. Combining Spitzer and Herschel data ranging from 3.6 μm to 500μm, along with H i, Hα, and GALEX UV data, we have studied the dust at high spatial resolutions of 150 pc, providing estimators of the total infrared (TIR) brightness and of the star formation rate. While the temperature of the warm dust at high brightness is driven by young massive stars, evolved stellar populations appear to drive the temperature of the cold dust. Plane-parallel models of photon dominated regions (PDRs) fail to reproduce fully the [C ii], [O i], and CO maps obtained in a first spectroscopic study of one 2' × 2' subregion of M 33, located on the inner, northern spiral arm and encompassing the H ii region BCLMP 302.

Herschel-spire Fourier transform spectrometer observations of excited CO and [C I] in the antennae (NGC 4038/39): Warm and cold molecular gas

Energy Technology Data Exchange (ETDEWEB)

Schirm, Maximilien R. P.; Wilson, Christine D.; Parkin, Tara J. [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Kamenetzky, Julia; Glenn, Jason; Rangwala, Naseem [Center for Astrophysics and Space Astronomy, 389-UCB, University of Colorado, Boulder, CO 80303 (United States); Spinoglio, Luigi; Pereira-Santaella, Miguel [Istituto di Astrofisica e Planetologia Spaziali, INAF-IAPS, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Baes, Maarten; De Looze, Ilse [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Barlow, Michael J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Clements, Dave L. [Astrophysics Group, Imperial College, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Karczewski, Oskar Ł. [Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom); Madden, Suzanne C.; Rémy-Ruyer, Aurélie; Wu, Ronin, E-mail: schirmmr@mcmaster.ca, E-mail: wilson@physics.mcmaster.ca [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France)

2014-02-01

We present Herschel Spectral and Photometric Imaging Receiver (SPIRE) Fourier Transform Spectrometer (FTS) observations of the Antennae (NGC 4038/39), a well-studied, nearby (22 Mpc), ongoing merger between two gas-rich spiral galaxies. The SPIRE-FTS is a low spatial ( FWHM ∼ 19''-43'') and spectral (∼1.2 GHz) resolution mapping spectrometer covering a large spectral range (194-671 μm, 450-1545 GHz). We detect five CO transitions (J = 4-3 to J = 8-7), both [C I] transitions, and the [N II] 205 μm transition across the entire system, which we supplement with ground-based observations of the CO J = 1-0, J = 2-1, and J = 3-2 transitions and Herschel Photodetecting Array Camera and Spectrometer (PACS) observations of [C II] and [O I] 63 μm. Using the CO and [C I] transitions, we perform both a local thermodynamic equilibrium (LTE) analysis of [C I] and a non-LTE radiative transfer analysis of CO and [C I] using the radiative transfer code RADEX along with a Bayesian likelihood analysis. We find that there are two components to the molecular gas: a cold (T {sub kin} ∼ 10-30 K) and a warm (T {sub kin} ≳ 100 K) component. By comparing the warm gas mass to previously observed values, we determine a CO abundance in the warm gas of x {sub CO} ∼ 5 × 10{sup –5}. If the CO abundance is the same in the warm and cold gas phases, this abundance corresponds to a CO J = 1-0 luminosity-to-mass conversion factor of α{sub CO} ∼ 7 M {sub ☉} pc{sup –2} (K km s{sup –1}){sup –1} in the cold component, similar to the value for normal spiral galaxies. We estimate the cooling from H{sub 2}, [C II], CO, and [O I] 63 μm to be ∼0.01 L {sub ☉}/M {sub ☉}. We compare photon-dominated region models to the ratio of the flux of various CO transitions, along with the ratio of the CO flux to the far-infrared flux in NGC 4038, NGC 4039, and the overlap region. We find that the densities recovered from our non-LTE analysis are consistent with a

Developments in fiber-positioning technology for the WEAVE instrument at the William Herschel Telescope

Science.gov (United States)

Schallig, Ellen; Lewis, Ian J.; Gilbert, James; Dalton, Gavin; Brock, Matthew; Abrams, Don Carlos; Middleton, Kevin; Aguerri, J. Alfonso L.; Bonifacio, Piercarlo; Carrasco, Esperanza; Trager, Scott C.; Vallenari, Antonella

2016-08-01

WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) on La Palma in the Canary Islands, Spain. It is a multi-object "pick-and-place" fibre-fed spectrograph with a 1000 fibre multiplex behind a new dedicated 2° prime focus corrector. The WEAVE positioner concept uses two robots working in tandem in order to reconfigure a fully populated field within the expected 1 hour dwell-time for the instrument (a good match between the required exposure times and the limit of validity for a given configuration due to the effects of differential refraction). In this paper we describe some of the final design decisions arising from the prototyping phase of the instrument design and provide an update on the current manufacturing status of the fibre positioner system.

SPITZER AND HERSCHEL MULTIWAVELENGTH CHARACTERIZATION OF THE DUST CONTENT OF EVOLVED H II REGIONS

Energy Technology Data Exchange (ETDEWEB)

Paladini, R. [NASA Herschel Science Center, California Institute of Technology, 1200, East California Boulevard, Pasadena, CA 91125 (United States); Umana, G. [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Veneziani, M.; Noriega-Crespo, A. [Infrared Processing and Analysis Center, California Institute of Technology, 1200, East California Boulevard, Pasadena, CA 91125 (United States); Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Piacentini, F. [Dipartimento di Fisica, Universita di Roma La Sapienza, I-00185 Roma (Italy); Pinheiro Goncalves, D. [Department of Astronomy and Astrophysics, University of Toronto 50 George Street, Toronto, ON M5S 3H4 (Canada); Paradis, D.; Bernard, J.-P. [Centre d' Etude Spatiale des Rayonnements, 9 Avenue du Colonel Roche, F-31028 Toulouse Cedex 4 (France); Tibbs, C. T. [Spitzer Science Center, California Institute of Technology, 1200, East California Boulevard, Pasadena, CA 91125 (United States); Natoli, P., E-mail: paladini@ipac.caltech.edu [Istituto Nazionale di Fisica Nucleare, Sezione Ferrara, I-44100 Ferrara (Italy)

2012-12-01

We have analyzed a uniform sample of 16 evolved H II regions located in a 2 Degree-Sign Multiplication-Sign 2 Degree-Sign Galactic field centered at (l,b) = (30 Degree-Sign , 0 Degree-Sign ) and observed as part of the Herschel Hi-GAL survey. The evolutionary stage of these H II regions was established using ancillary radio-continuum data. By combining Hi-GAL PACS (70 {mu}m, 160 {mu}m) and SPIRE (250 {mu}m, 350 {mu}m, and 500 {mu}m) measurements with MIPSGAL 24 {mu}m data, we built spectral energy distributions of the sources and showed that a two-component gray-body model is a good representation of the data. In particular, wavelengths >70 {mu}m appear to trace a cold dust component, for which we estimated an equilibrium temperature of the big grains (BGs) in the range 20-30 K, while for {lambda} < 70 {mu}m, the data indicate the presence of a warm dust component at temperatures of the order of 50-90 K. This analysis also revealed that dust is present in the interior of H II regions, although likely not in a large amount. In addition, the data seem to corroborate the hypothesis that the main mechanism responsible for the (partial) depletion of dust in H II regions is radiation-pressure-driven drift. In this framework, we speculated that the 24 {mu}m emission that spatially correlates with ionized gas might be associated with either very small grain or BG replenishment, as recently proposed for the case of wind-blown bubbles. Finally, we found that evolved H II regions are characterized by distinctive far-IR and submillimeter colors, which can be used as diagnostics for their identification in unresolved Galactic and extragalactic regions.

VERY STRONG EMISSION-LINE GALAXIES IN THE WFC3 INFRARED SPECTROSCOPIC PARALLEL SURVEY AND IMPLICATIONS FOR HIGH-REDSHIFT GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Atek, H.; Colbert, J.; Shim, H. [Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States); Siana, B.; Bridge, C. [Department of Astronomy, Caltech, Pasadena, CA 91125 (United States); Scarlata, C. [Department of Astronomy, University of Minnesota-Twin Cities, Minneapolis, MN 55455 (United States); Malkan, M.; Ross, N. R. [Department of Physics and Astronomy, University of California, Los Angeles, CA (United States); McCarthy, P.; Dressler, A.; Hathi, N. P. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Teplitz, H. [Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States); Henry, A.; Martin, C. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Bunker, A. J. [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Fosbury, R. A. E. [Space Telescope-European Coordinating Facility, Garching bei Muenchen (Germany)

2011-12-20

The WFC3 Infrared Spectroscopic Parallel Survey uses the Hubble Space Telescope (HST) infrared grism capabilities to obtain slitless spectra of thousands of galaxies over a wide redshift range including the peak of star formation history of the universe. We select a population of very strong emission-line galaxies with rest-frame equivalent widths (EWs) higher than 200 A. A total of 176 objects are found over the redshift range 0.35 < z < 2.3 in the 180 arcmin{sup 2} area that we have analyzed so far. This population consists of young and low-mass starbursts with high specific star formation rates (sSFR). After spectroscopic follow-up of one of these galaxies with Keck/Low Resolution Imaging Spectrometer, we report the detection at z = 0.7 of an extremely metal-poor galaxy with 12 + log(O/H) =7.47 {+-} 0.11. After estimating the active galactic nucleus fraction in the sample, we show that the high-EW galaxies have higher sSFR than normal star-forming galaxies at any redshift. We find that the nebular emission lines can substantially affect the total broadband flux density with a median brightening of 0.3 mag, with some examples of line contamination producing brightening of up to 1 mag. We show that the presence of strong emission lines in low-z galaxies can mimic the color-selection criteria used in the z {approx} 8 dropout surveys. In order to effectively remove low-redshift interlopers, deep optical imaging is needed, at least 1 mag deeper than the bands in which the objects are detected. Without deep optical data, most of the interlopers cannot be ruled out in the wide shallow HST imaging surveys. Finally, we empirically demonstrate that strong nebular lines can lead to an overestimation of the mass and the age of galaxies derived from fitting of their spectral energy distribution (SED). Without removing emission lines, the age and the stellar mass estimates are overestimated by a factor of 2 on average and up to a factor of 10 for the high-EW galaxies

Aerial infrared monitoring for nuclear fuel cycle facilities in Ukraine

International Nuclear Information System (INIS)

Stankevich, S.A.; Dudar, T.V.; Kovalenko, G.D.; Kartashov, V.V.

2015-01-01

The scientific research overall objective is rapid express detection and preliminary identification of pre-accidental conditions at nuclear fuel cycle facilities. We consider development of a miniature unmanned aerial vehicle equipped with high-precision infrared spectroradiometer able to detect remotely internal warming up of hazardous facilities by its thermal infrared radiation. The possibility of remote monitoring using unmanned aerial vehicle is considered at the example of the dry spent fuel storage facility of the Zaporizhzhya Nuclear Power Plant. Infrared remote monitoring is supposed to present additional information on the monitored facilities based on different physical principles rather than those currently in use. Models and specifications towards up-to-date samples of infrared surveying equipment and its small-sized unmanned vehicles are presented in the paper.

THE INFRARED PROPERTIES OF EMBEDDED SUPER STAR CLUSTERS: PREDICTIONS FROM THREE-DIMENSIONAL RADIATIVE TRANSFER MODELS

International Nuclear Information System (INIS)

Whelan, David G.; Johnson, Kelsey E.; Indebetouw, Remy; Whitney, Barbara A.; Wood, Kenneth

2011-01-01

With high-resolution infrared data becoming available that can probe the formation of high-mass stellar clusters for the first time, appropriate models that make testable predictions of these objects are necessary. We utilize a three-dimensional radiative transfer code, including a hierarchically clumped dusty envelope, to study the earliest stages of super star cluster (SSC) evolution. We explore a range of parameter space in geometric sequences that mimic the hypothesized evolution of an embedded SSC. The inclusion of a hierarchically clumped medium can make the envelope porous, in accordance with previous models and supporting observational evidence. The infrared luminosity inferred from observations can differ by a factor of two from the true value in the clumpiest envelopes depending on the viewing angle. The infrared spectral energy distribution also varies with viewing angle for clumpy envelopes, creating a range in possible observable infrared colors and magnitudes, silicate feature depths, and dust continua. General observable features of cluster evolution differ between envelopes that are relatively opaque or transparent to mid-infrared photons. For optically thick envelopes, evolution is marked by a gradual decline of the 9.8 μm silicate absorption feature depth and a corresponding increase in the visual/ultraviolet flux. For the optically thin envelopes, clusters typically begin with a strong hot dust component and silicates in emission, and these features gradually fade until the mid-infrared polycyclic aromatic hydrocarbon features are predominant. For the models with a smooth dust distribution, the Spitzer MIPS or Herschel PACS [70]-[160] color is a good probe of the stellar mass relative to the total mass or star formation efficiency (SFE). Likewise, the IRAC/MIPS [3.6]-[24] color can be used to constrain the R in and R out values of the envelope. However, clumpiness confuses the general trends seen in the smooth dust distribution models, making it

OT2_amoor_4: A census of debris disks in nearby young moving groups with Herschel.

Science.gov (United States)

Moór, A.

2011-09-01

Nearly all young stars harbour circumstellar disks, that serve as the reservoir for mass accretion onto the star, and later become the birthplace of planetary systems. After the disappearance of the gas component from the disk a dusty debris disk is formed that is believed to mark the location of the planetesimal belt as well. For outlining the evolution of such debris disks traditionally open clusters and field stars were studied, however we argue that the recently discovered young moving groups are more suitable objects for such analyses, due to their proximity and good coverage of the first 50 Myr period of the planetary system evolution. In this proposal we request 70/160 um Herschel/PACS photometric observations for so-far unobserved moving group members. These observations will provide a complete coverage of all known members within 80 pc of five nearby young moving groups (beta Pic Moving Group, Tucana-Horologium, Carina, Columba, and Argus), in the A to K spectral range. Based on the new observations we will identify new debris disks, characterize the disk population within individual moving groups, and study disk evolution by comparing the groups of different ages. The results will be used to verify predictions of the self-stirring model of the evolution of planetesimal disks. We will also compare the properties of debris disks in groups of the same age, looking for additional 'environmental' parameters that affect disk structure over a whole moving group. Our study will be a significant contribution to the census of debris disks in young moving groups, increasing the number of observed sources by a factor of 1.5. Since Spitzer could perform only a limited census and the so-far approved Herschel programs added very few additional moving group obervations, our programme is expected to have a high legacy value.

Mid-infrared Variability of Changing-look AGNs

International Nuclear Information System (INIS)

Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Peng, Bo; Yan, Lin; Dou, Liming

2017-01-01

It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer ( WISE ) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

Mid-infrared Variability of Changing-look AGNs

Energy Technology Data Exchange (ETDEWEB)

Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Peng, Bo [CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Sciences and Technology of China, Hefei, Anhui 230026 (China); Yan, Lin [Caltech Optical Observatories, Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Dou, Liming, E-mail: shengzf@mail.ustc.edu.cn, E-mail: twang@ustc.edu.cn [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)

2017-09-01

It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer ( WISE ) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

ON THE MULTIPLICITY OF THE ZERO-AGE MAIN-SEQUENCE O STAR HERSCHEL 36

International Nuclear Information System (INIS)

Arias, Julia I.; Barba, Rodolfo H.; Gamen, Roberto C.; Morrell, Nidia I.; Apellaniz, Jesus MaIz; Alfaro, Emilio J.; Sota, Alfredo; Walborn, Nolan R.; Bidin, Christian Moni

2010-01-01

We present the analysis of high-resolution optical spectroscopic observations of the zero-age main-sequence O star Herschel 36 spanning six years. This star is definitely a multiple system, with at least three components detected in its spectrum. Based on our radial-velocity (RV) study, we propose a picture of a close massive binary and a more distant companion, most probably in wide orbit about each other. The orbital solution for the binary, whose components we identify as O9 V and B0.5 V, is characterized by a period of 1.5415 ± 0.0006 days. With a spectral type O7.5 V, the third body is the most luminous component of the system and also presents RV variations with a period close to 498 days. Some possible hypotheses to explain the variability are briefly addressed and further observations are suggested.

Identifying specific interstellar polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Mulas, Giacomo; Malloci, Giuliano; Porceddu, Ignazio

2005-01-01

Interstellar Polycyclic Aromatic Hydrocarbons (PAHs) have been thought to be ubiquitous for more than twenty years, yet no single species in this class has been identified in the Interstellar Medium (ISM) to date. The unprecedented sensitivity and resolution of present Infrared Space Observatory (ISO) and forthcoming Herschel observations in the far infrared spectral range will offer a unique way out of this embarrassing impasse

MID-INFRARED PHOTOMETRY OF COLD BROWN DWARFS: DIVERSITY IN AGE, MASS, AND METALLICITY

International Nuclear Information System (INIS)

Leggett, S. K.; Burningham, Ben; Jones, H. R. A.; Lucas, P. W.; Pinfield, D. J.; Saumon, D.; Marley, M. S.; Warren, S. J.; Smart, R. L.; Tamura, Motohide

2010-01-01

We present new Spitzer Infrared Array Camera (IRAC) photometry of 12 very late-type T dwarfs: nine have [3.6], [4.5], [5.8], and [8.0] photometry and three have [3.6] and [4.5] photometry only. Combining this with previously published photometry, we investigate trends with type and color that are useful for both the planning and interpretation of infrared surveys designed to discover the coldest T or Y dwarfs. The online appendix provides a collation of MKO-system YJHKL'M' and IRAC photometry for a sample of M, L, and T dwarfs. Brown dwarfs with effective temperature (T eff ) below 700 K emit more than half their flux at wavelengths longer than 3 μm, and the ratio of the mid-infrared flux to the near-infrared flux becomes very sensitive to T eff at these low temperatures. We confirm that the color H (1.6 μm) - [4.5] is a good indicator of T eff with a relatively weak dependence on metallicity and gravity. Conversely, the colors H - K (2.2 μm) and [4.5] - [5.8] are sensitive to metallicity and gravity. Thus, near- and mid-infrared photometry provide useful indicators of the fundamental properties of brown dwarfs, and if temperature and gravity are known, then mass and age can be reliably determined from evolutionary models. There are 12 dwarfs currently known with H- [4.5] >3.0, and 500 K ∼ eff ∼<800 K, which we examine in detail. The ages of the dwarfs in the sample range from very young (0.1-1.0 Gyr) to relatively old (3-12 Gyr). The mass range is possibly as low as 5 Jupiter masses to up to 70 Jupiter masses, i.e., near the hydrogen burning limit. The metallicities also span a large range, from [m/H] = -0.3 to [m/H] = +0.3. The small number of T8-T9 dwarfs found in the UK Infrared Telescope Infrared Deep Sky Survey to date appear to be predominantly young low-mass dwarfs. Accurate mid-infrared photometry of cold brown dwarfs is essentially impossible from the ground, and extensions to the mid-infrared space missions, warm-Spitzer and Wide-Field Infrared

HERUS: A CO ATLAS FROM SPIRE SPECTROSCOPY OF LOCAL ULIRGs

Energy Technology Data Exchange (ETDEWEB)

Pearson, Chris; Rigopoulou, Dimitra [RAL Space, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Hurley, Peter [Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Farrah, Duncan [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Afonso, Jose [Instituto de Astrofísica e Ciências do Espaç co, Universidade de Lisboa, OAL, Tapada da Ajuda, PT1349-018 Lisboa (Portugal); Bernard-Salas, Jeronimo [The Open University, MK7 6, AA Milton Keynes (United Kingdom); Borys, Colin [Riot Games, 12333 W Olympic Blvd, Los Angeles, CA 90064 (United States); Clements, David L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Rd, London SW7 2AZ (United Kingdom); Cormier, Diane [Institut fur theoretische Astrophysik, Zentrum fur Astronomie der Universitat Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Efstathiou, Andreas [School of Sciences, European University Cyprus, Diogenes Street, Engomi, 1516 Nicosia (Cyprus); Gonzalez-Alfonso, Eduardo [Universidad de Alcala de Henares, Departamento de Fisica, Campus Universitario, E-28871 Alcala de Henares, Madrid (Spain); Lebouteiller, Vianney [CEA-Saclay, DSM/IRFU/SAp, F-91191 Gif-sur-Yvette (France); Spoon, Henrik [Cornell University, CRSR, Space Sciences Building, Ithaca, NY 14853 (United States)

2016-11-01

We present the Herschel SPIRE Fourier Transform Spectroscopy (FTS) atlas for a complete flux-limited sample of local ultraluminous infrared galaxies (ULIRGs) as part of the HERschel Ultra Luminous InfraRed Galaxy Survey (HERUS). The data reduction is described in detail and was optimized for faint FTS sources ,with particular care being taken for the subtraction of the background, which dominates the continuum shape of the spectra. To improve the final spectra, special treatment in the data reduction has been given to any observation suffering from artifacts in the data caused by anomalous instrumental effects. Complete spectra are shown covering 200–671 μ m, with photometry in the SPIRE bands at 250, 350, and 500 μ m. The spectra include near complete CO ladders for over half of our sample, as well as fine structure lines from [C i] 370 μ m, [C i] 609 μ m, and [N ii] 205 μ m. We also detect H{sub 2}O lines in several objects. We construct CO spectral line energy distributions (SLEDs) for the sample, and compare their slopes with the far-infrared (FIR) colors and luminosities. We show that the CO SLEDs of ULIRGs can be broadly grouped into three classes based on their excitation. We find that the mid- J (5 <  J  < 8) lines are better correlated with the total FIR luminosity, suggesting that the warm gas component is closely linked to recent star formation. The higher J transitions do not linearly correlate with the FIR luminosity, consistent with them originating in hotter, denser gas that is unconnected to the current star formation. We conclude that in most cases more than one temperature component is required to model the CO SLEDs.

A high-significance measurement of correlation between unresolved IRAS sources and optically-selected galaxy clusters

Energy Technology Data Exchange (ETDEWEB)

Hincks, Adam D.; Hajian, Amir [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Addison, Graeme E., E-mail: hincks@cita.utoronto.ca, E-mail: ahajian@cita.utoronto.ca, E-mail: gaddison@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)

2013-05-01

We cross-correlate the 100 μm Improved Reprocessing of the IRAS Survey (IRIS) map and galaxy clusters at 0.1 < z < 0.3 in the maxBCG catalogue taken from the Sloan Digital Sky Survey, measuring an angular cross-power spectrum over multipole moments 150 < l < 3000 at a total significance of over 40σ. The cross-spectrum, which arises from the spatial correlation between unresolved dusty galaxies that make up the cosmic infrared background (CIB) in the IRIS map and the galaxy clusters, is well-fit by a single power law with an index of −1.28±0.12, similar to the clustering of unresolved galaxies from cross-correlating far-infrared and submillimetre maps at longer wavelengths. Using a recent, phenomenological model for the spectral and clustering properties of the IRIS galaxies, we constrain the large-scale bias of the maxBCG clusters to be 2.6±1.4, consistent with existing analyses of the real-space cluster correlation function. The success of our method suggests that future CIB-optical cross-correlations using Planck and Herschel data will significantly improve our understanding of the clustering and redshift distribution of the faint CIB sources.

WISE Discovery of Hyper Luminous Galaxies at z=2-4 and Their Implications for Galaxy and AGN Evolution

Science.gov (United States)

Tsai, Chao Wei; Eisenhardt, Peter; Wu, Jingwen; Bridge, Carrie; Assef, Roberto; Benford, Dominic; Blain, Andrew; Cutri, Roc; Griffith, Robert L.; Jarrett, Thomas;

Geothermal survey handbook

Energy Technology Data Exchange (ETDEWEB)

1974-01-01

The objective of this handbook is to publicize widely the nature of geothermal surveys. It covers geothermal survey planning and measurement as well as measurement of thermal conductivity. Methods for the detection of eruptive areas, the measurement of radiative heat using snowfall, the measurement of surface temperature using infrared radiation and the measurement of thermal flow are described. The book also contains information on physical detection of geothermal reservoirs, the measurement of spring wells, thermographic measurement of surface heat, irregular layer surveying, air thermographics and aerial photography. Isotope measurement techniques are included.

The first VLBI image of an infrared-faint radio source

Science.gov (United States)

Middelberg, E.; Norris, R. P.; Tingay, S.; Mao, M. Y.; Phillips, C. J.; Hotan, A. W.

2008-11-01

Context: We investigate the joint evolution of active galactic nuclei and star formation in the Universe. Aims: In the 1.4 GHz survey with the Australia Telescope Compact Array of the Chandra Deep Field South and the European Large Area ISO Survey - S1 we have identified a class of objects which are strong in the radio but have no detectable infrared and optical counterparts. This class has been called Infrared-Faint Radio Sources, or IFRS. 53 sources out of 2002 have been classified as IFRS. It is not known what these objects are. Methods: To address the many possible explanations as to what the nature of these objects is we have observed four sources with the Australian Long Baseline Array. Results: We have detected and imaged one of the four sources observed. Assuming that the source is at a high redshift, we find its properties in agreement with properties of Compact Steep Spectrum sources. However, due to the lack of optical and infrared data the constraints are not particularly strong.

A NEAR-INFRARED SURVEY OF THE INNER GALACTIC PLANE FOR WOLF-RAYET STARS. I. METHODS AND FIRST RESULTS: 41 NEW WR STARS

International Nuclear Information System (INIS)

Shara, Michael M.; Gerke, Jill; Zurek, David; Moffat, Anthony F. J.; Doyon, Rene; Villar-Sbaffi, Alfredo; Stanonik, Kathryn; Artigau, Etienne; Drissen, Laurent

2009-01-01

The discovery of new Wolf-Rayet (WR) stars in our Galaxy via large-scale narrowband optical surveys has been severely limited by dust extinction. Recent improvements in infrared technology have made narrowband-broadband imaging surveys viable again. We report a new J, K, and narrowband imaging survey of 300 deg 2 of the plane of the Galaxy, spanning 150 degrees in Galactic longitude and reaching 1 degree above and below the Galactic plane. The survey has a useful limiting magnitude of K = 15 over most of the observed Galactic plane, and K = 14 within a few degrees of the Galactic center. Thousands of emission line candidates have been detected. In spectrographic follow-ups of 173 WR star candidates we have discovered 41 new WR stars, 15 of type WN and 26 of type WC. Star subtype assignments have been confirmed with K-band spectra, and distances approximated using the method of spectroscopic parallax. A few of the new WR stars are among the most distant known in our Galaxy. The distribution of these new WR stars is seen to follow that of previously known WR stars along the spiral arms of the Galaxy. Tentative radial velocities were also measured for most of the new WR stars.

COOL WHITE DWARFS IDENTIFIED IN THE SECOND DATA RELEASE OF THE UKIRT INFRARED DEEP SKY SURVEY

International Nuclear Information System (INIS)

Lodieu, N.; Leggett, S. K.; Nitta, A.; Bergeron, P.

2009-01-01

We have paired the second data release of the Large Area Survey of the UKIRT Infrared Deep Sky Survey with the fifth data release of the Sloan Digital Sky Survey to identify 10 cool white dwarf candidates, from their photometry and astrometry. Of these 10, one was previously known to be a very cool white dwarf. We have obtained optical spectroscopy for seven of the candidates using the GMOS-N spectrograph on Gemini North, and have confirmed all seven as white dwarfs. Our photometry and astrometry indicate that the remaining two objects are also white dwarfs. The model analysis of the photometry and available spectroscopy shows that the seven confirmed new white dwarfs, and the two new likely white dwarfs, have effective temperatures in the range of T eff = 5400-6600 K. Our analysis of the previously known white dwarf confirms that it is cool, with T eff = 3800 K. The cooling age for this dwarf is 8.7 Gyr, while that for the nine ∼ 6000 K white dwarfs is 1.8-3.6 Gyr. We are unable to determine the masses of the white dwarfs from the existing data, and therefore we cannot constrain the total ages of the white dwarfs. The large cooling age for the coolest white dwarf in the sample, combined with its low estimated tangential velocity, suggests that it is an old member of the thin disk, or a member of the thick disk of the Galaxy, with an age of 10-11 Gyr. The warmer white dwarfs appear to have velocities typical of the thick disk or even halo; these may be very old remnants of low-mass stars, or they may be relatively young thin-disk objects with unusually high space motion.

INFRARED LUMINOSITIES AND DUST PROPERTIES OF z ∼ 2 DUST-OBSCURED GALAXIES

International Nuclear Information System (INIS)

Bussmann, R. S.; Dey, Arjun; Jannuzi, B. T.; Borys, C.; Desai, V.; Sheth, K.; Soifer, B. T.; Le Floc'h, E.; Melbourne, J.

2009-01-01

We present SHARC-II 350 μm imaging of twelve 24 μm bright (F 24μm > 0.8 mJy) Dust-Obscured Galaxies (DOGs) and Combined Array for Research in Millimeter-wave Astronomy (CARMA) 1 mm imaging of a subset of two DOGs. These objects are selected from the Booetes field of the NOAO Deep Wide-Field Survey. Detections of four DOGs at 350 μm imply infrared (IR) luminosities which are consistent to within a factor of 2 of expectations based on a warm-dust spectral energy distribution (SED) scaled to the observed 24 μm flux density. The 350 μm upper limits for the 8 non-detected DOGs are consistent with both Mrk 231 and M82 (warm-dust SEDs), but exclude cold dust (Arp 220) SEDs. The two DOGs targeted at 1 mm were not detected in our CARMA observations, placing strong constraints on the dust temperature: T dust > 35-60 K. Assuming these dust properties apply to the entire sample, we find dust masses of ∼3 x 10 8 M sun . In comparison to other dusty z ∼ 2 galaxy populations such as submillimeter galaxies (SMGs) and other Spitzer-selected high-redshift sources, this sample of DOGs has higher IR luminosities (2 x 10 13 L sun versus 6 x 10 12 L sun for the other galaxy populations) that are driven by warmer dust temperatures (>35-60 K versus ∼30 K) and lower inferred dust masses (3 x 10 8 M sun versus 3 x 10 9 M sun ). Wide-field Herschel and Submillimeter Common-User Bolometer Array-2 surveys should be able to detect hundreds of these power-law-dominated DOGs. We use the existing Hubble Space Telescope and Spitzer/InfraRed Array Camera data to estimate stellar masses of these sources and find that the stellar to gas mass ratio may be higher in our 24 μm bright sample of DOGs than in SMGs and other Spitzer-selected sources. Although much larger sample sizes are needed to provide a definitive conclusion, the data are consistent with an evolutionary trend in which the formation of massive galaxies at z ∼ 2 involves a submillimeter bright, cold-dust, and star

Large-scale filaments associated with Milky Way spiral arms

Science.gov (United States)

Wang, Ke; Testi, Leonardo; Ginsburg, Adam; Walmsley, C. Malcolm; Molinari, Sergio; Schisano, Eugenio

2015-07-01

The ubiquity of filamentary structure at various scales throughout the Galaxy has triggered a renewed interest in their formation, evolution, and role in star formation. The largest filaments can reach up to Galactic scale as part of the spiral arm structure. However, such large-scale filaments are hard to identify systematically due to limitations in identifying methodology (i.e. as extinction features). We present a new approach to directly search for the largest, coldest, and densest filaments in the Galaxy, making use of sensitive Herschel Hi-GAL (Herschel Infrared Galactic Plane Survey) data complemented by spectral line cubes. We present a sample of the nine most prominent Herschel filaments, including six identified from a pilot search field plus three from outside the field. These filaments measure 37-99 pc long and 0.6-3.0 pc wide with masses (0.5-8.3) × 104 M⊙, and beam-averaged (28 arcsec, or 0.4-0.7 pc) peak H2 column densities of (1.7-9.3)× 1022 cm- 2. The bulk of the filaments are relatively cold (17-21 K), while some local clumps have a dust temperature up to 25-47 K. All the filaments are located within ≲60 pc from the Galactic mid-plane. Comparing the filaments to a recent spiral arm model incorporating the latest parallax measurements, we find that 7/9 of them reside within arms, but most are close to arm edges. These filaments are comparable in length to the Galactic scaleheight and therefore are not simply part of a grander turbulent cascade.