WorldWideScience

Sample records for herschel infrared survey

  1. A Herschel/PACS Far-infrared Line Emission Survey of Local Luminous Infrared Galaxies

    Science.gov (United States)

    Díaz-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-Muñoz, L.; Linden, S. T.; Inami, H.; Larson, K. L.; Evans, A. S.; Appleton, P.; Iwasawa, K.; Lord, S.; Sanders, D. B.; Surace, J. A.

    2017-09-01

    We present an analysis of {[{{O}}{{I}}]}63, [O III]88, [N II]122, and {[{{C}}{{II}}]}158 far-infrared (FIR) fine-structure line observations obtained with Herschel/PACS, for ˜240 local luminous infrared galaxies (LIRGs) in the Great Observatories All-sky LIRG Survey. We find pronounced declines (“deficits”) of line-to-FIR continuum emission for [N II]122, {[{{O}}{{I}}]}63, and {[{{C}}{{II}}]}158 as a function of FIR color and infrared luminosity surface density, {{{Σ }}}{IR}. The median electron density of the ionized gas in LIRGs, based on the [N II]122/[N II]205 ratio, is {n}{{e}} = 41 cm-3. We find that the dispersion in the {[{{C}}{{II}}]}158 deficit of LIRGs is attributed to a varying fractional contribution of photodissociation regions (PDRs) to the observed {[{{C}}{{II}}]}158 emission, f([{{C}} {{II}}{]}158{PDR}) = [{{C}} {{II}}{]}158{PDR}/{[{{C}}{{II}}]}158, which increases from ˜60% to ˜95% in the warmest LIRGs. The {[{{O}}{{I}}]}63/[{{C}} {{II}}{]}158{PDR} ratio is tightly correlated with the PDR gas kinetic temperature in sources where {[{{O}}{{I}}]}63 is not optically thick or self-absorbed. For each galaxy, we derive the average PDR hydrogen density, {n}{{H}}, and intensity of the interstellar radiation field, G, in units of {G}0 and find G/{n}{{H}} ratios of ˜0.1-50 {G}0 cm3, with ULIRGs populating the upper end of the distribution. There is a relation between G/{n}{{H}} and {{{Σ }}}{IR}, showing a critical break at {{{Σ }}}{IR}* ≃ 5 × 1010 L ⊙ kpc-2. Below {{{Σ }}}{IR}* , G/{n}{{H}} remains constant, ≃0.32 {G}0 cm3, and variations in {{{Σ }}}{IR} are driven by the number density of star-forming regions within a galaxy, with no change in their PDR properties. Above {{{Σ }}}{IR}* , G/{n}{{H}} increases rapidly with {{{Σ }}}{IR}, signaling a departure from the typical PDR conditions found in normal star-forming galaxies toward more intense/harder radiation fields and compact geometries typical of starbursting sources.

  2. First Extended Catalogue of Galactic bubble infrared fluxes from WISE and Herschel surveys

    Science.gov (United States)

    Bufano, F.; Leto, P.; Carey, D.; Umana, G.; Buemi, C.; Ingallinera, A.; Bulpitt, A.; Cavallaro, F.; Riggi, S.; Trigilio, C.; Molinari, S.

    2018-01-01

    In this paper, we present the first extended catalogue of far-infrared fluxes of Galactic bubbles. Fluxes were estimated for 1814 bubbles, defined here as the 'golden sample', and were selected from the Milky Way Project First Data Release (Simpson et al.) The golden sample was comprised of bubbles identified within the Wide-field Infrared Survey Explorer (WISE) dataset (using 12- and 22-μm images) and Herschel data (using 70-, 160-, 250-, 350- and 500-μm wavelength images). Flux estimation was achieved initially via classical aperture photometry and then by an alternative image analysis algorithm that used active contours. The accuracy of the two methods was tested by comparing the estimated fluxes for a sample of bubbles, made up of 126 H II regions and 43 planetary nebulae, which were identified by Anderson et al. The results of this paper demonstrate that a good agreement between the two was found. This is by far the largest and most homogeneous catalogue of infrared fluxes measured for Galactic bubbles and it is a step towards the fully automated analysis of astronomical datasets.

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

    Science.gov (United States)

    Wampfler, S. F.; Bruderer, S.; Karska, A.; Herczeg, G. J.; van Dishoeck, E. F.; Kristensen, L. E.; Goicoechea, J. R.; Benz, A. O.; Doty, S. D.; McCoey, C.; Baudry, A.; Giannini, T.; Larsson, B.

    2013-04-01

    Context. The OH radical is a key species in the water chemistry network of star-forming regions, because its presence is tightly related to the formation and destruction of water. Previous studies of the OH far-infrared emission from low- and intermediate-mass protostars suggest that the OH emission mainly originates from shocked gas and not from the quiescent protostellar envelopes. Aims: We aim to study the excitation of OH in embedded low- and intermediate-mass protostars, determine the influence of source parameters on the strength of the emission, investigate the spatial extent of the OH emission, and further constrain its origin. Methods: This paper presents OH observations from 23 low- and intermediate-mass young stellar objects obtained with the PACS integral field spectrometer on-board Herschel in the context of the "Water In Star-forming regions with Herschel" (WISH) key program. Radiative transfer codes are used to model the OH excitation. Results: Most low-mass sources have compact OH emission (≲5000 AU scale), whereas the OH lines in most intermediate-mass sources are extended over the whole 47.″0 × 47.″0 PACS detector field-of-view (≳20 000 AU). The strength of the OH emission is correlated with various source properties such as the bolometric luminosity and the envelope mass, but also with the [OI] and H2O emission. Rotational diagrams for sources with many OH lines show that the level populations of OH can be approximated by a Boltzmann distribution with an excitation temperature at around 70 K. Radiative transfer models of spherically symmetric envelopes cannot reproduce the OH emission 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

  4. Understanding Local Luminous Infrared Galaxies in the Herschel Era

    Science.gov (United States)

    Chu, Jason; Sanders, David B.; Larson, Kirsten L.; Mazzarella, Joseph M.; Howell, Justin; Diaz Santos, Tanio; Xu, C. Kevin; Paladini, Roberta; Schulz, Bernhard; Shupe, David L.; Appleton, Philip N.; Armus, Lee; Billot, Nicolas; Pan Chan, Hiu; Evans, Aaron S.; Fadda, Dario; Frayer, David T.; Haan, Sebastian; Mie Ishida, Catherine; Iwasawa, Kazushi; Kim, Dong-Chan; Lord, Steven D.; Murphy, Eric J.; Petric, Andreea; Privon, George C.; Surace, Jason A.; Treister, Ezequiel; Great Observatories All-Sky LIRG Survey, Cosmic Evolution Survey

    2017-06-01

    Luminous and ultraluminous infrared galaxies [(U)LIRGs] are some of the most extreme objects in the universe with their elevated star formation rates and/or presence of a powerful AGN, playing a central role in the evolution of galaxies throughout cosmic history. The 201 local (U)LIRGs (zPACS and SPIRE far infrared image atlas of the entire GOALS sample (encompassing the 70-500 micron wavelength range), and demonstrate the excellent data quality. The Herschel GOALS images presented here are the highest resolution, most sensitive and comprehensive far-infrared imaging survey of the nearest (U)LIRGs to date. This allows us for the first time to directly probe the critical far infrared and submillimeter wavelength regime of these systems, enabling us to accurately determine the bolometric luminosities, infrared surface brightnesses, star formation rates, and dust masses and temperatures on spatial scales of 2-5 kpc. In addition, the superb resolution of Herschel means we can resolve many of the galaxy pairs and systems within the GOALS sample, allowing us to measure far infrared fluxes of component galaxies. Finally, using the Herschel photometry in conjunction with Spitzer, WISE, and IRAS data, I will show our first results on the global properties of (U)LIRGs such as their average 3-500 micron infrared SEDs and far infrared colors, and compare them to lower infrared luminosity objects. We will also compare and contrast their infrared SED shapes with previously published SED templates from the literature. If time permits, I will also show initial results from our rest-frame optical spectroscopy program on z~2.3 infrared selected galaxies in the COSMOS field.

  5. Infrared astronomy seeing the heat : from William Herschel to the Herschel space observatory

    CERN Document Server

    Clements, David L

    2014-01-01

    Uncover the Secrets of the Universe Hidden at Wavelengths beyond Our Optical GazeWilliam Herschel's discovery of infrared light in 1800 led to the development of astronomy at wavelengths other than the optical. Infrared Astronomy - Seeing the Heat: from William Herschel to the Herschel Space Observatory explores the work in astronomy that relies on observations in the infrared. Author David L. Clements, a distinguished academic and science fiction writer, delves into how the universe works, from the planets in our own Solar System to the universe as a whole. The book first presents the major t

  6. The new galaxy evolution paradigm revealed by the Herschel surveys

    Science.gov (United States)

    Eales, Stephen; Smith, Dan; Bourne, Nathan; Loveday, Jon; Rowlands, Kate; van der Werf, Paul; Driver, Simon; Dunne, Loretta; Dye, Simon; Furlanetto, Cristina; Ivison, R. J.; Maddox, Steve; Robotham, Aaron; Smith, Matthew W. L.; Taylor, Edward N.; Valiante, Elisabetta; Wright, Angus; Cigan, Philip; De Zotti, Gianfranco; Jarvis, Matt J.; Marchetti, Lucia; Michałowski, Michał J.; Phillipps, Steven; Viaene, Sebastien; Vlahakis, Catherine

    2018-01-01

    The Herschel Space Observatory has revealed a very different galaxyscape from that shown by optical surveys which presents a challenge for galaxy-evolution models. The Herschel surveys reveal (1) that there was rapid galaxy evolution in the very recent past and (2) that galaxies lie on a single Galaxy Sequence (GS) rather than a star-forming 'main sequence' and a separate region of 'passive' or 'red-and-dead' galaxies. The form of the GS is now clearer because far-infrared surveys such as the Herschel ATLAS pick up a population of optically red star-forming galaxies that would have been classified as passive using most optical criteria. The space-density of this population is at least as high as the traditional star-forming population. By stacking spectra of H-ATLAS galaxies over the redshift range 0.001 < z < 0.4, we show that the galaxies responsible for the rapid low-redshift evolution have high stellar masses, high star-formation rates but, even several billion years in the past, old stellar populations - they are thus likely to be relatively recent ancestors of early-type galaxies in the Universe today. The form of the GS is inconsistent with rapid quenching models and neither the analytic bathtub model nor the hydrodynamical EAGLE simulation can reproduce the rapid cosmic evolution. We propose a new gentler model of galaxy evolution that can explain the new Herschel results and other key properties of the galaxy population.

  7. The Herschel Debris And Jcmt Sons Surveys

    Science.gov (United States)

    Matthews, Brenda

    2016-07-01

    The Herschel DEBRIS survey has been a great success, revealing a wide variety of resolved disks, suggesting a correlation between bright debris disks and systems of low-mass planets, and enabling us to estimate the true incidence of debris disks, rather than just a detection rate. I will review the survey and some of its key results and then highlight key areas of inquiry for future surveys.

  8. The Herschel Multi-tiered Extragalactic Survey: HerMES

    Science.gov (United States)

    Oliver, S.J.; Bock, J.; Altieri, B.; Amblard, A.; Arumugam, V.; Aussel, H.; Babbedge, T.; Beelen, A.; Bethermin, M.; Blain, A.; hide

    2012-01-01

    The Herschel Multi-tiered Extragalactic Survey, HerMES, is a legacy program designed to map a set of nested fields totalling approx. 380 deg(exp 2). Fields range in size from 0.01 to approx. 20 deg (exp 2), using Herschel-SPIRE (at 250, 350 and 500 micron), and Herschel-PACS (at 100 and 160 micron), with an additional wider component of 270 deg. (exp. 2) with SPIRE alone. These bands cover the peak of the redshifted thermal spectral energy distribution from interstellar dust and thus capture the re-processed optical and ultra-violet radiation from star formation that has been absorbed by dust, and are critical for forming a complete multi-wavelength understanding of galaxy formation and evolution. The survey will detect of order 100,000 galaxies at 5-sigma in some of the best studied fields in the sky. Additionally, HerMES is closely coordinated with the PACS Evolutionary Probe survey. Making maximum use of the full spectrum of ancillary data, from radio to X-ray wavelengths, it is designed to: facilitate redshift determination; rapidly identify unusual objects; and understand the relationships between thermal emission from dust and other processes. Scientific questions HerMES will be used to answer include: the total infrared emission of galaxies; the evolution of the luminosity function; the clustering properties of dusty galaxies; and the properties of populations of galaxies which lie below the confusion limit through lensing and statistical techniques. This paper defines the survey observations and data products, outlines the primary scientific goals of the HerMES team, and reviews some of the early results.

  9. The Herschel ATLAS

    Science.gov (United States)

    Eales, S.; Dunne, L.; Clements, D.; Cooray, A.; De Zotti, G.; Dye, S.; Ivison, R.; Jarvis, M.; Lagache, G.; Maddox, S.; hide

    2010-01-01

    The Herschel ATLAS is the largest open-time key project that will be carried out on the Herschel Space Observatory. It will survey 570 sq deg of the extragalactic sky, 4 times larger than all the other Herschel extragalactic surveys combined, in five far-infrared and submillimeter bands. We describe the survey, the complementary multiwavelength data sets that will be combined with the Herschel data, and the six major science programs we are undertaking. Using new models based on a previous submillimeter survey of galaxies, we present predictions of the properties of the ATLAS sources in other wave bands.

  10. Herschel/PACS Survey of Protoplanetary Disks in Taurus/Auriga-Observations of [O I] and [C II], and Far-infrared Continuum

    NARCIS (Netherlands)

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

    2013-01-01

    The Herschel Space Observatory was used to observe similar to 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 mu m, [O I] 145 mu m, [C II

  11. Herschel Observations of Far-infrared Cooling Lines in Intermediate Redshift (Ultra)-luminous Infrared Galaxies

    Science.gov (United States)

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

    2014-01-01

    We report the first results from a spectroscopic survey of the [C II] 158 μm line from a sample of intermediate redshift (0.2 1011.5 L ⊙), using the Spectral and Photometric Imaging REceiver-Fourier Transform Spectrometer on board the Herschel Space Observatory. This is the first survey of [C II] emission, an important tracer of star formation, at a redshift range where the star formation rate density of the universe increases rapidly. We detect strong [C II] 158 μm line emission from over 80% of the sample. We find that the [C II] line is luminous, in the range (0.8-4) × 10-3 of the far-infrared continuum luminosity of our sources, and appears to arise from photodissociation regions on the surface of molecular clouds. The L [C II]/L IR ratio in our intermediate redshift (U)LIRGs is on average ~10 times larger than that of local ULIRGs. Furthermore, we find that the L [C II]/L IR and L [C II]/L CO(1-0) ratios in our sample are similar to those of local normal galaxies and high-z star-forming galaxies. ULIRGs at z ~ 0.5 show many similarities to the properties of local normal and high-z star-forming galaxies. Our findings strongly suggest that rapid evolution in the properties of the star-forming regions of (U)LIRGs is likely to have occurred in the last 5 billion years. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  12. A CO survey on a sample of Herschel cold clumps

    Science.gov (United States)

    Fehér, O.; Juvela, M.; Lunttila, T.; Montillaud, J.; Ristorcelli, I.; Zahorecz, S.; Tóth, L. V.

    2017-10-01

    Context. The physical state of cold cloud clumps has a great impact on the process and efficiency of star formation and the masses of the forming stars inside these objects. The sub-millimetre survey of the Planck space observatory and the far-infrared follow-up mapping of the Herschel space telescope provide an unbiased, large sample of these cold objects. Aims: We have observed 12CO(1-0) and 13CO(1-0) emission in 35 high-density clumps in 26 Herschel fields sampling different environments in the Galaxy. Here, we aim to derive the physical properties of the objects and estimate their gravitational stability. Methods: The densities and temperatures of the clumps were calculated from both the dust continuum and the molecular line data. Kinematic distances were derived using 13CO(1-0) line velocities to verify previous distance estimates and the sizes and masses of the objects were calculated by fitting 2D Gaussian functions to their optical depth distribution maps on 250 μm. The masses and virial masses were estimated assuming an upper and lower limit on the kinetic temperatures and considering uncertainties due to distance limitations. Results: The derived excitation temperatures are between 8.5-19.5 K, and for most clumps between 10-15 K, while the Herschel-derived dust colour temperatures are more uniform, between 12-16 K. The sizes (0.1-3 pc), 13CO column densities (0.5-44 × 1015 cm-2) and masses (from less than 0.1 M⊙ to more than 1500 M⊙) of the objects all span broad ranges. We provide new kinematic distance estimates, identify gravitationally bound or unbound structures and discuss their nature. Conclusions: The sample contains objects on a wide scale of temperatures, densities and sizes. Eleven gravitationally unbound clumps were found, many of them smaller than 0.3 pc, but large, parsec-scale clouds with a few hundred solar masses appear as well. Colder clumps have generally high column densities but warmer objects appear at both low and higher

  13. GASPS-A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

    OpenAIRE

    Dent, W. R. F.; Thi, W. F.; Kamp, I.; Williams, J.P.; Menard, F; S.; Andrews; Ardila, D.; Aresu, G.; Augereau, J. -C.; Barrado y Navascues, D; Brittain, S.; Carmona, A.; Ciardi, D.; Danchi, W.; Donaldson, J

    2013-01-01

    We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ~250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 μm, the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 μ...

  14. GASPS—A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

    OpenAIRE

    Dent, W. R. F.; Ardila, D.; Ciardi, D.

    2013-01-01

    We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ∼250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 μm the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 μm...

  15. GASPS—A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics : Summary and Initial Statistics

    NARCIS (Netherlands)

    Dent, W. R. F.; Thi, W. F.; Kamp, I.; Williams, J. P.; Menard, F.; Andrews, S.; Ardila, D.; Aresu, G.; Augereau, J. -C.; Barrado y Navascues, D.; Brittain, S.; Carmona, A.; Ciardi, D.; Danchi, W.; Donaldson, J.; Duchene, G.; Eiroa, C.; Fedele, D.; Grady, C.; de Gregorio-Molsalvo, I.; Howard, C.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mathews, G.; Meeus, G.; Mendigutia, I.; Montesinos, B.; Morales-Calderon, M.; Mora, A.; Nomura, H.; Pantin, E.; Pascucci, I.; Phillips, N.; Pinte, C.; Podio, L.; Ramsay, S. K.; Riaz, B.; Riviere-Marichalar, P.; Roberge, A.; Sandell, G.; Solano, E.; Tilling, I.; Torrelles, J. M.; Vandenbusche, B.; Vicente, S.; White, G. J.; Woitke, P.

    We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ~250 young

  16. Initial Highlights from the Herschel Gould Belt Survey

    Science.gov (United States)

    André, Philippe; Men'shchikov, Alexander

    The Herschel Space Observatory provides a unique opportunity to improve our global un-derstanding of the earliest phases of star formation. I will present an overview of the first results from the Gould Belt survey (cf. http://gouldbelt-herschel.cea.fr/), one of the largest key projects with Herschel. The immediate objective of this SPIRE/PACS imaging survey is to obtain complete samples of nearby prestellar cores and Class 0 protostars with well char-acterized luminosities, temperatures, and density profiles, as well as robust core mass func-tions and protostar luminosity functions, in a variety of star-forming environments. Thanks to its high sensitivity and large spatial dynamic range, this survey can also probe, for the first time, the link between diffuse cirrus-like structures and compact self-gravitating cores. The main scientific goal is to elucidate the physical mechanisms responsible for the formation of prestellar cores out of the diffuse interstellar medium, crucial for understanding the origin of the stellar initial mass function. The first results, obtained toward the Aquila Rift and Polaris Flare regions during the 'Science Demonstration Phase' (SDP), are very promising (cf. http://herschel.esac.esa.int/SDPw kshops/presentations/IR/25A ndreG ouldBeltS DP 2009.pdf ).Basedonth

  17. Herschel/PACS Survey of Protoplanetary Disks in Taurus/Auriga—Observations of [O I] and [C II], and Far-infrared Continuum

    Science.gov (United States)

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

    2013-10-01

    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, H2O, 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.

  18. Herschel - PACS Survey Of Protoplanetary Disks In Taurus - Auriga Observations Of [O I] And [C Ii], And Far-Infrared Continuum

    Science.gov (United States)

    Howard, Christian; Sandell, Goeran; Vacca, William D.; Duchene, Gaspard; Matthews, Geoffrey; Augereau, Jean-Charles; Barbado, David; Dent, William R. F.; Eiroa, Carlos; Grady, Carol; hide

    2013-01-01

    The Herschel Space Observatory was used to observe approx. 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 micron, [O I] 145 micron, [C II] 158, micron OH, H2O, and CO. The strongest line seen is [O I] at 63 micron. We find a clear correlation between the strength of the [O I] 63 micron line and the 63 micron 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 micron 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 micron emission is only detected in strong outflow sources. The observed line ratios of [O I] 63 micron to [O I] 145 micron 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 micron and only three in continuum, at least one of which is a candidate debris disk.

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

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Christian D.; Sandell, Göran; Vacca, William D. [SOFIA-USRA, NASA Ames Research Center, MS 232-12, Building N232, Rm. 146, P.O. Box 1, Moffett Field, CA 94035-0001 (United States); Duchêne, Gaspard [Astronomy Department, University of California, Berkeley, CA 94720-3411 (United States); Mathews, Geoffrey [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Augereau, Jean-Charles; Ménard, Francois; Pinte, Christophe; Podio, Linda; Thi, Wing-Fai [UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d' Astrophysique (IPAG) UMR 5274, F-38041 Grenoble (France); Barrado, David; Riviere-Marichalar, Pablo [Centro de Astrobiología, Depto. Astrofísica (CSIC/INTA), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Dent, William R. F. [ALMA SCO, Alonso de Córdova 3107, Vitacura, Santiago (Chile); Eiroa, Carlos; Meeus, Gwendolyn [Dep. de Física Teórica, Fac. de Ciencias, UAM Campus Cantoblanco, E-28049 Madrid (Spain); Grady, Carol; Roberge, Aki [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Kamp, Inga; Vicente, Silvia [Kapteyn Astronomical Institute, Postbus 800, 9700 AV Groningen (Netherlands); Williams, Jonathan P. [Institute for Astronomy (IfA), University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2013-10-10

    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{sub 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.

  20. Analysis of the Herschel/Hexos Spectral Survey Toward Orion South: A Massive Protostellar Envelope with Strong External Irradiation

    NARCIS (Netherlands)

    Tahani, K.; Plume, R.; Bergin, E. A.; Tolls, V.; Phillips, T. G.; Caux, E.; Cabrit, S.; Goicoechea, J. R.; Goldsmith, P. F.; Johnstone, D.; Lis, D. C.; Pagani, L.; Menten, K. M.; Müller, H. S. P.; Ossenkopf-Okada, V.; Pearson, J. C.; van der Tak, F. F. S.

    2016-01-01

    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

  1. HERschel key program heritage: A far-infrared source catalog for the Magellanic Clouds

    Energy Technology Data Exchange (ETDEWEB)

    Seale, Jonathan P.; Meixner, Margaret; Sewiło, Marta [The Johns Hopkins University, Department of Physics and Astronomy, 366 Bloomberg Center, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Babler, Brian [Department of Astronomy, 475 North Charter St., University of Wisconsin, Madison, WI 53706 (United States); Engelbracht, Charles W.; Misselt, Karl; Montiel, Edward [Steward Observatory, University of Arizona, 933 North Cherry Ave., Tucson, AZ 85721 (United States); Gordon, Karl; Roman-Duval, Julia [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Hony, Sacha; Okumura, Koryo; Panuzzo, Pasquale; Sauvage, Marc [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Boyer, Martha L. [Observational Cosmology Laboratory, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Chen, C.-H. Rosie [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Indebetouw, Remy [National Radio Astronomy Observatory, 520 Edgemont Road Charlottesville, VA 22903 (United States); Matsuura, Mikako [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Oliveira, Joana M.; Loon, Jacco Th. van [School of Physical and Geographical Sciences, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom); Srinivasan, Sundar [UPMC-CNRS UMR7095, Institute d' Astrophysique de Paris, F-75014 Paris (France); and others

    2014-12-01

    Observations from the HERschel Inventory of the Agents of Galaxy Evolution (HERITAGE) have been used to identify dusty populations of sources in the Large and Small Magellanic Clouds (LMC and SMC). We conducted the study using the HERITAGE catalogs of point sources available from the Herschel Science Center from both the Photodetector Array Camera and Spectrometer (PACS; 100 and 160 μm) and Spectral and Photometric Imaging Receiver (SPIRE; 250, 350, and 500 μm) cameras. These catalogs are matched to each other to create a Herschel band-merged catalog and then further matched to archival Spitzer IRAC and MIPS catalogs from the Spitzer Surveying the Agents of Galaxy Evolution (SAGE) and SAGE-SMC surveys to create single mid- to far-infrared (far-IR) point source catalogs that span the wavelength range from 3.6 to 500 μm. There are 35,322 unique sources in the LMC and 7503 in the SMC. To be bright in the FIR, a source must be very dusty, and so the sources in the HERITAGE catalogs represent the dustiest populations of sources. The brightest HERITAGE sources are dominated by young stellar objects (YSOs), and the dimmest by background galaxies. We identify the sources most likely to be background galaxies by first considering their morphology (distant galaxies are point-like at the resolution of Herschel) and then comparing the flux distribution to that of the Herschel Astrophysical Terahertz Large Area Survey (ATLAS) survey of galaxies. We find a total of 9745 background galaxy candidates in the LMC HERITAGE images and 5111 in the SMC images, in agreement with the number predicted by extrapolating from the ATLAS flux distribution. The majority of the Magellanic Cloud-residing sources are either very young, embedded forming stars or dusty clumps of the interstellar medium. Using the presence of 24 μm emission as a tracer of star formation, we identify 3518 YSO candidates in the LMC and 663 in the SMC. There are far fewer far-IR bright YSOs in the SMC than the LMC

  2. The Great Observatories All-Sky LIRG Survey: Herschel Image Atlas and Aperture Photometry

    Science.gov (United States)

    Chu, Jason K.; Sanders, D. B.; Larson, K. L.; Mazzarella, J. M.; Howell, J. H.; Díaz-Santos, T.; Xu, K. C.; Paladini, R.; Schulz, B.; Shupe, D.; Appleton, P.; Armus, L.; Billot, N.; Chan, B. H. P.; Evans, A. S.; Fadda, D.; Frayer, D. T.; Haan, S.; Ishida, C. M.; Iwasawa, K.; Kim, D.-C.; Lord, S.; Murphy, E.; Petric, A.; Privon, G. C.; Surace, J. A.; Treister, E.

    2017-04-01

    Far-infrared images and photometry are presented for 201 Luminous and Ultraluminous Infrared Galaxies [LIRGs: log ({L}{IR}/{L}⊙ )=11.00{--}11.99, ULIRGs: log ({L}{IR}/{L}⊙ )=12.00{--}12.99], in the Great Observatories All-Sky LIRG Survey (GOALS), based on observations with the Herschel Space Observatory Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE) instruments. The image atlas displays each GOALS target in the three PACS bands (70, 100, and 160 μm) and the three SPIRE bands (250, 350, and 500 μm), optimized to reveal structures at both high and low surface brightness levels, with images scaled to simplify comparison of structures in the same physical areas of ˜100 × 100 kpc2. Flux densities of companion galaxies in merging systems are provided where possible, depending on their angular separation and the spatial resolution in each passband, along with integrated system fluxes (sum of components). This data set constitutes the imaging and photometric component of the GOALS Herschel OT1 observing program, and is complementary to atlases presented for the Hubble Space Telescope, Spitzer Space Telescope, and Chandra X-ray Observatory. Collectively, these data will enable a wide range of detailed studies of active galactic nucleus and starburst activity within the most luminous infrared galaxies in the local universe. Based on Herschel Space Observatory observations. Herschel is an ESA space observatory with science instruments provided by the European-led Principal Investigator consortia, and important participation from NASA.

  3. Recent Results from the Herschel Orion Protostar Survey

    Science.gov (United States)

    Fischer, William J.; Megeath, T.; Ali, B.; Watson, D.; Manoj, P.; Vavrek, R.; Poteet, C.; Tobin, J.; Stanke, T.; Stutz, A.; HOPS Team

    2011-05-01

    The Herschel Orion Protostar Survey (HOPS) is an ongoing 200-hour open-time key project with the Herschel Space Observatory to study protostars in the Orion molecular cloud complex. HOPS is obtaining PACS 70 and 160 micron imaging of 286 Orion protostars and PACS spectroscopy of a subset of 36, sampling the expected peaks of their spectral energy distributions (SEDs). The Herschel data are complemented by Spitzer 3-24 micron photometry and 5-40 micron spectroscopy, high angular resolution near-IR imaging with Hubble and ground-based telescopes, and millimeter observations of the surrounding gas. With these combined data we can determine the fundamental properties (multiplicity, gas infall rate, bolometric luminosity, outflow cavity geometry) of a large sample of protostars in a single cloud complex. With far-IR imaging and 1.6-160 micron SEDs for 171 protostars and 55-200 micron spectroscopy for 10 protostars expected to be in hand by mid-March 2011, we will present a selection of recent results.

  4. The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI)

    NARCIS (Netherlands)

    Graauw, T. de; Helmich, F.P.; Phillips, T.G.; Stutzki, J.; Caux, E.; Whyborn, N.D.; Dieleman, P.; Roelfsema, P.R.; Aarts, H.; Assendorp, R.; Bachiller, R.; Baechtold, W.; Barcia, A.; Beintema, D.A.; Belitsky, V.; Benz, A.O.; Bieber, R.; Boogert, A.; Borys, C.; Bumble, B.; Caïs, P.; Caris, M.; Cerulli-Irelli, P.; Chattopadhyay, G.; Cherednichenko, S.; Ciechanowicz, M.; Coeur-Joly, O.; Comito, C.; Cros, A.; Jonge, A. de; Lange, G. de; Delforges, B.; Delorme, Y.; Boggende, T. den; Desbat, J.M.; Diez-González, C.; Di Giorgio, A.M.; Dubbeldam, L.; Edwards, K.; Eggens, M.; Erickson, N.; Evers, J.; Fich, M.; Finn, T.; Franke, B.; Gaier, T.; Gal, C.; Gao, J.R.; Gallego, J.D.; Gauffre, S.; Gill, J.J.; Glenz, S.; Golstein, H.; Goulooze, H.; Gunsing, T.; Güsten, R.; Hartogh, P.; Hatch, W.A.; Higgins, R.; Honingh, E.C.; Huisman, R.; Jackson, B.D.; Jacobs, H.; Jacobs, K.; Jarchow, C.; Javadi, H.; Jellema, W.; Justen, M.; Karpov, A.; Kasemann, C.; Kawamura, J.; Keizer, G.; Kester, D.; Klapwijk, T.M.; Klein, T.; Kollberg, E.; Kooi, J.; Kooiman, P.P.; Kopf, B.; Krause, M.; Krieg, J.M.; Kramer, C.; Kruizenga, B.; Kuhn, T.; Laauwen, W.; Lai, R.; Larsson, B.; Leduc, H.G.; Leinz, C.; Lin, R.H.; Liseau, R.; Liu, G.S.; Loose, A.; López-Fernandez, I.; Lord, S.; Luinge, W.; Marston, A.; Martín-Pintado, J.; Maestrini, A.; Maiwald, F.W.; McCoey, C.; Mehdi, I.; Megej, A.; Melchior, M.; Meinsma, L.; Merkel, H.; Michalska, M.; Monstein, C.; Moratschke, D.; Morris, P.; Muller, H.; Murphy, J.A.; Naber, A.; Natale, E.; Nowosielski, W.; Nuzzolo, F.; Olberg, M.; Olbrich, M.; Orfei, R.; Orleanski, P.; Ossenkopf, V.; Peacock, T.; Pearson, J.C.; Peron, I.; Phillip-May, S.; Piazzo, L.; Planesas, P.; Rataj, M.; Ravera, L.; Risacher, C.; Salez, M.; Samoska, L.A.; Saraceno, P.; Schieder, R.; Schlecht, E.; Schlöder, F.; Schmülling, F.; Schultz, M.; Schuster, K.; Siebertz, O.; Smit, H.; Szczerba, R.; Shipman, R.; Steinmetz, E.; Stern, J.A.; Stokroos, M.; Teipen, R.; Teyssier, D.; Tils, T.; Trappe, N.; Baaren, C. van; Leeuwen, B.J. van; Stadt, H. van de; Visser, H.; Wildeman, K.J.; Wafelbakker, C.K.; Ward, J.S.; Wesselius, P.; Wild, W.; Wulff, S.; Wunsch, H.J.; Tielens, X.; Zaal, P.; Zirath, H.; Zmuidzinas, J.; Zwart, F.

    2010-01-01

    Aims. This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) that was launched onboard ESA's Herschel Space Observatory in May 2009. Methods. The instrument is a set of 7 heterodyne receivers that are electronically tuneable, covering 480-1250 GHz with SIS mixers and the

  5. The Formation of Massive Stars: from Herschel to Near-Infrared

    Directory of Open Access Journals (Sweden)

    Paolo Persi

    2014-12-01

    Full Text Available We have studied a number of selected high mass star forming regions, including high resolution near-infrared broad- and narrow-band imaging, Herschel (70, 160, 250, 350 and 500 μm and Spitzer (3.6, 4.5, 5.8 and 8.0 m images. The preliminary results of one of this region, IRAS 19388+2357(MOL110 are discussed. In this region a dense core has been detected in the far-infrared, and a young stellar cluster has been found around this core. Combining near-IR data with Spitzer and Herschel photometry we have derived the spectral energy distribution of Mol110. Finally comparing our H2 and Kc narrow-band images, we have found an H2 jet in this region.

  6. The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution

    Science.gov (United States)

    Fischer, William J.; Megeath, S. Thomas; Furlan, Elise; Ali, Babar; Stutz, Amelia M.; Tobin, John J.; Osorio, Mayra; Stanke, Thomas; Manoj, P.; Poteet, Charles A.; Booker, Joseph J.; Hartmann, Lee; Wilson, Thomas L.; Myers, Philip C.; Watson, Dan M.

    2017-05-01

    The Herschel Orion Protostar Survey obtained well-sampled 1.2-870 μm spectral energy distributions (SEDs) of over 300 protostars in the Orion molecular clouds, home to most of the young stellar objects (YSOs) in the nearest 500 pc. We plot the bolometric luminosities and temperatures for 330 Orion YSOs, 315 of which have bolometric temperatures characteristic of protostars. The histogram of the bolometric temperature is roughly flat; 29% of the protostars are in Class 0. The median luminosity decreases by a factor of four with increasing bolometric temperature; consequently, the Class 0 protostars are systematically brighter than the Class I protostars, with a median luminosity of 2.3 L⊙ as opposed to 0.87 L⊙. At a given bolometric temperature, the scatter in luminosities is three orders of magnitude. Using fits to the SEDs, we analyze how the luminosities corrected for inclination and foreground reddening relate to the mass in the inner 2500 au of the best-fit model envelopes. The histogram of the envelope mass is roughly flat, while the median-corrected luminosity peaks at 15 L⊙ for young envelopes and falls to 1.7 L⊙ for late-stage protostars with remnant envelopes. The spread in luminosity at each envelope mass is three orders of magnitude. Envelope masses that decline exponentially with time explain the flat mass histogram and the decrease in luminosity, while the formation of a range of stellar masses explains the dispersion in luminosity.

  7. The Herschel Orion Protostar Survey: Spectral Energy Distributions and Fits Using a Grid of Protostellar Models

    Science.gov (United States)

    Furlan, E.; Fischer, W. J.; Ali, B.; Stutz, A. M.; Stanke, T.; Tobin, J. J.; Megeath, S. T.; Osorio, M.; Hartmann, L.; Calvet, N.; Poteet, C. A.; Booker, J.; Manoj, P.; Watson, D. M.; Allen, L.

    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 μm and sample the peak of the protostellar envelope emission at ˜100 μm. 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.

  8. 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.

  9. 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.

  10. Infrared-faint radio sources remain undetected at far-infrared wavelengths. Deep photometric observations using the Herschel Space Observatory

    Science.gov (United States)

    Herzog, A.; Norris, R. P.; Middelberg, E.; Spitler, L. R.; Leipski, C.; Parker, Q. A.

    2015-08-01

    Context. Showing 1.4 GHz flux densities in the range of a few to a few tens of mJy, infrared-faint radio sources (IFRS) are a type of galaxy characterised by faint or absent near-infrared counterparts and consequently extreme radio-to-infrared flux density ratios up to several thousand. Recent studies showed that IFRS are radio-loud active galactic nuclei (AGNs) at redshifts ≳2, potentially linked to high-redshift radio galaxies (HzRGs). Aims: This work explores the far-infrared emission of IFRS, providing crucial information on the star forming and AGN activity of IFRS. Furthermore, the data enable examining the putative relationship between IFRS and HzRGs and testing whether IFRS are more distant or fainter siblings of these massive galaxies. Methods: A sample of six IFRS was observed with the Herschel Space Observatory between 100 μm and 500 μm. Using these results, we constrained the nature of IFRS by modelling their broad-band spectral energy distribution (SED). Furthermore, we set an upper limit on their infrared SED and decomposed their emission into contributions from an AGN and from star forming activity. Results: All six observed IFRS were undetected in all five Herschel far-infrared channels (stacking limits: σ = 0.74 mJy at 100 μm, σ = 3.45 mJy at 500 μm). Based on our SED modelling, we ruled out the following objects to explain the photometric characteristics of IFRS: (a) known radio-loud quasars and compact steep-spectrum sources at any redshift; (b) starburst galaxies with and without an AGN and Seyfert galaxies at any redshift, even if the templates were modified; and (c) known HzRGs at z ≲ 10.5. We find that the IFRS analysed in this work can only be explained by objects that fulfil the selection criteria of HzRGs. More precisely, IFRS could be (a) known HzRGs at very high redshifts (z ≳ 10.5); (b) low-luminosity siblings of HzRGs with additional dust obscuration at lower redshifts; (c) scaled or unscaled versions of Cygnus A at any

  11. Cryogenic far-infrared laser absorptivity measurements of the Herschel Space Observatory telescope mirror coatings.

    Science.gov (United States)

    Fischer, Jacqueline; Klaassen, Tjeerd; Hovenier, Niels; Jakob, Gerd; Poglitsch, Albrecht; Sternberg, Oren

    2004-07-01

    Far-infrared laser calorimetry was used to measure the absorptivity, and thus the emissivity, of aluminum-coated silicon carbide mirror samples produced during the coating qualification run of the Herschel Space Observatory telescope to be launched by the European Space Agency in 2007. The samples were measured at 77 K to simulate the operating temperature of the telescope in its planned orbit about the second Lagrangian point, L2, of the Earth-Sun system. Together, the telescope's equilibrium temperature in space and the emissivity of the mirror surfaces will determine the far-infrared-submillimeter background and thus the sensitivity of two of the three astronomical instruments aboard the observatory if stray-light levels can be kept low relative to the mirror emission. Absorptivities of both clean and dust-contaminated samples were measured at 70, 118, 184, and 496 microm. Theoretical fits to the data predict absorptivities of 0.2-0.4% for the clean sample and 0.2-0.8% for the dusty sample, over the spectral range of the Herschel Space Observatory instruments.

  12. MODELING THE HD 32297 DEBRIS DISK WITH FAR-INFRARED HERSCHEL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, J. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Lebreton, J.; Augereau, J.-C. [UJF - Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Roberge, A. [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Krivov, A. V., E-mail: jessd@astro.umd.edu [Astrophysikalishes Institut, Friedrich-Schiller-Universitaet Jena, Schillergaesschen 2-3, D-07745 Jena (Germany)

    2013-07-20

    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 {mu}m. 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 {mu}m 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 {mu}m with the Herschel PACS instrument, making HD 32297 one of only a handful of debris disks with circumstellar gas detected.

  13. VizieR Online Data Catalog: The Herschel Orion Protostar Survey (HOPS): SEDs (Furlan+, 2016)

    Science.gov (United States)

    Furlan, E.; Fischer, W. J.; Ali, B.; Stutz, A. M.; Stanke, T.; Tobin, J. J.; Megeath, S. T.; Osorio, M.; Hartmann, L.; Calvet, N.; Poteet, C. A.; Booker, J.; Manoj, P.; Watson, D. M.; Allen, L.

    2016-06-01

    To summarize, starting from a sample of 410 Herschel Orion Protostar Survey (HOPS) targets (see section 2), but excluding likely contaminants and objects not observed or detected by PACS, there are 330 remaining objects that have Spitzer and Herschel data and are considered protostars (based on their Spitzer classification from Megeath et al. 2012, J/AJ/144/192). They form the sample studied in this work. In order to construct SEDs for our sample of 330 YSOs, we combined our own Herschel/PACS observations (see Proposal KPOTtmegeath2) with data from the literature and existing catalogs (see section 3.1). To extend the SEDs into the submillimeter, most of the YSOs were also observed in the continuum at 350 and 870um with the Atacama Pathfinder Experiment (APEX) telescope (Stutz et al. 2013, J/ApJ/767/36). (5 data files).

  14. De-blending deep Herschel surveys: A multi-wavelength approach

    Science.gov (United States)

    Pearson, W. J.; Wang, L.; van der Tak, F. F. S.; Hurley, P. D.; Burgarella, D.; Oliver, S. J.

    2017-07-01

    Aims: Cosmological surveys in the far-infrared are known to suffer from confusion. The Bayesian de-blending tool, XID+, currently provides one of the best ways to de-confuse deep Herschel SPIRE images, using a flat flux density prior. This work is to demonstrate that existing multi-wavelength data sets can be exploited to improve XID+ by providing an informed prior, resulting in more accurate and precise extracted flux densities. Methods: Photometric data for galaxies in the COSMOS field were used to constrain spectral energy distributions (SEDs) using the fitting tool CIGALE. These SEDs were used to create Gaussian prior estimates in the SPIRE bands for XID+. The multi-wavelength photometry and the extracted SPIRE flux densities were run through CIGALE again to allow us to compare the performance of the two priors. Inferred ALMA flux densities (FinferALMA), at 870 μm and 1250 μm, from the best fitting SEDs from the second CIGALE run were compared with measured ALMA flux densities (FmeasALMA) as an independent performance validation. Similar validations were conducted with the SED modelling and fitting tool MAGPHYS and modified black-body functions to test for model dependency. Results: We demonstrate a clear improvement in agreement between the flux densities extracted with XID+ and existing data at other wavelengths when using the new informed Gaussian prior over the original uninformed prior. The residuals between FmeasALMA and FinferALMA were calculated. For the Gaussian priors these residuals, expressed as a multiple of the ALMA error (σ), have a smaller standard deviation, 7.95σ for the Gaussian prior compared to 12.21σ for the flat prior; reduced mean, 1.83σ compared to 3.44σ; and have reduced skew to positive values, 7.97 compared to 11.50. These results were determined to not be significantly model dependent. This results in statistically more reliable SPIRE flux densities and hence statistically more reliable infrared luminosity estimates. Herschel

  15. VizieR Online Data Catalog: Herschel Multi-tiered Extragalactic Survey (Oliver+, 2012)

    Science.gov (United States)

    Oliver, S. J.; Bock, J.; Altieri, B.; Amblard, A.; Arumugam, V.; Aussel, H.; Babbedge, T.; Beelen, A.; Bethermin, M.; Blain, A.; Boselli, A.; Bridge, C.; Brisbin, D.; Buat, V.; Burgarella, D.; Castro-Rodriguez, N.; Cava, A.; Chanial, P.; Cirasuolo, M.; Clements, D. L.; Conley, A.; Conversi, L.; Cooray, A.; Dowell, C. D.; Dubois, E. N.; Dwek, E.; Dye, S.; Eales, S.; Elbaz, D.; Farrah, D.; Feltre, A.; Ferrero, P.; Fiolet, N.; Fox, M.; Franceschini, A.; Gear, W.; Giovannoli, E.; Glenn, J.; Gong, Y.; Gonzalez Solares, E. A.; Griffin, M.; Halpern, M.; Harwit, M.; Hatziminaoglou, E.; Heinis, S.; Hurley, P.; Hwang, H. S.; Hyde, A.; Ibar, E.; Ilbert, O.; Isaak, K.; Ivison, R. J.; Lagache, G.; Le Floc'h, E.; Levenson, L.; Faro, B. L.; Lu, N.; Madden, S.; Maffei, B.; Magdis, G.; Mainetti, G.; Marchetti, L.; Marsden, G.; Marshall, J.; Mortier, A. M. J.; Nguyen, H. T.; O'Halloran, B.; Omont, A.; Page, M. J.; Panuzzo, P.; Papageorgiou, A.; Patel, H.; Pearson, C. P.; Perez-Fournon, I.; Pohlen, M.; Rawlings, J. I.; Raymond, G.; Rigopoulou, D.; Riguccini, L.; Rizzo, D.; Rodighier!, O. G.; Ros Eboom, I. G.; Rowan-Robinson, M.; Sanchez Portal, M.; Schulz, B.; Scott, D.; Seymour, N.; Shupe, D. L.; Smith, A. J.; Stevens, J. A.; Symeonidis, M.; Trichas, M.; Tugwell, K. E.; Vaccari, M.; Valtchanov, I.; Vieira, J. D.; Viero, M.; Vigroux, L.; Wang, L.; Ward, R.; Wardlow, J.; Wright, G.; Xu, C. K.; Zemcov, M.

    2017-03-01

    SPIRE maps (250, 350 and 500 microns) and PACS maps (100 and 160 microns) covering an area of more than 385 square degrees in the sky resulting from observations taken as part of HerMES (KPGTsoliver1), a Herschel Key Project whose main objective was to chart the formation and evolution of infrared galaxies throughout cosmic history, measuring the bolometric emission of infrared galaxies and their clustering properties. The associated catalogues extracted from these maps include over 1,200,000 entries representing over 340,000 galaxies. They consist of 'blind extraction' catalogues containing photometric information derived directly from these maps, 'band merged' catalogues extracted at SPIRE 250 micron positions plus 'cross-identification' catalogues based on prior Spitzer MIPS 24 micron source positions. The latest data releases contain also information derived from the complementary Herschel programmes HeLMS (GT2mviero1) and HeRS (OT2mviero2). (4 data files).

  16. The Herschel Planetary Nebula Survey (HerPlaNS). I. Data overview and analysis demonstration with NGC 6781

    NARCIS (Netherlands)

    Ueta, T.; Ladjal, D.; Exter, K.M.; Otsuka, M.; Szczerba, R.; Siódmiak, N.; Guerra, Aleman I.R.; van, Hoof P. A. M.; Kastner, J.H.; Montez, R.; McDonald, I.; Wittkowski, M.; Sandin, C.; Ramstedt, S.; De, Marco O.; Villaver, E.; Chu, Y.-H.; Vlemmings, W.; Izumiura, H.; Sahai, R.; Lopez, J.A.; Balick, B.; Zijlstra, A.; Tielens, A.G.G.M.; Rattray, R. E.; Behar, E.; Blackman, E. G.; Hebden, K.; Hora, J. L.; Murakawa, K.; Nordhaus, J.; Nordon, R.; Yamamura, I.

    2014-01-01

    Context. This is the first of a series of investigations into far-IR characteristics of 11 planetary nebulae (PNe) under the Herschel Space Observatory open time 1 program, Herschel Planetary Nebula Survey (HerPlaNS).Aims: Using the HerPlaNS data set, we look into the PN energetics and variations of

  17. The JCMT and Herschel Gould Belt Surveys: a comparison of SCUBA-2 and Herschel data of dense cores in the Taurus dark cloud L1495

    Science.gov (United States)

    Ward-Thompson, D.; Pattle, K.; Kirk, J. M.; Marsh, K.; Buckle, J.; Hatchell, J.; Nutter, D. J.; Griffin, M. J.; Di Francesco, J.; André, P.; Beaulieu, S.; Berry, D.; Broekhoven-Fiene, H.; Currie, M.; Fich, M.; Jenness, T.; Johnstone, D.; Kirk, H.; Mottram, J.; Pineda, J.; Quinn, C.; Sadavoy, S.; Salji, C.; Tisi, S.; Walker-Smith, S.; White, G.; Hill, T.; Könyves, V.; Palmeirim, P.; Pezzuto, S.

    2016-11-01

    We present a comparison of Submillimetre Common User Bolometer Array-2 (SCUBA-2) 850-μm and Herschel 70-500-μm observations of the L1495 filament in the Taurus Molecular Cloud with the goal of characterizing the SCUBA-2 Gould Belt Survey (GBS) data set. We identify and characterize starless cores in three data sets: SCUBA-2 850-μm, Herschel 250-μm, and Herschel 250-μm spatially filtered to mimic the SCUBA-2 data. SCUBA-2 detects only the highest-surface-brightness sources, principally detecting protostellar sources and starless cores embedded in filaments, while Herschel is sensitive to most of the cloud structure, including extended low-surface-brightness emission. Herschel detects considerably more sources than SCUBA-2 even after spatial filtering. We investigate which properties of a starless core detected by Herschel determine its detectability by SCUBA-2, and find that they are the core's temperature and column density (for given dust properties). For similar-temperature cores, such as those seen in L1495, the surface brightnesses of the cores are determined by their column densities, with the highest-column-density cores being detected by SCUBA-2. For roughly spherical geometries, column density corresponds to volume density, and so SCUBA-2 selects the densest cores from a population at a given temperature. This selection effect, which we quantify as a function of distance, makes SCUBA-2 ideal for identifying those cores in Herschel catalogues that are closest to forming stars. Our results can now be used by anyone wishing to use the SCUBA-2 GBS data set.

  18. FAR-INFRARED LINE SPECTRA OF SEYFERT GALAXIES FROM THE HERSCHEL-PACS SPECTROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Spinoglio, Luigi; Pereira-Santaella, Miguel; Busquet, Gemma [Istituto di Astrofisica e Planetologia Spaziali, INAF, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Dasyra, Kalliopi M. [Observatoire de Paris, LERMA (CNRS:UMR8112), 61 Av. de l' Observatoire, F-75014, Paris (France); Calzoletti, Luca [Agenzia Spaziale Italiana (ASI) Science Data Center, I-00044 Frascati (Roma) (Italy); Malkan, Matthew A. [Astronomy Division, University of California, Los Angeles, CA 90095-1547 (United States); Tommasin, Silvia, E-mail: luigi.spinoglio@iaps.inaf.it [Weizmann Institute of Science, Department of Neurobiology, Rehovot 76100 (Israel)

    2015-01-20

    We observed the far-IR fine-structure lines of 26 Seyfert galaxies with the Herschel-PACS spectrometer. These observations are complemented with Spitzer Infrared Spectrograph and Herschel SPIRE spectroscopy. We used the ionic lines to determine electron densities in the ionized gas and the [C I] lines, observed with SPIRE, to measure the neutral gas densities, while the [O I] lines measure the gas temperature, at densities below ∼10{sup 4} cm{sup –3}. Using the [O I]145 μm/63 μm and [S III]33/18 μm line ratios, we find an anti-correlation of the temperature with the gas density. Various fine-structure line ratios show density stratifications in these active galaxies. On average, electron densities increase with the ionization potential of the ions. The infrared lines arise partly in the narrow line region, photoionized by the active galactic nucleus (AGN), partly in H II regions photoionized by hot stars, and partly in photo-dissociated regions. We attempt to separate the contributions to the line emission produced in these different regions by comparing our observed emission line ratios to theoretical values. In particular, we tried to separate the contribution of AGNs and star formation by using a combination of Spitzer and Herschel lines, and we found that besides the well-known mid-IR line ratios, the line ratio of [O III]88 μm/[O IV]26 μm can reliably discriminate the two emission regions, while the far-IR line ratio of [C II]157 μm/[O I]63 μm is only able to mildly separate the two regimes. By comparing the observed [C II]157 μm/[N II]205 μm ratio with photoionization models, we also found that most of the [C II] emission in the galaxies we examined is due to photodissociation regions.

  19. Far-infrared spectroscopy of a lensed starburst: a blind redshift from Herschel

    Science.gov (United States)

    George, R. D.; Ivison, R. J.; Hopwood, R.; Riechers, D. A.; Bussmann, R. S.; Cox, P.; Dye, S.; Krips, M.; Negrello, M.; Neri, R.; Serjeant, S.; Valtchanov, I.; Baes, M.; Bourne, N.; Clements, D. L.; De Zotti, G.; Dunne, L.; Eales, S. A.; Ibar, E.; Maddox, S.; Smith, M. W. L.; Valiante, E.; van der Werf, P.

    2013-11-01

    We report the redshift of HATLAS J132427.0+284452 (hereafter HATLAS J132427), a gravitationally lensed starburst galaxy, the first determined `blind' by the Herschel Space Observatory. This is achieved via the detection of [C II] consistent with z = 1.68 in a far-infrared spectrum taken with the SPIRE Fourier Transform Spectrometer (FTS). We demonstrate that the [C II] redshift is secure via detections of CO J = 2 → 1 and 3 → 2 using the Combined Array for Research in Millimeter-wave Astronomy and the Institut de Radioastronomie Millimétrique's Plateau de Bure Interferometer. The intrinsic properties appear typical of high-redshift starbursts despite the high lensing-amplified fluxes, proving the ability of the FTS to probe this population with the aid of lensing. The blind detection of [C II] demonstrates the potential of the SPICA Far-infrared Instrument imaging spectrometer, proposed for the much more sensitive Space Infrared Telescope for Cosmology and Astrophysics mission, to determine redshifts of multiple dusty galaxies simultaneously without the benefit of lensing.

  20. Herschel Open Time Key Programme—TNOs are Cool: A Survey of the Transneptunian Region

    Science.gov (United States)

    Müller, Th. G.; Lellouch, E.; Böhnhardt, H.; Stansberry, J.; Barucci, A.; Crovisier, J.; Delsanti, A.; Doressoundiram, A.; Dotto, E.; Duffard, R.; Fornasier, S.; Groussin, O.; Gutierrez, P. J.; Hainaut, O.; Harris, A.; Hartogh, P.; Hestroffer, D.; Horner, J.; Jewitt, D.; Kidger, M.; Kiss, C.; Lacerda, P.; Lara, L.; Lim, T.; Mueller, M.; Moreno, R.; Ortiz, J.-L.; Rengel, M.; Santos-Sanz, P.; Swinyard, B.; Thomas, N.; Trilling, D.

    2008-09-01

    debris disk, and extra-solar ones as well. We will present an overview of this project. Herschel will be the largest space telescope of its kind when launched (early 2009). Herschel's 3.5-metre diameter mirror will collect long-wavelength infrared radiation from some of the coolest and most distant objects in the Universe. Herschel will be the only space observatory to cover the spectral range from far-infrared to sub-millimetre wavelengths. Herschel's Photodetector Array Camera and Spectrometer (PACS) and its Spectral and Photometric Imaging Receiver (SPIRE) are perfectly suited for the characterisation of trans-Neptunian objects (TNOs), the observable targets of our own debris disk.

  1. First Results from the Herschel Gould Belt Survey in Taurus and Comparison with Other Clouds

    Science.gov (United States)

    Kirk, Jason

    The unparalleled sensitivity and mapping speed of the ESA Herschel Space Observatory makes it possible to now map entire star formation regions in the time it would once have taken to map a single prestellar core. The Herschel Gould Belt Survey is a key program designed to fully map the clouds of the Gould Belt at five wavelengths between 70 and 500 μm. These clouds span a range of physical conditions from the sterility of Polaris to the active cluster forming complexes of Orion and Aquila. These clouds allow us to examine the genesis of the core mass function and how the history of star formation in different regions varies. The early results have demonstrated the markedly different populations of cores in these regions and have revealed the nearly ubiquitous relationship of those cores with dense filaments.

  2. Characterizing the Youngest Herschel-detected Protostars. II. Molecular Outflows from the Millimeter and the Far-infrared

    Science.gov (United States)

    Tobin, John J.; Stutz, Amelia M.; Manoj, P.; Megeath, S. Thomas; Karska, Agata; Nagy, Zsofia; Wyrowski, Friedrich; Fischer, William J.; Watson, Dan M.; Stanke, Thomas

    2016-11-01

    We present Combined Array for Research in Millimeter-wave Astronomy (CARMA) CO (J=1\\to 0) observations and Herschel PACS spectroscopy, characterizing the outflow properties toward extremely young and deeply embedded protostars in the Orion molecular clouds. The sample comprises a subset of the Orion protostars known as the PACS Bright Red Sources (PBRS; Stutz et al.). We observed 14 PBRS with CARMA and 8 of these 14 with Herschel, acquiring full spectral scans from 55 to 200 μm. Outflows are detected in CO (J=1\\to 0) from 8 of 14 PBRS, with two additional tentative detections; outflows are also detected from the outbursting protostar HOPS 223 (V2775 Ori) and the Class I protostar HOPS 68. The outflows have a range of morphologies; some are spatially compact, 13) CO lines and/or H2O lines from 5 of 8 PBRS and only for those with detected CO outflows. The far-infrared CO rotation temperatures of the detected PBRS are marginally colder (˜230 K) than those observed for most protostars (˜300 K), and only one of these five PBRS has detected [O I] 63 μm emission. The high envelope densities could be obscuring some [O I] emission and cause a ˜20 K reduction to the CO rotation temperatures. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. GASPS--A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

    Science.gov (United States)

    Dent, W.R.F.; Thi, W. F.; Kamp, I.; Williams, J. P.; Menard, F.; Andrews, S.; Ardila, D.; Aresu, G.; Augereau, J.-C.; Barrado y Navascues, D.; hide

    2013-01-01

    We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted approx. 250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 micron the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 micron, [CII] at 157 µm, as well as several transitions of H2O and high-excitation CO lines at selected wavelengths between 78 and 180 micron. Additionally, GASPS included continuum photometry at 70, 100 and 160 micron, around the peak of the dust emission. The targets were SED Class II– III T Tauri stars and debris disks from seven nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy of the program. We summarize some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability. The [OI] line at 63 micron was the brightest line seen in almost all objects, by a factor of 10. Overall [OI] 63 micron detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI] 63 µm detection of approx.10(exp -5) Solar M.. Normalizing to a distance of 140 pc, 84% of objects with dust masses =10 (exp -5) Solar M can be detected in this line in the present survey; 32% of those of mass 10(exp -6) – 10 (exp -5) Solar M, and only a very small number

  4. GASPS—A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

    Science.gov (United States)

    Dent, W. R. F.; Thi, W. F.; Kamp, I.; Williams, J. P.; Menard, F.; Andrews, S.; Ardila, D.; Aresu, G.; Augereau, J.-C.; Barrado y Navascues, D.; Brittain, S.; Carmona, A.; Ciardi, D.; Danchi, W.; Donaldson, J.; Duchene, G.; Eiroa, C.; Fedele, D.; Grady, C.; de Gregorio-Molsalvo, I.; Howard, C.; Huélamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mathews, G.; Meeus, G.; Mendigutía, I.; Montesinos, B.; Morales-Calderon, M.; Mora, A.; Nomura, H.; Pantin, E.; Pascucci, I.; Phillips, N.; Pinte, C.; Podio, L.; Ramsay, S. K.; Riaz, B.; Riviere-Marichalar, P.; Roberge, A.; Sandell, G.; Solano, E.; Tilling, I.; Torrelles, J. M.; Vandenbusche, B.; Vicente, S.; White, G. J.; Woitke, P.

    2013-05-01

    We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the ACS instrument on the Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ~250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63 μm the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI]145 μm, [CII] at 157 μm, as well as several transitions of H2O and high-excitation CO lines at selected wavelengths between 78 and 180 μm. Additionally, GASPS included continuum photometry at 70, 100 and 160 μm, around the peak of the dust emission. The targets were SED Class II-III T Tauri stars and debris disks from seven nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy of the program. We summarise some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability. The [OI] line at 63 μm was the brightest line seen in almost all objects, by a factor of ~10. Overall [OI]63 μm detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI]63 μm detection of ~10-5 Msolar. Normalising to a distance of 140 pc, 84% of objects with dust masses >=10-5 Msolar can be detected in this line in the present survey; 32% of those of mass 10-6-10-5 Msolar, and only a very small number of unusual objects with lower masses can be detected. This is

  5. Fast computation of the Narcissus reflection coefficient for the Herschel far-infrared/submillimeter-wave Cassegrain telescope

    Science.gov (United States)

    Lucke, Robert L.; Fischer, Jacqueline; Polegre, Arturo M.; Beintema, Douwe A.

    2005-10-01

    Placement of a scatter cone at the center of the secondary of a Cassegrain telescope greatly reduces Narcissus reflection. To calculate the remaining Narcissus reflection, a time-consuming physical optics code such as GRASP8 is often used to model the effects of reflection and diffraction. Fortunately, the Cassegrain geometry is sufficiently simple that a combination of theoretical analysis and Fourier propagation can yield rapid, accurate results at submillimeter wavelengths. We compare these results with those from GRASP8 for the heterodyne instrument for the far-infrared on the Herschel Space Observatory and confirm the effectiveness of the chosen scatter cone design.

  6. Protostars in Orion: New results from the Herschel Orion Protostar Survey Key Program

    Science.gov (United States)

    Ali, Babar; Fischer, W.; Megeath, T.; Tobin, J.; Poteet, C.; Hartmann, L.; Watson, D.; Manoj, P.; Allen, L.; Stutz, A.; Krause, O.; Henning, T.; Stanke, T.; Bergin, E.; Calvet, N.; Maret, S.; Furlan, E.; Neufeld, D.; Osorio, M.; Wilson, T.

    2011-01-01

    We present new far-IR photometry results on 131 proto-stars from the Herschel Orion Protostar Survey (HOPS). HOPS is a 200-hour Herschel key program that will systematically survey 286 protostars encompassing a wide range of source luminosities, evolutionary phases, and environments in a single molecular cloud in the 60-210 micron window where we will sample the peak of the thermal emission from the protostellar envelope. We will focus on PACS imaging at 70 and 160 um taken as part of the imaging component of the HOPS program. From these data we extract 70 and 160 um photometry which are then combined with existing ground-based and HST near-IR imaging, IRAC and MIPS 3-24 um photometry and IRS 5-35 um spectra to create 1.6-160 um SEDs. These SEDS are integrated to find the bolometric luminosities and compared to the results of radiative transfer models (Whitney et al. 2003, ApJ, 591, 1049) to constrain the envelope morphologies, envelope densities, and infall rates. Our initial results (Fischer et al. 2010, A&A, 518, L122) on only protostars 4 stars showed a range of evolutionary states for the protostars. In this contribution, we extend our sample to 131 protostars -- the first large survey of its kind in the far-IR. We will examine the distribution of luminosities and SED properties as a function of environment. We will also present preliminary fits to radiative transfer models of the protostars.

  7. Mining the Herschel-Astrophysical Terahertz Large Area Survey: submillimetre-selected blazars in equatorial fields

    Science.gov (United States)

    López-Caniego, M.; González-Nuevo, J.; Massardi, M.; Bonavera, L.; Herranz, D.; Negrello, M.; De Zotti, G.; Carrera, F. J.; Danese, L.; Fleuren, S.; Hardcastle, M.; Jarvis, M. J.; Klöckner, H.-R.; Mauch, T.; Procopio, P.; Righini, S.; Sutherland, W.; Auld, R.; Baes, M.; Buttiglione, S.; Clark, C. J. R.; Cooray, A.; Dariush, A.; Dunne, L.; Dye, S.; Eales, S.; Hopwood, R.; Hoyos, C.; Ibar, E.; Ivison, R. J.; Maddox, S.; Valiante, E.

    2013-04-01

    The Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) provides an unprecedented opportunity to search for blazars at sub-mm wavelengths. We cross-matched the Faint Images of the Radio Sky at Twenty-cm (FIRST) radio source catalogue with the 11 655 sources brighter than 35 mJy at 500 μm in the ˜135 deg2 of the sky covered by the H-ATLAS equatorial fields at 9h and 15h, plus half of the field at 12h. We found that 379 of the H-ATLAS sources have a FIRST counterpart within 10 arcsec, including eight catalogued blazars (plus one known blazar that was found at the edge of one of the H-ATLAS maps). To search for additional blazar candidates we have devised new diagnostic diagrams and found that known blazars occupy a region of the log (S500 μm/S350 μm) versus log (S500 μm/S1.4 GHz) plane separated from that of sub-mm sources with radio emission powered by star formation, but shared with radio galaxies and steep-spectrum radio quasars. Using this diagnostic we have selected 12 further possible candidates that turn out to be scattered in the (r - z) versus (u - r) plane or in the Wide-Field Infrared Survey Explorer colour-colour diagram, where known blazars are concentrated in well defined strips. This suggests that the majority of them are not blazars. Based on an inspection of all the available photometric data, including unpublished VISTA Kilo-degree Infrared Galaxy survey photometry and new radio observations, we found that the spectral energy distributions (SEDs) of only one out of the 12 newly selected sources are compatible with being synchrotron dominated at least up to 500 μm, i.e. with being a blazar. Another object may consist of a faint blazar nucleus inside a bright star-forming galaxy. The possibility that some blazar hosts are endowed with active star formation is supported by our analysis of the SEDs of Planck Early Release Compact Source Catalogue blazars detected at both 545 and 857 GHz. The estimated rest-frame synchrotron peak

  8. Herschel far-infrared observations of the Carina Nebula complex. III. Detailed cloud structure and feedback effects

    Science.gov (United States)

    Roccatagliata, V.; Preibisch, T.; Ratzka, T.; Gaczkowski, B.

    2013-06-01

    Context. The star formation process in large clusters/associations can be strongly influenced by the feedback from high-mass stars. Whether the resulting net effect of the feedback is predominantly negative (cloud dispersal) or positive (triggering of star formation due to cloud compression) is still an open question. Aims: The Carina Nebula complex (CNC) represents one of the most massive star-forming regions in our Galaxy. We use our Herschel far-infrared observations to study the properties of the clouds over the entire area of the CNC (with a diameter of ≈3.2°, which corresponds to ≈125 pc at a distance of 2.3 kpc). The good angular resolution (10''-36'') of the Herschel maps corresponds to physical scales of 0.1-0.4 pc, and allows us to analyze the small-scale (i.e., clump-size) structures of the clouds. Methods: The full extent of the CNC was mapped with PACS and SPIRE in the 70, 160, 250, 350, and 500 μm bands. We determined temperatures and column densities at each point in these maps by modeling the observed far-infrared spectral energy distributions. We also derived a map showing the strength of the UV radiation field. We investigated the relation between the cloud properties and the spatial distribution of the high-mass stars and computed total cloud masses for different density thresholds. Results: Our Herschel maps resolve for the first time the small-scale structure of the dense clouds over the entire spatial extent of the CNC. Several particularly interesting regions, including the prominent pillars south of η Car, are analyzed in detail. We compare the cloud masses derived from the Herschel data with previous mass estimates based on sub-mm and molecular line data. Our maps also reveal a peculiar wave-like pattern in the northern part of the Carina Nebula. Finally, we characterize two prominent cloud complexes at the periphery of our Herschel maps, which are probably molecular clouds in the Galactic background. Conclusions: We find that the

  9. Tracing Protostellar Envelope Evolution with HOPS, the Herschel Orion Protostar Survey

    Science.gov (United States)

    Fischer, Will; Megeath, Tom; Furlan, Elise; Ali, Babar; Stutz, Amy; Booker, Joseph; Tobin, John; Stanke, Thomas; Osorio, Mayra

    2013-07-01

    HOPS, the Herschel Orion Protostar Survey, is an unprecedented program of large surveys with the Herschel, Spitzer, Hubble, and APEX observatories, as well as near-IR observations from the IRTF and other telescopes. Together these are providing a comprehensive observational assessment of protostellar evolution, from the earliest phases (see poster by A. Stutz) through the dissipation of the protostellar envelope. The BLT (bolometric luminosity and temperature) diagram for the ˜300 HOPS protostars resembles those constructed for other nearby star-forming regions. We fit the 1-870 um SEDs of the protostars with our grid of radiative transfer models to determine their luminosities, envelope densities, cavity angles, and inclinations (see poster by E. Furlan). High-resolution HST images of the scattered light nebulae provide additional constraints on envelope density, disk geometry, cavity geometry, and inclination angle (see poster by J. Booker). Finally, near-IR atomic hydrogen lines provide independent estimates of reddening and accretion luminosity in the less embedded sources. This multi-pronged modeling approach provides a more reliable assessment of envelope evolution than raw observational diagnostics like the bolometric temperature. We will compare the distributions of envelope densities and protostellar luminosities to the predictions of star-formation models.

  10. VizieR Online Data Catalog: Herschel Galactic plane survey of [NII] (Goldsmith+, 2015)

    Science.gov (United States)

    Goldsmith, P. F.; Yildiz, U. A.; Langer, W. D.; Pineda, J. L.

    2017-10-01

    Observations of both fine structure transitions of [N II], at 121.898 μm (2459.371 GHz) and 205.178 μm (1461.134 GHz) (Brown et al. 1994ApJ...428L..37B), were carried out with the PACS spectrometer (Poglitsch et al. 2010A&A...518L...2P) on Herschel (Pilbratt et al. 2010A&A...518L...1P). At 10 selected positions, the lower frequency transition was also observed with the high spectral resolution Heterodyne Instrument for the Far-Infrared (HIFI; de Graauw et al. 2010A&A...518L...6D). Based on the expected relative intensities of the [N II] and [C II] lines (Bennett et al. 1994ApJ...434..587B), observations were largely restricted to the inner galaxy, with both lines detected only in the range -60°=

  11. Optical/infrared ancillary photometry of young stars for the Herschell Key Project GASPS

    Science.gov (United States)

    Duchene, Gaspard; Dent, William; Montesinos, Benjamin

    2009-08-01

    This proposal aims at using the queue-mode 1.3m telescope at CTIO to gather near-contemporaneous photometric measurements of a sample of objects that will be observed with the Herschel Space Observatory in the upcoming months as part of the Open Time Key Program GASPS. This project is aimed at characterizing the gas content of circumstellar disks around young stars throughout the planet formation phase. In order to model the Herschel data in a coherent manner, it is necessary to determine each star's basic properties (effective temperature, mass, luminosity), which implies obtaining a complete broadband spectral energy distribution to combine with existing longer data (AKARI, Spitzer, Herschel and millimeter single-dish and interferometric fluxes). Here we propose to obtain new simultaneous optical and IR photometric measurements of 16 targets that cannot be observed from Northern observatories. In addition to provide a sound basis for our disk modeling effort, the observations proposed here will also offer new insight on the location, morphology and evolution of the disks' inner rim in conjunction with the currently ongoing AKARI observations.

  12. 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.

  13. Far-Infrared and Nebular Star-Formation Rate of Dusty Star Forming Galaxies from Herschel, CANDELS and 3D-HST at z~1

    Science.gov (United States)

    Hasan, Farhanul; Nayyeri, Hooshang; Cooray, Asantha R.; Herschel Group: University of California Irvine. Dept. of Physics & Astronomy. Led by professor Asantha Cooray, Reed College Undergraduate Research Committee

    2017-06-01

    We present a combined Herschel/PACS and SPIRE and HST/WFC3 observations of the five CANDELS fields, EGS, GOODS-N, GOODS-S, COSMOS and UDS, to study star-formation activity in dusty star-forming galaxies (DSFGs) at z~1. We use 3D-HST photometry and Grism spectroscopic redshifts to construct the Spectral Energy Distributions (SED) of galaxies in the near UV, optical and near infrared, along with IRAC measurements at 3.6-8 μm in the mid-infrared, and Herschel data at 250-500 μm in the far-infrared. The 3D-HST grism line measurements are used to estimate the star-formation rate from nebular emission. In particular, we compare the H-alpha measured SFRs (corrected for attenuation) to that of direct observations of the far-infrared from Herschel. We further look at the infrared excess in this sample of dusty star-forming galaxies (denoted by LIR/LUV) as a function of the UV slope. We find that the population of high-z DSFGs sit above the trend expected for normal star-forming galaxies. Additionally, we study the dependence of SFR on total dust attenuation and confirm a strong correlation between SFR(Ha) and the balmer decrement (Hα/Hβ).

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

    Science.gov (United States)

    Yıldız, U. A.; Kristensen, L. E.; van Dishoeck, E. F.; San José-García, I.; Karska, A.; Harsono, D.; Tafalla, M.; Fuente, A.; Visser, R.; Jørgensen, J. K.; Hogerheijde, M. R.

    2013-08-01

    Context. In the deeply embedded stage of star formation, protostars start to heat and disperse their surrounding cloud cores. The evolution of these sources has traditionally been traced through dust continuum spectral energy distributions (SEDs), but the use of CO excitation as an evolutionary probe has not yet been explored due to the lack of high-J CO observations. Aims: The aim is to constrain the physical characteristics (excitation, kinematics, column density) of the warm gas in low-mass protostellar envelopes using spectrally resolved Herschel data of CO and compare those with the colder gas traced by lower excitation lines. Methods: Herschel-HIFI observations of high-J lines of 12CO, 13CO, and C18O (up to Ju = 10, Eu up to 300 K) are presented toward 26 deeply embedded low-mass Class 0 and Class I young stellar objects, obtained as part of the Water In Star-forming regions 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 for all objects and can generally be decomposed into a narrow and a broad component owing to the quiescent envelope and entrained outflow material, respectively. The 12CO excitation temperature increases with velocity from ~60 K up to ~130 K. The median excitation temperatures for 12CO, 13CO, and C18O derived from single-temperature fits to the Ju = 2-10 integrated intensities are ~70 K, 48 K and 37 K, respectively, with no significant difference between Class 0 and Class I sources and no trend with Menv or Lbol. Thus, in contrast to the continuum SEDs, the spectral line energy distributions (SLEDs) do not show any evolution during the embedded stage. In contrast, the integrated line intensities of all CO isotopologs show a clear decrease with evolutionary stage as the envelope is

  15. WEAVE-QSO: A Massive Intergalactic Medium Survey for the William Herschel Telescope

    Science.gov (United States)

    Pieri, M. M.; Bonoli, S.; Chaves-Montero, J.; Pâris, I.; Fumagalli, M.; Bolton, J. S.; Viel, M.; Noterdaeme, P.; Miralda-Escudé, J.; Busca, N. G.; Rahmani, H.; Peroux, C.; Font-Ribera, A.; Trager, S. C.

    2016-12-01

    In these proceedings we describe the WEAVE-QSO survey, which will observe around 400,000 high redshift quasars starting in 2018. This survey is part of a broader WEAVE survey to be conducted at the 4.2m William Herschel Telescope. We will focus on chiefly on the science goals, but will also briefly summarise the target selection methods anticipated and the expected survey plan. Understanding the apparent acceleration in the expansion of the Universe is one of the key scientific challenges of our time. Many experiments have been proposed to study this expansion, using a variety of techniques. Here we describe a survey that can measure this acceleration and therefore help elucidate the nature of dark energy: a survey of the Lyα forest (and quasar absorption in general) in spectra towards z>2 quasars (QSOs). Further constraints on neutrino masses and warm dark matter are also anticipated. The same data will also shed light on galaxy formation via study of the properties of inflowing/outflowing gas associated with nearby galaxies and in a cosmic web context. Gas properties are sensitive to density, temperature, UV radiation, metallicity and abundance pattern, and so constraint galaxy formation in a variety of ways. WEAVE-QSO will study absorbers with a dynamic range spanning more than 8 orders of magnitude in column density, their thermal broadening, and a host of elements and ionization species. A core principal of the WEAVE-QSO survey is the targeting of QSOs with near 100% efficiency principally through use of the J-PAS (r < 23.2) and Gaia (r ≲ 20) data.

  16. Herschel Planetary Nebula Survey (HerPLaNS): Construction of a Detailed Dusty Photoionization Model of NGC6781

    Science.gov (United States)

    Otsuka, Masaaki; Ueta, Toshiya; Chu, You-Hua; Asano, Kentaro; HerPLaNS Consortium

    2017-10-01

    As one of the follow-up studies of Herschel Planetary Nebula Survey (HerPlaNS; Ueta et al. 2014), we focus on a bipolar planetary nebula (PN) NGC6781 to characterize the dusty nebula and the central star based on our own Herschel data and the rich archival spectroscopic/photometric image data in the wavelengths from UV to far-IR. With CLOUDY, we constructed a comprehensive photoionization model of NGC6781 ever made including data from UV to radio. We succeeded to reproduce the observed spectral energy distribution (SED) and the atomic gas, H2, CO, and OH molecular line fluxes. We found that about 40% of the total dust mass would be from warm-cold dust components.

  17. 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

  18. 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.

  19. Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets

    Science.gov (United States)

    Podio, L.; Kamp, I.; Flower, D.; Howard, C.; Sandell, G.; Mora, A.; Aresu, G.; Brittain, S.; Dent, W. R. F.; Pinte, C.; White, G. J.

    2012-09-01

    Context. Observations of the atomic and molecular line emission associated with jets and outflows emitted by young stellar objects provide sensitive diagnostics of the excitation conditions, and can be used to trace the various evolutionary stages they pass through as they evolve to become main sequence stars. Aims: To understand the relevance of atomic and molecular cooling in shocks, and how accretion and ejection efficiency evolves with the evolutionary state of the sources, we will study the far-infrared counterparts of bright optical jets associated with Class I and II sources in Taurus (T Tau, DG Tau A, DG Tau B, FS Tau A+B, and RW Aur). Methods: We have analysed Herschel/PACS observations of a number of atomic ([O i]63 μm, 145 μm, [C ii]158 μm) and molecular (high-J CO, H2O, OH) lines, collected within the open time key project GASPS (PI: W. R. F. Dent). To constrain the origin of the detected lines we have compared the obtained FIR emission maps with the emission from optical-jets and millimetre-outflows, and the measured line fluxes and ratios with predictions from shock and disk models. Results: All of the targets are associated with extended emission in the atomic lines; in particular, the strong [O i] 63 μm emission is correlated with the direction of the optical jet/mm-outflow. The line ratios suggest that the atomic lines can be excited in fast dissociative J-shocks occurring along the jet. The molecular emission, on the contrary, originates from a compact region, that is spatially and spectrally unresolved, and lines from highly excited levels are detected (e.g., the o-H2O 818-707 line, and the CO J = 36-35 line). Disk models are unable to explain the brightness of the observed lines (CO and H2O line fluxes up to 10-15-6 × 10-16 W m-2). Slow C- or J-shocks with high pre-shock densities reproduce the observed H2O and high-J CO lines; however, the disk and/or UV-heated outflow cavities may contribute to the observed emission. Conclusions

  20. Herschel far-infrared photometry of the Swift Burst Alert Telescope active galactic nuclei sample of the local universe - III. Global star-forming properties and the lack of a connection to nuclear activity

    Science.gov (United States)

    Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio; Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.

    2017-04-01

    We combine the Herschel Space Observatory PACS (Photoconductor Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging Receiver) photometry with archival WISE (Wide-field Infrared Survey Explorer) photometry to construct the spectral energy distributions (SEDs) for over 300 local (z 0.5), especially at higher luminosities (L14 - 195 keV > 1042.5 erg s-1). Finally, we measure the local SFR-AGN luminosity relationship, finding a slope of 0.18, large scatter (0.37 dex), and no evidence for an upturn at high AGN luminosity. We conclude with a discussion on the implications of our results within the context of galaxy evolution with and without AGN feedback.

  1. The Herschel Orion Protostar Survey: Correcting for Inclination in BLT Diagrams and Reassessing the Class 0 Lifetime

    Science.gov (United States)

    Fischer, William J.; Megeath, S.; Stutz, A. M.; Tobin, J. J.; Ali, B.; Stanke, T.; Osorio, M.; Furlan, E.; HOPS Team

    2013-01-01

    We describe recent results from the Herschel Orion Protostar Survey (HOPS), a multiwavelength study of Spitzer-identified protostars in the Orion Molecular Cloud complex. Over 300 protostars in the Orion A and B molecular clouds, the largest star-forming region in the nearest 500 pc, have been observed with 70 μm and 160 μm Herschel/PACS imaging and spectroscopy and with near-IR, mid-IR, and submillimeter imaging and spectroscopy. Using a custom grid of radiative transfer models, we have fit the resulting spectral energy distributions of the sources to estimate their fundamental properties, including infall rate, luminosity, and outflow cavity angle. We also use the model fits to correct the bolometric luminosities and temperatures (BLT properties) of the sources for the effects of foreground extinction and inclination. After the inclination correction, we find that many of the putative young Class 0 sources seem to be highly inclined, more evolved Class I sources. Furthermore, we have discovered a class of protostars previously unidentified by Spitzer that may be young or highly inclined Class 0 sources. We re-evaluate the Class 0 lifetime in light of these new results.

  2. 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

  3. 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...

  4. Herschel Observations of EXtra-Ordinary Sources (HEXOS): Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL

    NARCIS (Netherlands)

    Crockett, N. R.; Bergin, E. A.; Bell, T. A.; Blake, G.; Cernicharo, J.; Emprechtinger, M.; Gupta, H.; Lord, S.; Pearson, J.; Plume, R.; Schilke, P.; van der Tak, F.; Wang, S.; Yu, S.

    We present a full spectral survey of the Kleiman-Low nebula within the Orion Molecular Cloud (Orion KL), one of the most chemically rich regions in the galaxy, using the HIFI instrument on board the Herschel Space Observatory. These observations, shown in the figure below, span a frequency range of

  5. TNOs are cool : A survey of the trans-Neptunian region V. Physical characterization of 18 Plutinos using Herschel-PACS observations

    NARCIS (Netherlands)

    Mommert, M.; Harris, A. W.; Kiss, C.; Pal, A.; Santos-Sanz, P.; Stansberry, J.; Delsanti, A.; Vilenius, E.; Mueller, T. G.; Peixinho, N.; Lellouch, E.; Szalai, N.; Henry, F.; Duffard, R.; Fornasier, S.; Hartogh, P.; Mueller, M.; Ortiz, J. L.; Protopapa, S.; Rengel, M.; Thirouin, A.

    Context. The Herschel open time key programme TNOs are Cool: A survey of the trans-Neptunian region aims to derive physical and thermal properties for a set of similar to 140 Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. One goal of

  6. High-pressure, low-abundance water in bipolar outflows. Results from a Herschel-WISH survey

    Science.gov (United States)

    Tafalla, M.; Liseau, R.; Nisini, B.; Bachiller, R.; Santiago-García, J.; van Dishoeck, E. F.; Kristensen, L. E.; Herczeg, G. J.; Yıldız, U. A.

    2013-03-01

    Context. Water is a potential tracer of outflow activity because it is heavily depleted in cold ambient gas and is copiously produced in shocks. Aims: We present a survey of the water emission in a sample of more than 20 outflows from low-mass young stellar objects with the goal of characterizing the physical and chemical conditions of the emitting gas. Methods: We used the HIFI and PACS instruments on board the Herschel Space Observatory to observe the two fundamental lines of ortho-water at 557 and 1670 GHz. These observations were part of the "Water In Star-forming regions with Herschel" (WISH) key program, and have been complemented with CO and H2 data. Results: The emission of water has a different spatial and velocity distribution from that of the J = 1-0 and 2-1 transitions of CO. On the other hand, it has a similar spatial distribution to H2, and its intensity follows the H2 intensity derived from IRAC images. This suggests that water traces the outflow gas at hundreds of kelvins that is responsible for the H2 emission, and not the component at tens of kelvins typical of low-J CO emission. A warm origin of the water emission is confirmed by a remarkable correlation between the intensities of the 557 and 1670 GHz lines, which also indicates that the emitting gas has a narrow range of excitations. A radiative transfer analysis shows that while there is some ambiguity in the exact combination of density and temperature values, the gas thermal pressure nT is constrained within less than a factor of 2. The typical nT over the sample is 4 × 109 cm-3K, which represents an increase of 104 with respect to the ambient value. The data also constrain the water column density within a factor of 2 and indicate values in the sample between 2 × 1012 and 1014 cm-2. When these values are combined with estimates of the H2 column density, the typical water abundance is only 3 × 10-7, with an uncertainty of a factor of 3. Conclusions: Our data challenge current C

  7. Outflows, infall and evolution of a sample of embedded low-mass protostars. The William Herschel Line Legacy (WILL) survey

    Science.gov (United States)

    Mottram, J. C.; van Dishoeck, E. F.; Kristensen, L. E.; Karska, A.; San José-García, I.; Khanna, S.; Herczeg, G. J.; André, Ph.; Bontemps, S.; Cabrit, S.; Carney, M. T.; Drozdovskaya, M. N.; Dunham, M. M.; Evans, N. J.; Fedele, D.; Green, J. D.; Harsono, D.; Johnstone, D.; Jørgensen, J. K.; Könyves, V.; Nisini, B.; Persson, M. V.; Tafalla, M.; Visser, R.; Yıldız, U. A.

    2017-04-01

    Context. Herschel observations of water and highly excited CO (J > 9) have allowed the physical and chemical conditions in the more active parts of protostellar outflows to be quantified in detail for the first time. However, to date, the studied samples of Class 0/I protostars in nearby star-forming regions have been selected from bright, well-known sources and have not been large enough for statistically significant trends to be firmly established. Aims: We aim to explore the relationships between the outflow, envelope and physical properties of a flux-limited sample of embedded low-mass Class 0/I protostars. Methods: We present spectroscopic observations in H2O, CO and related species with Herschel HIFI and PACS, as well as ground-based follow-up with the JCMT and APEX in CO, HCO+ and isotopologues, of a sample of 49 nearby (d < 500 pc) candidate protostars selected from Spitzer and Herschel photometric surveys of the Gould Belt. This more than doubles the sample of sources observed by the WISH and DIGIT surveys. These data are used to study the outflow and envelope properties of these sources. We also compile their continuum spectral energy distributions (SEDs) from the near-IR to mm wavelengths in order to constrain their physical properties (e.g. Lbol, Tbol and Menv). Results: Water emission is dominated by shocks associated with the outflow, rather than the cooler, slower entrained outflowing gas probed by ground-based CO observations. These shocks become less energetic as sources evolve from Class 0 to Class I. Outflow force, measured from low-J CO, also decreases with source evolutionary stage, while the fraction of mass in the outflow relative to the total envelope (I.e. Mout/Menv) remains broadly constant between Class 0 and I. The median value of 1% is consistent with a core to star formation efficiency on the order of 50% and an outflow duty cycle on the order of 5%. Entrainment efficiency, as probed by FCO/Ṁacc, is also invariant with source

  8. 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

  9. Herschel survey and modelling of externally-illuminated photoevaporating protoplanetary disks

    Science.gov (United States)

    Champion, J.; Berné, O.; Vicente, S.; Kamp, I.; Le Petit, F.; Gusdorf, A.; Joblin, C.; Goicoechea, J. R.

    2017-08-01

    Context. Protoplanetary disks undergo substantial mass-loss by photoevaporation, a mechanism that is crucial to their dynamical evolution. However, the processes regulating the gas energetics have not so far been well constrained by observations. Aims: We aim to study the processes involved in disk photoevaporation when it is driven by far-UV photons (i.e. 6 electric effect and cooling by [OI] and [CII] FIR lines. This specific energetic regime is associated to an equilibrium dynamical point of the photoevaporation flow: the mass-loss rate is self-regulated to keep the envelope column density at a value that maintains the temperature at the disk surface around 1000 K. From the physical parameters derived from our best-fit models, we estimate mass-loss rates - of the order of 10-7M⊙/yr - that are in agreement with earlier spectroscopic observation of ionised gas tracers. This holds only if we assume photoevaporation in the supercritical regime where the evaporation flow is launched from the disk surface at sound speed. Conclusions: We have identified the energetic regime regulating FUV-photoevaporation in proplyds. This regime could be implemented into models of the dynamical evolution of protoplanetary disks. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables of observational data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A69

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

    Science.gov (United States)

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

    2017-07-01

    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 suggests that gas shocked by jets and/or outflows can be traced by far-IR (FIR) emission in certain sources. Aims: We want to provide a consistent catalogue of selected atomic ([OI] and [CII]) and molecular (CO, H2O, and OH) line fluxes observed in the FIR, separate and characterize the contribution from the jet and the disc to the observed line emission, and place the observations in an evolutionary picture. Methods: The atomic and molecular FIR (60-190 μm) line emission of protoplanetary discs around 76 T Tauri stars located in Taurus are analysed. The observations were carried out within the Herschel key programme Gas in Protoplanetary Systems (GASPS). The spectra were obtained with the Photodetector Array Camera and Spectrometer (PACS). The sample is first divided in outflow and non-outflow sources according to literature tabulations. With the aid of archival stellar/disc and jet/outflow tracers and model predictions (PDRs and shocks), correlations are explored to constrain the physical mechanisms behind the observed line emission. Results: Outflow sources exhibit brighter atomic and molecular emission lines and higher detection rates than non-outflow sources. The line detection fractions decrease with SED evolutionary status (from Class I to Class III). We find correlations between [OI] 63.18 μm and [OI] 6300 Å, o-H2O 78.74 μm, CO 144.78 μm, OH 79.12+79.18 μm, and the continuum flux at 24 μm. The atomic line ratios can be explain either by fast (Vshock > 50 km s-1) dissociative J-shocks at low densities (n 103 cm-3) occurring along the jet and/or PDR emission (G0 > 102, n 103-106 cm-3). To account for the [CII] absolute fluxes, PDR emission or UV irradiation of

  11. 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

  12. 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.

  13. Planck intermediate results. XXVII. High-redshift infrared galaxy overdensity candidates and lensed sources discovered by Planck and confirmed by Herschel-SPIRE

    Science.gov (United States)

    Planck Collaboration; Aghanim, N.; Altieri, B.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Beelen, A.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bethermin, M.; Bielewicz, P.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Burigana, C.; Calabrese, E.; Canameras, R.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Couchot, F.; Crill, B. P.; Curto, A.; Danese, L.; Dassas, K.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Falgarone, E.; Flores-Cacho, I.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Frye, B.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Guéry, D.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Helou, G.; Hernández-Monteagudo, C.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Floc'h, E.; Leonardi, R.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; MacKenzie, T.; Maffei, B.; Mandolesi, N.; Maris, M.; Martin, P. G.; Martinache, C.; Martínez-González, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mennella, A.; Migliaccio, M.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Natoli, P.; Negrello, M.; Nesvadba, N. P. H.; Novikov, D.; Novikov, I.; Omont, A.; Pagano, L.; Pajot, F.; Pasian, F.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ristorcelli, I.; Rocha, G.; Roudier, G.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Spencer, L. D.; Stolyarov, V.; Sunyaev, R.; Sutton, D.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Valtchanov, I.; Van Tent, B.; Vieira, J. D.; Vielva, P.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Welikala, N.; Zacchei, A.; Zonca, A.

    2015-10-01

    We have used the Planck all-sky submillimetre and millimetre maps to search for rare sources distinguished by extreme brightness, a few hundred millijanskies, and their potential for being situated at high redshift. These "cold" Planck sources, selected using the High Frequency Instrument (HFI) directly from the maps and from the Planck Catalogue of Compact Sources (PCCS), all satisfy the criterion of having their rest-frame far-infrared peak redshifted to the frequency range 353-857 GHz. This colour-selection favours galaxies in the redshift range z = 2-4, which we consider as cold peaks in the cosmic infrared background. With a 4.´5 beam at the four highest frequencies, our sample is expected to include overdensities of galaxies in groups or clusters, lensed galaxies, and chance line-of-sight projections. We perform a dedicated Herschel-SPIRE follow-up of 234 such Planck targets, finding a significant excess of red 350 and 500μm sources, in comparison to reference SPIRE fields. About 94% of the SPIRE sources in the Planck fields are consistent with being overdensities of galaxies peaking at 350μm, with 3% peaking at 500μm, and none peaking at 250μm. About 3% are candidate lensed systems, all 12 of which have secure spectroscopic confirmations, placing them at redshifts z> 2.2. Only four targets are Galactic cirrus, yielding a success rate in our search strategy for identifying extragalactic sources within the Planck beam of better than 98%. The galaxy overdensities are detected with high significance, half of the sample showing statistical significance above 10σ. The SPIRE photometric redshifts of galaxies in overdensities suggest a peak at z ≃ 2, assuming a single common dust temperature for the sources of Td = 35 K. Under this assumption, we derive an infrared (IR) luminosity for each SPIRE source of about 4 × 1012L⊙, yielding star formation rates of typically 700 M⊙ yr-1. If the observed overdensities are actual gravitationally-bound structures

  14. MSX INFRARED MINOR PLANET SURVEY V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Midcourse Space Experiment Infrared Minor Planet Survey (MIMPS) includes infrared data for 168 main-belt asteroids serendipitously observed by the Midcourse...

  15. Neutral gas heating by X-rays in primitive galaxies: Infrared observations of the blue compact dwarf I Zw 18 with Herschel

    Science.gov (United States)

    Lebouteiller, V.; Péquignot, D.; Cormier, D.; Madden, S.; Pakull, M. W.; Kunth, D.; Galliano, F.; Chevance, M.; Heap, S. R.; Lee, M.-Y.; Polles, F. L.

    2017-06-01

    Context. The neutral interstellar medium of galaxies acts as a reservoir to fuel star formation. The dominant heating and cooling mechanisms in this phase are uncertain in extremely metal-poor star-forming galaxies. The low dust-to-gas mass ratio and low polycyclic aromatic hydrocarbon abundance in such objects suggest that the traditional photoelectric effect heating may not be effective. Aims: Our objective is to identify the dominant thermal mechanisms in one such galaxy, I Zw 18 (1/30Z⊙), assess the diagnostic value of fine-structure cooling lines, and estimate the molecular gas content. Even though molecular gas is an important catalyst and tracer of star formation, constraints on the molecular gas mass remain elusive in the most metal-poor galaxies. Methods: Building on a previous photoionization model describing the giant H ii region of I Zw 18-NW within a multi-sector topology, we provide additional constraints using, in particular, the [C ii] 157 μm and [O i] 63 μm lines and the dust mass recently measured with the Herschel Space Telescope. Results: The heating of the H i region appears to be mainly due to photoionization by radiation from a bright X-ray binary source, while the photoelectric effect is negligible. Significant cosmic ray heating is not excluded. Inasmuch as X-ray heating dominates in the H i gas, the infrared fine-structure lines provide an average X-ray luminosity of order 4 × 1040 erg s-1 over the last few 104 yr in the galaxy. The upper limits to the [Ne v] lines provide strong constraints on the soft X-ray flux arising from the binary. A negligible mass of H2 is predicted. Nonetheless, up to 107 M⊙ of H2 may be hidden in a few sufficiently dense clouds of order ≲5 pc (≲0.05'') in size. Regardless of the presence of significant amounts of H2 gas, [C ii] and [O i] do not trace the so-called "CO-dark gas", but they trace the almost purely atomic medium. Although the [C ii]+[O i] to total infrared ratio in I Zw 18 is similar to

  16. Serendipitous observations of asteroids in Herschel PACS and SPIRE maps

    Science.gov (United States)

    Szakáts, R.; Kiss, Cs.; Marton, G.; Varga-Verebélyi, E.; Müller, T.; Pál, A.

    2017-09-01

    We present our methods and results in finding serendipitous solar system objects on Herschel PACS and SPIRE maps. We can use this data to supplement the Herschel PACS and SPIRE point source catalogs with flags of possible contamination and to obtain thermal infrared fluxes for these asteroids.

  17. Water in star-forming regions with Herschel (WISH). III. Far-infrared cooling lines in low-mass young stellar objects

    Science.gov (United States)

    Karska, A.; Herczeg, G. J.; van Dishoeck, E. F.; Wampfler, S. F.; Kristensen, L. E.; Goicoechea, J. R.; Visser, R.; Nisini, B.; San José-García, I.; Bruderer, S.; Śniady, P.; Doty, S.; Fedele, D.; Yıldız, U. A.; Benz, A. O.; Bergin, E.; Caselli, P.; Herpin, F.; Hogerheijde, M. R.; Johnstone, D.; Jørgensen, J. K.; Liseau, R.; Tafalla, M.; van der Tak, F.; Wyrowski, F.

    2013-04-01

    Context. Understanding the physical phenomena involved in the earlierst stages of protostellar evolution requires knowledge of the heating and cooling processes that occur in the surroundings of a young stellar object. Spatially resolved information from its constituent gas and dust provides the necessary constraints to distinguish between different theories of accretion energy dissipation into the envelope. Aims. Our aims are to quantify the far-infrared line emission from low-mass protostars and the contribution of different atomic and molecular species to the gas cooling budget, to determine the spatial extent of the emission, and to investigate the underlying excitation conditions. Analysis of the line cooling will help us characterize the evolution of the relevant physical processes as the protostar ages. Methods. Far-infrared Herschel-PACS spectra of 18 low-mass protostars of various luminosities and evolutionary stages are studied in the context of the WISH key program. For most targets, the spectra include many wavelength intervals selected to cover specific CO, H2O, OH, and atomic lines. For four targets the spectra span the entire 55-200 μm region. The PACS field-of-view covers ~47" with the resolution of 9.4". Results. Most of the protostars in our sample show strong atomic and molecular far-infrared emission. Water is detected in 17 out of 18 objects (except TMC1A), including 5 Class I sources. The high-excitation H2O 818-707 63.3 μm line (Eu/kB = 1071 K) is detected in 7 sources. CO transitions from J = 14-13 up to J = 49 - 48 are found and show two distinct temperature components on Boltzmann diagrams with rotational temperatures of ~350 K and ~700 K. H2O has typical excitation temperatures of ~150 K. Emission from both Class 0 and I sources is usually spatially extended along the outflow direction but with a pattern that depends on the species and the transition. In the extended sources, emission is stronger off source and extended on &≥10,000 AU

  18. DIGIT, GASPS, DEBRIS and DUNES: four HERSCHEL Open Time Key Programs to survey the dust cycle in circumstellar disks

    OpenAIRE

    Augereau, J. -C.; Absil, Olivier; Bouvier, J.; Duchêne, G.; Lestrade, J.-F.; Maret, S.; Martin-Zaïdi, C.; Ménard, F.; Morbidelli, A; Olofsson, J.; Pantin, E.; Pinte, C.; Thébault, P.

    2008-01-01

    Four accepted HERSCHEL open time key programs, DIGIT, GASPS, DEBRIS and DUNES, will study the evolution of the dust grains in circumstellar disks around young and Main Sequence stars. There is a strong implication of the french community in these four projects which represent a total of 930 hours (>38 days) of her\\ observing time. The DIGIT and GASPS projects will focus on the first stages of planet formation, while the DEBRIS and DUNES projects will search for extra-solar Kuiper Belt analogs...

  19. 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.

  20. 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

  1. DIGIT, GASPS, DEBRIS and DUNES: four HERSCHEL Open Time Key Programs to survey the dust cycle in circumstellar disks

    Science.gov (United States)

    Augereau, J.-C.; Absil, O.; Bouvier, J.; Duchêne, G.; Lestrade, J.-F.; Maret, S.; Martin-Zaïdi, C.; Ménard, F.; Morbidelli, A.; Olofsson, J.; Pantin, E.; Pinte, C.; Thébault, P.

    2008-11-01

    Four accepted HERSCHEL open time key programs, DIGIT, GASPS, DEBRIS and DUNES, will study the evolution of the dust grains in circumstellar disks around young and Main Sequence stars. There is a strong implication of the french community in these four projects which represent a total of 930 hours (>38 days) of her\\ observing time. The DIGIT and GASPS projects will focus on the first stages of planet formation, while the DEBRIS and DUNES projects will search for extra-solar Kuiper Belt analogs around nearby Main Sequence stars. In this paper, we give an overview of the scientific goals of the four projects and of the numerical tools that we will be providing to the teams to model and interpret the her\\ observations from these programs.

  2. TNOs are cool: A survey of the trans-Neptunian region. V. Physical characterization of 18 Plutinos using Herschel-PACS observations

    Science.gov (United States)

    Mommert, M.; Harris, A. W.; Kiss, C.; Pál, A.; Santos-Sanz, P.; Stansberry, J.; Delsanti, A.; Vilenius, E.; Müller, T. G.; Peixinho, N.; Lellouch, E.; Szalai, N.; Henry, F.; Duffard, R.; Fornasier, S.; Hartogh, P.; Mueller, M.; Ortiz, J. L.; Protopapa, S.; Rengel, M.; Thirouin, A.

    2012-05-01

    Context. The Herschel open time key programme TNOs are Cool: A survey of the trans-Neptunian region aims to derive physical and thermal properties for a set of ~140 Centaurs and trans-Neptunian objects (TNOs), including resonant, classical, detached and scattered disk objects. One goal of the project is to determine albedo and size distributions for specific classes and the overall population of TNOs. Aims: We present Herschel-PACS photometry of 18 Plutinos and determine sizes and albedos for these objects using thermal modeling. We analyze our results for correlations, draw conclusions on the Plutino size distribution, and compare to earlier results. Methods: Flux densities are derived from PACS mini scan-maps using specialized data reduction and photometry methods. In order to improve the quality of our results, we combine our PACS data with existing Spitzer MIPS data where possible, and refine existing absolute magnitudes for the targets. The physical characterization of our sample is done using a thermal model. Uncertainties of the physical parameters are derived using customized Monte Carlo methods. The correlation analysis is performed using a bootstrap Spearman rank analysis. Results: We find the sizes of our Plutinos to range from 150 to 730 km and geometric albedos to vary between 0.04 and 0.28. The average albedo of the sample is 0.08 ± 0.03, which is comparable to the mean albedo of Centaurs, Jupiter family comets and other TNOs. We were able to calibrate the Plutino size scale for the first time and find the cumulative Plutino size distribution to be best fit using a cumulative power law with q = 2 at sizes ranging from 120-400 km and q = 3 at larger sizes. We revise the bulk density of 1999 TC36 and find ρ = 0.64-0.11+0.15 g cm-3. On the basis of a modified Spearman rank analysis technique our Plutino sample appears to be biased with respect to object size but unbiased with respect to albedo. Furthermore, we find biases based on geometrical aspects

  3. Wide-Field Infrared Survey Telescope (WFIRST) Integrated Modeling

    Science.gov (United States)

    Liu, Kuo-Chia; Blaurock, Carl

    2017-01-01

    Contents: introduction to WFIRST (Wide-Field Infrared Survey Telescope) and integrated modeling; WFIRST stability requirement summary; instability mitigation strategies; dynamic jitter results; STOP (structural-thermal-optical performance) (thermal distortion) results; STOP and jitter capability limitations; model validation philosophy.

  4. 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 the colder gas traced by lower excitation lines. Methods: Herschel-HIFI observations of high-J lines of 12CO, 13CO, and C18O (up to Ju = 10, Eu up to 300 K) are presented toward 26 deeply embedded low-mass Class 0 and Class I young stellar objects, obtained as part of the Water In Star-forming regions...... for all objects and can generally be decomposed into a narrow and a broad component owing to the quiescent envelope and entrained outflow material, respectively. The 12CO excitation temperature increases with velocity from ~60 K up to ~130 K. The median excitation temperatures for 12CO, 13CO, and C18O...... derived from single-temperature fits to the Ju = 2-10 integrated intensities are ~70 K, 48 K and 37 K, respectively, with no significant difference between Class 0 and Class I sources and no trend with Menv or Lbol. Thus, in contrast to the continuum SEDs, the spectral line energy distributions (SLEDs) do...

  5. The Herschel HIFI water line survey in the low-mass proto-stellar outflow L1448

    Science.gov (United States)

    Santangelo, G.; Nisini, B.; Giannini, T.; Antoniucci, S.; Vasta, M.; Codella, C.; Lorenzani, A.; Tafalla, M.; Liseau, R.; van Dishoeck, E. F.; Kristensen, L. E.

    2012-02-01

    Aims: As part of the WISH (Water In Star-forming regions with Herschel) key project, systematic observations of H2O transitions in young outflows are being carried out with the aim of understanding the role of water in shock chemistry and its physical and dynamical properties. We report on the observations of several ortho- and para-H2O lines performed with the HIFI instrument toward two bright shock spots (R4 and B2) along the outflow driven by the L1448 low-mass proto-stellar system, located in the Perseus cloud. These data are used to identify the physical conditions giving rise to the H2O emission and to infer any dependence on velocity. Methods: We used a large velocity gradient (LVG) analysis to derive the main physical parameters of the emitting regions, namely n(H2), Tkin, N(H2O) and emitting-region size. We compared these with other main shock tracers, such as CO, SiO and H2 and with shock models available in the literature. Results: These observations provide evidence that the observed water lines probe a warm (Tkin ~ 400-600 K) and very dense (n ~ 106-107 cm-3) gas that is not traced by other molecules, such as low-J CO and SiO, but is traced by mid-IR H2 emission. In particular, H2O shows strong differences with SiO in the excitation conditions and in the line profiles in the two observed shocked positions, pointing to chemical variations across the various velocity regimes and chemical evolution in the different shock spots. Physical and kinematical differences can be seen at the two shocked positions. At the R4 position, two velocity components with different excitation can be distinguished, of which the component at higher velocity (R4-HV) is less extended and less dense than the low velocity component (R4-LV). H2O column densities of about 2 × 1013 and 4 × 1014 cm-2 were derived for the R4-LV and the R4-HV components, respectively. The conditions inferred for the B2 position are similar to those of the R4-HV component, with H2O column density in

  6. The molecular circumnuclear disk (CND) in Centaurus A. A multi-transition CO and [CI] survey with Herschel, APEX, JCMT, and SEST

    National Research Council Canada - National Science Library

    Israel, F. P; Güsten, R; Meijerink, R; Loenen, A. F; Requena-Torres, M. A; Stutzki, J; van der Werf, P; Harris, A; Kramer, C; Martin-Pintado, J; Weiss, A

    2014-01-01

    ... A) obtained with the Herschel Space Observatory in the 400-1000 GHz range as well as previously unpublished measurements obtained with the ground-based observatories SEST, JCMT and APEX in the 90-800 GHz range...

  7. A Far-infrared Spectroscopic Survey of Intermediate Redshift (Ultra) Luminous Infrared Galaxies

    Science.gov (United States)

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

    2014-11-01

    We present Herschel far-IR photometry and spectroscopy as well as ground-based CO observations of an intermediate redshift (0.21 1011.5 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\\prime _CO or L IR/M_H2), 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.

  8. Mapping dust in Orion protostars: from Herschel to APEX

    Science.gov (United States)

    Stanke, Thomas; Stutz, Amelia; Megeath, Thomas; HOPS Team

    2013-07-01

    HOPS (Herschel Orion Protostar Survey) is a 70 and 160mum Herschel PACS survey towards a sample of Spitzer identified protostar candidates in the Orion A and B giant molecular clouds. In this poster we give an overview of our efforts to obtain longer wavelength dust continuum maps, using the Laboca and Saboca cameras (870 and 350mum, respectively) at the APEX telescope, which provide maps at spatial resolutions well matched to the Herschel PACS data. The Laboca maps cover the entire field surveyed also by Herschel, providing a dust continuum measurement for all protostars observed by Herschel. The Saboca maps are restricted to smaller maps, mainly targeting PACS-bright protostar candidates, new protostar candidates not seen previously by Spitzer and identified from the Herschel maps, and also all bright cores found in the Laboca maps which do not have a protostellar association (i.e., starless cores). The data are used to provide long-wavelength submm photometry constraining the protostellar envelope masses. The 350mum Saboca data spatially resolve the emission from the outer envelope and are used to constrain their radial density distribution. Furthermore, combined with the Herschel data, we derive column density and temperature maps of the dense gas surrounding the protostars.

  9. Water in star-forming regions with Herschel (WISH). IV. A survey of low-J H2O line profiles toward high-mass protostars

    Science.gov (United States)

    van der Tak, F. F. S.; Chavarría, L.; Herpin, F.; Wyrowski, F.; Walmsley, C. M.; van Dishoeck, E. F.; Benz, A. O.; Bergin, E. A.; Caselli, P.; Hogerheijde, M. R.; Johnstone, D.; Kristensen, L. E.; Liseau, R.; Nisini, B.; Tafalla, M.

    2013-06-01

    Context. Water is a key constituent of star-forming matter, but the origin of its line emission and absorption during high-mass star formation is not well understood. Aims: We study the velocity profiles of low-excitation H2O lines toward 19 high-mass star-forming regions and search for trends with luminosity, mass, and evolutionary stage. Methods: We decompose high-resolution Herschel-HIFI line spectra near 990, 1110 and 1670 GHz into three distinct physical components. Dense cores (protostellar envelopes) are usually seen as narrow absorptions in the H2O 1113 and 1669 GHz ground-state lines, the H2O 987 GHz excited-state line, and the H218O 1102 GHz ground-state line. In a few sources, the envelopes appear in emission in some or all studied lines, indicating higher temperatures or densities. Broader features due to outflows are usually seen in absorption in the H2O 1113 and 1669 GHz lines, in 987 GHz emission, and not seen in H218O, indicating a lower column density and a higher excitation temperature than the envelope component. A few outflows are detected in H218O, indicating higher column densities of shocked gas. In addition, the H2O 1113 and 1669 GHz spectra show narrow absorptions by foreground clouds along the line of sight. The lack of corresponding features in the 987 GHz and H218O lines indicates a low column density and a low excitation temperature for these clouds, although their derived H2O ortho/para ratios are close to 3. Results: The intensity of the ground state lines of H2O at 1113 and 1669 GHz does not show significant trends with source luminosity, envelope mass, or evolutionary state. In contrast, the flux in the excited-state 987 GHz line appears correlated with luminosity and the H218O line flux appears correlated with the envelope mass. Furthermore, appearance of the envelope in absorption in the 987 GHz and H218O lines seems to be a sign of an early evolutionary stage, as probed by the mid-infrared brightness and the Lbol/Menv ratio of

  10. Guide for Airborne Infrared Roof Moisture Surveys

    Science.gov (United States)

    1978-01-01

    CONTROLLING OFFICE NAME AND ADDRESS . REPORT DATE U. S. Air Force Strategic Air Command Jan 78 Offutt Air Force Base 37 Oaha, Nebraska 68113T4 MO I OING...Hampshire, and Offutt AFB, Nebraska," Miscellaneous Paper M-77-2, Jan 1977, U. S. Army Engineer Waterways Experiment Station, CE, Vicksburg, Mississippi...Suite 705 916-422-6424 New York, New York 10020 Murray-McCormack Aerial Surveys Kucera & Associates, Inc. Sacramento, California 700 Reynolds Road

  11. 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.

  12. Star Formation Rate Indicators in Wide-Field Infrared Survey ...

    Indian Academy of Sciences (India)

    2016-01-27

    field Infrared Survey Explorer (WISE) traces the SFR, we analyse 3.4, 4.6, 12 and 22 m data in a sample of ∼ 140,000 star-forming galaxies or star-forming regions covering a wide range in metallicity 7.66 < 12 + \\log (O/H) ...

  13. X-Shooter Survey of Near-Infrared DIBs

    NARCIS (Netherlands)

    Cox, N.L.J.; Cami, J.; Kaper, L.; Foing, B.H.; Ehrenfreund, P.; Ochsendorf, B.B.; van Hooff, S.H.M.; Salama, F.

    2014-01-01

    We present the first results of an exploratory VLT/X-Shooter survey of near-infrared diffuse interstellar bands (DIBs) in diffuse to translucent interstellar clouds. These observations confirm the presence of recently discoved NIR DIBs and provide more accurate rest wavelengths and line widths.

  14. The Herschel Bright Sources (HerBS): sample definition and SCUBA-2 observations

    Science.gov (United States)

    Bakx, Tom J. L. C.; Eales, S. A.; Negrello, M.; Smith, M. W. L.; Valiante, E.; Holland, W. S.; Baes, M.; Bourne, N.; Clements, D. L.; Dannerbauer, H.; De Zotti, G.; Dunne, L.; Dye, S.; Furlanetto, C.; Ivison, R. J.; Maddox, S.; Marchetti, L.; Michałowski, M. J.; Omont, A.; Oteo, I.; Wardlow, J. L.; van der Werf, P.; Yang, C.

    2018-01-01

    We present the Herschel Bright Sources (HerBS) sample, a sample of bright, high-redshift Herschel sources detected in the 616.4 deg2 Herschel Astrophysical Terahertz Large Area Survey. The HerBS sample contains 209 galaxies, selected with a 500 μm flux density greater than 80 mJy and an estimated redshift greater than 2. The sample consists of a combination of hyperluminous infrared galaxies and lensed ultraluminous infrared galaxies during the epoch of peak cosmic star formation. In this paper, we present Submillimetre Common-User Bolometer Array 2 (SCUBA-2) observations at 850 μm of 189 galaxies of the HerBS sample, 152 of these sources were detected. We fit a spectral template to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) and 850 μm SCUBA-2 flux densities of 22 sources with spectroscopically determined redshifts, using a two-component modified blackbody spectrum as a template. We find a cold- and hot-dust temperature of 21.29_{-1.66}^{+1.35} and 45.80_{-3.48}^{+2.88} K, a cold-to-hot dust mass ratio of 26.62_{-6.74}^{+5.61} and a β of 1.83_{-0.28}^{+0.14}. The poor quality of the fit suggests that the sample of galaxies is too diverse to be explained by our simple model. Comparison of our sample to a galaxy evolution model indicates that the fraction of lenses are high. Out of the 152 SCUBA-2 detected galaxies, the model predicts 128.4 ± 2.1 of those galaxies to be lensed (84.5 per cent). The SPIRE 500 μm flux suggests that out of all 209 HerBS sources, we expect 158.1 ± 1.7 lensed sources, giving a total lensing fraction of 76 per cent.

  15. 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.

  16. 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

    line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs...

  17. First results from Faint Infrared Grism Survey (FIGS)

    DEFF Research Database (Denmark)

    Tilvi, V.; Pirzkal, N.; Malhotra, S.

    2016-01-01

    in the Faint Infrared Grism Survey (FIGS). These spectra, taken with G102 grism on Hubble Space Telescope (HST), show a significant emission line detection (6{\\sigma}) in multiple observational position angles (PA), with total integrated Ly{\\alpha} line flux of 1.06+/- 0.12 e10-17erg s-1cm-2. The line flux...... is nearly a factor of four higher than the previous MOSFIRE spectroscopic observations of faint Ly{\\alpha} emission at {\\lambda} = 1.0347{\\mu}m, yielding z = 7.5078+/- 0.0004. This is consistent with other recent observations implying that ground-based near-infrared spectroscopy underestimates total...

  18. Herschel spectroscopic observations of PPNe and PNe

    Science.gov (United States)

    García-Lario, Pedro; Ramos-Medina, J.; Sánchez-Contreras, C.

    2017-10-01

    We are building a catalogue of interactively reprocessed observations of evolved stars observed with Herschel. The catalogue will offer not only the PACS and SPIRE spectroscopic data for each observation, but also complementary information from other infrared space observatories. As a first step, we are concentrating our efforts on two main activities: 1) the interactive data-reduction of more than 500 individual spectra obtained with PACS in the 55-210 μm range, available in the Herschel Science Archive; 2) the creation of a catalogue, accesible via a web-based interface and through the Virtual Observatory. Our ultimate goal is to carry out a comprehensive and systematic study of the far infrared properties of low-and intermediate-mass evolved stars using these data and enable science based on Herschel archival data. The objects cover the whole range of possible evolutionary stages in this short-lived phase of stellar evolution, from the AGB to the PN stage, displaying a wide variety of chemical and physical properties.

  19. The molecular circumnuclear disk (CND) in Centaurus A. A multi-transition CO and [CI] survey with Herschel, APEX, JCMT, and SEST

    NARCIS (Netherlands)

    Israel, F. P.; Güsten, R.; Meijerink, R.; Loenen, A. F.; Requena-Torres, M. A.; Stutzki, J.; van der Werf, P.; Harris, A.; Kramer, C.; Martin-Pintado, J.; Weiss, A.

    This paper presents emission line intensities of CO and C° from the compact circumnuclear disk in the center of NGC 5128 (Centaurus A) obtained with the Herschel Space Observatory in the 400-1000 GHz range as well as previously unpublished measurements obtained with the ground-based observatories

  20. "TNOs are Cool": A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations

    NARCIS (Netherlands)

    Lellouch, E.; Santos-Sanz, P.; Lacerda, P.; Mommert, M.; Duffard, R.; Ortiz, J. L.; Müller, T. G.; Fornasier, S.; Stansberry, J.; Kiss, Cs.; Vilenius, E.; Mueller, M.; Peixinho, N.; Moreno, R.; Groussin, O.; Delsanti, A.; Harris, A. W.

    2013-01-01

    Aims: The goal of this work is to characterize the ensemble thermal properties of the Centaurs / trans-Neptunian population. Methods: Thermal flux measurements obtained with Herschel/PACS and Spitzer/MIPS provide size, albedo, and beaming factors for 85 objects (13 of which are presented here for

  1. "TNOs are Cool" : A survey of the trans-Neptunian region IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations

    NARCIS (Netherlands)

    Lellouch, E.; Santos-Sanz, P.; Lacerda, P.; Mommert, M.; Duffard, R.; Ortiz, J. L.; Mueller, T. G.; Fornasier, S.; Stansberry, J.; Kiss, Cs.; Vilenius, E.; Mueller, M.; Peixinho, N.; Moreno, R.; Groussin, O.; Delsanti, A.; Harris, A. W.

    Aims. The goal of this work is to characterize the ensemble thermal properties of the Centaurs/trans-Neptunian population. Methods. Thermal flux measurements obtained with Herschel/PACS and Spitzer/MIPS provide size, albedo, and beaming factors for 85 objects (13 of which are presented here for the

  2. 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.

  3. Herschel Observations of Interstellar Chloronium

    Science.gov (United States)

    Neufeld, David A.; Roueff, Evelyne; Snell, Ronald L.; Lis, Dariusz; Benz, Arnold O.; Bruderer, Simon; Black, John H.; De Luca, Massimo; Gerin, Maryvonne; Goldsmith, Paul F.; Gupta, Harshal; Indriolo, Nick; Le Bourlot, Jacques; Le Petit, Franck; Larsson, Bengt; Melnick, Gary J.; Menten, Karl M.; Monje, Raquel; Nagy, Zsófia; Phillips, Thomas G.; Sandqvist, Aage; Sonnentrucker, Paule; van der Tak, Floris; Wolfire, Mark G.

    2012-03-01

    Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have observed para-chloronium (H2Cl+) toward six sources in the Galaxy. We detected interstellar chloronium absorption in foreground molecular clouds along the sight lines to the bright submillimeter continuum sources Sgr A (+50 km s-1 cloud) and W31C. Both the para-H35 2Cl+ and para-H37 2Cl+ isotopologues were detected, through observations of their 111-000 transitions at rest frequencies of 485.42 and 484.23 GHz, respectively. For an assumed ortho-to-para ratio (OPR) of 3, the observed optical depths imply that chloronium accounts for ~4%-12% of chlorine nuclei in the gas phase. We detected interstellar chloronium emission from two sources in the Orion Molecular Cloud 1: the Orion Bar photodissociation region and the Orion South condensation. For an assumed OPR of 3 for chloronium, the observed emission line fluxes imply total beam-averaged column densities of ~2 × 1013 cm-2 and ~1.2 × 1013 cm-2, respectively, for chloronium in these two sources. We obtained upper limits on the para-H35 2Cl+ line strengths toward H2 Peak 1 in the Orion Molecular cloud and toward the massive young star AFGL 2591. The chloronium abundances inferred in this study are typically at least a factor ~10 larger than the predictions of steady-state theoretical models for the chemistry of interstellar molecules containing chlorine. Several explanations for this discrepancy were investigated, but none has proven satisfactory, and thus the large observed abundances of chloronium remain puzzling. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  4. William Herschel and Comets

    Science.gov (United States)

    Sullivan, Woodruff

    2018-01-01

    I examine the observational and theoretical researches of William Herschel on 21 comets that he observed over the period 1781 to 1812. Herschel's focus, unlike most contemporaries, was on their physical structure, not their orbits. He forged a strong connection between comets and his nebulae with a scheme of cometary "maturation" (1812) involved a comet traveling from star to star after its central "planetary body'; was born from gravitational collapse of a nebula. During close passages of a star, the comet brightened and lost mass from its atmosphere; at other times, when between stars, it encountered nebulae and was rejuvenated by picking up more mass. Laplace soon adopted these ideas to improve his nebula hypothesis for solar system formation.

  5. A Spitzer Survey for Outflows in Infrared Dark Clouds

    Science.gov (United States)

    Hora, Joseph L.; Cyganowski, Claudia; Smith, Howard; Foster, Jonathan; Povich, Matthew; Finn, Susanna; Jackson, James

    2015-08-01

    We recently completed a survey of Infrared Dark Clouds (IRDCs) with Spitzer to search for new outflows and to study the low-mass young stellar object (YSO) population associated with the IRDCs. The star formation activity of the sample ranges from candidate starless cores to IR-bright massive YSOs. The new, much deeper data will enable us to probe these clouds to lower mass limits to obtain a better census of YSOs in the regions, and to find outflows from deeply embedded objects using the 4.5 micron emission that were previously undetected. We will present some early results from this survey.

  6. FIGS—Faint Infrared Grism Survey: Description and Data Reduction

    Science.gov (United States)

    Pirzkal, Norbert; Malhotra, Sangeeta; Ryan, Russell E.; Rothberg, Barry; Grogin, Norman; Finkelstein, Steven L.; Koekemoer, Anton M.; Rhoads, James; Larson, Rebecca L.; Christensen, Lise; Cimatti, Andrea; Ferreras, Ignacio; Gardner, Jonathan P.; Gronwall, Caryl; Hathi, Nimish P.; Hibon, Pascale; Joshi, Bhavin; Kuntschner, Harald; Meurer, Gerhardt R.; O'Connell, Robert W.; Oestlin, Goeran; Pasquali, Anna; Pharo, John; Straughn, Amber N.; Walsh, Jeremy R.; Watson, Darach; Windhorst, Rogier A.; Zakamska, Nadia L.; Zirm, Andrew

    2017-09-01

    The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8 μm-1.15 μm continuous coverage) with a total exposure time of 40 orbits (≈100 kilo-seconds) per field. This reaches a 3σ continuum depth of ≈ 26 AB magnitudes and probes emission lines to ˜ {10}-17 {erg} {{{s}}}-1 {{cm}}-2. This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10,000 spectra of over 2000 distinct sources brighter than {m}F105W=26.5 mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D spectra for each object in the survey.

  7. Brown Dwarfs in the UKIRT Infrared Deep Sky Survey (UKIDSS)

    Science.gov (United States)

    Hambly, Nigel; UKIDSS Consortium

    2003-06-01

    During the final quarter of 2003, UKIRT will take delivery of WFCAM. This new wide--field camera will have a FOV of 0.2 square degrees, and is therefore well suited to large--scale survey work. A consortium of more than 60 astronomers has successfully bid for a large fraction of all UKIRT time over the next 5 years to undertake several public surveys using this new facility. These surveys are collectively known as the UKIRT Infrared Deep Sky Survey (UKIDSS). In this short paper I will describe the project and review the prospects for BD research using UKIDSS data, highlighting some of the major science goals related to BDs that we hope will be achieved.

  8. 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

    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...

  9. AKARI Mid-Infrared All-Sky Survey Diffuse Map

    Science.gov (United States)

    Ishihara, Daisuke; Onaka, Takashi; Akari Team; Kaneda, Hidehiro; Oyabu, Shinki; Mouri, Akio; Kondo, Toru; Suzuki, Satoshi; Yamagishi, Mitsuyoshi

    2012-07-01

    AKARI, the Japanese infrared astronomical satellite launched in February 2006, exhausted its liquid helium cryogen in August 2007. For about one and a half years of the cold mission phase, AKARI performed all-sky surveys in the two mid-infrared photometric bands centered at 9 and 18 microns with higher spatial resolutions and sensitivities than IRAS. Both bands cover slightly shorter wavelength ranges than the IRAS 12 and 25 micron bands and thus provide different information on the infrared sky. In particular, the AKARI 9 micron band map has unique advantage in tracing the distribution of polycyclic aromatic hydrocarbons (PAHs) for the whole sky. To enable discussion on faint diffuse interstellar emission, we have improved the AKARI mid-infrared all-sky diffuse maps by correcting artifacts such as those caused by space ionizing radiation and scattered light from the moon and very bright sources. The quality of these diffuse maps are now being checked within the AKARI team. We plan to release them to the public in near future.

  10. 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

  11. SHINE, The SpHere INfrared survey for Exoplanets

    Science.gov (United States)

    Chauvin, G.; Desidera, S.; Lagrange, A.-M.; Vigan, A.; Feldt, M.; Gratton, R.; Langlois, M.; Cheetham, A.; Bonnefoy, M.; Meyer, M.

    2017-12-01

    The SHINE survey for SPHERE High-contrast ImagiNg survey for Exoplanets, is a large near-infrared survey of 400-600 young, nearby stars and represents a significant component of the SPHERE consortium Guaranteed Time Observations consisting in 200 observing nights. The scientific goals are: i) to characterize known planetary systems (architecture, orbit, stability, luminosity, atmosphere); ii) to search for new planetary systems using SPHERE's unprecedented performance; and finally iii) to determine the occurrence and orbital and mass function properties of the wide-orbit, giant planet population as a function of the stellar host mass and age. Combined, the results will increase our understanding of planetary atmospheric physics and the processes of planetary formation and evolution.

  12. "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

  13. 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....

  14. "TNOs are Cool": A survey of the trans-Neptunian region. XIII. Statistical analysis of multiple trans-Neptunian objects observed with Herschel Space Observatory

    Science.gov (United States)

    Kovalenko, I. D.; Doressoundiram, A.; Lellouch, E.; Vilenius, E.; Müller, T.; Stansberry, J.

    2017-11-01

    Context. Gravitationally bound multiple systems provide an opportunity to estimate the mean bulk density of the objects, whereas this characteristic is not available for single objects. Being a primitive population of the outer solar system, binary and multiple trans-Neptunian objects (TNOs) provide unique information about bulk density and internal structure, improving our understanding of their formation and evolution. Aims: The goal of this work is to analyse parameters of multiple trans-Neptunian systems, observed with Herschel and Spitzer space telescopes. Particularly, statistical analysis is done for radiometric size and geometric albedo, obtained from photometric observations, and for estimated bulk density. Methods: We use Monte Carlo simulation to estimate the real size distribution of TNOs. For this purpose, we expand the dataset of diameters by adopting the Minor Planet Center database list with available values of the absolute magnitude therein, and the albedo distribution derived from Herschel radiometric measurements. We use the 2-sample Anderson-Darling non-parametric statistical method for testing whether two samples of diameters, for binary and single TNOs, come from the same distribution. Additionally, we use the Spearman's coefficient as a measure of rank correlations between parameters. Uncertainties of estimated parameters together with lack of data are taken into account. Conclusions about correlations between parameters are based on statistical hypothesis testing. Results: We have found that the difference in size distributions of multiple and single TNOs is biased by small objects. The test on correlations between parameters shows that the effective diameter of binary TNOs strongly correlates with heliocentric orbital inclination and with magnitude difference between components of binary system. The correlation between diameter and magnitude difference implies that small and large binaries are formed by different mechanisms. Furthermore

  15. A survey of infrared and visual image fusion methods

    Science.gov (United States)

    Jin, Xin; Jiang, Qian; Yao, Shaowen; Zhou, Dongming; Nie, Rencan; Hai, Jinjin; He, Kangjian

    2017-09-01

    Infrared (IR) and visual (VI) image fusion is designed to fuse multiple source images into a comprehensive image to boost imaging quality and reduce redundancy information, which is widely used in various imaging equipment to improve the visual ability of human and robot. The accurate, reliable and complementary descriptions of the scene in fused images make these techniques be widely used in various fields. In recent years, a large number of fusion methods for IR and VI images have been proposed due to the ever-growing demands and the progress of image representation methods; however, there has not been published an integrated survey paper about this field in last several years. Therefore, we make a survey to report the algorithmic developments of IR and VI image fusion. In this paper, we first characterize the IR and VI image fusion based applications to represent an overview of the research status. Then we present a synthesize survey of the state of the art. Thirdly, the frequently-used image fusion quality measures are introduced. Fourthly, we perform some experiments of typical methods and make corresponding analysis. At last, we summarize the corresponding tendencies and challenges in IR and VI image fusion. This survey concludes that although various IR and VI image fusion methods have been proposed, there still exist further improvements or potential research directions in different applications of IR and VI image fusion.

  16. Water in star-forming regions with Herschel (WISH). VI. Constraints on UV and X-ray irradiation from a survey of hydrides in low- to high-mass young stellar objects

    Science.gov (United States)

    Benz, A. O.; Bruderer, S.; van Dishoeck, E. F.; Melchior, M.; Wampfler, S. F.; van der Tak, F.; Goicoechea, J. R.; Indriolo, N.; Kristensen, L. E.; Lis, D. C.; Mottram, J. C.; Bergin, E. A.; Caselli, P.; Herpin, F.; Hogerheijde, M. R.; Johnstone, D.; Liseau, R.; Nisini, B.; Tafalla, M.; Visser, R.; Wyrowski, F.

    2016-05-01

    Context. Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time thanks to the Herschel Space Observatory. Ionized hydrides such as CH+ and OH+ (and also HCO+), which affect the chemistry of molecules such as water, provide complementary information on irradiation by far-UV (FUV) or X-rays and gas temperature. Aims: We explore hydrides of the most abundant heavier elements in an observational survey covering young stellar objects (YSOs) with different mass and evolutionary state. The focus is on hydrides associated with the dense protostellar envelope and outflows, contrary to previous work that focused on hydrides in diffuse foreground clouds. Methods: Twelve YSOs were observed with HIFI on Herschel in six spectral settings providing fully velocity-resolved line profiles as part of the Water in star-forming regions with Herschel (WISH) program. The YSOs include objects of low (Class 0 and I), intermediate, and high mass, with luminosities ranging from 4 L⊙ to 2 × 105 L⊙. Results: The targeted lines of CH+, OH+, H2O+, C+, and CH are detected mostly in blue-shifted absorption. H3O+ and SH+ are detected in emission and only toward some high-mass objects. The observed line parameters and correlations suggest two different origins related to gas entrained by the outflows and to the circumstellar envelope. The derived column densities correlate with bolometric luminosity and envelope mass for all molecules, best for CH, CH+, and HCO+. The column density ratios of CH+/OH+ are estimated from chemical slab models, assuming that the H2 density is given by the specific density model of each object at the beam radius. For the low-mass YSOs the observed ratio can be reproduced for an FUV flux of 2-400 times the interstellar radiation field (ISRF) at the location of the molecules. In two high

  17. 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

  18. 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.

  19. Predicting future space near-IR grism surveys using the WFC3 infrared spectroscopic parallels survey

    Energy Technology Data Exchange (ETDEWEB)

    Colbert, James W.; Atek, Hakim [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Teplitz, Harry; Rafelski, Marc [Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States); Bunker, Andrew [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Ross, Nathaniel; Malkan, Matt [Department of Physics and Astronomy, University of California, Los Angeles, CA (United States); Scarlata, Claudia; Bedregal, Alejandro G. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Dominguez, Alberto; Masters, Dan; Siana, Brian [Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521 (United States); Dressler, Alan; McCarthy, Patrick [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Henry, Alaina [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Martin, Crystal L. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)

    2013-12-10

    We present near-infrared emission line counts and luminosity functions from the Hubble Space Telescope Wide Field Camera 3 Infrared Spectroscopic Parallels (WISP) program for 29 fields (0.037 deg{sup 2}) observed using both the G102 and G141 grism. Altogether we identify 1048 emission line galaxies with observed equivalent widths greater than 40 Å, 467 of which have multiple detected emission lines. We use simulations to correct for significant (>20%) incompleteness introduced in part by the non-dithered, non-rotated nature of the grism parallels. The WISP survey is sensitive to fainter flux levels ((3-5) × 10{sup –17} erg s{sup –1} cm{sup –2}) than the future space near-infrared grism missions aimed at baryonic acoustic oscillation cosmology ((1-4) × 10{sup –16} erg s{sup –1} cm{sup –2}), allowing us to probe the fainter emission line galaxies that the shallower future surveys may miss. Cumulative number counts of 0.7 < z < 1.5 galaxies reach 10,000 deg{sup –2} above an Hα flux of 2 × 10{sup –16} erg s{sup –1} cm{sup –2}. Hα-emitting galaxies with comparable [O III] flux are roughly five times less common than galaxies with just Hα emission at those flux levels. Galaxies with low Hα/[O III] ratios are very rare at the brighter fluxes that future near-infrared grism surveys will probe; our survey finds no galaxies with Hα/[O III] < 0.95 that have Hα flux greater than 3 × 10{sup –16} erg s{sup –1} cm{sup –2}. Our Hα luminosity function contains a comparable number density of faint line emitters to that found by the Near IR Camera and Multi-Object Spectrometer near-infrared grism surveys, but significantly fewer (factors of 3-4 less) high-luminosity emitters. We also find that our high-redshift (z = 0.9-1.5) counts are in agreement with the high-redshift (z = 1.47) narrowband Hα survey of HiZELS (Sobral et al.), while our lower redshift luminosity function (z = 0.3-0.9) falls slightly below their z = 0.84 result. The evolution

  20. Herschel PACS Observations and Modeling of Debris Disks in the Tucana-Horologium Association

    OpenAIRE

    Donaldson, J. K.; Roberge, A.; Chen, C H; Augereau, J. -C.; Dent, W. R. F.; Eiroa, C.; Krivov, A. V.; Mathews, G. S.; Meeus, G.; Ménard, F.; Riviere-Marichalar, P.; Sandell, G.

    2012-01-01

    We present Herschel PACS photometry of seventeen 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" (GASPS). Six of the seventeen 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...

  1. 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

  2. Isothermal dust models of Herschel-ATLAS galaxies

    Science.gov (United States)

    Smith, D. J. B.; Hardcastle, M. J.; Jarvis, M. J.; Maddox, S. J.; Dunne, L.; Bonfield, D. G.; Eales, S.; Serjeant, S.; Thompson, M. A.; Baes, M.; Clements, D. L.; Cooray, A.; De Zotti, G.; Gonzàlez-Nuevo, J.; van der Werf, P.; Virdee, J.; Bourne, N.; Dariush, A.; Hopwood, R.; Ibar, E.; Valiante, E.

    2013-12-01

    We use galaxies from the Herschel-ATLAS (H-ATLAS) survey, and a suite of ancillary simulations based on an isothermal dust model, to study our ability to determine the effective dust temperature, luminosity and emissivity index of 250 μm selected galaxies in the local Universe (z < 0.5). As well as simple far-infrared spectral energy distribution (SED) fitting of individual galaxies based on χ2 minimization, we attempt to derive the best global isothermal properties of 13 826 galaxies with reliable optical counterparts and spectroscopic redshifts. Using our simulations, we highlight the fact that applying traditional SED fitting techniques to noisy observational data in the Herschel Space Observatory bands introduces artificial anti-correlation between derived values of dust temperature and emissivity index. This is true even for galaxies with the most robust statistical detections in our sample, making the results of such fitting difficult to interpret. We apply a method to determine the best-fitting global values of isothermal effective temperature and emissivity index for z < 0.5 galaxies in H-ATLAS, deriving Teff = 22.3 ± 0.1 K and β = 1.98 ± 0.02 (or Teff = 23.5 ± 0.1 K and β = 1.82 ± 0.02 if we attempt to correct for bias by assuming that Teff and βeff are independent and normally distributed). We use our technique to test for an evolving emissivity index, finding only weak evidence. The median dust luminosity of our sample is log10(Ldust/L⊙) = 10.72 ± 0.05, which (unlike Teff) shows little dependence on the choice of β used in our analysis, including whether it is variable or fixed. In addition, we use a further suite of simulations based on a fixed emissivity index isothermal model to emphasize the importance of the H-ATLAS PACS data for deriving dust temperatures at these redshifts, even though they are considerably less sensitive than the SPIRE data. Finally, we show that the majority of galaxies detected by H-ATLAS are normal star

  3. HELP: XID+, the probabilistic de-blender for Herschel SPIRE maps

    Science.gov (United States)

    Hurley, P. D.; Oliver, S.; Betancourt, M.; Clarke, C.; Cowley, W. I.; Duivenvoorden, S.; Farrah, D.; Griffin, M.; Lacey, C.; Le Floc'h, E.; Papadopoulos, A.; Sargent, M.; Scudder, J. M.; Vaccari, M.; Valtchanov, I.; Wang, L.

    2017-01-01

    We have developed a new prior-based source extraction tool, XID+, to carry out photometry in the Herschel SPIRE (Spectral and Photometric Imaging Receiver) maps at the positions of known sources. XID+ is developed using a probabilistic Bayesian framework that provides a natural framework in which to include prior information, and uses the Bayesian inference tool Stan to obtain the full posterior probability distribution on flux estimates. In this paper, we discuss the details of XID+ and demonstrate the basic capabilities and performance by running it on simulated SPIRE maps resembling the COSMOS field, and comparing to the current prior-based source extraction tool DESPHOT. Not only we show that XID+ performs better on metrics such as flux accuracy and flux uncertainty accuracy, but we also illustrate how obtaining the posterior probability distribution can help overcome some of the issues inherent with maximum-likelihood-based source extraction routines. We run XID+ on the COSMOS SPIRE maps from Herschel Multi-Tiered Extragalactic Survey using a 24-μm catalogue as a positional prior, and a uniform flux prior ranging from 0.01 to 1000 mJy. We show the marginalized SPIRE colour-colour plot and marginalized contribution to the cosmic infrared background at the SPIRE wavelengths. XID+ is a core tool arising from the Herschel Extragalactic Legacy Project (HELP) and we discuss how additional work within HELP providing prior information on fluxes can and will be utilized. The software is available at https://github.com/H-E-L-P/XID_plus. We also provide the data product for COSMOS. We believe this is the first time that the full posterior probability of galaxy photometry has been provided as a data product.

  4. Applications of thermal infrared imagery for energy conservation and environmental surveys

    Science.gov (United States)

    Carney, J. R.; Vogel, T. C.; Howard, G. E., Jr.; Love, E. R.

    1977-01-01

    The survey procedures, developed during the winter and summer of 1976, employ color and color infrared aerial photography, thermal infrared imagery, and a handheld infrared imaging device. The resulting imagery was used to detect building heat losses, deteriorated insulation in built-up type building roofs, and defective underground steam lines. The handheld thermal infrared device, used in conjunction with the aerial thermal infrared imagery, provided a method for detecting and locating those roof areas that were underlain with wet insulation. In addition, the handheld infrared device was employed to conduct a survey of a U.S. Army installation's electrical distribution system under full operating loads. This survey proved to be cost effective procedure for detecting faulty electrical insulators and connections that if allowed to persist could have resulted in both safety hazards and loss in production.

  5. CMB Polarization B-mode Delensing with SPTpol and Herschel

    Science.gov (United States)

    Manzotti, A.; Story, K. T.; Wu, W. L. K.; Austermann, J. E.; Beall, J. A.; Bender, A. N.; Benson, B. A.; Bleem, L. E.; Bock, J. J.; Carlstrom, J. E.; Chang, C. L.; Chiang, H. C.; Cho, H.-M.; Citron, R.; Conley, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Dodelson, S.; Everett, W.; Gallicchio, J.; George, E. M.; Gilbert, A.; Halverson, N. W.; Harrington, N.; Henning, J. W.; Hilton, G. C.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hou, Z.; Hrubes, J. D.; Huang, N.; Hubmayr, J.; Irwin, K. D.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Li, D.; McMahon, J. J.; Meyer, S. S.; Mocanu, L. M.; Natoli, T.; Nibarger, J. P.; Novosad, V.; Padin, S.; Pryke, C.; Reichardt, C. L.; Ruhl, J. E.; Saliwanchik, B. R.; Sayre, J. T.; Schaffer, K. K.; Smecher, G.; Stark, A. A.; Vanderlinde, K.; Vieira, J. D.; Viero, M. P.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Zemcov, M.

    2017-09-01

    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 deg2 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 Herschel 500 μm map of the cosmic infrared background. We find that our delensing procedure reduces the measured B-mode power spectrum by 28% in the multipole range 300work 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.

  6. Emission Line Metallicities from the Faint Infrared Grism Survey

    Science.gov (United States)

    Pharo, John; Christensen, Lise; Malhotra, Sangeeta; Rhoads, James; Smith, Mark; Harish, Santosh; yang, huan; FIGS Collaboration

    2018-01-01

    We present the redshifts and line identifications for 71 emission-line galaxies (ELGs) with z ~ 0.3 - 3 in the HUDF as part of the Faint Infrared Grism Survey (FIGS). We have calculated gas-phase metallicity for 39 ELGs using the R23 method, and for 14 ELGs for which we have [OIII]4363 measurements at S/N > 3, which enables the direct measurement of metallicity from the [OIII] electron temperature. The ELGs were selected by an automatic search of one-dimensional slitless spectroscopy from the WFC3 G102 grism on the Hubble Space Telescope. We matched the ELG candidate spectra with high-resolution optical spectra from MUSE, which allowed confirmation and identification of single-line FIGS detections and provided lower-wavelength line measurements. Once individual line fluxes were measured, we produced metallicities via the [OIII]4363 and R23 methods and analyzed the metallicity in relation to mass, star formation rate, and other properties.

  7. A NuSTAR SURVEY OF NEARBY ULTRALUMINOUS INFRARED GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Stacy H.; Rigby, Jane R.; Ptak, Andrew [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Alexander, D. M. [Department of Physics, Durham University, Durham, DH1 3LE (United Kingdom); Bauer, Franz E. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Boggs, Stephen E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Brandt, W. Niel; Luo, Bin [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Christensen, Finn E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Comastri, Andrea [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Farrah, Duncan [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Gandhi, Poshak [School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ (United Kingdom); Hailey, Charles J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Harrison, Fiona A. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Hickox, Ryan C. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Koss, Michael [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); and others

    2015-11-20

    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 possible. Six of the nine sources observed were detected sufficiently well by NuSTAR to model in detail their broadband X-ray spectra, and recover the levels of obscuration and intrinsic X-ray luminosities. Only one source (IRAS 13120–5453) has a spectrum consistent with a Compton-thick active galactic nucleus (AGN), but we cannot rule out that a second source (Arp 220) harbors an extremely highly obscured AGN as well. Variability in column density (reduction by a factor of a few compared to older observations) is seen in IRAS 05189–2524 and Mrk 273, altering the classification of these borderline sources from Compton-thick to Compton-thin. The ULIRGs in our sample have surprisingly low observed fluxes in high-energy (>10 keV) X-rays, especially compared to their bolometric luminosities. They have lower ratios of unabsorbed 2–10 keV to bolometric luminosity, and unabsorbed 2–10 keV to mid-IR [O iv] 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.

  8. Andromeda Optical & Infrared Disk Survey: Stellar Populations and Mass Decomposition

    Science.gov (United States)

    Sick, Jonathan; Courteau, Stephane; Cuillandre, Jean-Charles; Dalcanton, Julianne; de Jong, Roelof S.; McDonald, Michael; Tully, R. Brent

    2015-01-01

    M31 is ideal for understanding the structure and stellar populations of spiral galaxies thanks to its proximity and our external vantage point. The Andromeda Optical & Infrared Disk Survey (ANDROIDS) has used MegaCam and WIRCam on the Canada-France Hawaii Telescope to map the M31 bulge and disk out to R=40 kpc in ugriJKs bands. Through careful sky monitoring and modelling, ANDROIDS is uniquely able to observe both the resolved stars and integrated spectral energy distributions (SEDs) over M31's entire disk (complimenting HST's PHAT program). By simultaneously fitting stellar populations with isochrones and SED models for M31, we can assess the systematic uncertainties of SED fits to more distant unresolved systems, and constrain the stellar populations that contribute to each bandpass. We pay close attention to the near-IR light of asymptotic giant branch (AGB) stars in stellar population models. ANDROIDS has also surveyed M31 in narrowband TiO and CN bands, enabling a clean classification of Carbon AGB stars, and a mapping the ratio of Carbon and M-type AGB stars (C/M) across the entire disk. The correlation between C/M and stellar metallicity is useful for constraining the NIR colors of more distant galaxies. We also present a hierarchical Bayesian model of pixel-by-pixel stellar populations, yielding the most detailed map of M31's stellar mass and star formation history to date. We find that a full six-band optical-NIR fit provides the best constraints to stellar mass, a triumph for modern NIR stellar population synthesis models, though the results are consistent with an optical-only fits. Fits based on the popular g-i color combination find M/L* ratios biased by 0.1 dex, while color-mass-to-light prescriptions in the literature may differ by 0.3 dex. This result affirms that panchromatic SED modelling is crucial even for stellar mass estimation, let alone age and metallicity. Overall, we estimate the stellar mass of M31, within R=30 kpc, to be 10.3 (+2.3, -1

  9. 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

  10. The Herschel DUNES Open Time Key Programme

    Science.gov (United States)

    Danchi, William C.

    2009-01-01

    We will use the unique photometric capabilities provided by Herschel to perform a deep and systematic survey for faint, cold debris disks around nearby stars. Our sensitivity-limited Open Time Key Programme (OTKP) aims at finding and characterizing faint extrasolar analogues to the Edgeworth-Kuiper Belt (EKB) in an unbiased, statistically significant sample of nearby FGK main-sequence stars. Our target set spans a broad range of stellar ages (from 0.1 to 10 Gyr) and is volume-limited (distances 5. The observations in the other Herschel bands will allow us to characterize, model, and constrain the disks. As a result, it will be possible for us to reach fractional dust luminosities of a few times 10-7, close to the EKB level in the Solar System. This will provide an unprecedented lower limit to the fractional abundance of planetesimal systems and allow us to assess the presence of giant planets, which would play dynamical roles similar to those played by Jupiter and Neptune in the Solar System. The proposed observations will provide new and unique evidence for the presence of mature planetary systems in the solar neighbourhood and, in turn, will address the universality of planet/planetary system formation in disks around young stars.

  11. Molecular Gas Content of an Extremely Star-forming Herschel Observed Lensed Dusty Galaxy at z=2.685

    Science.gov (United States)

    Nayyeri, Hooshang; Cooray, Asantha R.; H-ATLAS

    2017-01-01

    We present the results of combined deep near-infrared, far infrared and millimeter observations of an extremely star forming lensed dusty star-forming galaxy (DSFG) identified from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). The high redshift DSFG is gravitationally lensed by a massive WISE identified cluster at z~1 (spectroscopically confirmed with Keck/DEIMOS and Gemini/GMOS) producing multiply lensed images and arcs observed in the optical. The DSFG is spectroscopically confirmed at z=2.685 from CO(1-0) observations by GBT and separately from CO(3-2) observations by CARMA. We use the combined spectroscopic and imaging observations to construct a detailed lens model of the background DSFG which allowed us to study the sources plane properties of the target. Multi-band data from Keck/NIRC2, HST/WFC3 and Herschel yields star formation rate and stellar mass well above the main sequence. Observations of the dust continuum by the Sub-millimeter Array yields an observed total ISM mass of 6.5E+11 M* which is responsible for the intense observed star formation rates. Comparing the measured SFR with molecular gas measurements from CO(1-0) observations reveals that this system has relatively short gas depletion time scale which is consistent with the starburst phase observed in high redshift sub-millimeter galaxies.

  12. Fourier-space combination of Planck and Herschel images

    Science.gov (United States)

    Abreu-Vicente, J.; Stutz, A.; Henning, Th.; Keto, E.; Ballesteros-Paredes, J.; Robitaille, T.

    2017-08-01

    Context. Herschel has revolutionized our ability to measure column densities (NH) and temperatures (T) of molecular clouds thanks to its far infrared multiwavelength coverage. However, the lack of a well defined background intensity level in the Herschel data limits the accuracy of the NH and T maps. Aims: We aim to provide a method that corrects the missing Herschel background intensity levels using the Planck model for foreground Galactic thermal dust emission. For the Herschel/PACS data, both the constant-offset as well as the spatial dependence of the missing background must be addressed. For the Herschel/SPIRE data, the constant-offset correction has already been applied to the archival data so we are primarily concerned with the spatial dependence, which is most important at 250 μm. Methods: We present a Fourier method that combines the publicly available Planck model on large angular scales with the Herschel images on smaller angular scales. Results: We have applied our method to two regions spanning a range of Galactic environments: Perseus and the Galactic plane region around l = 11deg (HiGal-11). We post-processed the combined dust continuum emission images to generate column density and temperature maps. We compared these to previously adopted constant-offset corrections. We find significant differences (≳20%) over significant ( 15%) areas of the maps, at low column densities (NH ≲ 1022 cm-2) and relatively high temperatures (T ≳ 20 K). We have also applied our method to synthetic observations of a simulated molecular cloud to validate our method. Conclusions: Our method successfully corrects the Herschel images, including both the constant-offset intensity level and the scale-dependent background variations measured by Planck. Our method improves the previous constant-offset corrections, which did not account for variations in the background emission levels. The image FITS files used in this paper are only available at the CDS via anonymous ftp

  13. A Herschel resolved debris disc around HD 105211

    Science.gov (United States)

    Hengst, S.; Marshall, J. P.; Horner, J.; Marsden, S. C.

    2017-07-01

    Debris discs are the dusty aftermath of planet formation processes around main-sequence stars. Analysis of these discs is often hampered by the absence of any meaningful constraint on the location and spatial extent of the disc around its host star. Multi-wavelength, resolved imaging ameliorates the degeneracies inherent in the modelling process, making such data indispensable in the interpretation of these systems. The Herschel Space Observatory observed HD 105211 (η Cru, HIP 59072) with its Photodetector Array Camera and Spectrometer (PACS) instrument in three far-infrared wavebands (70, 100 and 160 μm). Here we combine these data with ancillary photometry spanning optical to far-infrared wavelengths in order to determine the extent of the circumstellar disc. The spectral energy distribution and multi-wavelength resolved emission of the disc are simultaneously modelled using a radiative transfer and imaging codes. Analysis of the Herschel/PACS images reveals the presence of extended structure in all three PACS images. From a radiative transfer model we derive a disc extent of 87.0 ± 2.5 au, with an inclination of 70.7 ± 2.2° to the line of sight and a position angle of 30.1 ± 0.5°. Deconvolution of the Herschel images reveals a potential asymmetry but this remains uncertain as a combined radiative transfer and image analysis replicates both the structure and the emission of the disc using a single axisymmetric annulus.

  14. Herschel/PACS Survey of protoplanetary disks in Taurus/ Auriga- Investigating the source of [OI] 63 μm line emission

    Science.gov (United States)

    Howard, Christian D.; Sandell, G.{ö.}ran; Vacca, William

    2012-03-01

    GASPS is a large Herschel Open time Key project studying the evolution of gas in protoplanetary disks. We target about 240 nearby objects in Taurus and young associations covering stellar ages between 0.3 - 30 Myr. We use the PACS instrument to observe continuum and selected gas tracers, like [{O}{I}] at 63 and 145 μm, [{C}{II}] at 158 μm as well as several molecular lines like OH, H_2O and CO. The strongest line we see is the [{O}{I}] at 63 μm. However, although it is clear that [{O}{I}] 63 μm traces gas in the disk, it is also strong in jets and outflows. Using the sources observed so far (42 sources detected in both line and continuum of 75 sources observed in spectroscopy and 92 in photometry) in Taurus/Auriga we explore how the [{O}{I}] 63 μm line strength correlates with 63 μm continuum, disk mass, accretion rate, stellar luminosity, and strength of the [{O}{I}] 6300 Å emission for both outflow and non-outflow sources. We find a clear, tight correlation between the strength of the [{O}{I}] 63 μm line emission and 63 μm continuum for non-outflow sources and a weaker correlation for outflow sources. In outflow sources the line can be up to 20 times stronger than in non-outflow sources, indicating that the [{O}{I}] 63 μm emission from the outflow will dominate over the disk emission. For the few sources where we also detect the [{O}{I}] 145 μm line, we find line ratios of 145 to 63 μm of 0.04 - 0.05, suggesting optically thin lines originating from gas with a temperature of a few 100 K, which suggests that the emission comes from the inner part/surface layers of the disk or from the shock regions in the outflow.

  15. "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

  16. The Evolution of Gas in Protoplanetary Systems: The Herschel GASPS Open Time Key Programme

    Science.gov (United States)

    Roberge, A.; Dent, W.

    2010-01-01

    The Gas in Protoplanetary Systems (GASPS) Open Time Key Programme for the Herschel Space Observatory will be the first extensive, systematic survey of gas in circumstellar disks over the critical transition from gas-rich protoplanetary through to gas-poor debris. The brightest spectral lines from disks lie in the far-infrared and arise from radii spanning roughly 10 to 100 AU, where giant planets are expected to form. Herschel is uniquely able to observe this wavelength regime with the sensitivity to allow a large scale survey. We will execute a 2-phase study using the PACS instrument. Phase I is a spectroscopic survey about 250 young stars for fine structure emission lines of [CII] (at 157 microns) and [OI] (at 63 microns). In Phase II, the brightest sources will be followed up with additional PACS spectroscopy ([OI] at 145 microns and some rotational lines of water). We expect that the gas mass sensitivity will be more than an order of magnitude lower than that achieved by ISO and Spitzer or expected for SOFIA. We will also measure the dust continuum to an equivalent mass sensitivity. We will observe several nearby clusters with ages from 1 to 30 Myr, encompassing a wide range of disk masses and stellar luminosities. The sample covers disk evolution from protoplanetary disks through to young debris disks, i.e. the main epoch of planet formation. With this extensive dataset, the GASPS project will: 1) trace gas and dust in the planet formation region across a large multivariate parameter space, 2) provide the first definitive measurement of the gas dissipation timescale in disks, 3) elucidate the evolutionary link between protoplanetary and debris disks, 4) investigate water abundances in the planetforming regions of disks, and 5) provide a huge database of disk observations and models with long-lasting legacy value for follow-up studies.

  17. The Evolution of Gas in Protoplanetary Systems: The Herschel GASPS Open Time Key Programme

    Science.gov (United States)

    Roberge, Aki; Dent, W.; Herschel GASPS Team

    2010-01-01

    The Gas in Protoplanetary Systems (GASPS) Open Time Key Programme for the Herschel Space Observatory will be the first extensive, systematic survey of gas in circumstellar disks over the critical transition from gas-rich protoplanetary through to gas-poor debris. The brightest spectral lines from disks lie in the far-infrared and arise from radii spanning roughly 10 to 100 AU, where giant planets are expected to form. Herschel is uniquely able to observe this wavelength regime with the sensitivity to allow a large scale survey. We will execute a 2-phase study using the PACS instrument. Phase I is a spectroscopic survey about 250 young stars for fine structure emission lines of [CII] (at 157 microns) and [OI] (at 63 microns). In Phase II, the brightest sources will be followed up with additional PACS spectroscopy ([OI] at 145 microns and some rotational lines of water). We expect that the gas mass sensitivity will be more than an order of magnitude lower than that achieved by ISO and Spitzer or expected for SOFIA. We will also measure the dust continuum to an equivalent mass sensitivity. We will observe several nearby clusters with ages from 1 to 30 Myr, encompassing a wide range of disk masses and stellar luminosities. The sample covers disk evolution from protoplanetary disks through to young debris disks, i.e. the main epoch of planet formation. With this extensive dataset, the GASPS project will: 1) trace gas and dust in the planet formation region across a large multivariate parameter space, 2) provide the first definitive measurement of the gas dissipation timescale in disks, 3) elucidate the evolutionary link between protoplanetary and debris disks, 4) investigate water abundances in the planet-forming regions of disks, and 5) provide a huge database of disk observations and models with long-lasting legacy value for follow-up studies.

  18. A survey on infrared thermography for convective heat transfer measurements

    Energy Technology Data Exchange (ETDEWEB)

    Astarita, T.; Cardone, G.; Carlomagno, G.M.; Meola, C. [Universita degli Studi di Napoli ' ' Federico II' ' (Italy). Dipartimento di Energetica

    2000-11-01

    During the past several years infrared thermography has evolved into a powerful investigative means, of thermo-fluid-dynamic analysis to measure convective heat fluxes as well as to investigate the surface flow field behaviour over complicated body shapes. The basic concepts that govern this innovative measurement technique together with some particular aspects linked to its use are herein reviewed. Different operating methods together with their implementations are also discussed. Finally, the capability of infrared thermography to deal with several simple, or complex, fluid flow configurations is analysed. (author)

  19. Integration of infrared thermography & photogrammetric surveying of built landscape

    NARCIS (Netherlands)

    Scaioni, Marco; Rosina, E.; L'Erario, A.; Díaz-Vilariño, L.

    2017-01-01

    The thermal analysis of buildings represents a key-step for reduction of energy consumption, also in the case of Cultural Heritage. Here the complexity of the constructions and the adopted materials might require special analysis and tailored solutions. Infrared Thermography (IRT) is an important

  20. 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.

  1. Cryogenic Far-IR Laser Absorptivity Measurements of the Herschel Space Observatory Telescope Mirror Coatings

    NARCIS (Netherlands)

    Fischer, J.; Klaassen, T.O.; Hovenier, J.W.; Jakob, G.; Poglitsch, A.; Sternberg, O.

    2004-01-01

    Far-infrared laser calorimetry was used to measure the absorptivity, and thus the emissivity, of aluminum-coated silicon carbide mirror samples produced during the coating qualification run of the Herschel Space Observatory telescope to be launched by the European Space Agency in 2007. The samples

  2. 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

  3. 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...

  4. WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time

    Science.gov (United States)

    Malkan, Matthew

    2013-10-01

    Our WFC3 Infrared Spectroscopic Parallels {WISPs} have shown the power of slitless spectroscopy to probe galaxy evolution from 0.5WISP is particularly sensitive to low-mass, metal-poor, galaxies with extreme star formation rates. These are missed by conventional continuum-selected surveys. The broad, continuous, spectral coverage of the G102 and G141 grisms {0.8-1.7 um} provides the best measurement of the de-reddened star formation rate, and the mass-metallicity relation, throughout this epoch, over which ground-based searches are severely limited.We propose to extend this cost-effective WFC3 Survey by using 375 pure parallel orbits for grism spectroscopy in 50 deep {4-5 orbit} and 50 shallow {3-orbit} fields. This will complete a sample of 6000 galaxies with [OII], [OIII], Ha, Hb, or [SII] in the redshift desert. Our primary science goals are: {1} Derive the extinction-corrected Ha luminosity function, and the resulting cosmic history of star formation across 0.51 to low masses, with the support of our ongoing ground-based follow-up. {3} Examine the role of metal-poor dwarfs and extreme starbursts in galaxy assembly. {4} Use the Balmer break and D4000 diagnostics to find and determine the ages of absorption-line galaxies down to J=24-25. {5} Search for rare objects such as Lya emitters at z>6, reddened AGN, close physical pairs of galaxies, T- and Y-dwarf stars {of which we have already found three}.The WISP value-added public data release is likely to be one of Hubble's major legacies of 0.8-1.7 um spectroscopy.

  5. Gravitational lens models based on submillimeter array imaging of Herschel -selected strongly lensed sub-millimeter galaxies at z > 1.5

    Energy Technology Data Exchange (ETDEWEB)

    Bussmann, R. S.; Gurwell, M. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pérez-Fournon, I. [Instituto de Astrofísica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Amber, S. [Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA (United Kingdom); Calanog, J.; De Bernardis, F.; Wardlow, J. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (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); Fu, Hai [Department of Physics and Astronomy, The University of Iowa, 203 Van Allen Hall, Iowa City, IA 52242 (United States); Harris, A. I. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Krips, M. [Institut de RadioAstronomie Millimétrique, 300 Rue de la Piscine, Domaine Universitaire, 38406 Saint Martin d' Hères (France); Lapi, A. [Department Fisica, Univ. Tor Vergata, Via Ricerca Scientifica 1, 00133 Rome, Italy and SISSA, Via Bonomea 265, 34136 Trieste (Italy); Maiolino, R. [Cavendish Laboratory, University of Cambridge, 19 J.J. Thomson Ave., Cambridge CB3 OHE (United Kingdom); Omont, A. [Institut d' Astrophysique de Paris, UMR 7095, CNRS, UPMC Univ. Paris 06, 98bis boulevard Arago, F-75014 Paris (France); Riechers, D. [Department of Astronomy, Space Science Building, Cornell University, Ithaca, NY 14853-6801 (United States); Baker, A. J. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Birkinshaw, M. [HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Bock, J. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); and others

    2013-12-10

    Strong gravitational lenses are now being routinely discovered in wide-field surveys at (sub-)millimeter wavelengths. We present Submillimeter Array (SMA) high-spatial resolution imaging and Gemini-South and Multiple Mirror Telescope optical spectroscopy of strong lens candidates discovered in the two widest extragalactic surveys conducted by the Herschel Space Observatory: the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). From a sample of 30 Herschel sources with S {sub 500} > 100 mJy, 21 are strongly lensed (i.e., multiply imaged), 4 are moderately lensed (i.e., singly imaged), and the remainder require additional data to determine their lensing status. We apply a visibility-plane lens modeling technique to the SMA data to recover information about the masses of the lenses as well as the intrinsic (i.e., unlensed) sizes (r {sub half}) and far-infrared luminosities (L {sub FIR}) of the lensed submillimeter galaxies (SMGs). The sample of lenses comprises primarily isolated massive galaxies, but includes some groups and clusters as well. Several of the lenses are located at z {sub lens} > 0.7, a redshift regime that is inaccessible to lens searches based on Sloan Digital Sky Survey spectroscopy. The lensed SMGs are amplified by factors that are significantly below statistical model predictions given the 500 μm flux densities of our sample. We speculate that this may reflect a deficiency in our understanding of the intrinsic sizes and luminosities of the brightest SMGs. The lensed SMGs span nearly one decade in L {sub FIR} (median L {sub FIR} = 7.9 × 10{sup 12} L {sub ☉}) and two decades in FIR luminosity surface density (median Σ{sub FIR} = 6.0 × 10{sup 11} L {sub ☉} kpc{sup –2}). The strong lenses in this sample and others identified via (sub-)mm surveys will provide a wealth of information regarding the astrophysics of galaxy formation and evolution over a wide range in redshift.

  6. Integration of Infrared Thermography and Photogrammetric Surveying of Built Landscape

    Science.gov (United States)

    Scaioni, M.; Rosina, E.; L'Erario, A.; Dìaz-Vilariño, L.

    2017-05-01

    The thermal analysis of buildings represents a key-step for reduction of energy consumption, also in the case of Cultural Heritage. Here the complexity of the constructions and the adopted materials might require special analysis and tailored solutions. Infrared Thermography (IRT) is an important non-destructive investigation technique that may aid in the thermal analysis of buildings. The paper reports the application of IRT on a listed building, belonging to the Cultural Heritage and to a residential one, as a demonstration that IRT is a suitable and convenient tool for analysing the existing buildings. The purposes of the analysis are the assessment of the damages and energy efficiency of the building envelope. Since in many cases the complex geometry of historic constructions may involve the thermal analysis, the integration of IRT and accurate 3D models were developed during the latest years. Here authors propose a solution based on the up-to-date photogrammetric solutions for purely image-based 3D modelling, including automatic image orientation/sensor calibration using Structure-from-Motion and dense matching. Thus, an almost fully automatic pipeline for the generation of accurate 3D models showing the temperatures on a building skin in a realistic manner is described, where the only manual task is given by the measurement of a few common points for co-registration of RGB and IR photogrammetric projects.

  7. Adaptive Optics Imaging Survey of Luminous Infrared Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Laag, E A; Canalizo, G; van Breugel, W; Gates, E L; de Vries, W; Stanford, S A

    2006-03-13

    We present high resolution imaging observations of a sample of previously unidentified far-infrared galaxies at z < 0.3. The objects were selected by cross-correlating the IRAS Faint Source Catalog with the VLA FIRST catalog and the HST Guide Star Catalog to allow for adaptive optics observations. We found two new ULIGs (with L{sub FIR} {ge} 10{sup 12} L{sub {circle_dot}}) and 19 new LIGs (with L{sub FIR} {ge} 10{sup 11} L{sub {circle_dot}}). Twenty of the galaxies in the sample were imaged with either the Lick or Keck adaptive optics systems in H or K{prime}. Galaxy morphologies were determined using the two dimensional fitting program GALFIT and the residuals examined to look for interesting structure. The morphologies reveal that at least 30% are involved in tidal interactions, with 20% being clear mergers. An additional 50% show signs of possible interaction. Line ratios were used to determine powering mechanism; of the 17 objects in the sample showing clear emission lines--four are active galactic nuclei and seven are starburst galaxies. The rest exhibit a combination of both phenomena.

  8. Spectrometer Technology Development for Far-Infrared Line Surveys

    Science.gov (United States)

    Glenn, Jason

    2005-01-01

    The objective of this proposal was to build and demonstrate a new direct-detection diffraction grating concept and couple it to an array of bolometers. The spectrometer was to be built around a parallel-plate waveguide diffraction grating, WaFIRS: Waveguide Far-InfraRed Spectrometer. The grating is two dimensional in nature, which provides a compact configuration to suit NASA s needs for cryogenic spectrometers for future opportunities, such as infrared/submillimeter spectrometers for a suborbital balloon platform, for SOFIA, for SPICA (a Japanese satellite), and for SAFIR. Our goal was to build a spectrometer (Z-Spec) for 1.0 - 1.5 mm and demonstrate spectral resolution, throughput, and background-limited performance. This grant would partially cover the expenses and we were subsequently awarded a second grant, NAGS-12788, to complete the project. We have one-year received a no-cost extension on NAG.5-12788, to be completed in 3/31/06.

  9. Near-infrared spectroscopic survey of brown dwarfs using NIRSPEC on the Keck II Telescope

    Science.gov (United States)

    McLean, Ian S.

    2003-02-01

    Since commissioning the near-infrared spectrometer (NIRSPEC) on the Keck II telescope in April 1999 we have been carrying out an extensive spectroscopic survey of low-mass stars and brown dwarfs. At least two objects in every spectral sub-class from M6 to T8 have been observed in the J band at a resolution of R ~ 2,000. For a subset of these we have obtained complete near-infrared flux-calibrated spectra from 0.9 - 2.5 μm. In addition, J band spectra at even higher resolution (R ~ 20,000) have been obtained for many sub-classes. The results of the NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) are summarized in this paper and presented as an illustration of the progress in infrared technology and the scientific productivity of the Keck telescopes.

  10. 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

  11. 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...

  12. A spectroscopic survey of young brown dwarfs in the near-infrared

    Science.gov (United States)

    McGovern, Mark Roland

    Motivated by the discovery of numerous Jupiter-sized brown dwarfs in infrared imaging surveys, and stimulated by the advent of sensitive near-infrared (NIR) spectrometers on very large telescopes, this thesis presents the results of a unique observational survey to investigate and characterize the near-infrared spectra of low-mass stars and brown dwarfs. The project, called the NIRSPEC Brown Dwarf Spectroscopic Survey (or BDSS) was carried out with the Keck 10- m telescope on Mauna Kea, Hawaii using the facility cryogenic NIR spectrometer (NIRSPEC) developed at UCLA by Professor Ian McLean. Beginning in April 1999, immediately after NIRSPEC was delivered to the telescope, this infrared spectroscopic survey was developed in multiple phases to obtain the largest self-consistent set of high quality spectra yet obtained for the two new classes of very cool objects known as L and T dwarfs (T eff ~ 2200-750K). This work presents the results of two of the major phases of the BDSS and includes near-infrared spectra from over 150 low-mass stars and brown dwarfs. In the first phase of the project the emphasis was on the effects of decreasing effective temperature (T eff ) on the infrared spectral morphology. Observations were concentrated on the J -band region of the spectrum from 1.14- 1.36 microns. Over 50 objects spanning the spectral types from M6 to T8 were observed in this band. With the spectral resolving power of the NIRSPEC instrument (R ~ 2000) we developed nine spectral indices to classify these objects in the J -band. From this data base it was possible for the first time to create a pure infrared spectral classification system for the L dwarfs, and to confirm the existing infrared classification system for T dwarfs. This is an important development because most of the flux from L and T dwarfs is radiated in the near-infrared, where they are several magnitudes brighter than at visible wavelengths, and classification via NIR properties is not only important but

  13. Characterizing interstellar filaments with Herschel in nearby molecular clouds

    Science.gov (United States)

    Arzoumanian, D.; André, P.; Peretto, N.; Könyves, V.; Schneider, N.; Didelon, P.; Palmeirim, P.

    2012-03-01

    Herschel observations of molecular clouds reveal the presence of complex filamentary structures which are shown to be the main sites of core and protostar formation (André et al. 2010). Understanding the properties of these filaments is a first step toward establishing a broader scenario of star formation in the Galaxy. Thanks to their unprecedented spatial dynamic range in the submillimeter regime, the Herschel images provide detailed quantitative information on these filaments, making it possible to characterize their properties in a statistical manner (Arzoumanian et al. 2011). I will discuss the properties of filaments seen by Herschel in 5 regions from the Gould Belt survey (IC5146, Aquila, Pipe, Taurus, Polaris), located at distances from 150 pc to 460 pc and having different star formation activities (filaments with column densities from ˜ 1020 cm-2 in Polaris to >1023 cm-2 in Aquila). The radial density profiles of the filaments show a power-law behavior at large radii of r-2 (shallower than the hydrostatic isothermal Ostriker model described by ρ ˜ r-4 ) with a flat inner part, which is remarkably uniform (˜ 0.1 pc ) for all filaments in our sample (˜ 150 filaments) regardless of column density. The observed filaments are not strictly isothermal, their dust temperature profiles show a slight (˜ 3K) but significant decrease in temperature toward the center. I will complement the analysis based on Herschel with preliminary line-width measurements with the IRAM 30m telescope. We find evidence of an increase in non-thermal velocity dispersion with column density, denser filaments being more turbulent than more diffuse ones (Arzoumanian et al. in prep.).

  14. 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.

  15. Infrared survey of the Pisgah Crater area, San Bernardino County, California - a geologic interpretation

    Science.gov (United States)

    Gawarecki, Stephen J.

    1968-01-01

    The infrared survey of the Pisgah Crater Area, San Bernardino County, California was primarily undertaken to establish parameters by which rock types, structures, and textures peculiar to this locale could be recognized or differentiated. A secondary purpose was to provide an adequate evaluation and calibration of airborne and ground-based instruments used in the survey. Pisgah Crater and its vicinity was chosen as one of the fundamental test sites for the NASA remote sensing program because of its relatively fresh basaltic flows and pyroclastics. Its typical exposure of basalt also made it a possible lunar analogue. A fundamental test site for the purpose of the program is defined as a readily accessible area for which the topography, geology, hydrology, soils, vegetation and other features are relatively well known. All remote sensor instrument teams, i.e. infrared, radar, microwave, and photography, were obligated to use the fundamental test sites for instrument evaluation and to establish terrain identification procedures. Pisgah Crater, nearby Sunshine Cone, and their associated lava flows are in the southern Mojave Desert about 40 miles east-southeast of Barstow, California. (See fig. 1.) U. S. Highway 66 skirts .the northern part of the area and provides access via asphalt-paved and dirt roads to the Crater and to the perimeters of the flows. Pisgah Crater, which is a pumiceous cone, is owned and occasionally quarried by the Atchison, Topeka and Santa Fe Railroad. The remaining part of the area to the south is within the boundary of the Marine Corps Base, Twentynine Palms, California and is currently being used as a gunnery, and bombing range. The proximate area to east, west, and north of Pisgah Crater is public domain. Originally, an area totaling 10 square miles was outlined for detailed study. (See plate 1.) This included an 8 mile long strip extending south- east from and including Pisgah Crater to Lavic Dry Lake, and a 2 mile strip aligned to include a

  16. HERSCHEL FAR-INFRARED SPECTRAL-MAPPING OF ORION BN/KL OUTFLOWS: SPATIAL DISTRIBUTION OF EXCITED CO, H{sub 2}O, OH, O, AND C{sup +} IN SHOCKED GAS

    Energy Technology Data Exchange (ETDEWEB)

    Goicoechea, Javier R.; Cernicharo, José; Cuadrado, Sara; Etxaluze, Mireya [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC). Sor Juana Ines de la Cruz 3, E-28049 Cantoblanco, Madrid (Spain); Chavarría, Luis [Centro de Astrobiología, CSIC-INTA, Ctra. de Torrejón a Ajalvir km 4, E-28850 Madrid (Spain); Neufeld, David A. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Vavrek, Roland [Herschel Science Center, ESA/ESAC, P.O. Box 78, Villanueva de la Cañada, E-28691 Madrid (Spain); Bergin, Edwin A. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Encrenaz, Pierre [LERMA, UMR 8112 du CNRS, Observatoire de Paris, École Normale Supérieure, F-75014 Paris (France); Melnick, Gary J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 66, Cambridge, MA 02138 (United States); Polehampton, Edward, E-mail: jr.goicoechea@icmm.csic.es [RAL Space, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2015-01-20

    We present ∼2' × 2' spectral-maps of Orion Becklin-Neugebauer/Kleinmann-Low (BN/KL) outflows taken with Herschel at ∼12'' resolution. For the first time in the far-IR domain, we spatially resolve the emission associated with the bright H{sub 2} shocked regions ''Peak 1'' and ''Peak 2'' from that of the hot core and ambient cloud. We analyze the ∼54-310 μm spectra taken with the PACS and SPIRE spectrometers. More than 100 lines are detected, most of them rotationally excited lines of {sup 12}CO (up to J = 48-47), H{sub 2}O, OH, {sup 13}CO, and HCN. Peaks 1/2 are characterized by a very high L(CO)/L {sub FIR} ≈ 5 × 10{sup –3} ratio and a plethora of far-IR H{sub 2}O emission lines. The high-J CO and OH lines are a factor of ≈2 brighter toward Peak 1 whereas several excited H{sub 2}O lines are ≲50% brighter toward Peak 2. Most of the CO column density arises from T {sub k} ∼ 200-500 K gas that we associate with low-velocity shocks that fail to sputter grain ice mantles and show a maximum gas-phase H{sub 2}O/CO ≲ 10{sup –2} abundance ratio. In addition, the very excited CO (J > 35) and H{sub 2}O lines reveal a hotter gas component (T {sub k} ∼ 2500 K) from faster (v {sub S} > 25 km s{sup –1}) shocks that are able to sputter the frozen-out H{sub 2}O and lead to high H{sub 2}O/CO ≳ 1 abundance ratios. The H{sub 2}O and OH luminosities cannot be reproduced by shock models that assume high (undepleted) abundances of atomic oxygen in the preshock gas and/or neglect the presence of UV radiation in the postshock gas. Although massive outflows are a common feature in other massive star-forming cores, Orion BN/KL seems more peculiar because of its higher molecular luminosities and strong outflows caused by a recent explosive event.

  17. Planck, Herschel & Spitzer unveil overdense z>2 regions

    Science.gov (United States)

    Dole, Herve; Chary, Ranga-Ram; Chary, Ranga; Frye, Brenda; Martinache, Clement; Guery, David; Le Floc'h, Emeric; Altieri, Bruno; Flores-Cacho, Ines; Giard, Martin; Hurier, Guillaume; Lagache, Guilaine; Montier, Ludovic; Nesvadba, Nicole; Omont, Alain; Pointecouteau, Etienne; Pierini, Daniele; Puget, Jean-Loup; Scott, Douglas; Soucail, Genevieve

    2014-12-01

    At which cosmic epoch did massive galaxy clusters assemble their baryons? How does star formation occur in the most massive, most rapidly collapsing dark-matter-dense environments in the early Universe? To answer these questions, we take the completely novel approach to select the most extreme z>~2 star-forming overdensities seen over the entire sky. This selection nicely complements the other existing selections for high redshift clusters (i.e., by stellar mass, or by total mass like Sunyaev-Zeldovish (SZ) or X-ray selection). We make use of the Planck all-sky submillimetre survey to systematically identify the rarest, most luminous high-redshift sub-mm sources on the sky, either strongly gravitationally lensed galaxies, or the joint FIR/sub-mm emission from multiple intense starbursts. We observed 228 Planck sources with Herschel/SPIRE and discovered that most of them are overdensities of red galaxies with extremely high star formation rates (typically 7.e3 Msun/yr for a structure). Only Spitzer data can allow a better understanding of these promising Planck+Herschel selected sources, as is shown on a first set of IRAC data on 40 targets in GO9: (i) the good angular resolution and sensitivity of IRAC allows a proper determination of the clustered nature of each Herschel/SPIRE source; (ii) IRAC photometry (often associated with J, K) allows a good estimate of the colors and approximate photometric redshift. Note spectroscopic redshifts are available for two cluster candidates, at z=1.7 and z=2.3, confirming their high redshift nature. The successful GO9 observation of 40 fields showed that about half to be >7sigma overdensities of red IRAC sources. These observations were targeting the whole range of Herschel overdensities and significances. We need to go deeper into the Spitzer sample and acquire complete coverage of the most extreme Herschel overdensities (54 new fields). Such a unique sample has legacy value, and this is the last opportunity prior to JWST

  18. More Results from a Long-Term Infrared Survey of M-Class Asteroids

    Science.gov (United States)

    Clark, Beth E.; Shepard, M. K.; Rivkin, A. S.

    2006-09-01

    In collaboration with Shepard et al. (abstract this volume), we are continuing a long-term infrared spectroscopic survey of main-belt M-class (and other X-complex) asteroids. When an asteroid is observed to have rotational variability in radar cross-section, one possible explanation is compositional variability, which should be reflected in a correlated infrared spectral rotational variability. One third of the 12 M-types observed to date show radar albedos unambiguously consistent with metallic compositions. How is this reflected in infrared-derived composition? Our goal is to parallel the tripling in the number of radar observed M-class targets with rotationally-resolved infrared and 3-micron observations within the next five years. This year, we will present results focusing on asteroid 129 Antigone. Acknowledgements. This work was supported by grants from the Research Corporation and the National Science Foundation (AST-0605903). BEC, MKS, and ASR are guest astronomers at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii.

  19. VICS82: The VISTA-CFHT Stripe 82 Near-infrared Survey

    Science.gov (United States)

    Geach, J. E.; Lin, Y.-T.; Makler, M.; Kneib, J.-P.; Ross, N. P.; Wang, W.-H.; Hsieh, B.-C.; Leauthaud, A.; Bundy, K.; McCracken, H. J.; Comparat, J.; Caminha, G. B.; Hudelot, P.; Lin, L.; Van Waerbeke, L.; Pereira, M. E. S.; Mast, D.

    2017-07-01

    We present the VISTA-CFHT Stripe 82 (VICS82) survey: a near-infrared (J+K s ) survey covering 150 square degrees of the Sloan Digital Sky Survey (SDSS) equatorial Stripe 82 to an average depth of J = 21.9 AB mag and K s = 21.4 AB mag (80% completeness limits; 5σ point-source depths are approximately 0.5 mag brighter). VICS82 contributes to the growing legacy of multiwavelength data in the Stripe 82 footprint. The addition of near-infrared photometry to the existing SDSS Stripe 82 coadd ugriz photometry reduces the scatter in stellar mass estimates to δ {log}({M}\\star )≈ 0.3 dex for galaxies with {M}\\star > {10}9 {M}⊙ at z≈ 0.5, and offers improvement compared to optical-only estimates out to z≈ 1, with stellar masses constrained within a factor of approximately 2.5. When combined with other multiwavelength imaging of the Stripe, including moderate-to-deep ultraviolet (GALEX), optical and mid-infrared (Spitzer-IRAC) coverage, as well as tens of thousands of spectroscopic redshifts, VICS82 gives access to approximately 0.5 Gpc3 of comoving volume. Some of the main science drivers of VICS82 include (a) measuring the stellar mass function of {L}\\star galaxies out to z˜ 1; (b) detecting intermediate-redshift quasars at 2≲ z≲ 3.5; (c) measuring the stellar mass function and baryon census of clusters of galaxies, and (d) performing cross-correlation experiments of cosmic microwave background lensing in the optical/near-infrared that link stellar mass to large-scale dark matter structure. Here we define and describe the survey, highlight some early science results, and present the first public data release, which includes an SDSS-matched catalog as well as the calibrated pixel data themselves.

  20. 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.

  1. A Near-infrared Survey of the Rosette Complex: Clues of Early Cluster Evolution

    Science.gov (United States)

    Román-Zúñiga, Carlos G.; Lada, Elizabeth A.; Ferreira, Bruno

    2008-05-01

    The majority of stars in our galaxy are born in embedded clusters, which can be considered the fundamental units of star formation. We have recently surveyed the star forming content of the Rosette Complex using FLAMINGOS in order to investigate the properties of its embedded clusters. We discuss the results of our near-infrared imaging survey. In particular, we on the first evidence for the early evolution and expansion of the embedded clusters. In addition we present data suggesting a temporal sequence of cluster formation across the cloud and discuss the influence of the HII region on the star forming history of the Rosette.

  2. 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

  3. Extreme Conditions in a Close Analog to the Young Solar System: Herschel Observations of ε Eridani

    NARCIS (Netherlands)

    Greaves, J.S.; Sibthorpe, B.; Acke, B.; Pantin, E.E.; Vandenbussche, B.; Olofsson, G.; Dominik, C.; Barlow, M.J.; Bendo, G.J.; Blommaert, J.A.D.L.; Brandeker, A.; de Vries, B.L.; Dent, W.R.F.; Di Francesco, J.; Fridlund, M.; Gear, W.K.; Harvey, P.M.; Hogerheijde, M.R.; Holland, W.S.; Ivison, R.J.; Liseau, R.; Matthews, B.C.; Pilbratt, G.L.; Walker, H.J.; Waelkens, C.

    2014-01-01

    Far-infrared Herschel images of the epsilon 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

  4. The HERschel Inventory of the Agents of Galaxy Evolution in the Magellanic Clouds, a HERschel Open Time Key Program

    Science.gov (United States)

    Meixner, Margaret; Panuzzo, P.; Roman-Duval, J.; Engelbracht, C.; Babler, B.; Seale, J.; Hony, S.; Montiel, E.; Sauvage, M.; Gordon, K.; hide

    2013-01-01

    We present an overview or the HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds project, which is a Herschel Space Observatory open time key program. We mapped the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 100, 160, 250, 350, and 500 micron with the Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS) instruments on board Herschel using the SPIRE/PACS parallel mode. The overriding science goal of HERITAGE is to study the life cycle of matter as traced by dust in the LMC and SMC. The far-infrared and submillimeter emission is an effective tracer of the interstellar medium (ISM) dust, the most deeply embedded young stellar objects (YSOs), and the dust ejected by the most massive stars. We describe in detail the data processing, particularly for the PACS data, which required some custom steps because of the large angular extent of a single observational unit and overall the large amount of data to be processed as an ensemble. We report total global fluxes for LMC and SMC and demonstrate their agreement with measurements by prior missions. The HERITAGE maps of the LMC and SMC are dominated by the ISM dust emission and bear most resemblance to the tracers of ISM gas rather than the stellar content of the galaxies. We describe the point source extraction processing and the critetia used to establish a catalog for each waveband for the HERITAGE program. The 250 micron band is the most sensitive and the source catalogs for this band have approx. 25,000 objects for the LMC and approx. 5500 objects for the SMC. These data enable studies of ISM dust properties, submillimeter excess dust emission, dust-to-gas ratio, Class 0 YSO candidates, dusty massive evolved stars, supemova remnants (including SN1987A), H II regions, and dust evolution in the LMC and SMC. All images and catalogs are delivered to the Herschel Science Center as part of the conummity support

  5. THE HERSCHEL INVENTORY OF THE AGENTS OF GALAXY EVOLUTION IN THE MAGELLANIC CLOUDS, A HERSCHEL OPEN TIME KEY PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Meixner, M.; Roman-Duval, J.; Seale, J.; Gordon, K.; Beck, T.; Boyer, M. L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Panuzzo, P.; Hony, S.; Sauvage, M.; Okumura, K.; Chanial, P. [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Engelbracht, C.; Montiel, E.; Misselt, K. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Babler, B. [Department of Astronomy, 475 North Charter Street, University of Wisconsin, Madison, WI 53706 (United States); Bernard, J.-P. [CNRS, IRAP, 9 Av. Colonel Roche, BP 44346, F-31028 Toulouse Cedex 4 (France); Bolatto, A. [Department of Astronomy, Laboratory for Millimeter-Wave Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Bot, C. [Universite de Strasbourg, Observatoire Astronomique de Strasbourg, 11, Rue de l' Universite, F-67000 Strasbourg (France); Carlson, L. R. [Sterrewacht Leiden, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Clayton, G. C., E-mail: meixner@stsci.edu [Department of Physics and Astronomy, Louisiana State University, 233-A Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); and others

    2013-09-15

    We present an overview of the HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds project, which is a Herschel Space Observatory open time key program. We mapped the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 100, 160, 250, 350, and 500 {mu}m with the Spectral and Photometric Imaging Receiver (SPIRE) and Photodetector Array Camera and Spectrometer (PACS) instruments on board Herschel using the SPIRE/PACS parallel mode. The overriding science goal of HERITAGE is to study the life cycle of matter as traced by dust in the LMC and SMC. The far-infrared and submillimeter emission is an effective tracer of the interstellar medium (ISM) dust, the most deeply embedded young stellar objects (YSOs), and the dust ejected by the most massive stars. We describe in detail the data processing, particularly for the PACS data, which required some custom steps because of the large angular extent of a single observational unit and overall the large amount of data to be processed as an ensemble. We report total global fluxes for the LMC and SMC and demonstrate their agreement with measurements by prior missions. The HERITAGE maps of the LMC and SMC are dominated by the ISM dust emission and bear most resemblance to the tracers of ISM gas rather than the stellar content of the galaxies. We describe the point source extraction processing and the criteria used to establish a catalog for each waveband for the HERITAGE program. The 250 {mu}m band is the most sensitive and the source catalogs for this band have {approx}25,000 objects for the LMC and {approx}5500 objects for the SMC. These data enable studies of ISM dust properties, submillimeter excess dust emission, dust-to-gas ratio, Class 0 YSO candidates, dusty massive evolved stars, supernova remnants (including SN1987A), H II regions, and dust evolution in the LMC and SMC. All images and catalogs are delivered to the Herschel Science Center as part of the community support

  6. A HERSCHEL SEARCH FOR COLD DUST IN BROWN DWARF DISKS: FIRST RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Paul M.; Evans, Neal J. II [Astronomy Department, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Henning, Thomas [Max-Planck-Institut for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Menard, Francois; Pinte, Christophe [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique (IPAG) UMR 5274, BP 53, 38041 Grenoble cedex 9 (France); Wolf, Sebastian; Liu Yao [Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstr. 15, 24098 Kiel (Germany); Cieza, Lucas A. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Pascucci, Ilaria [Lunar and Planetary Laboratory, Department of Planetary Sciences, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States); Merin, Bruno, E-mail: pmh@astro.as.utexas.edu, E-mail: nje@astro.as.utexas.edu, E-mail: henning@mpia.de, E-mail: menard@obs.ujf-grenoble.fr, E-mail: christophe.pinte@obs.ujf-grenoble.fr, E-mail: wolf@astrophysik.uni-kiel.de, E-mail: yliu@pmo.ac.cn, E-mail: lcieza@ifa.hawaii.edu, E-mail: pascucci@lpl.arizona.edu, E-mail: Bruno.Merin@sciops.esa.int [Herschel Science Centre, SRE-SDH, ESA, P.O. Box 78, 28691 Villanueva de la Canada, Madrid (Spain)

    2012-01-15

    We report initial results from a Herschel program to search for far-infrared emission from cold dust around a statistically significant sample of young brown dwarfs. The first three objects in our survey are all detected at 70 {mu}m, and we report the first detection of a brown dwarf at 160 {mu}m. The flux densities are consistent with the presence of substantial amounts of cold dust in the outer disks around these objects. We modeled the spectral energy distributions (SEDs) with two different radiative transfer codes. We find that a broad range of model parameters provide a reasonable fit to the SEDs, but that the addition of our 70 {mu}m, and especially the 160 {mu}m, detection enables strong lower limits to be placed on the disk masses since most of the mass is in the outer disk. We find likely disk masses in the range of a few Multiplication-Sign 10{sup -6} to 10{sup -4} M{sub Sun }. Our models provide a good fit to the SEDs and do not require dust settling.

  7. 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.; hide

    2013-01-01

    Panchromatic observations of the best candidate hyperluminous infrared galaxies from the widest Herschel extragalactic imaging survey have led to the discovery of at least four intrinsically luminous z = 2.41 galaxies across an ˜100 kpc region-a cluster of starbursting protoellipticals. Via subarcsecond interferometric imaging we have measured accurate gas and star formation surface densities. The two brightest galaxies span 3 kpc FWHM in submillimeter/radio continuum and CO J = 4-3, and double that in CO J = 1-0. The broad CO line is due partly to the multitude of constituent galaxies and partly to large rotational velocities in two counter-rotating gas disks-a scenario predicted to lead to the most intense starbursts, which will therefore come in pairs. The disks have Mdyn of several ×10(sup 11) solar Mass, and gas fractions of 40%. Velocity dispersions are modest so the disks are unstable, potentially on scales commensurate with their radii: these galaxies are undergoing extreme bursts of star formation, not confined to their nuclei, at close to the Eddington limit. Their specific star formation rates place them greater than or approx. equal to 5 × above the main sequence, which supposedly comprises large gas disks like these. Their high star formation efficiencies are difficult to reconcile with a simple volumetric star formation law. N-body and dark matter simulations suggest that this system is the progenitor of a B(inary)-type ˜10(sup 14.6) -solar mass cluster.

  8. Mapping the Milky Way: William Herschel's Star Gages

    Science.gov (United States)

    Timberlake, Todd

    2013-01-01

    William Herschel (Fig. 1) is rightfully known as one of the greatest astronomers of all time. Born in Hanover (in modern Germany) in 1738, Herschel immigrated to England in 1757 and began a successful career as a professional musician. Later in life Herschel developed a strong interest in astronomy. He began making his own reflecting telescopes in…

  9. Clustering of far-infrared galaxies in the AKARI All-Sky Survey North

    Science.gov (United States)

    Pollo, A.; Takeuchi, T. T.; Solarz, A.; Rybka, P.; Suzuki, T. L.; Pȩpiak, A.; Oyabu, S.

    2013-10-01

    We present the measurements of the angular two-point correlation function for AKARI 90-μm point sources, detected outside the Milky Way plane and other regions characterized by high Galactic extinction in the northern Galactic hemisphere, and categorized as extragalactic sources according to our far-infrared-color based criterion. Together with our previous work (Pollo et al., 2013) this is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS. We present the first attempt to estimate the spatial clustering properties of AKARI All-Sky galaxies and we conclude that they are mostly a very nearby ( z ≤ 0.1) population of moderately clustered galaxies. We measure their correlation length r 0 ~ 4.5 h -1 Mpc, which is consistent with the assumption that the FIS AKARI All-Sky surveys observes mostly a nearby star-forming population of galaxies.

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

    Science.gov (United States)

    Karska, A.; Kristensen, L. E.; van Dishoeck, E. F.; Drozdovskaya, M. N.; Mottram, J. C.; Herczeg, G. J.; Bruderer, S.; Cabrit, S.; Evans, N. J.; Fedele, D.; Gusdorf, A.; Jørgensen, J. K.; Kaufman, M. J.; Melnick, G. J.; Neufeld, D. A.; Nisini, B.; Santangelo, G.; Tafalla, M.; Wampfler, S. F.

    2014-12-01

    Context. Protostars interact with their surroundings through jets and winds impinging on the envelope and creating shocks, but the nature of these shocks is still poorly understood. Aims: Our aim is to survey far-infrared molecular line emission from a uniform and significant sample of deeply-embedded low-mass young stellar objects (YSOs) in order to characterize shocks and the possible role of ultraviolet radiation in the immediate protostellar environment. Methods: Herschel/PACS spectral maps of 22 objects in the Perseus molecular cloud were obtained as part of the William Herschel Line Legacy (WILL) survey. Line emission from H2O, CO, and OH is tested against shock models from the literature. Results: Observed line ratios are remarkably similar and do not show variations with physical parameters of the sources (luminosity, envelope mass). Most ratios are also comparable to those found at off-source outflow positions. Observations show good agreement with the shock models when line ratios of the same species are compared. Ratios of various H2O lines provide a particularly good diagnostic of pre-shock gas densities, nH ~ 105 cm-3, in agreement with typical densities obtained from observations of the post-shock gas when a compression factor on the order of 10 is applied (for non-dissociative shocks). The corresponding shock velocities, obtained from comparison with CO line ratios, are above 20 km s-1. However, the observations consistently show H2O-to-CO and H2O-to-OH line ratios that are one to two orders of magnitude lower than predicted by the existing shock models. Conclusions: The overestimated model H2O fluxes are most likely caused by an overabundance of H2O in the models since the excitation is well-reproduced. Illumination of the shocked material by ultraviolet photons produced either in the star-disk system or, more locally, in the shock, would decrease the H2O abundances and reconcile the models with observations. Detections of hot H2O and strong OH

  11. A new population of protostars discovered by Herschel

    Science.gov (United States)

    Stutz, A. M.; Tobin, J.; Fischer, W.; S. T. Megeath; Stanke, T.; Ali, B.; Henning, T.

    2012-03-01

    We present a newly discovered Herschel--detected class of very red protostars found in the Herschel Orion Protostar Survey (HOPS). In contrast to the known Orion protostars targeted with HOPS, the new sources are undetected or very faint in the Spitzer 24 μm imaging. A subset of these sources is redder than any of the known Orion Class 0 protostars, and appear similar in their 70 μm to 24 μm colors to the most extreme Class 0 objects known. These new Orion protostars are likely to be in a very early and short lived stage of protostellar evolution. As a sample of extremely red sources at a common distance, they represent an important new population of protostars. The majority of these reddest sources exhibit associated IRAC 4.5, and 5.8 μm extended emission that suggests the presence of an outflow, confirming their protostellar nature. In addition, many of these sources are located within classical filaments as traced by Spitzer absorption features and APEX 870 μm dust emission maps. Fits of the broad--band SEDs to radiative transfer models of protostars suggest that the extremely red 70 μm to 24 μm colors result from a combination of nearly edge--on viewing angles and high envelope infall rates. We analyze the properties of the filaments from which these sources form using sub--mm and IRAM 30 m N_2H^+ measurements. Finally, we present the initial results of a search for outflows using IRAM 30 m CO maps. As a population of cold protostars detected by Herschel but not Spitzer, the PBRS extend the Spitzer--identified sample to earlier stages of envelope evolution, allowing the most complete census yet of the Orion protostellar population.

  12. 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

    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...... line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs...... excitation components. The warm PACS component (300 K) is associated with the broad HIFI component, and the hot PACS component (700 K) is associated with the offset HIFI component. The former originates in either outflow cavity shocks or the disk wind, and the latter in irradiated shocks. The low water...

  13. Precision Pointing for the Wide-Field Infrared Survey Telescope(WFIRST)

    Science.gov (United States)

    Stoneking, Eric T.; Hsu, Oscar C.; Welter, Gary

    2017-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission, scheduled for a mid-2020's launch, is currently in its definition phase. The mission is designed to investigate essential questions in the areas of dark energy, exoplanets, and infrared astrophysics. WFIRST will use a 2.4-meter primary telescope (same size as the Hubble Space Telescope's primary mirror) and two instruments: the Wide Field Instrument (WFI) and the Coronagraph Instrument (CGI). In order to address the critical science requirements, the WFIRST mission will conduct large-scale surveys of the infrared sky, requiring both agility and precision pointing (11.6 milli-arcsec stability, 14 milli-arcsec jitter). This paper describes some of the challenges this mission profile presents to the Guidance, Navigation, and Control (GNC) subsystem, and some of the design elements chosen to accommodate those challenges. The high-galactic-latitude survey is characterized by 3-minute observations separated by slews ranging from 0.025 deg to 0.8 deg. The need for observation efficiency drives the slew and settle process to be as rapid as possible. A description of the shaped slew profile chosen to minimize excitation of structural oscillation, and the handoff from star tracker-gyro control to fine guidance sensor control is detailed. Also presented is the fine guidance sensor (FGS), which is integral with the primary instrument (WFI). The FGS is capable of tracking up to 18 guide stars, enabling robust FGS acquisition and precision pointing. To avoid excitation of observatory structural jitter, reaction wheel speeds are operationally maintained within set limits. In addition, the wheel balance law is designed to maintain 1-Hz separation between the wheel speeds to avoid reinforcing jitter excitation at any particular frequency. The wheel balance law and operational implications are described. Finally, the candidate GNC hardware suite needed to meet the requirements of the mission is presented.

  14. The Strong Gravitationally Lensed Herschel Galaxy HLock01: Optical Spectroscopy Reveals a Close Galaxy Merger with Evidence of Inflowing Gas

    Science.gov (United States)

    Marques-Chaves, Rui; Pérez-Fournon, Ismael; Gavazzi, Raphael; Martínez-Navajas, Paloma I.; Riechers, Dominik; Rigopoulou, Dimitra; Cabrera-Lavers, Antonio; Clements, David L.; Cooray, Asantha; Farrah, Duncan; Ivison, Rob J.; Jiménez-Ángel, Camilo E.; Nayyeri, Hooshang; Oliver, Seb; Omont, Alain; Scott, Douglas; Shu, Yiping; Wardlow, Julie

    2018-02-01

    The submillimeter galaxy (SMG) HERMES J105751.1+573027 (hereafter HLock01) at z = 2.9574 ± 0.0001 is one of the brightest gravitationally lensed sources discovered in the Herschel Multi-tiered Extragalactic Survey. Apart from the high flux densities in the far-infrared, it is also extremely bright in the rest-frame ultraviolet (UV), with a total apparent magnitude m UV ≃ 19.7 mag. We report here deep spectroscopic observations with the Gran Telescopio Canarias of the optically bright lensed images of HLock01. Our results suggest that HLock01 is a merger system composed of the Herschel-selected SMG and an optically bright Lyman break-like galaxy (LBG), separated by only 3.3 kpc in projection. While the SMG appears very massive (M * ≃ 5 × 1011 M ⊙), with a highly extinguished stellar component (A V ≃ 4.3 ), the LBG is a young, lower-mass (M * ≃ 1 × 1010 M ⊙), but still luminous (10× {L}UV}* ) satellite galaxy. Detailed analysis of the high signal-to-noise ratio (S/N) rest-frame UV spectrum of the LBG shows complex kinematics of the gas, exhibiting both blueshifted and redshifted absorption components. While the blueshifted component is associated with strong galactic outflows from the massive stars in the LBG, as is common in most star-forming galaxies, the redshifted component may be associated with gas inflow seen along a favorable sightline to the LBG. We also find evidence of an extended gas reservoir around HLock01 at an impact parameter of 110 kpc, through the detection of C II λλ1334 absorption in the red wing of a bright Lyα emitter at z ≃ 3.327. The data presented here highlight the power of gravitational lensing in high S/N studies to probe deeply into the physics of high-z star-forming galaxies.

  15. 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

  16. 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...

  17. THE COORDINATED RADIO AND INFRARED SURVEY FOR HIGH-MASS STAR FORMATION. II. SOURCE CATALOG

    Energy Technology Data Exchange (ETDEWEB)

    Purcell, C. R.; Hoare, M. G.; Lumsden, S. L.; Urquhart, J. S. [School of Physics and Astronomy, E.C. Stoner Building, University of Leeds, Leeds LS2 9JT (United Kingdom); Cotton, W. D. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Chandler, C. [National Radio Astronomy Observatory, Array Operations Center, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387 (United States); Churchwell, E. B. [The University of Wisconsin, Department of Astronomy, 475 North Charter Street, Madison, WI 53706 (United States); Diamond, P.; Fuller, G.; Garrington, S. T. [Jodrell Bank Centre for Astrophysics, The Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Rd, Manchester, M13 9PL (United Kingdom); Dougherty, S. M. [National Research Council of Canada, Herzberg Institute for Astrophysics, Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, British Columbia V2A 6J9 (Canada); Fender, R. P. [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Gledhill, T. M. [Science and Technology Research Institute, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Goldsmith, P. F. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Hindson, L. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Jackson, J. M. [Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Kurtz, S. E. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico - Morelia, Apartado Postal 3-72, C.P. 58090 Morelia, Michoacan (Mexico); Marti, J., E-mail: C.R.Purcell@leeds.ac.uk [Departamento de Fisica, EPSJ, Universidad de Jaen, Campus Las Lagunillas s/n, Edif. A3, E-23071 Jaen (Spain); and others

    2013-03-01

    The CORNISH project is the highest resolution radio continuum survey of the Galactic plane to date. It is the 5 GHz radio continuum part of a series of multi-wavelength surveys that focus on the northern GLIMPSE region (10 Degree-Sign < l < 65 Degree-Sign ), observed by the Spitzer satellite in the mid-infrared. Observations with the Very Large Array in B and BnA configurations have yielded a 1.''5 resolution Stokes I map with a root mean square noise level better than 0.4 mJy beam{sup -1}. Here we describe the data-processing methods and data characteristics, and present a new, uniform catalog of compact radio emission. This includes an implementation of automatic deconvolution that provides much more reliable imaging than standard CLEANing. A rigorous investigation of the noise characteristics and reliability of source detection has been carried out. We show that the survey is optimized to detect emission on size scales up to 14'' and for unresolved sources the catalog is more than 90% complete at a flux density of 3.9 mJy. We have detected 3062 sources above a 7{sigma} detection limit and present their ensemble properties. The catalog is highly reliable away from regions containing poorly sampled extended emission, which comprise less than 2% of the survey area. Imaging problems have been mitigated by down-weighting the shortest spacings and potential artifacts flagged via a rigorous manual inspection with reference to the Spitzer infrared data. We present images of the most common source types found: H II regions, planetary nebulae, and radio galaxies. The CORNISH data and catalog are available online at http://cornish.leeds.ac.uk.

  18. 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.

  19. The Extremely Luminous Quasar Survey in the SDSS Footprint. I. Infrared-based Candidate Selection

    Science.gov (United States)

    Schindler, Jan-Torge; Fan, Xiaohui; McGreer, Ian D.; Yang, Qian; Wu, Jin; Jiang, Linhua; Green, Richard

    2017-12-01

    Studies of the most luminous quasars at high redshift directly probe the evolution of the most massive black holes in the early universe and their connection to massive galaxy formation. However, extremely luminous quasars at high redshift are very rare objects. Only wide-area surveys have a chance to constrain their population. The Sloan Digital Sky Survey (SDSS) has so far provided the most widely adopted measurements of the quasar luminosity function at z> 3. However, a careful re-examination of the SDSS quasar sample revealed that the SDSS quasar selection is in fact missing a significant fraction of z≳ 3 quasars at the brightest end. We identified the purely optical-color selection of SDSS, where quasars at these redshifts are strongly contaminated by late-type dwarfs, and the spectroscopic incompleteness of the SDSS footprint as the main reasons. Therefore, we designed the Extremely Luminous Quasar Survey (ELQS), based on a novel near-infrared JKW2 color cut using Wide-field Infrared Survey Explorer mission (WISE) AllWISE and 2MASS all-sky photometry, to yield high completeness for very bright ({m}{{i}}learning algorithms on SDSS and WISE photometry for quasar-star classification and photometric redshift estimation. The ELQS will spectroscopically follow-up ˜230 new quasar candidates in an area of ˜12,000 deg2 in the SDSS footprint to obtain a well-defined and complete quasar sample for an accurate measurement of the bright-end quasar luminosity function (QLF) at 3.0≤slant z≤slant 5.0. In this paper, we present the quasar selection algorithm and the quasar candidate catalog.

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

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, X. P.; Leisawitz, D. T.; Benford, D. J.; Padgett, D. L. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Rebull, L. M. [Spitzer Science Center (SSC), California Institute of Technology, M/S 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Assef, R. J. [Jet Propulsion Laboratory, MS 169-530, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2012-01-10

    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.

  1. 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.

  2. NEAR-INFRARED CIRCULAR POLARIZATION SURVEY IN STAR-FORMING REGIONS: CORRELATIONS AND TRENDS

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jungmi; Tamura, Motohide [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Hough, James H.; Lucas, Phil W. [Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Kusakabe, Nobuhiko; Kandori, Ryo [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Nagata, Tetsuya [Department of Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Nakajima, Yasushi [Center of Information and Communication Technology, Hitotsubashi University, 2-1 Naka, Kunitachi, Tokyo 186-8601 (Japan); Nagayama, Takahiro, E-mail: jungmi.kwon@astron.s.u-tokyo.ac.jp [Department of Astrophysics, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065 (Japan)

    2014-11-01

    We have conducted a systematic near-infrared circular polarization (CP) survey in star-forming regions, covering high-mass, intermediate-mass, and low-mass young stellar objects. All the observations were made using the SIRPOL imaging polarimeter on the Infrared Survey Facility 1.4 m telescope at the South African Astronomical Observatory. We present the polarization properties of 10 sub-regions in 6 star-forming regions. The polarization patterns, extents, and maximum degrees of linear and circular polarizations are used to determine the prevalence and origin of CP in the star-forming regions. Our results show that the CP pattern is quadrupolar in general, the CP regions are extensive, up to 0.65 pc, the CP degrees are high, up to 20%, and the CP degrees decrease systematically from high- to low-mass young stellar objects. The results are consistent with dichroic extinction mechanisms generating the high degrees of CP in star-forming regions.

  3. THROES: A caTalogue of HeRschel Observations of Evolved Stars.

    Science.gov (United States)

    Ramos-Medina, J.; Sánchez-Contreras, C.; García-Lario, P.

    2017-03-01

    We are building a catalogue of interactively reprocessed observations of all evolved stars observed with Herschel. The catalogue will offer not only the reduced PACS spectroscopic data for each observation, but also complementary information from other infrared observatories. As a first step, we are concentrating our efforts on two main activities: 1) the reprocessing and data-reduction of more than 120 individual sources, observed by Herschel/PACS in the 55-210 micron range, available in the Herschel Science Archive (HSA). 2) the creation of a catalogue, accesible via a web-based interface and through the Virtual Observatory (VO). Our ultimate goal is to carry out a comprehensive and systematic study of the far infrared properties of low-and intermediate-mass evolved stars using these data. These objects cover the whole range of possible evolutionary stages in this short-lived phase of stellar evolu- tion, from AGB phase to the PN stage, displaying a wide variety of chemical and physical properties.

  4. A FLAMINGOS Deep Near Infrared Imaging Survey of the Rosette Complex I: Identification and Distribution of the Embedded Population

    OpenAIRE

    Roman-Zuniga, Carlos; Elston, Richard; Ferreira, Bruno; Lada, Elizabeth

    2007-01-01

    We present the results of a deep near-infrared imaging survey of the Rosette Complex. We studied the distribution of young embedded sources using a variation of the Nearest Neighbor Method applied to a carefully selected sample of near-infrared excess (NIRX) stars which trace the latest episode of star formation in the complex. Our analysis confirmed the existence of seven clusters previously detected in the molecular cloud, and identified four more clusters across the complex. We determined ...

  5. White dwarfs in the UKIRT infrared deep sky survey data release

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, P.-E.; Kalirai, J. S. [Space Telescope Science Institute, 700 San Martin Drive, Baltimore, MD 21218 (United States); Leggett, S. K. [Gemini Observatory, Northern Operations Center, 670 North A' ohoku Place, Hilo, HI 96720 (United States); Lodieu, N. [Instituto de Astrofísica de Canarias (IAC), C/Vía Láctea s/n, E-38200 La Laguna, Tenerife (Spain); Freytag, B. [Astronomical Observatory, Uppsala University, Regementsvägen 1, Box 515, SE-75120 Uppsala (Sweden); Bergeron, P. [Département de Physique, Université de Montréal, C. P. 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7 (Canada); Ludwig, H.-G., E-mail: tremblay@stsci.edu [Zentrum für Astronomie der Universität Heidelberg, Landessternwarte, Königstuhl 12, D-69117 Heidelberg (Germany)

    2014-06-20

    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{sup –1} ≤v {sub tan} ≤ 60 km s{sup –1}. They are likely thick disk 10-11 Gyr old objects. In addition, we find a resolved double degenerate system with v {sub tan} ∼ 155 km s{sup –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 {sub eff} (K) < 6000. We review the possible explanations for the spectral evolution from helium-dominated toward hydrogen-rich atmospheres at low temperatures.

  6. 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 similar to 4.5 relative to a simple catalogue level matching and results in a similar to 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 similar to 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.

  7. Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

    Science.gov (United States)

    Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas; hide

    2016-01-01

    The slitless spectrometer plays an important role in the Wide-Field InfraRed Survey Telescope (WFIRST) mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies. The concept of the compound grism as a slitless spectrometer has been presented previously. The presentation briefly discusses the challenges and solutions of the optical design, and recent specification updates, as well as a brief comparison between the prototype and the latest design. However, the emphasis of this paper is the progress of the grism prototype: the fabrication and test of the complicated diffractive optical elements and powered prism, as well as grism assembly alignment and testing. Especially how to use different tools and methods, such as IR phase shift and wavelength shift interferometry, to complete the element and assembly tests. The paper also presents very encouraging results from recent element tests to assembly tests. Finally we briefly touch the path forward plan to test the spectral characteristic, such as spectral resolution and response.

  8. Methods for Global Survey of Natural Gas Flaring from Visible Infrared Imaging Radiometer Suite Data

    Directory of Open Access Journals (Sweden)

    Christopher D. Elvidge

    2015-12-01

    Full Text Available A set of methods are presented for the global survey of natural gas flaring using data collected by the National Aeronautics and Space Administration/National Oceanic and Atmospheric Administration NASA/NOAA Visible Infrared Imaging Radiometer Suite (VIIRS. The accuracy of the flared gas volume estimates is rated at ±9.5%. VIIRS is particularly well suited for detecting and measuring the radiant emissions from gas flares through the collection of shortwave and near-infrared data at night, recording the peak radiant emissions from flares. In 2012, a total of 7467 individual flare sites were identified. The total flared gas volume is estimated at 143 (±13.6 billion cubic meters (BCM, corresponding to 3.5% of global production. While the USA has the largest number of flares, Russia leads in terms of flared gas volume. Ninety percent of the flared gas volume was found in upstream production areas, 8% at refineries and 2% at liquified natural gas (LNG terminals. The results confirm that the bulk of natural gas flaring occurs in upstream production areas. VIIRS data can provide site-specific tracking of natural gas flaring for use in evaluating efforts to reduce and eliminate routine flaring.

  9. The Stellar Mass of M31 as inferred by the Andromeda Optical & Infrared Disk Survey

    Science.gov (United States)

    Sick, Jonathan; Courteau, Stephane; Cuillandre, Jean-Charles; Dalcanton, Julianne; de Jong, Roelof; McDonald, Michael; Simard, Dana; Tully, R. Brent

    2015-04-01

    Our proximity and external vantage point make M31 an ideal testbed for understanding the structure of spiral galaxies. The Andromeda Optical and Infrared Disk Survey (ANDROIDS) has mapped M31's bulge and disk out to R=40 kpc in ugriJKs bands with CFHT using a careful sky calibration. We use Bayesian modelling of the optical-infrared spectral energy distribution (SED) to estimate profiles of M31's stellar populations and mass along the major axis. This analysis provides evidence for inside-out disk formation and a declining metallicity gradient. M31's i-band mass-to-light ratio (M/Li *) decreases from 0.5 dex in the bulge to ~ 0.2 dex at 40 kpc. The best-constrained stellar population models use the full ugriJKs SED but are also consistent with optical-only fits. Therefore, while NIR data can be successfully modelled with modern stellar population synthesis, NIR data do not provide additional constraints in this application. Fits to the gi-SED alone yield M/Li * that are systematically lower than the full SED fit by 0.1 dex. This is still smaller than the 0.3 dex scatter amongst different relations for M/Li via g - i colour found in the literature. We advocate a stellar mass of M *(30 kpc) = 10.3+2.3 -1.7 × 1010 M⊙ for the M31 bulge and disk.

  10. 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.

  11. Herschel-ATLAS: modelling the first strong gravitational lenses

    Science.gov (United States)

    Dye, S.; Negrello, M.; Hopwood, R.; Nightingale, J. W.; Bussmann, R. S.; Amber, S.; Bourne, N.; Cooray, A.; Dariush, A.; Dunne, L.; Eales, S. A.; Gonzalez-Nuevo, J.; Ibar, E.; Ivison, R. J.; Maddox, S.; Valiante, E.; Smith, M.

    2014-05-01

    We have determined the mass density radial profiles of the first five strong gravitational lens systems discovered by the Herschel Astrophysical Terahertz Large Area Survey. We present an enhancement of the semilinear lens inversion method of Warren & Dye which allows simultaneous reconstruction of several different wavebands and apply this to dual-band imaging of the lenses acquired with the Hubble Space Telescope. The five systems analysed here have lens redshifts which span a range 0.22 ≤ z ≤ 0.94. Our findings are consistent with other studies by concluding that: (1) the logarithmic slope of the total mass density profile steepens with decreasing redshift; (2) the slope is positively correlated with the average total projected mass density of the lens contained within half the effective radius and negatively correlated with the effective radius; (3) the fraction of dark matter contained within half the effective radius increases with increasing effective radius and increases with redshift.

  12. News Note: Herschel-Darwin commemoration dinner

    Science.gov (United States)

    de Coning, Chris

    2016-08-01

    On the evening of 15 June 1836 Charles Darwin had dinner with John Herschel in Cape Town. The year 2016 makes it 180 years since this event took place. Auke Slotegraaf and Chris de Coning decided that the event should be commemorated. A total of 15 people attended the dinner, which was held on 15 June at a restaurant in the house occupied by the astronomer Fearon Fallows in 1821. It was a very informal evening and there were three speakers.

  13. The Herschel/SPIRE Spectrometer Useful Scripts

    Science.gov (United States)

    Polehampton, E.; Hopwood, R.; Valtchanov, I.; Lu, N.; Marchili, N.; Naylor, D.; van der Wiel, M.; Fulton, T.

    2015-09-01

    In most cases, the Standard Product Generation (SPG) processing pipelines for the Herschel SPIRE Fourier Transform Spectrometer (FTS) produce well-calibrated spectra of high quality. However, some Astronomical sources, such as those with a faint continuum, require additional processing to achieve more meaningful spectra. In consultation with the astronomical community, a set of scripts were developed to assist in the post-pipeline analysis of the spectra.

  14. Infrared near-Earth-object survey modeling for observatories interior to the Earth's orbit

    Science.gov (United States)

    Buie, M.

    2014-07-01

    The search for and dynamical characterization of the near-Earth population of objects (NEOs) has been a busy topic for surveys for many years. Most of the work thus far has been from ground-based optical surveys such as the Catalina Sky Survey and LINEAR. These surveys have essentially reached a complete inventory of objects down to 1 km diameter and have shown that the known objects do not pose any significant impact threat. Smaller objects are correspondingly smaller threats but there are more of them and fewer of them have so far been discovered. The next generation of surveys is looking to extend their reach down to much smaller sizes. From an impact risk perspective, those objects as small as 30--40 m are still of interest (similar in size to the Tunguska bolide). Smaller objects than this are largely of interest from a space resource or in-situ analysis efforts. A recent mission concept promoted by the B612 Foundation and Ball Aerospace calls for an infrared survey telescope in a Venus-like orbit, known as the Sentinel Mission. This wide-field facility has been designed to complete the inventory down to a 140 m diameter while also providing substantial constraints on the NEO population down to a Tunguska-sized object. I have been working to develop a suite of tools to provide survey modeling for this class of survey telescope. The purpose of the tool is to uncover hidden complexities that govern mission design and operation while also working to quantitatively understand the orbit quality provided on its catalog of objects without additional followup assets. The baseline mission design calls for a 6.5 year survey lifetime. This survey model is a statistically based tool for establishing completeness as a function of object size and survey duration. Effects modeled include the ability to adjust the field-of-regard (includes all pointing restrictions), field-of-view, focal plane array fill factor, and the observatory orbit. Consequences tracked include time

  15. The Herschels: A very fashionable scientific family

    Science.gov (United States)

    Winterburn, Emily

    2011-01-01

    What is special about the Herschel family? It is a family that has attracted the attention of historians of science for many years and has done so for a number of reasons. Some simply marvel at the family's ability to have produced generations upon generation of great men and women of science. Others have highlighted the work of individuals within the family and how their work changed the way astronomy was done, what it was about, and then later did the same for science as a whole. The unusually high status enjoyed by Herschel women, Caroline Herschel in particular, has not escaped notice, though I will here question some of the conclusions drawn about her motivations. Most of all, however I will argue in this paper, they should be interesting to a modern audience for the way in which they managed time and again, generation on generation, to make science fashionable and popular. In this paper I will look at three generations of this family - from William and Caroline discovering comets and planets in the late eighteenth century, through John and his claim that society needs science to be properly civilised, to John and Margaret's children and their varied takes on the relationship between astronomy, science and the public. I will look at the role astronomy played in each of their lives, how they were taught and taught each other and how in each generation they managed to make their work the talk of the town.

  16. Herschel SPIRE FTS relative spectral response calibration

    Science.gov (United States)

    Fulton, Trevor; Hopwood, Rosalind; Baluteau, Jean-Paul; Benielli, Dominique; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Naylor, David; Polehampton, Edward; Swinyard, Bruce; Valtchanov, Ivan

    2014-07-01

    Herschel/SPIRE Fourier transform spectrometer (FTS) observations contain emission from both the Herschel Telescope and the SPIRE Instrument itself, both of which are typically orders of magnitude greater than the emission from the astronomical source, and must be removed in order to recover the source spectrum. The effects of the Herschel Telescope and the SPIRE Instrument are removed during data reduction using relative spectral response calibration curves and emission models. We present the evolution of the methods used to derive the relative spectral response calibration curves for the SPIRE FTS. The relationship between the calibration curves and the ultimate sensitivity of calibrated SPIRE FTS data is discussed and the results from the derivation methods are compared. These comparisons show that the latest derivation methods result in calibration curves that impart a factor of between 2 and 100 less noise to the overall error budget, which results in calibrated spectra for individual observations whose noise is reduced by a factor of 2-3, with a gain in the overall spectral sensitivity of 23 % and 21 % for the two detector bands, respectively.

  17. 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.

  18. The Herschel view of GAS in Protoplanetary Systems (GASPS) : First comparisons with a large grid of models

    NARCIS (Netherlands)

    Pinte, C.; Woitke, P.; Menard, F.; Duchene, G.; Kamp, I.; Meeus, G.; Mathews, G.; Howard, C. D.; Grady, C. A.; Thi, W. -F.; Tilling, I.; Augereau, J. -C.; Dent, W. R. F.; Alacid, J. M.; Andrews, S.; Ardila, D. R.; Aresu, G.; Barrado, D.; Brittain, S.; Ciardi, D. R.; Danchi, W.; Eiroa, C.; Fedele, D.; de Gregorio-Monsalvo, I.; Heras, A.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mendigutia, I.; Montesinos, B.; Mora, A.; Morales-Calderon, M.; Nomura, H.; Pantin, E.; Pascucci, I.; Phillips, N.; Podio, L.; Poelman, D. R.; Ramsay, S.; Riaz, B.; Rice, K.; Riviere-Marichalar, P.; Roberge, A.; Sandell, G.; Solano, E.; Vandenbussche, B.; Williams, J. P.; White, G. J.; Wright, G.; Walker, H.

    The Herschel GASPS key program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of

  19. 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

  20. A Deep Near-infrared Survey toward the Aquila Molecular Cloud. I. Molecular Hydrogen Outflows

    Science.gov (United States)

    Zhang, Miaomiao; Fang, Min; Wang, Hongchi; Sun, Jia; Wang, Min; Jiang, Zhibo; Anathipindika, Sumedh

    2015-08-01

    We have performed an unbiased, deep near-infrared survey toward the Aquila molecular cloud with a sky coverage of ∼1 deg2. We identified 45 molecular hydrogen emission-line objects (MHOs), of which only 11 were previously known. Using the Spitzer archival data, we also identified 802 young stellar objects (YSOs) in this region. Based on the morphology and the location of MHOs and YSO candidates, we associate 43 MHOs with 40 YSO candidates. The distribution of jet length shows an exponential decrease in the number of outflows with increasing length, and the molecular hydrogen outflows seem to be oriented randomly. Moreover, there is no obvious correlation between jet lengths, jet opening angles, or jet {{{H}}}21-0S(1) luminosities and the spectral indices of the possible driving sources in this region. We also suggest that molecular hydrogen outflows in the Aquila molecular cloud are rather weak sources of turbulence, unlikely to generate the observed velocity dispersion in the region of survey.

  1. DISCOVERY OF THREE DISTANT, COLD BROWN DWARFS IN THE WFC3 INFRARED SPECTROSCOPIC PARALLELS SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Masters, D.; Siana, B. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); McCarthy, P.; Hathi, N. P.; Dressler, A. [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States); Burgasser, A. J. [Center for Astrophysics and Space Science, University of California, San Diego, La Jolla, CA 92093 (United States); Malkan, M.; Ross, N. R. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Scarlata, C. [Astronomy Department, University of Minnesota, Minneapolis, MN 55455 (United States); Henry, A. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Colbert, J.; Atek, H. [Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States); Rafelski, M.; Teplitz, H. [Infrared Processing and Analysis Center, Caltech, Pasadena, CA 91125 (United States); Bunker, A. [Department of Physics, University of Oxford, Oxford (United Kingdom)

    2012-06-10

    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 {approx}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{proportional_to}M{sup -{alpha}} with {alpha} = 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.

  2. Herschel observations of the Galactic H II region RCW 79

    Science.gov (United States)

    Liu, Hong-Li; Figueira, Miguel; Zavagno, Annie; Hill, Tracey; Schneider, Nicola; Men'shchikov, Alexander; Russeil, Delphine; Motte, Frédérique; Tigé, Jérémy; Deharveng, Lise; Anderson, Loren D.; Li, Jin-Zeng; Wu, Yuefang; Yuan, Jing-Hua; Huang, Maohai

    2017-06-01

    Context. Triggered star formation around H II regions could be an important process. The Galactic H II region RCW 79 is a prototypical object for triggered high-mass star formation. Aims: We aim to obtain a census of the young stellar population observed at the edges of the H II region and to determine the properties of the young sources in order to characterize the star formation processes that take place at the edges of this ionized region. Methods: We take advantage of Herschel data from the surveys HOBYS, "Evolution of Interstellar Dust", and Hi-Gal to extract compact sources. We use the algorithm getsources. We complement the Herschel data with archival 2MASS, Spitzer, and WISE data to determine the physical parameters of the sources (e.g., envelope mass, dust temperature, and luminosity) by fitting the spectral energy distribution. Results: We created the dust temperature and column density maps along with the column density probability distribution function (PDF) for the entire RCW 79 region. We obtained a sample of 50 compact sources in this region, 96% of which are situated in the ionization-compressed layer of cold and dense gas that is characterized by the column density PDF with a double-peaked lognormal distribution. The 50 sources have sizes of 0.1-0.4 pc with a typical value of 0.2 pc, temperatures of 11-26 K, envelope masses of 6-760 M⊙, densities of 0.1-44 × 105 cm-3, and luminosities of 19-12 712 L⊙. The sources are classified into 16 class 0, 19 intermediate, and 15 class I objects. Their distribution follows the evolutionary tracks in the diagram of bolometric luminosity versus envelope mass (Lbol-Menv) well. A mass threshold of 140 M⊙, determined from the Lbol-Menv diagram, yields 12 candidate massive dense cores that may form high-mass stars. The core formation efficiency (CFE) for the 8 massive condensations shows an increasing trend of the CFE with density. This suggests that the denser the condensation, the higher the fraction of its

  3. HERSCHEL-ATLAS: A BINARY HyLIRG PINPOINTING A CLUSTER OF STARBURSTING PROTOELLIPTICALS

    Energy Technology Data Exchange (ETDEWEB)

    Ivison, R. J. [UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Swinbank, A. M.; Smail, Ian [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Harris, A. I. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Bussmann, R. S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Cooray, A.; Fu, H. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Cox, P.; Krips, M.; Neri, R. [Institut de Radioastronomie Millimetrique, 300 rue de la Piscine, F-38406 Saint-Martin d' Heres (France); Kovacs, A. [Department of Astronomy, University of Minnesota, Minneapolis, MN 55414 (United States); Narayanan, D. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Negrello, M. [INAF, Osservatorio Astronomico di Padova, I-35122 Padova (Italy); Penarrubia, J.; Targett, T. A. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Richard, J. [Centre de Recherche Astrophysique de Lyon, Universite Lyon 1, 9 Avenue Charles Andre, F-69561 Saint Genis Laval Cedex (France); Riechers, D. A. [Department of Astronomy, Space Science Building, Cornell University, Ithaca, NY 14853-6801 (United States); Rowlands, K. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Staguhn, J. G. [The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Amber, S. [Department of Physical Sciences, The Open University, Milton Keynes (United Kingdom); and others

    2013-08-01

    Panchromatic observations of the best candidate hyperluminous infrared galaxies from the widest Herschel extragalactic imaging survey have led to the discovery of at least four intrinsically luminous z = 2.41 galaxies across an Almost-Equal-To 100 kpc region-a cluster of starbursting protoellipticals. Via subarcsecond interferometric imaging we have measured accurate gas and star formation surface densities. The two brightest galaxies span {approx}3 kpc FWHM in submillimeter/radio continuum and CO J = 4-3, and double that in CO J = 1-0. The broad CO line is due partly to the multitude of constituent galaxies and partly to large rotational velocities in two counter-rotating gas disks-a scenario predicted to lead to the most intense starbursts, which will therefore come in pairs. The disks have M{sub dyn} of several Multiplication-Sign 10{sup 11} M{sub Sun }, and gas fractions of {approx}40%. Velocity dispersions are modest so the disks are unstable, potentially on scales commensurate with their radii: these galaxies are undergoing extreme bursts of star formation, not confined to their nuclei, at close to the Eddington limit. Their specific star formation rates place them {approx}> 5 Multiplication-Sign above the main sequence, which supposedly comprises large gas disks like these. Their high star formation efficiencies are difficult to reconcile with a simple volumetric star formation law. N-body and dark matter simulations suggest that this system is the progenitor of a B(inary)-type Almost-Equal-To 10{sup 14.6}-M{sub Sun} cluster.

  4. Gas and dust in the TW Hydrae association as seen by the Herschel Space Observatory

    Science.gov (United States)

    Riviere-Marichalar, P.; Pinte, C.; Barrado, D.; Thi, W. F.; Eiroa, C.; Kamp, I.; Montesinos, B.; Donaldson, J.; Augereau, J. C.; Huélamo, N.; Roberge, A.; Ardila, D.; Sandell, G.; Williams, J. P.; Dent, W. R. F.; Menard, F.; Lillo-Box, J.; Duchêne, G.

    2013-07-01

    Context. Circumstellar discs are the places where planets form, therefore knowledge of their evolution is crucial for our understanding of planet formation. The Herschel Space Observatory is providing valuable data for studying disc systems, thanks to its sensitivity and wavelength coverage. This paper is one of several devoted to analysing and modelling Herschel-PACS observations of various young stellar associations from the GASPS open time key programme. Aims: The aim of this paper is to elucidate the gas and dust properties of circumstellar discs in the ~10 Myr TW Hya association (TWA) using new far-infrared (IR) imaging and spectroscopy from Herschel-PACS. Methods: We obtained far-IR photometric data at 70, 100, and 160 μm of 14 TWA members; spectroscopic observations centred on the [OI] line at 63.18 μm were also obtained for 9 of the 14. The new photometry for each star was incorporated into its full spectral energy distribution. Results: We detected excess IR emission that is characteristic of circumstellar discs from five TWA members, and computed upper limits for another nine. Two TWA members (TWA 01 and TWA 04B) also show [OI] emission at 63.18 μm. Discs in the TWA association display a variety of properties, with a wide range of dust masses and inner radii, based on modified blackbody modelling. Both transitional and debris discs are found in the sample. Models for sources with a detected IR excess give dust masses in the range from ~0.15 M⊕ to ~63 M⊕. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  5. 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

  6. Deep wide-field near-infrared survey of the Carina Nebula

    Science.gov (United States)

    Preibisch, T.; Ratzka, T.; Kuderna, B.; Ohlendorf, H.; King, R. R.; Hodgkin, S.; Irwin, M.; Lewis, J. R.; McCaughrean, M. J.; Zinnecker, H.

    2011-06-01

    Context. The Great Nebula in Carina is a giant H ii region and a superb location in which to study the physics of violent massive star formation, but the population of the young low-mass stars remained very poorly studied until recently. Aims: Our aim was to produce a near-infrared survey that is deep enough to detect the full low-mass stellar population (i.e. down to ≈0.1 M⊙ and for extinctions up to AV ≈ 15 mag) and wide enough to cover all important parts of the Carina Nebula complex (CNC), including the clusters Tr 14, 15, and 16 as well as the South Pillars region. Methods: We used HAWK-I at the ESO VLT to survey the central ≈0.36 deg2 area of the Carina Nebula. These data reveal more than 600 000 individual infrared sources down to magnitudes as faint as J ≈ 23, H ≈ 22, and Ks ≈ 21. The results of a recent deep X-ray survey (which is complete down to stellar masses of ~0.5-1 M⊙) are used to distinguish between young stars in Carina and background contaminants. We analyze color - magnitude diagrams (CMDs) to derive information about the ages and masses of the low-mass stars. Results: The ages of the low-mass stars agree with previous age estimates for the massive stars. The CMD suggests that ≈3200 of the X-ray selected stars have masses of M∗ ≥ 1 M⊙; this number is in good agreement with extrapolations of the field IMF based on the number of high-mass (M∗ ≥ 20 M⊙) stars and shows that there is no deficit of low-mass stars in the CNC. The HAWK-I images confirm that about 50% of all young stars in Carina are in a widely distributed, non-clustered spatial configuration. Narrow-band images reveal six molecular hydrogen emission objects (MHOs) that trace jets from embedded protostars. However, none of the optical HH objects shows molecular hydrogen emission, suggesting that the jet-driving protostars are located very close to the edges of the globules in which they are embedded. Conclusions: The near-infrared excess fractions for the

  7. 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

  8. Water in low-mass star-forming regions with Herschel: HIFI spectroscopy of NGC 1333

    OpenAIRE

    Kristensen, L. E.; Dominik, C.; Whyborn, N.

    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 (HIFI) on the Herschel Space Observatory observed three deeply embedded protostars in the low-mass star-forming region NGC 1333 in several H_(2)^(16)O, H_(2)^(18)O, and CO transitions. Line profiles are r...

  9. 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 z generation astrophysicists in the

  10. A far-infrared molecular and atomic line survey of the Orion KL region

    Science.gov (United States)

    Lerate, M. R.; Barlow, M. J.; Swinyard, B. M.; Goicoechea, J. R.; Cernicharo, J.; Grundy, T. W.; Lim, T. L.; Polehampton, E. T.; Baluteau, J.-P.; Viti, S.; Yates, J.

    2006-08-01

    We have carried out a high spectral resolution (λ/Δλ ~ 6800-9700) line survey towards the Orion Kleinmann-Low (KL) cluster from 44 to 188 μm. The observations were taken with the Long Wavelength Spectrometer (LWS) in Fabry-Pérot mode, on board the Infrared Space Observatory (ISO). A total of 152 lines are clearly detected and a further 34 features are present as possible detections. The spectrum is dominated by the molecular species H2O, OH and CO, along with [OI] and [CII] lines from photodissociation region (PDR) or shocked gas and [O III] and [NIII] lines from the foreground M42 HII region. Several isotopic species, as well as NH3, are also detected. HDO and H3O+ are tentatively detected for the first time in the far-infrared (FIR) range towards Orion KL. A basic analysis of the line observations is carried out, by comparing with previous measurements and published models and deriving rotational temperatures and column densities in the case of the molecular species. Analysis of the [OI] and [CII] fine structure lines indicates that although a shock model can reproduce the observed [OI] surface brightness levels, it falls short of the observed [CII] level by more than a factor of 30. A PDR model can reproduce the [OI] 63.2 μm and [CII] surface brightness levels within 35 per cent, although overpredicting the LWS [OI] 145.5 μm-emission by a factor of 2.7. The 70 water lines and 22 OH lines detected by the survey appear with mainly P Cygni profiles at the shortest survey wavelengths and with mainly pure emission profiles at the longest survey wavelengths. The emission and absorption velocity peaks of the water and OH lines indicate that they are associated with gas expanding in the outflow from the KL cluster. The estimated column densities are (2-5) × 1014 cm-2 for H2O and (2.5-5.1) × 1016 cm-2 for OH. The 26 detected CO lines confirm the presence of three distinct components, with temperature and column density combinations ranging from 660 K, 6 × 1017

  11. Near-Infrared Surveys and the Potential of an Upgraded WFCAM on UKIRT

    Science.gov (United States)

    Green, Richard F.; Kerr, Tom; Varricatt, Watson; Bold, Matthew; Kendrick, Rick; Hodapp, Klaus

    2015-08-01

    Near-infrared surveys provide the samples of faint objects essential for characterizing the assembly and evolution of galaxies, both at earliest cosmic times and near the peak of star formation and black hole activity. Near-IR broad and medium-band filter measurements are critical for accurate photometric redshifts and spectral energy distributions. The same areal coverage combined with time domain sampling reveals the variability properties of pre-main sequence stars in regions of active star formation, particularly in the presence of appreciable reddening. The possibility of deep, very wide-area K-band coverage creates the opportunity to trace the outer regions of the Galaxy and the Local Group. Targeting for James Webb Space Telescope will depend on accurate contemporaneous Near-IR astrometry. NASA's mission objectives for protecting working spacecraft from orbital debris are facilitated by near-IR characterization of debris, particularly for objects dark in the visible like solar panels.As one realization of advanced survey capability, we describe a proposed upgrade to the Wide-Field camera on the UKIRT 3.8-m. The powerful performance of an array of Teledyne Hawaii-4RG detectors combined with a new corrector and filters promise a Northern Hemisphere capability matched to the next generation of science requirements. Anticipated improvements include (nearly) contiguous detectors (alleviating the need for a large-step dither pattern), higher DQE, and no restriction on field because of guide stars. We would be assured of better wide-area astrometry and sensitivity compared to the generation of devices used for UKIDSS and HEMISPHERE.

  12. Aerial ungulate surveys with a combination of infrared and high–resolution natural colour images

    Directory of Open Access Journals (Sweden)

    Franke, U.

    2012-01-01

    Full Text Available Information on animal population sizes is crucial for wildlife management. In aerial surveys, we used a silent light aircraft (microlight and a combination of a computer–linked thermal infrared camera (640 x 480 pixels to detect ungulates and high–resolution visual images (5,616 x 3,744 pixels to identify specific species. From winter 2008/2009 to winter 2010/2011, we flew 48 missions over three German national parks and a German/ French biosphere reserve. Within each study area, we followed non–overlapping linear transects with a flying altitude ~450 m above ground level and scanned 1,500–2,000 ha every two hours of flight time. Animals best detected and identified were red deer and fallow deer. Detection rates with respect to the type and density of vegetation cover ranged from 0% (young spruce to 75% (young defoliated beech to 100% (open land. This non–invasive method is cost–effective and suitable for many landscapes.

  13. Unbiased Large Spectroscopic Surveys of Galaxies Selected by SPICA Using Dust Bands

    Science.gov (United States)

    Kaneda, H.; Ishihara, D.; Oyabu, S.; Yamagishi, M.; Wada, T.; Armus, L.; Baes, M.; Charmandaris, V.; Czerny, B.; Efstathiou, A.; Fernández-Ontiveros, J. A.; Ferrara, A.; González-Alfonso, E.; Griffin, M.; Gruppioni, C.; Hatziminaoglou, E.; Imanishi, M.; Kohno, K.; Kwon, J.; Nakagawa, T.; Onaka, T.; Pozzi, F.; Scott, D.; Smith, J.-D. T.; Spinoglio, L.; Suzuki, T.; van der Tak, F.; Vaccari, M.; Vignali, C.; Wang, L.

    2017-11-01

    The mid-infrared range contains many spectral features associated with large molecules and dust grains such as polycyclic aromatic hydrocarbons and silicates. These are usually very strong compared to fine-structure gas lines, and thus valuable in studying the spectral properties of faint distant galaxies. In this paper, we evaluate the capability of low-resolution mid-infrared spectroscopic surveys of galaxies that could be performed by SPICA. The surveys are designed to address the question how star formation and black hole accretion activities evolved over cosmic time through spectral diagnostics of the physical conditions of the interstellar/circumnuclear media in galaxies. On the basis of results obtained with Herschel far-infrared photometric surveys of distant galaxies and Spitzer and AKARI near- to mid-infrared spectroscopic observations of nearby galaxies, we estimate the numbers of the galaxies at redshift z > 0.5, which are expected to be detected in the polycyclic aromatic hydrocarbon features or dust continuum by a wide (10 deg2) or deep (1 deg2) blind survey, both for a given observation time of 600 h. As by-products of the wide blind survey, we also expect to detect debris disks, through the mid-infrared excess above the photospheric emission of nearby main-sequence stars, and we estimate their number. We demonstrate that the SPICA mid-infrared surveys will efficiently provide us with unprecedentedly large spectral samples, which can be studied further in the far-infrared with SPICA.

  14. THE DEBRIS DISK AROUND {gamma} DORADUS RESOLVED WITH HERSCHEL

    Energy Technology Data Exchange (ETDEWEB)

    Broekhoven-Fiene, Hannah; Matthews, Brenda C.; Booth, Mark; Kavelaars, J. J.; Koning, Alice [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 3P6 (Canada); Kennedy, Grant M.; Wyatt, Mark C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Sibthorpe, Bruce [UK Astronomy Technology Center, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Lawler, Samantha M. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Qi, Chenruo [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Su, Kate Y. L.; Rieke, George H. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Greaves, Jane S. [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews KY16 9SS (United Kingdom)

    2013-01-01

    We present observations of the debris disk around {gamma} Doradus, an F1V star, from the Herschel Key Programme DEBRIS (Disc Emission via Bias-free Reconnaissance in the Infrared/Submillimetre). The disk is well resolved at 70, 100, and 160 {mu}m, resolved along its major axis at 250 {mu}m, detected but not resolved at 350 {mu}m, and confused with a background source at 500 {mu}m. It is one of our best resolved targets and we find it to have a radially broad dust distribution. The modeling of the resolved images cannot distinguish between two configurations: an arrangement of a warm inner ring at several AU (best fit 4 AU) and a cool outer belt extending from {approx}55 to 400 AU or an arrangement of two cool, narrow rings at {approx}70 AU and {approx}190 AU. This suggests that any configuration between these two is also possible. Both models have a total fractional luminosity of {approx}10{sup -5} and are consistent with the disk being aligned with the stellar equator. The inner edge of either possible configuration suggests that the most likely region to find planets in this system would be within {approx}55 AU of the star. A transient event is not needed to explain the warm dust's fractional luminosity.

  15. Herschel SPIRE FTS telescope model correction

    Science.gov (United States)

    Hopwood, Rosalind; Fulton, Trevor; Polehampton, Edward T.; Valtchanov, Ivan; Benielli, Dominique; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Pearson, Chris P.; Swinyard, Bruce M.

    2014-07-01

    Emission from the Herschel telescope is the dominant source of radiation for the majority of SPIRE Fourier transform spectrometer (FTS) observations, despite the exceptionally low emissivity of the primary and secondary mirrors. Accurate modelling and removal of the telescope contribution is, therefore, an important and challenging aspect of FTS calibration and data reduction pipeline. A dust-contaminated telescope model with time invariant mirror emissivity was adopted before the Herschel launch. However, measured FTS spectra show a clear evolution of the telescope contribution over the mission and strong need for a correction to the standard telescope model in order to reduce residual background (of up to 7 Jy) in the final data products. Systematic changes in observations of dark sky, taken over the course of the mission, provide a measure of the evolution between observed telescope emission and the telescope model. These dark sky observations have been used to derive a time dependent correction to the telescope emissivity that reduces the systematic error in the continuum of the final FTS spectra to ˜0.35 Jy.

  16. 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.

  17. Long Hole Film Cooling Dataset for CFD Development . Part 1; Infrared Thermography and Thermocouple Surveys

    Science.gov (United States)

    Shyam, Vikram; Thurman, Douglas; Poinsatte, Phillip; Ameri, Ali; Eichele, Peter; Knight, James

    2013-01-01

    An experiment investigating flow and heat transfer of long (length to diameter ratio of 18) cylindrical film cooling holes has been completed. In this paper, the thermal field in the flow and on the surface of the film cooled flat plate is presented for nominal freestream turbulence intensities of 1.5 and 8 percent. The holes are inclined at 30deg above the downstream direction, injecting chilled air of density ratio 1.0 onto the surface of a flat plate. The diameter of the hole is 0.75 in. (0.01905 m) with center to center spacing (pitch) of 3 hole diameters. Coolant was injected into the mainstream flow at nominal blowing ratios of 0.5, 1.0, 1.5, and 2.0. The Reynolds number of the freestream was approximately 11,000 based on hole diameter. Thermocouple surveys were used to characterize the thermal field. Infrared thermography was used to determine the adiabatic film effectiveness on the plate. Hotwire anemometry was used to provide flowfield physics and turbulence measurements. The results are compared to existing data in the literature. The aim of this work is to produce a benchmark dataset for Computational Fluid Dynamics (CFD) development to eliminate the effects of hole length to diameter ratio and to improve resolution in the near-hole region. In this report, a Time-Filtered Navier Stokes (TFNS), also known as Partially Resolved Navier Stokes (PRNS), method that was implemented in the Glenn-HT code is used to model coolant-mainstream interaction. This method is a high fidelity unsteady method that aims to represent large scale flow features and mixing more accurately.

  18. Widening of Protostellar Outflows: An Infrared Outflow Survey in Low-luminosity Objects

    Science.gov (United States)

    Hsieh, Tien-Hao; Lai, Shih-Ping; Belloche, Arnaud

    2017-04-01

    We present an outflow survey toward 20 low-luminosity objects (LLOs), namely, protostars with an internal luminosity lower than 0.2 {L}⊙ . Although a number of studies have reported the properties of individual LLOs, the reasons for their low luminosity remain uncertain. To answer this question, we need to know the evolutionary status of LLOs. Protostellar outflows are found to widen as their parent cores evolve, and therefore the outflow opening angle could be used as an evolutionary indicator. The infrared scattered light escapes out through the outflow cavity and highlights the cavity wall, giving us the opportunity to measure the outflow opening angle. Using the Canada-France-Hawaii Telescope, we detected outflows toward eight LLOs out of 20 at Ks band, and based on archival Spitzer IRAC1 images, we added four outflow-driving sources from the remaining 12 sources. By fitting these images with radiative transfer models, we derive the outflow opening angles and inclination angles. To study the widening of outflow cavities, we compare our sample with the young stellar objects from Arce & Sargent and Velusamy et al. in a plot of opening angle versus bolometric temperature taken as an evolutionary indicator. Our LLO targets match well the trend of increasing opening angle with bolometric temperature reported by Arce & Sargent and are broadly consistent with that reported by Velusamy et al., suggesting that the opening angle could be a good evolutionary indicator for LLOs. Accordingly, we conclude that at least 40% of the outflow-driving LLOs in our sample are young Class 0 objects.

  19. THE SPITZER INTERACTING GALAXIES SURVEY: A MID-INFRARED ATLAS OF STAR FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Brassington, N. J. [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB (United Kingdom); Zezas, A.; Ashby, M. L. N.; Lanz, L.; Smith, Howard A.; Willner, S. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Klein, C., E-mail: n.brassington@herts.ac.uk [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2015-05-15

    The Spitzer Interacting Galaxies Survey is a sample of 103 nearby galaxies in 48 systems, selected using association likelihoods and therefore free from disturbed morphology biases. All galaxies have been observed with Infrared Array Camera and MIPS 24 μm bands from the Spitzer Space Telescope. This catalog presents the global flux densities and colors of all systems and correlations between the interacting systems and their specific star formation rate (sSFR). This sample contains a wide variety of galaxy interactions with systems ranging in mass, mass ratios, and gas-content as well as interaction strength. This study seeks to identify the process of triggering star formation in galaxy interactions, therefore, we focus on the non-active galactic nucleus spiral galaxies only. From this subset of 70 spiral galaxies we have determined that this sample has enhanced sSFR compared to a sample of non-interacting field galaxies. Through optical data we have classified each system by “interaction strength”; the strongly interacting (Stage 4) galaxies have higher sSFR values than the weakly (Stage 2) and moderately (Stage 3) interacting systems. However, the Stage 2 and 3 systems have statistically identical sSFR properties, despite the lack of optical interaction signatures exhibited by the Stage 2 galaxies. We suggest that the similarity of sSFR in these stages could be a consequence of some of these Stage 2 systems actually being post-perigalactic and having had sufficient time for their tidal features to fade to undetectable levels. This interpretation is consistent with the correlation of sSFR with separation, which we have determined to have little variation up to 100 kpc.

  20. Identifying Cool Brown Dwarfs and Subdwarfs in the Solar Neighborhood: Prospects for a Near-Infrared Proper Motion Survey

    Science.gov (United States)

    Burgasser, A. J.

    2003-12-01

    Low-temperature stars and brown dwarfs emit predominantly in the near-infrared, and recent wide-field surveys sampling these wavelengths (2MASS, DENIS, SDSS) have unveiled a vast repository of intrinsically faint objects, including large numbers of field brown dwarfs and members of two new spectral classes. On the other hand, proper motion surveys have been exceptionally efficient at uncovering both the nearest stars and stars with high intrinsic motions; i.e., halo/thick disk dwarfs and white dwarfs. Unfortunately, proper motion surveys are insensitive to faint stars and brown dwarfs as they have been conducted primarily at optical bands. I therefore make a case for a wide-field near-infrared proper motion survey that would detect the nearest cool stars and brown dwarfs in an efficient and photometrically unbiased manner. I demonstrate how the currently known population of field brown dwarfs are easily discernible in such a survey, and how substellar subdwarfs could potentially be found in substantial numbers. This survey could make use of existing catalog data as its first epoch. I also describe a straightforward NIR survey program using a 2Kx2K IR camera on a dedicated 1-2m class automated telescope. This somewhat more ambitious program could repeatedly scan the sky on a 6-month cycle, and would be useful for cool dwarf searches, general variability studies, searches for transits around late-type stars, and deep survey programs. This research is supported by NASA through Hubble Fellowship grant HST-HF-01137.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  1. Photogeologic and thermal infrared reconnaissance surveys of the Los Negritos-Ixtlan de los Hervores geothermal area, Michoacan, Mexico

    Science.gov (United States)

    Gomez, Valle R.; Friedman, J.D.; Gawarecki, S.J.; Banwell, C.J.

    1970-01-01

    New techniques, involving interpretation of panchromatic, ektachrome and ektachrome infrared aerographic photogaphs and thermographic infrared imagery recording emission from the earth's surface in middle and far infrared wavelengths (3-5??m and 8-14??m), are being introduced in geothermal investigations in Mexico to identify outstanding structural and geologic features in a rapid and economical manner. The object of this work is to evaluate the new airborne infrared techniques and equipment as a complement to the data obtained from panchromatic aerial photography. This project is part of the Mexican remote sensing program of natural resources carried out under the auspices of the Comision Nacional del Espacio Exterior and in which the Research Institute (Instituto de Investigaciones de la Industria Electrica) is actively participating. The present study was made cooperatively with the U.S. National Aeronautics and Space Administration and the U.S. Geological Survey. The Los Negritos-Ixtlan de los Hervores geothermal fields are located east of Lake Chapala at the intersection of the Sierra Madre occidental and the west-central segment of the neovolcanic axis of Mexico. The two principal zones of hydrothermal activity occur in a tectonic trench filled with lake sediments of the Quaternary intercalated with Quaternary and Holocene volcanic rocks and characterized by an intricate system of block-fault tectonics, part of the Chapala-Acambay tectonic system, along which there has been volcanic activity in modern time. Surface manifestations of geothermal activity consist of relatively high heat flow and hot springs, small geysers and small steam vents aligned along an E-W axis at Ixtlan, possibly at the intersection of major fault trends and mud volcanoes and hot pools aligned NE-SW at Los Negritos. More than 20 exit points of thermal waters are shown on infrared imagery to be aligned along an extension of the Ixtlan fault between Ixtlan and El Salitre. A narrow zone of

  2. Astronomy from Space: The Hubble, Herschel and James Webb Space Telescopes

    Science.gov (United States)

    Gardner, Jonathan P.

    2009-01-01

    Space-based astronomy is going through a renaissance, with three Great Observatories currently flying: Hubble in the visible and ultraviolet, Spitzer in the infrared and Chandra in X-rays. The future looks equally bright. The final servicing mission to Hubble will take place in February 2009 and promises to make the observatory more capable than ever with two new cameras, and refurbishment that will allow it to last at least five years. The upcoming launch of the Herschel Space Telescope will open the far-infrared to explore the cool and dusty Universe. Finally, we look forward to the launch of the James Webb Space Telescope in 2013, which wil provide a successor to both Hubble and Spitzer. In this talk, the author discusses some of the highlights of scientific discovery in the last 10 years and reveals the promise to the next 10 years.

  3. Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys

    Science.gov (United States)

    di Maio, Rosa; Meola, Carosena; Fedi, Maurizio; Carlomagno, Giovanni Maria

    2010-05-01

    An integration of high-resolution non-destructive techniques is presented for the inspection and evaluation of ancient architectonic structures. Infrared thermography (IRT) represents a valuable tool for nondestructive evaluation of architectonic structures and artworks because it is capable of giving indications about most of the degradation sources of artworks and buildings of both historical interest and civil use. In particular, it is possible to detect cracks, disbondings, alteration of material consistency, etc. Indeed, by choosing the most adequate thermographic technique, it is possible to monitor the conservation state of artworks in time and to detect the presence of many types of defects (e.g., voids, cracks, disbondings, etc.) in different types of materials (e.g., concrete, masonry structures, bronze, etc.). The main advantages of infrared thermography when dealing with precious artworks may be summarized with three words: non-contact, non-invasive, and two-dimensionality. It is possible to inspect either a large surface such as the facade of a palace, or a very small surface of only few square millimetres. Conversely, the inspection depth is quite small; generally, of the order of centimetres. However, as demonstrated in previous work, IRT well matches with electric-and electromagnetic-type geophysical methods to characterize the overlapping zone from low-to-high depth in masonry structures. In particular, the use of high-frequency electromagnetic techniques, such as the ground penetrating radar (GPR), permits to reach investigation depths of some ten of centimetres by choosing appropriate frequencies of the transmitted electromagnetic signal. In the last decade a large utilisation of the GPR methodology to non-destructive analysis of engineering and architectural materials and structures has been experienced. This includes diverse features, such as definition of layer thickness, characterisation of different constructive materials, identification of

  4. CONSTRAINING THE EXOZODIACAL LUMINOSITY FUNCTION OF MAIN-SEQUENCE STARS: COMPLETE RESULTS FROM THE KECK NULLER MID-INFRARED SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Mennesson, B.; Serabyn, E.; Colavita, M. M.; Bryden, G.; Doré, O.; Traub, W. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Millan-Gabet, R. [NASA Exoplanet Science Center, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Absil, O. [Département d' Astrophysique, Géophysique et Océanographie, Université de Liège, 17 Allée du Six Août, 4000 Liège (Belgium); Wyatt, M. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Danchi, W.; Kuchner, M.; Stapelfeldt, K. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Defrère, D.; Hinz, P. [Steward Observatory, Department of Astronomy, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Ragland, S. [Keck Observatory, 65-1120 Mamalahoa Highway, Kamuela, HI 96743 (United States); Scott, N. [Center for High Angular Resolution Astronomy, Georgia State University, Mount Wilson, CA 91023 (United States); Woillez, J., E-mail: Bertrand.Mennesson@jpl.nasa.gov [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Munchen (Germany)

    2014-12-20

    Forty-seven nearby main-sequence stars were surveyed with the Keck Interferometer mid-infrared Nulling instrument (KIN) between 2008 and 2011, searching for faint resolved emission from exozodiacal dust. Observations of a subset of the sample have already been reported, focusing essentially on stars with no previously known dust. Here we extend this previous analysis to the whole KIN sample, including 22 more stars with known near- and/or far-infrared excesses. In addition to an analysis similar to that of the first paper of this series, which was restricted to the 8-9 μm spectral region, we present measurements obtained in all 10 spectral channels covering the 8-13 μm instrumental bandwidth. Based on the 8-9 μm data alone, which provide the highest signal-to-noise measurements, only one star shows a large excess imputable to dust emission (η Crv), while four more show a significant (>3σ) excess: β Leo, β UMa, ζ Lep, and γ Oph. Overall, excesses detected by KIN are more frequent around A-type stars than later spectral types. A statistical analysis of the measurements further indicates that stars with known far-infrared (λ ≥ 70 μm) excesses have higher exozodiacal emission levels than stars with no previous indication of a cold outer disk. This statistical trend is observed regardless of spectral type and points to a dynamical connection between the inner (zodi-like) and outer (Kuiper-Belt-like) dust populations. The measured levels for such stars are clustering close to the KIN detection limit of a few hundred zodis and are indeed consistent with those expected from a population of dust that migrated in from the outer belt by Poynting-Robertson drag. Conversely, no significant mid-infrared excess is found around sources with previously reported near-infrared resolved excesses, which typically have levels of the order of 1% over the photospheric flux. If dust emission is really at play in these near-infrared detections, the absence of a strong mid-infrared

  5. Herschel Photometry of the Tucana-Horologium Association

    Science.gov (United States)

    Donaldson, Jessica; Roberge, A.; Dent, W.

    2011-01-01

    The GASPS Open Time Key Programme for the Herschel Space Observatory represents a new opportunity to survey protoplanetary disks and young debris disks at far-IR wavelengths. We present preliminary PACS 70 and 160 micron photometry of eighteen stars in the 30 Myr-old Tucana-Horologium association. Of these eighteen, six were detected in the 70 micron band. Two were also detected in the 160 micron band. We constructed SEDs for these systems using optical data from Hipparcos (B and V), near-IR data from 2MASS (J, H, and K), mid-IR data from IRAS and Spitzer MIPS (12 and 24 microns, respectively), and the new far-IR data from PACS. For the stars showing IR excess emission, we fit the data using models of optically thin debris disks with realistic dust grain properties. Our SED fitting constrains six disk parameters: the disk mass, grain size distribution, minimum and maximum grain sizes, and the minimum and maximum radial distance of the disk. The best-fit parameters give us a sense of the dust abundance and spatial distribution in these systems.

  6. 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.

  7. A FLAMINGOS Deep Near-Infrared Imaging Survey of the Rosette Complex. I. Identification and Distribution of the Embedded Population

    Science.gov (United States)

    Román-Zúñiga, Carlos G.; Elston, Richard; Ferreira, Bruno; Lada, Elizabeth A.

    2008-01-01

    We present the results of a deep near-infrared imaging survey of the Rosette complex made with FLAMINGOS at the 2.1 m telescope at Kitt Peak National Observatory. We studied the distribution of young embedded sources using a variation of the nearest neighbor method applied to a carefully selected sample of near-infrared excess (NIRX) stars that trace the latest episode of star formation in the complex. Our analysis confirmed the existence of seven clusters previously detected in the molecular cloud, and identified four more clusters across the complex. We determined that 60% of the young stars in the complex and 86% of the stars within the molecular cloud are contained in clusters, implying that the majority of stars in the Rosette formed in embedded clusters. Also, half of the young embedded population is contained in four clusters that coincide with the central core of the cloud, where the main interaction with the H II region is taking place. We compare the sizes, infrared excess fractions, and average extinction toward individual clusters to investigate their early evolution and expansion. In particular, the size and degree of central condensation within the clusters appear to be related to the degree of infrared excess and mean extinction in a way that suggests that the clusters form as compact entities and then quickly expand after formation. We found that the average infrared excess fraction of clusters increases as a function of distance from NGC 2244, implying a temporal sequence of star formation across the complex. This sequence appears to be primordial, possibly resulting from the formation and evolution of the molecular cloud and not from the interaction with the H II region. Instead, the main influence of the H II region could be to enhance or inhibit the underlying pattern of star formation in the cloud.

  8. Resolved imaging of the HR 8799 Debris disk with Herschel

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Brenda; Booth, Mark; Broekhoven-Fiene, Hannah; Marois, Christian [National Research Council of Canada Herzberg Astronomy and Astrophsyics, 5071 W. Saanich Road, Victoria, BC, V9E 2E7 (Canada); Kennedy, Grant; Wyatt, Mark [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Sibthorpe, Bruce [SRON Netherlands Institute for Space Research, P.O. Box 800, NL-9700 AV Groningen (Netherlands); Macintosh, Bruce [Lawrence Livermore National Labs, 7000 East Ave, Livermore, CA 94550 (United States)

    2014-01-01

    We present Herschel far-infrared and submillimeter maps of the debris disk associated with the HR 8799 planetary system. We resolve the outer disk emission at 70, 100, 160, and 250 μm and detect the disk at 350 and 500 μm. A smooth model explains the observed disk emission well. We observe no obvious clumps or asymmetries associated with the trapping of planetesimals that is a potential consequence of planetary migration in the system. We estimate that the disk eccentricity must be <0.1. As in previous work by Su et al., we find a disk with three components: a warm inner component and two outer components, a planetesimal belt extending from 100 to 310 AU, with some flexibility (±10 AU) on the inner edge, and the external halo that extends to ∼2000 AU. We measure the disk inclination to be 26° ± 3° from face-on at a position angle of 64° E of N, establishing that the disk is coplanar with the star and planets. The spectral energy distribution of the disk is well fit by blackbody grains whose semi-major axes lie within the planetesimal belt, suggesting an absence of small grains. The wavelength at which the spectrum steepens from blackbody, 47 ± 30 μm, however, is short compared with other A star debris disks, suggesting that there are atypically small grains likely populating the halo. The PACS longer wavelength data yield a lower disk color temperature than do MIPS data (24 and 70 μm), implying two distinct halo dust-grain populations.

  9. 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.

  10. Germanium blocked impurity band far infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Preliminary Analysis of Ground-based Orbit Determination Accuracy for the Wide Field Infrared Survey Telescope (WFIRST)

    Science.gov (United States)

    Sease, Brad

    2017-01-01

    The Wide Field Infrared Survey Telescope is a 2.4-meter telescope planned for launch to the Sun-Earth L2 point in 2026. This paper details a preliminary study of the achievable accuracy for WFIRST from ground-based orbit determination routines. The analysis here is divided into two segments. First, a linear covariance analysis of early mission and routine operations provides an estimate of the tracking schedule required to meet mission requirements. Second, a simulated operations scenario gives insight into the expected behavior of a daily Extended Kalman Filter orbit estimate over the first mission year given a variety of potential momentum unloading schemes.

  12. Herschel SPIRE FTS spectral mapping calibration

    Science.gov (United States)

    Benielli, Dominique; Polehampton, Edward; Hopwood, Rosalind; Griñón Marín, Ana Belén; Fulton, Trevor; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Makiwa, Gibion; Marchili, Nicola; Naylor, David; Spencer, Locke; Swinyard, Bruce; Valtchanov, Ivan; van der Wiel, Matthijs

    2014-07-01

    The Herschel SPIRE Fourier transform spectrometer (FTS) performs spectral imaging in the 447-1546 GHz band. It can observe in three spatial sampling modes: sparse mode, with a single pointing on sky, or intermediate or full modes with 1 and 1/2 beam spacing, respectively. In this paper, we investigate the uncertainty and repeatability for fully sampled FTS mapping observations. The repeatability is characterised using nine observations of the Orion Bar. Metrics are derived based on the ratio of the measured intensity in each observation compared to that in the combined spectral cube from all observations. The mean relative deviation is determined to be within 2 %, and the pixel-by-pixel scatter is ˜ 7 %. The scatter increases towards the edges of the maps. The uncertainty in the frequency scale is also studied, and the spread in the line centre velocity across the maps is found to be ˜ 15 km s - 1. Other causes of uncertainty are also discussed including the effect of pointing and the additive uncertainty in the continuum.

  13. 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

  14. Gas and dust in the beta Pictoris moving group as seen by the Herschel Space Observatory

    Science.gov (United States)

    Riviere-Marichalar, P.; Barrado, D.; Montesinos, B.; Duchêne, G.; Bouy, H.; Pinte, C.; Menard, F.; Donaldson, J.; Eiroa, C.; Krivov, A. V.; Kamp, I.; Mendigutía, I.; Dent, W. R. F.; Lillo-Box, J.

    2014-05-01

    Context. Debris discs are thought to be formed through the collisional grinding of planetesimals, and then can be considered as the outcome of planet formation. Understanding the properties of gas and dust in debris discs can help us comprehend the architecture of extrasolar planetary systems. Herschel Space Observatory far-infrared (IR) photometry and spectroscopy have provided a valuable dataset for the study of debris discs gas and dust composition. This paper is part of a series of papers devoted to the study of Herschel-PACS observations of young stellar associations. Aims: This work aims at studying the properties of discs in the beta Pictoris moving group (BPMG) through far-IR PACS observations of dust and gas. Methods: We obtained Herschel-PACS far-IR photometric observations at 70, 100, and 160 μm of 19 BPMG members, together with spectroscopic observations for four of them. These observations were centred at 63.18 μm and 157 μm, aiming to detect [OI] and [CII] emission. We incorporated the new far-IR observations in the SED of BPMG members and fitted modified blackbody models to better characterise the dust content. Results: We have detected far-IR excess emission towards nine BPMG members, including the first detection of an IR excess towards HD 29391.The star HD 172555, shows [OI] emission, while HD 181296 shows [CII] emission, expanding the short list of debris discs with a gas detection. No debris disc in BPMG is detected in both [OI] and [CII]. The discs show dust temperatures in the range 55-264 K, with low dust masses (<6.6 × 10-5 M⊕ to 0.2 M⊕) and radii from blackbody models in the range 3 to ~82 AU. All the objects with a gas detection are early spectral type stars with a hot dust component. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  15. 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.

  16. 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.

  17. The Taiwan ECDFS Near-Infrared Survey: Very Bright End of the Luminosity Function at z > 7

    Science.gov (United States)

    Hsieh, Bau-Ching; Wang, Wei-Hao; Yan, Haojing; Lin, Lihwai; Karoji, Hiroshi; Lim, Jeremy; Ho, Paul T. P.; Tsai, Chao-Wei

    2012-04-01

    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 Ks data (~25.3 ABmag, 5σ) for an area of 0.5 × 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 phot of 7.8, and its colors and luminosity indicate a young (45M years old) starburst galaxy with a stellar mass of 3.2 × 1010 M ⊙. 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.

  18. 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.

  19. 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.

  20. The second Herschel★-ATLAS Data Release - III: optical and near-infrared counterparts in the North Galactic Plane field

    Science.gov (United States)

    Furlanetto, C.; Dye, S.; Bourne, N.; Maddox, S.; Dunne, L.; Eales, S.; Valiante, E.; Smith, M. W.; Smith, D. J. B.; Ivison, R. J.; Ibar, E.

    2018-01-01

    This paper forms part of the second major public data release of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). In this work, we describe the identification of optical and near-infrared counterparts to the submillimetre detected sources in the 177 deg2 North Galactic Plane (NGP) field. We used the likelihood ratio method to identify counterparts in the Sloan Digital Sky Survey and in the UKIRT Imaging Deep Sky Survey within a search radius of 10 arcsec of the H-ATLAS sources with a 4σ detection at 250 μm. We obtained reliable (R ≥ 0.8) optical counterparts with r deep radio data which covers a small region of the NGP field, we found that 80 - 90 per cent of our reliable identifications are correct.

  1. L1448-MM Observations by the Herschel Key Program, "Dust, Ice, and Gas In Time" (DIGIT)

    Science.gov (United States)

    Lee, Jinhee; Lee, Jeong-Eun; Lee, Seokho; Green, Joel. D.; Evans, Neal J., II; Choi, Minho; Kristensen, Lars; Dionatos, Odysseas; Jørgensen, Jes K.; the DIGIT Team

    2013-11-01

    We present Herschel/Photodetector Array Camera and Spectrometer (PACS) observations of L1448-MM, a Class 0 protostar with a prominent outflow. Numerous emission lines are detected at 55 1000 K) environment, indicative of a shock origin. For OH, IR-pumping processes play an important role in the level population. The molecular emission in L1448-MM is better explained with a C-shock model, but the atomic emission of PACS [O I] and Spitzer/Infrared Spectrograph [Si II] emission is not consistent with C-shocks, suggesting multiple shocks in this region. Water is the major line coolant of L1448-MM in the PACS wavelength range, and the best-fit LVG models predict that H2O and CO emit (50%-80%) of their line luminosity in the PACS wavelength range.

  2. K2 and Herschel/PACS light curve of the Centaur 2060 Chiron

    Science.gov (United States)

    Marton, G.; Kiss, C.; Müller, T. G.; Lellouch, E.; Pál, A.; Molnár, L.

    2017-09-01

    Recently 2060 Chiron was identified to harbor a ring system (Ortiz et al. 2015) similar to the other Centaur 10199 Chariklo (Braga-Ribas et al. 2014). We observed 2060 Chiron in the visible range in Campaign 12 of the Kepler/K2 mission, that lasted from Dec 15 2016 to March 4 2017. We obtained the thermal light curve with the PACS photometer camera of the Herschel Space Observatory as a "Must Do Observation", taken at 70 and 160 μm on 25 December, 2012. The presence of the ring affects the rotational light curve both in the visible range and in the thermal infrared. With our new observations we can disentangle the contribution of the main body and the ring material.

  3. Herschel reveals a molecular outflow in a z = 2.3 ULIRG

    Science.gov (United States)

    George, R. D.; Ivison, R. J.; Smail, Ian; Swinbank, A. M.; Hopwood, R.; Stanley, F.; Swinyard, B. M.; Valtchanov, I.; Werf, P. P. van der

    2014-08-01

    We report the results from a 19-h integration with the Spectral and Photometric Imaging REceiver (SPIRE) Fourier Transform Spectrometer aboard the Herschel Space Observatory which has revealed the presence of a molecular outflow from the Cosmic Eyelash (SMM J2135-0102) via the detection of blueshifted OH absorption. Detections of several fine-structure emission lines indicate low-excitation H ii regions contribute strongly to the [C ii] luminosity in this z = 2.3 ultra-luminous infrared galaxy (ULIRG). The OH feature suggests a maximum wind velocity of 700 km s- 1, which is lower than the expected escape velocity of the host dark matter halo, ≈ 1000 km s- 1. A large fraction of the available molecular gas could thus be converted into stars via a burst protracted by the resulting gas fountain, until an active galactic nucleus (AGN)-driven outflow can eject the remaining gas.

  4. The Herschel* PEP-HERMES Luminosity Function- I. Probing the Evolution of PACS Selected Galaxies to z approx. equal to 4

    Science.gov (United States)

    Gruppioni, Carlotta; Pozzi, F.; Rodighiero, G.; Delvecchio, I.; Berta, S.; Pozzetti, L.; Zamorani, G.; Andreani, P.; Cimatti, A.; Ilbert, O.; hide

    2013-01-01

    We exploit the deep and extended far-IR data sets (at 70, 100 and 160 µm) of the Herschel Guaranteed Time Observation (GTO) PACS Evolutionary Probe (PEP) Survey, in combination with the Herschel Multi-tiered Extragalactic Survey data at 250, 350 and 500 µm, to derive the evolution of the rest-frame 35-, 60-, 90- and total infrared (IR) luminosity functions (LFs) up to z 4.We detect very strong luminosity evolution for the total IR LF (LIR ? (1 + z)(sup 3.55 +/- 0.10) up to z 2, and ? (1 + z)(sup 1.62 +/- 0.51) at 2 less than z less than approximately 4) combined with a density evolution (? (1 + z)(sup -0.57 +/- 0.22) up to z 1 and ? (1 + z)(sup -3.92 +/- 0.34) at 1 less than z less than approximately 4). In agreement with previous findings, the IR luminosity density (?IR) increases steeply to z 1, then flattens between z 1 and z 3 to decrease at z greater than approximately 3. Galaxies with different spectral energy distributions, masses and specific star formation rates (SFRs) evolve in very different ways and this large and deep statistical sample is the first one allowing us to separately study the different evolutionary behaviours of the individual IR populations contributing to ?IR. Galaxies occupying the well-established SFR-stellar mass main sequence (MS) are found to dominate both the total IR LF and ?IR at all redshifts, with the contribution from off-MS sources (=0.6 dex above MS) being nearly constant (20 per cent of the total ?IR) and showing no significant signs of increase with increasing z over the whole 0.8 < z <2.2 range. Sources with mass in the range 10 = log(M/solar mass) = 11 are found to dominate the total IR LF, with more massive galaxies prevailing at the bright end of the high-z (greater than approximately 2) LF. A two-fold evolutionary scheme for IR galaxies is envisaged: on the one hand, a starburst-dominated phase in which the Super Massive Black Holes (SMBH) grows and is obscured by dust (possibly triggered by a major merging event

  5. What Determines the Density Structure of Molecular Clouds? A Case Study of Orion B with Herschel

    Science.gov (United States)

    Schneider, N.; André, Ph.; Könyves, V.; Bontemps, S.; Motte, F.; Federrath, C.; Ward-Thompson, D.; Arzoumanian, D.; Benedettini, M.; Bressert, E.; Didelon, P.; Di Francesco, J.; Griffin, M.; Hennemann, M.; Hill, T.; Palmeirim, P.; Pezzuto, S.; Peretto, N.; Roy, A.; Rygl, K. L. J.; Spinoglio, L.; White, G.

    2013-04-01

    A key parameter to the description of all star formation processes is the density structure of the gas. In this Letter, we make use of probability distribution functions (PDFs) of Herschel column density maps of Orion B, Aquila, and Polaris, obtained with the Herschel Gould Belt survey (HGBS). We aim to understand which physical processes influence the PDF shape, and with which signatures. The PDFs of Orion B (Aquila) show a lognormal distribution for low column densities until A V ~ 3 (6), and a power-law tail for high column densities, consistent with a ρvpropr -2 profile for the equivalent spherical density distribution. The PDF of Orion B is broadened by external compression due to the nearby OB stellar aggregates. The PDF of a quiescent subregion of the non-star-forming Polaris cloud is nearly lognormal, indicating that supersonic turbulence governs the density distribution. But we also observe a deviation from the lognormal shape at A V > 1 for a subregion in Polaris that includes a prominent filament. We conclude that (1) the point where the PDF deviates from the lognormal form does not trace a universal A V -threshold for star formation, (2) statistical density fluctuations, intermittency, and magnetic fields can cause excess from the lognormal PDF at an early cloud formation stage, (3) core formation and/or global collapse of filaments and a non-isothermal gas distribution lead to a power-law tail, and (4) external compression broadens the column density PDF, consistent with numerical simulations. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  6. The Discovery of Extremely Young Protostars in Orion with Herschel and APEX

    Science.gov (United States)

    Stutz, Amelia; Tobin, John; Stanke, Thomas; Megeath, Tom; Fischer, Will; Robitaille, Thomas; Henning, Thomas; Ali, Babar; Di Francesco, James; Furlan, Elise; Osorio, Mayra; HOPS Team

    2013-07-01

    We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using 24 um - 870 um imaging obtained with the Spitzer, Herschel, and APEX telescopes as part of the Herschel Orion Protostar Survey (HOPS). We find a sample of 15 new extremely red protostar candidates that can reliably identified as protostars (Stutz et al., 2013). Taking the previously known sample of 300 Spitzer protostars and the new sample of 15 Herschel identified protostars together, we find 18 extremely red protostars (i.e., log λFλ70 / λFλ24 > 1.65). These are the reddest protostars known in Orion and we name them "PACS Bright Red sources", or PBRS. Our analysis reveals that the PBRs sample is composed of Class 0 like sources with very red spectral energy distributions (SEDs; Tbol 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2 Msun - 2 Msun and luminosities of 0.7 Lsun - 10 Lsun. 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 possibly high mass infall rates. We estimate the ages of the PBRs to be between 5000 and 25000 years. We find that the fraction of PBRS is more than 5 times higher in the Orion B cloud than in Orion A; this may be due to differences in the star formation histories or in the star forming environment.

  7. 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

  8. 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.

  9. Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys

    Science.gov (United States)

    Carlomagno, Giovanni Maria; Di Maio, Rosa; Fedi, Maurizio; Meola, Carosena

    2011-09-01

    This work is focused on the integration of infrared thermography and ground penetrating radar for the inspection of architectonic structures. First, laboratory tests were carried out with both techniques by considering an ad hoc specimen made of concrete and with the insertion of anomalies of a different nature and at different depths. Such tests provided helpful information for ongoing inspections in situ, which were later performed in two important Italian archaeological sites, namely Pompeii (Naples) and Nora (Cagliari). In the first site, the exploration was devoted to the analysis of the wall paintings of Villa Imperiale with the aim of evaluating the state of conservation of frescoes as well of the underneath masonry structure. As main findings, the applied techniques allowed outlining some areas, which were damaged by ingression in-depth of moisture and/or by disaggregation of the constituent materials, and also for recognition of previous restoration. In the archaeological area of Nora, instead, the attention was driven towards the evaluation of the state of degradation of the theatre remnants. Our prospections show that the front side of the theatre, being more strongly affected by degradation, needs a massive restoration work. As a general result, we demonstrated that a joint interpretation of infrared thermography and ground penetrating radar data supplies detailed 3D information from near-surface to deep layers, which may assist in restoration planning.

  10. Clustering of far-infrared galaxies in the AKARI All-Sky Survey

    Science.gov (United States)

    Pollo, A.; Takeuchi, T. T.; Suzuki, T. L.; Oyabu, S.

    2013-03-01

    We present the first measurement of the angular two-point correlation function for AKARI 90-μm point sources, detected outside of the Milky Way plane and other regions characterized by high Galactic extinction, and categorized as extragalactic sources according to our far-infrared-color based criterion (Pollo et al., 2010). This is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS measurements. Although a full description of the clustering properties of these galaxies will be obtained by more detailed studies, using either a spatial correlation function, or better information about properties and, at least, photometric redshifts of these galaxies, the angular correlation function remains the first diagnostic tool to establish the clustering properties of the catalog and the observed galaxy population. We find a non-zero clustering signal in both hemispheres extending up to ~40 degrees, without any significant fluctuations at larger scales. The observed correlation function is well fitted by a power-law function. The notable differences between the northern and southern hemispheres are found, which can probably be attributed to the photometry problems, and might point to the necessity of performing a better calibration in the data from the southern hemisphere.

  11. Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub

    Science.gov (United States)

    Rayner, T. S. M.; Griffin, M. J.; Schneider, N.; Motte, F.; Könyves, V.; André, P.; Di Francesco, J.; Didelon, P.; Pattle, K.; Ward-Thompson, D.; Anderson, L. D.; Benedettini, M.; Bernard, J.-P.; Bontemps, S.; Elia, D.; Fuente, A.; Hennemann, M.; Hill, T.; Kirk, J.; Marsh, K.; Men'shchikov, A.; Nguyen Luong, Q.; Peretto, N.; Pezzuto, S.; Rivera-Ingraham, A.; Roy, A.; Rygl, K.; Sánchez-Monge, Á.; Spinoglio, L.; Tigé, J.; Treviño-Morales, S. P.; White, G. J.

    2017-10-01

    We present far-infrared observations of Monoceros R2 (a giant molecular cloud at approximately 830 pc distance, containing several sites of active star formation), as observed at 70 μm, 160 μm, 250 μm, 350 μm, and 500 μm by the Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) instruments on the Herschel Space Observatory as part of the Herschel imaging survey of OB young stellar objects (HOBYS) Key programme. The Herschel data are complemented by SCUBA-2 data in the submillimetre range, and WISE and Spitzer data in the mid-infrared. In addition, C18O data from the IRAM 30-m Telescope are presented, and used for kinematic information. Sources were extracted from the maps with getsources, and from the fluxes measured, spectral energy distributions were constructed, allowing measurements of source mass and dust temperature. Of177 Herschel sources robustly detected in the region (a detection with high signal-to-noise and low axis ratio at multiple wavelengths), including protostars and starless cores, 29 are found in a filamentary hub at the centre of the region (a little over 1% of the observed area). These objects are on average smaller, more massive, and more luminous than those in the surrounding regions (which together suggest that they are at a later stage of evolution), a result that cannot be explained entirely by selection effects. These results suggest a picture in which the hub may have begun star formation at a point significantly earlier than the outer regions, possibly forming as a result of feedback from earlier star formation. Furthermore, the hub may be sustaining its star formation by accreting material from the surrounding filaments. Full Tables 4 and D.1-D.9 and the C180 datacube are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A22

  12. A Kinematic Survey in the Perseus Molecular Cloud: Results from the APOGEE Infrared Survey of Young Nebulous Clusters (IN-SYNC)

    Science.gov (United States)

    Covey, Kevin R.; Cottaar, M.; Foster, J. B.; Nidever, D. L.; Meyer, M.; Tan, J.; Da Rio, N.; Flaherty, K. M.; Stassun, K.; Frinchaboy, P. M.; Majewski, S.; APOGEE IN-SYNC Team

    2014-01-01

    Demographic studies of stellar clusters indicate that relatively few persist as bound structures for 100 Myrs or longer. If cluster dispersal is a 'violent' process, it could strongly influence the formation and early evolution of stellar binaries and planetary systems. Unfortunately, measuring the dynamical state of 'typical' (i.e., ~300-1000 member) young star clusters has been difficult, particularly for clusters still embedded within their parental molecular cloud. The near-infrared spectrograph for the Apache Point Observatory Galactic Evolution Experiment (APOGEE), which can measure precise radial velocities for 230 cluster stars simultaneously, is uniquely suited to diagnosing the dynamics of Galactic star formation regions. We give an overview of the INfrared Survey of Young Nebulous Clusters (IN-SYNC), an APOGEE ancillary science program that is carrying out a comparative study of young clusters in the Perseus molecular cloud: NGC 1333, a heavily embedded cluster, and IC 348, which has begun to disperse its surrounding molecular gas. These observations appear to rule out a significantly super-virial velocity dispersion in IC 348, contrary to predictions of models where a cluster's dynamics is strongly influenced by the dispersal of its primordial gas. We also summarize the properties of two newly identified spectroscopic binaries; binary systems such as these play a key role in the dynamical evolution of young clusters, and introduce velocity offsets that must be accounted for in measuring cluster velocity dispersions.

  13. A search for a distant companion to the sun with the wide-field infrared survey explorer

    Energy Technology Data Exchange (ETDEWEB)

    Luhman, K. L., E-mail: kluhman@astro.psu.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-01-20

    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.

  14. Wide-field infrared survey explorer observations of young stellar objects in the Lynds 1509 dark cloud in Auriga

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wilson M.; McCollum, Bruce; Fajardo-Acosta, Sergio [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Padgett, Deborah L. [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Terebey, Susan; Angione, John [Department of Physics and Astronomy, California State University, Los Angeles, CA 90032 (United States); Rebull, Luisa M. [Spitzer Science Center, California Institute of Technology, MC 314-6, Pasadena, CA 91125 (United States); Leisawitz, David, E-mail: wliu@ipac.caltech.edu [National Aeronautics and Space Administration, Goddard Space Flight Center, Code 605, Greenbelt, MD 20771 (United States)

    2014-06-01

    The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4 μm, 4.6 μm, 12 μm, and 22 μm, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

  15. Modeling an Optical and Infrared Search for Extraterrestrial Intelligence Survey with Exoplanet Direct Imaging

    Science.gov (United States)

    Vides, Christina; Macintosh, Bruce; Ruffio, Jean-Baptiste; Nielsen, Eric; Povich, Matthew Samuel

    2018-01-01

    Gemini Planet Imager (GPI) is a direct high contrast imaging instrument coupled to the Gemini South Telescope. Its purpose is to image extrasolar planets around young (~Intelligence), we modeled GPI’s capabilities to detect an extraterrestrial continuous wave (CW) laser broadcasted within the H-band have been modeled. By using sensitivity evaluated for actual GPI observations of young target stars, we produced models of the CW laser power as a function of distance from the star that could be detected if GPI were to observe nearby (~ 3-5 pc) planet-hosting G-type stars. We took a variety of transmitters into consideration in producing these modeled values. GPI is known to be sensitive to both pulsed and CW coherent electromagnetic radiation. The results were compared to similar studies and it was found that these values are competitive to other optical and infrared observations.

  16. 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.; 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.

    2018-01-01

    With the advent of wide-area submillimeter surveys, a large number of high-redshift gravitationally lensed dusty star-forming galaxies (DSFGs) has been revealed. Due to the simplicity of the selection criteria for candidate lensed sources in such surveys, identified as those with S500μm > 100 mJy, uncertainties associated with the modelling of the selection function are expunged. The combination of these attributes makes submillimeter 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 Millimetre 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 which contains both dark matter and baryons. We used three different density distributions, one based on analytical fits to the halos 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 ˜1013M⊙ for the SIS and SISSA models, above which we assumed that the density distribution could be represented by an NFW 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.

  17. A near infrared laser frequency comb for high precision Doppler planet surveys

    Directory of Open Access Journals (Sweden)

    Bally J.

    2011-07-01

    Full Text Available Perhaps the most exciting area of astronomical research today is the study of exoplanets and exoplanetary systems, engaging the imagination not just of the astronomical community, but of the general population. Astronomical instrumentation has matured to the level where it is possible to detect terrestrial planets orbiting distant stars via radial velocity (RV measurements, with the most stable visible light spectrographs reporting RV results the order of 1 m/s. This, however, is an order of magnitude away from the precision needed to detect an Earth analog orbiting a star such as our sun, the Holy Grail of these efforts. By performing these observations in near infrared (NIR there is the potential to simplify the search for distant terrestrial planets by studying cooler, less massive, much more numerous class M stars, with a tighter habitable zone and correspondingly larger RV signal. This NIR advantage is undone by the lack of a suitable high precision, high stability wavelength standard, limiting NIR RV measurements to tens or hundreds of m/s [1, 2]. With the improved spectroscopic precision provided by a laser frequency comb based wavelength reference producing a set of bright, densely and uniformly spaced lines, it will be possible to achieve up to two orders of magnitude improvement in RV precision, limited only by the precision and sensitivity of existing spectrographs, enabling the observation of Earth analogs through RV measurements. We discuss the laser frequency comb as an astronomical wavelength reference, and describe progress towards a near infrared laser frequency comb at the National Institute of Standards and Technology and at the University of Colorado where we are operating a laser frequency comb suitable for use with a high resolution H band astronomical spectrograph.

  18. Concentration of mycotoxins and chemical composition of corn silage: a farm survey using infrared thermography.

    Science.gov (United States)

    Schmidt, P; Novinski, C O; Junges, D; Almeida, R; de Souza, C M

    2015-09-01

    This work evaluated the chemical composition and mycotoxin incidence in corn silage from 5 Brazilian dairy-producing regions: Castro, in central-eastern Paraná State (n=32); Toledo, in southwestern Paraná (n=20); southeastern Goiás (n=14); southern Minas Gerais (n=23); and western Santa Catarina (n=20). On each dairy farm, an infrared thermography camera was used to identify 3 sampling sites that exhibited the highest temperature, a moderate temperature, and the lowest temperature on the silo face, and 1 sample was collected from each site. The chemical composition and concentrations of mycotoxins were evaluated, including the levels of aflatoxins B1, B2, G1, and G2; zearalenone; ochratoxin A; deoxynivalenol; and fumonisins B1 and B2. The corn silage showed a highly variable chemical composition, containing, on average, 7.1±1.1%, 52.5±5.4%, and 65.2±3.6% crude protein, neutral detergent fiber, and total digestible nutrients, respectively. Mycotoxins were found in more than 91% of the samples, with zearalenone being the most prevalent (72.8%). All samples from the Castro region contained zearalenone at a high average concentration (334±374µg/kg), even in well-preserved silage. The incidence of aflatoxin B1 was low (0.92%). Silage temperature and the presence of mycotoxins were not correlated; similarly, differences were not observed in the concentration or incidence of mycotoxins across silage locations with different temperatures. Infrared thermography is an accurate tool for identifying heat sites, but temperature cannot be used to predict the chemical composition or the incidence of mycotoxins that have been analyzed, within the silage. The pre-harvest phase of the ensiling process is most likely the main source of mycotoxins in silage. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Gas in the protoplanetary disc of HD 169142 : Herschel's view

    NARCIS (Netherlands)

    Meeus, G.; Pinte, C.; Woitke, P.; Montesinos, B.; Mendigutia, I.; Riviere-Marichalar, P.; Eiroa, C.; Mathews, G. S.; Vandenbussche, B.; Howard, C. D.; Roberge, A.; Sandell, G.; Duchene, G.; Menard, F.; Grady, C. A.; Dent, W. R. F.; Kamp, I.; Augereau, J. C.; Thi, W. F.; Tilling, I.; Alacid, J. M.; Andrews, S.; Ardila, D. R.; Aresu, G.; Barrado, D.; Brittain, S.; Ciardi, D. R.; Danchi, W.; Fedele, D.; de Gregorio-Monsalvo, I.; Heras, A.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mora, A.; Morales-Calderon, M.; Nomura, H.; Pantin, E.; Pascucci, I.; Phillips, N.; Podio, L.; Poelman, D. R.; Ramsay, S.; Riaz, B.; Rice, K.; Solano, E.; White, G. J.; Williams, J. P.; Wright, G.; Walker, H.

    In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed

  20. Direct detection of the Enceladus water torus with Herschel

    NARCIS (Netherlands)

    Hartogh, P.; Lellouch, E.; Moreno, R.; Bockelee-Morvan, D.; Biver, N.; Cassidy, T.; Rengel, M.; Jarchow, C.; Cavalie, T.; Crovisier, J.; Helmich, F. P.; Kidger, M.

    Cryovolcanic activity near the south pole of Saturn's moon Enceladus produces plumes of H2O-dominated gases and ice particles, which escape and populate a torus-shaped cloud. Using submillimeter spectroscopy with Herschel, we report the direct detection of the Enceladus water vapor torus in four

  1. Herschel-ATLAS: Planck sources in the phase 1 fields

    Science.gov (United States)

    Herranz, D.; González-Nuevo, J.; Clements, D. L.; De Zotti, G.; Lopez-Caniego, M.; Lapi, A.; Rodighiero, G.; Danese, L.; Fu, H.; Cooray, A.; Baes, M.; Bendo, G. J.; Bonavera, L.; Carrera, F. J.; Dole, H.; Eales, S.; Ivison, R. J.; Jarvis, M.; Lagache, G.; Massardi, M.; Michałowski, M. J.; Negrello, M.; Rigby, E.; Scott, D.; Valiante, E.; Valtchanov, I.; Van der Werf, 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°2. There are 28 ERCSC sources detected by Planck at 857 GHz in this area. As many as 16 of them are probably high Galactic latitude cirrus; 10 additional sources can be clearly identified as bright, low-z galaxies; one further source is resolved by Herschel as two relatively bright sources; and the last is resolved into an unusual condensation of low-flux, probably high-redshift point sources, around a strongly lensed Herschel-ATLAS source at z = 3.26. Our results demonstrate that the higher sensitivity and higher angular resolution H-ATLAS maps provide essential information for the interpretation of candidate sources extracted from Planck sub-mm maps. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA

  2. 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),

  3. Flux calibration of the Herschel(star)-SPIRE photometer

    NARCIS (Netherlands)

    Bendo, G. J.; Griffin, M. J.; Bock, J. J.; Conversi, L.; Dowell, C. D.; Lim, T.; Lu, N.; North, C. E.; Papageorgiou, A.; Pearson, C. P.; Pohlen, M.; Polehampton, E. T.; Schulz, B.; Shupe, D. L.; Sibthorpe, B.; Spencer, L. D.; Swinyard, B. M.; Valtchanov, I.; Xu, C. K.

    We describe the procedure used to flux calibrate the three-band submillimetre photometer in the Spectral and Photometric Imaging Receiver instrument on the Herschel Space Observatory. This includes the equations describing the calibration scheme, a justification for using Neptune as the primary

  4. High Mass Star Formation Revealed by Herschel PACS Spectroscopy

    NARCIS (Netherlands)

    Kwon, Woojin; van der Tak, Floris; Karska, Agata; Herczeg, Gregory; Braine, Jonathan; Herpin, Fabrice; Wyrowski, Friedrich; van Dishoeck, Ewine

    In the past few decades a big picture of low mass star formation has successfully been drawn. However, high mass star formation is little known yet, mainly due to its complexity, distance, and rarity. The Photodetector Array Camera and Spectrometer (PACS) on-board the Herschel Space Observatory

  5. The Great Observatories Origins Deep Survey. VLT/ISAAC near-infrared imaging of the GOODS-South field

    Science.gov (United States)

    Retzlaff, J.; Rosati, P.; Dickinson, M.; Vandame, B.; Rité, C.; Nonino, M.; Cesarsky, C.; GOODS Team

    2010-02-01

    Aims: We present the final public data release of the VLT/ISAAC near-infrared imaging survey in the GOODS-South field. The survey covers an area of 172.5, 159.6 and 173.1 arcmin{}^2 in the J, H, and K_s bands, respectively. For point sources total limiting magnitudes of J=25.0, H=24.5, and K_s=24.4 (5σ, AB) are reached within 75% of the survey area. Thus these observations are significantly deeper than the previous EIS Deep Public Survey which covers the same region. The image quality is characterized by a point spread function ranging between 0.34´´ and 0.65´´ FWHM. The images are registered to a common astrometric grid defined by the GSC 2 with an accuracy of 0.06 arcsec RMS over the whole field. The overall photometric accuracy, including all systematic effects, adds up to 0.05 mag. The data are publicly available from the ESO science archive facility. Methods: We describe the data reduction, the calibration, and the quality control process. The final data set is characterized in terms of astrometric and photometric properties, including the PSF and the curve of growth. We establish an empirical model for the sky background noise in order to quantify the variation of limiting depth and statistical photometric errors over the survey area. We define a catalog of K_s-selected sources which contains JHK_s photometry for 7079 objects. Differential aperture corrections were applied to the color measurements in order to avoid possible biases as a result of the variation of the PSF. We briefly discuss the resulting color distributions in the context of available redshift data. Furthermore, we estimate the completeness fraction and relative contamination due to spurious detections for source catalogs extracted from the survey data. For this purpose, an empirical study based on a deep K_s image of the Hubble Ultra Deep Field is combined with extensive image simulations. Results: With respect to previous deep near-infrared surveys, the surface density of faint

  6. New Herschel-identified Orion Protostars: Characterizing An Extreme Population Of Cold Sources

    Science.gov (United States)

    Stutz, Amelia Marie; Megeath, T.; Tobin, J.; Fischer, W.; Stanke, T.; Ali, B.; Di Francesco, J.; Henning, T.; Manoj, P.; Watson, D.; HOPS Team

    2012-01-01

    We present a new population of serendipitously identified Orion protostars. These protostars, designated PACS Bright Red Sources (PBRS), were identified in PACS 70 um observations for the Herschel Orion Protostar Survey (HOPS). Here we focus on the nine reddest PBRS in our sample: in contrast to the known Orion protostars targeted in HOPS, the reddest PBRS are undetected or very faint in the Spitzer 24 um imaging. They are redder than any of the known Orion Class 0 protostars, and appear similar in their 70 um to 24 um colors to the most extreme Class 0 objects known. These new Orion protostars are likely to be in a very early and short lived stage of protostellar evolution: the population of red PBRS is generally characterized by very low bolometric temperatures of 25 K and bolometric luminosities of ranging from 1 to about 10 solar luminosities. Here we present our initial characterization of these sources through analysis of the observed Spitzer, Herschel, and APEX broad-band SEDs. In addition, we will present results from our observational campaign to obtain auxiliary long-wavelength data aimed at characterizing the PBRS.

  7. SNAPshot observations of the largest sample of lensed candidates in the Equatorial and Southern Sky identified with Herschel

    Science.gov (United States)

    Marchetti, Lucia

    2017-08-01

    We propose WFC3/IR F110W Snapshot observations of 200 gravitational lensing systems selected using Herschel submm data taken in all the major Herschel extragalactic surveys (over 850 square degrees). This proposal aims to build upon the successful results of our cycle-19 snapshot (ID:12488) to complete the study of the brightest lensed galaxies ever discovered by Herschel in the Equatorial and Southern Sky. Our successful submm-based selection method identifies lensing events at much higher redshift than any other optical-based selection and is independent of the nature of the magnifier. With these data we will (1) characterize the morphology of the lenses and thus statistically determine what populations are responsible for the gravitational optical depth of the Universe, (2) make accurate fits to the lens light profiles disentangling the foreground lenses from the background sources (3) constrain (and in some cases directly detect) the rest-frame optical emission from the background sources providing estimates of the background source extinction, (4) identify the most extreme star-forming galaxies and rare lensing configurations in the Universe providing the best candidates for future ALMA follow-up, (5) measure the evolution of both the lens mass-density profile, constraing their assembly history, and the lens IMF. This HST program is well-timed with our on-going large spectroscopic program with SALT (3-year program, started in late 2015). This synergy guarantees the timely spectroscopic characterization of our targets securing a long-lasting legacy for this program.

  8. Candidate high-z proto-clusters 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.

    2018-01-01

    By determining the nature of all the Planck compact sources within 808.4 deg2 of large Herschel surveys, we have identified 27 candidate proto-clusters 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 proto-clusters 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 proto-clusters 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 clusters, but can miss proto-clusters at z cluster members indicate our candidate proto-clusters all likely all lie at z > 1. Our candidate proto-clusters 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 proto-clusters are physical clusters, multiple proto-clusters along the line of sight, or chance alignments of unassociated sources.

  9. New insights into the earliest phases of low-mass star formation with the Herschel Space Observatory

    Science.gov (United States)

    Di Francesco, J.

    The Herschel Space Observatory has been revolutionizing our understanding of the the earliest phases of star formation. In this contribution, we describe early results from the Gould Belt Survey, a Herschel Key Project to map 15 nearby molecular clouds in continuum emission from 70 μm to 500 μm. In particular, I describe how the sensitive and wide maps of the Aquila Rift have strongly confirmed the similarity between the shapes of the stellar Initial Mass Function and the prestellar core mass function (CMF). Also, the Herschel map sensitivity to larger scale emission has revealed that prestellar cores form almost exclusively within dense filaments that exceed a critical mass per unit length defined by temperature (and gravity). Finally, filaments in three clouds, IC 5146, Polaris and Aquila, are found to have similar widths of ˜0.1 pc, approximately the scale where the turbulent velocity equals the sound speed of 10 K gas. This common width suggests filaments themselves are formed through collisional shocks of turbulent flows and evolve in quasi-virial balance through mass accretion.

  10. The Fueling of Active Galaxies: A Near-Infrared Imaging Survey of Seyfert and Normal Galaxies

    Science.gov (United States)

    Kundu, A.; Mulchaey, J. S.; Regan, M. W.

    1996-12-01

    Galactic bars are frequently invoked as a candidate for facilitating the transfer of mass from the interstellar medium of active galaxies to their central engines. However, studies of large Seyfert samples show little evidence that Seyferts occur preferentially in barred systems. The failure to find evidence for bars in many Seyfert galaxies may be due to the fact that most studies have concentrated on optical wavelengths where the presence of extinction or a young stellar population might mask any bar structures. In contrast, the near-infrared is expected to be a good place to study the host galaxy of Seyferts because neither dust nor young stars strongly affect the observed emission at these wavelengths. To study the role bars play in the fueling of active galaxies, we have obtained K' images of a large sample of nearby Seyfert and `` normal'' \\ galaxies, matched in redshift, Hubble type, inclination and blue luminosity. We use these images to compare the incidence of bars in Seyfert and normal galaxies and constrain the importance of bars in the fueling of nuclear activity.

  11. 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

  12. Wide-Field InfraRed Survey Telescope (WFIRST) Mission and Synergies with LISA and LIGO-Virgo

    Science.gov (United States)

    Gehrels, N.; Spergel, D.

    2015-01-01

    The Wide-Field InfraRed Survey Telescope (WFIRST) is a NASA space mission in study for launch in 2024. It has a 2.4 m telescope, wide-field IR instrument operating in the 0.7 - 2.0 micron range and an exoplanet imaging coronagraph instrument operating in the 400 - 1000 nm range. The observatory will perform galaxy surveys over thousands of square degrees to J=27 AB for dark energy weak lensing and baryon acoustic oscillation measurements and will monitor a few square degrees for dark energy SN Ia studies. It will perform microlensing observations of the galactic bulge for an exoplanet census and direct imaging observations of nearby exoplanets with a pathfinder coronagraph. The mission will have a robust and wellfunded guest observer program for 25% of the observing time. WFIRST will be a powerful tool for time domain astronomy and for coordinated observations with gravitational wave experiments. Gravitational wave events produced by mergers of nearby binary neutron stars (LIGO-Virgo) or extragalactic supermassive black hole binaries (LISA) will produce electromagnetic radiation that WFIRST can observe.

  13. 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).

  14. Automated cross-identifying radio to infrared surveys using the LRPY algorithm: a case study

    Science.gov (United States)

    Weston, S. D.; Seymour, N.; Gulyaev, S.; Norris, R. P.; Banfield, J.; Vaccari, M.; Hopkins, A. M.; Franzen, T. M. O.

    2018-02-01

    Cross-identifying complex radio sources with optical or infra red (IR) counterparts in surveys such as the Australia Telescope Large Area Survey (ATLAS) has traditionally been performed manually. However, with new surveys from the Australian Square Kilometre Array Pathfinder detecting many tens of millions of radio sources, such an approach is no longer feasible. This paper presents new software (LRPY - Likelihood Ratio in PYTHON) to automate the process of cross-identifying radio sources with catalogues at other wavelengths. LRPY implements the likelihood ratio (LR) technique with a modification to account for two galaxies contributing to a sole measured radio component. We demonstrate LRPY by applying it to ATLAS DR3 and a Spitzer-based multiwavelength fusion catalogue, identifying 3848 matched sources via our LR-based selection criteria. A subset of 1987 sources have flux density values for all IRAC bands which allow us to use criteria to distinguish between active galactic nuclei (AGNs) and star-forming galaxies (SFG). We find that 936 radio sources ( ≈ 47 per cent) meet both of the Lacy and Stern AGN selection criteria. Of the matched sources, 295 have spectroscopic redshifts and we examine the radio to IR flux ratio versus redshift, proposing an AGN selection criterion below the Elvis radio-loud AGN limit for this dataset. Taking the union of all three AGNs selection criteria we identify 956 as AGNs ( ≈ 48 per cent). From this dataset, we find a decreasing fraction of AGNs with lower radio flux densities consistent with other results in the literature.

  15. Investigation of faint galactic carbon stars from the first Byurakan spectral survey. III. Infrared characteristics

    OpenAIRE

    Gigoyan, K. S.; A. Sarkissian; Rossi, C.; Russeil, D.,; Kostandyan, G.; Calabresi, M.; Zamkotsian, F.; Meftah, M.

    2017-01-01

    Infra-Red(IR) astronomical databases, namely, IRAS, 2MASS, WISE, and Spitzer, are used to analyze photometric data of 126 carbon stars whose spectra are visible in the First Byurakan Survey low-resolution spectral plates. Among these, six new objects, recently confirmed on the digitized FBS plates, are included. For three of them, moderate-resolution CCD optical spectra are also presented. In this work several IR color-color diagrams are studied. Early and late-type C stars are separated in t...

  16. THE SPITZER INFRARED SPECTROGRAPH SURVEY OF PROTOPLANETARY DISKS IN ORION A. I. DISK PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. H. [Korea Astronomy and Space Science Institute (KASI), 776, Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Watson, Dan M.; Manoj, P.; Forrest, W. J. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Furlan, Elise [Infrared Processing and Analysis Center, Caltech, 770 S. Wilson Avenue, Pasadena, CA 91125 (United States); Najita, Joan [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Sargent, Benjamin [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Dr., Rochester, NY 14623 (United States); Hernández, Jesús [Centro de Investigaciones de Astronomía, Apdo. Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Calvet, Nuria [Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States); Adame, Lucía [Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza, Nuevo León, C.P. 66451, México (Mexico); Espaillat, Catherine [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Megeath, S. T. [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606 (United States); Muzerolle, James, E-mail: quarkosmos@kasi.re.kr [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

    2016-09-01

    We present our investigation of 319 Class II objects in Orion A observed by Spitzer /IRS. We also present the follow-up observations of 120 of these Class II objects in Orion A from the Infrared Telescope Facility/SpeX. We measure continuum spectral indices, equivalent widths, and integrated fluxes that pertain to disk structure and dust composition from IRS spectra of Class II objects in Orion A. We estimate mass accretion rates using hydrogen recombination lines in the SpeX spectra of our targets. Utilizing these properties, we compare the distributions of the disk and dust properties of Orion A disks with those of Taurus disks with respect to position within Orion A (Orion Nebular Cluster [ONC] and L1641) and with the subgroups by the inferred radial structures, such as transitional disks (TDs) versus radially continuous full disks (FDs). Our main findings are as follows. (1) Inner disks evolve faster than the outer disks. (2) The mass accretion rates of TDs and those of radially continuous FDs are statistically significantly displaced from each other. The median mass accretion rate of radially continuous disks in the ONC and L1641 is not very different from that in Taurus. (3) Less grain processing has occurred in the disks in the ONC compared to those in Taurus, based on analysis of the shape index of the 10 μ m silicate feature ( F {sub 11.3}/ F {sub 9.8}). (4) The 20–31 μ m continuum spectral index tracks the projected distance from the most luminous Trapezium star, θ {sup 1} Ori C. A possible explanation is UV ablation of the outer parts of disks.

  17. Radio and infrared study of the star-forming region IRAS 20286+4105

    Science.gov (United States)

    Ramachandran, Varsha; Das, S. R.; Tej, A.; Vig, S.; Ghosh, S. K.; Ojha, D. K.

    2017-03-01

    In this paper, we present a multiwavelength investigation of the star-forming complex IRAS 20286+4105, located in the Cygnus X region. Near-infrared K-band data are used to revisit the cluster/stellar group identified in previous studies. Radio continuum observations at 610 and 1280 MHz show the presence of a H II region possibly powered by a star of spectral type B0-B0.5. The cometary morphology of the ionized region is explained by invoking the bow-shock model, where the likely association with a nearby supernova remnant is also explored. A compact radio knot with a non-thermal spectral index is detected towards the centre of the cloud. Mid-infrared data from the Spitzer Legacy Survey of the Cygnus X region show the presence of six Class I young stellar objects inside the cloud. Thermal dust emission in this complex is modelled using Herschel far-infrared data to generate dust temperature and column density maps. Herschel images also show the presence of two clumps in this region, the masses of which are estimated to be ∼175 and 30 M⊙. The mass-radius relation and the surface density of the clumps mean that they do not qualify as massive star-forming sites. An overall picture of a runaway star ionizing the cloud and a triggered population of intermediate-mass, Class I sources located towards the cloud centre emerges from this multiwavelength study. Variation in the dust emissivity spectral index is shown to exist in this region and is seen to have an inverse relation with the dust temperature.

  18. Star formation towards the Galactic H II region RCW 120. Herschel observations of compact sources

    Science.gov (United States)

    Figueira, M.; Zavagno, A.; Deharveng, L.; Russeil, D.; Anderson, L. D.; Men'shchikov, A.; Schneider, N.; Hill, T.; Motte, F.; Mège, P.; LeLeu, G.; Roussel, H.; Bernard, J.-P.; Traficante, A.; Paradis, D.; Tigé, J.; André, P.; Bontemps, S.; Abergel, A.

    2017-04-01

    Context. The expansion of H II regions can trigger the formation of stars. An overdensity of young stellar objects is observed at the edges of H II regions but the mechanisms that give rise to this phenomenon are not clearly identified. Moreover, it is difficult to establish a causal link between H II -region expansion and the star formation observed at the edges of these regions. A clear age gradient observed in the spatial distribution of young sources in the surrounding might be a strong argument in favor of triggering. Aims: We aim to characterize the star formation observed at the edges of H II regions by studying the properties of young stars that form there. We aim to detect young sources, derive their properties and their evolution stage in order to discuss the possible causal link between the first-generation massive stars that form the H II region and the young sources observed at their edges. Methods: We have observed the Galactic H II region RCW 120 with Herschel PACS and SPIRE photometers at 70, 100, 160, 250, 350 and 500 μm. We produced temperature and H2 column density maps and use the getsources algorithm to detect compact sources and measure their fluxes at Herschel wavelengths. We have complemented these fluxes with existing infrared data. Fitting their spectral energy distributions with a modified blackbody model, we derived their envelope dust temperature and envelope mass. We computed their bolometric luminosities and discuss their evolutionary stages. Results: The overall temperatures of the region (without background subtraction) range from 15 K to 24 K. The warmest regions are observed towards the ionized gas. The coldest regions are observed outside the ionized gas and follow the emission of the cold material previously detected at 870 μm and 1.3 mm. The H2 column density map reveals the distribution of the cold medium to be organized in filaments and highly structured. Column densities range from 7 × 1021 cm-2 up to 9 × 1023 cm-2

  19. 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 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.

  20. Feasibility Study of Soil Quality Survey using Visible and Near Infrared Spectroscopy in Rice Paddy Fields in China

    Directory of Open Access Journals (Sweden)

    Hongyi Li

    2014-06-01

    Full Text Available Survey and monitoring of soil quality are needed to prevent soil degradation and are important for sustainable farming and food production. Conventional soil survey involves intensive soil sampling and laboratory analysis, which are time consuming and expensive. Visible and near infrared spectroscopy of soil has proved to be accurate, cheap and robust and has huge potential for survey of soil quality. To test its potential, 327 soil samples were taken from long-term paddy rice fields in four provinces in south of China and covered a wide range of soil types and texture. The samples were air-dried, ground and passed through a 2 mm sieve. They were then scanned by an ASD vis–NIR spectrometer with wavelength range from 350 to 2500 nm. Organic matter (OM, pH, total nitrogen (TN and available nitrogen (N_av were also measured on soil samples to build calibration models and also to validate the models’ accuracy. On the basis of the ratio of prediction deviation (RPD, which is standard deviation (SD of prediction divided by the root mean square error of prediction (RMSEP, the accuracy of leave-one-out cross-validation of soil N_av model was classified very good (RPD=1.96 and soil OM and TN was good (RPD=1.78 and RPD=1.81, respectively. However, the model accuracy of pH was poor due to non-direct soil spectral response for soil pH in vis–NIR spectroscopy. The independent validation results showed excellent accuracy for soil N_av (RPD=3.26, good accuracy for OM and TN (RPD=1.76 and RPD=1.78 and relative poor accuracy for soil pH (RPD=1.27. This feasibility study is encouraging for the application of vis–NIR surveys of soil quality accuracy at regional and national scales; it found good to excellent accuracy for some important soil properties in quality survey.

  1. Understanding sub-stellar populations using wide-field infrared surveys

    Directory of Open Access Journals (Sweden)

    Hewett P.C.

    2011-07-01

    Full Text Available This paper discusses benchmark brown dwarfs in various environments, and focuses on those in wide binary systems. We present a summary of the recently discovered T dwarf population from the UKIDSS Large Area Survey, and describe the constraints that it places on our knowledge of the sub-stellar initial mass function. We also present some exciting results from our ongoing search for wide companions to this sample, that has so far revealed an M4-T8.5 binary system at ∼12 parsecs and also the first ever Tdwarf-white dwarf binary system. The T dwarfs in these binaries have their properties constrained by the primary object and are thus benchmark objects that are already testing the predictions of theoretical model atmospheres.

  2. The Physical Characteristics of Interstellar Medium in NGC 3665 with Herschel Observations

    Science.gov (United States)

    Xiao, Meng-Yuan; Zhao, Yinghe; Gu, Qiu-Sheng; Shi, Yong

    2018-02-01

    We present the analysis of the physical properties of the interstellar medium in the nearby early-type galaxy NGC 3665, based on the far-infrared photometric and spectroscopic data as observed by the Herschel Space Observatory. The fit to the spectral energy distribution reveals a high dust content in the galaxy, with a dust-to-stellar mass ratio of {M}dust}/M * ∼ 1.1 × 10‑4 that is nearly three times larger than the mean value of local S0+S0a galaxies. For the ionized regions (H II regions), the electron density (n e ) is around 49.5 ± 11.9 cm‑3 based on the [N II] 122 μm/[N II] 205 μm ratio. For the photodissociation regions, the heating efficiency ranges from 1.26 × 10‑3 to 1.37 × 10‑3 based on the ([C II]+[O I] 63 μm)/{L}TIR}, which is slightly lower than other local galaxies; the hydrogen nucleus density and the strength of the far-UV radiation field are n ∼ 104 cm‑3 and G 0 ∼ 10‑0.25, respectively. The above results are consistent with the presence of weak active galactic nuclei and a low level of star-forming activity in NGC 3665. Our results give strong support to the “morphological quenching” scenario, where a compact, massive bulge can stabilize the amount of cool gas against star formation. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. Herschel Extreme Lensing Line Observations: [CII] Variations in Galaxies at Redshifts z=1-3*

    Science.gov (United States)

    Malhotra, Sangeeta; Rhoads, James E.; Finkelstein, K.; Yang, Huan; Carilli, Chris; Combes, Francoise; Dassas, Karine; Finkelstein, Steven; Frye, Brenda; Gerin, Maryvonne; hide

    2017-01-01

    We observed the [C II] line in 15 lensed galaxies at redshifts 1 less than z less than 3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3sigma 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(exp 7) solar luminosity to 3.7 × 10(exp 9) solar luminosity (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.

  4. ESA joins forces with Japan on new infrared sky surveyor

    Science.gov (United States)

    2006-02-01

    Prof. David Southwood, ESA’s Director of Science, said: “The successful launch of ASTRO-F(Akari) is a big step. A decade ago, our Infrared Space Observatory (ISO) opened up this field of astronomy, and the Japanese took part then. It is wonderful to be cooperating again with Japan in this discipline.” “Our involvement with the Japanese in this programme responds to our long-term commitment in infrared astronomy, whose potential for discovery is huge. We are now off and rolling with ASTRO-F/Akari, but we are also working extremely hard towards the launch of the next-generation infrared telescope, ESA’s Herschel spacecraft, which will go up in the next two years”, he continued. “This will still not be the end of the story. Infrared astronomy is also a fundamental part of the future vision for ESA’s space research, as outlined in the ‘Cosmic Vision 2015-2025’ programme. The truth is, subjects such as the formation of stars and exoplanets, or the evolution of the early universe, are themes at the very core of our programme.” The mission : On 21 February, at 22:28 Central European Time, (22 February, 06:28 local time), a Japanese M-V rocket blasted off from the Uchinoura Space Centre, in the Kagoshima district of Japan, carrying the new infrared satellite into space. In about two weeks' time, ASTRO-F will be in polar orbit around the Earth at an altitude of 745 kilometres. From there, after two months of system check-outs and performance verification, it will survey the whole sky in about half a year, with much better sensitivity, spatial resolution and wider wavelength coverage than its only infrared surveyor predecessor, the Anglo-Dutch-US IRAS satellite (1983). The all-sky survey will be followed by a ten-month phase during which thousands of selected astronomical targets will be observed in detail. This will enable scientists to look at these individual objects for a longer time, and thus with increased sensitivity, to conduct their spectral

  5. A Systematic Mid-Infrared Survey of A Sample of Tidal Disruption Events Discovered by ZTF

    Science.gov (United States)

    Yan, Lin; Van, Sjoert; Kulkarni, Shri; Kasliwal, Mansi; Gezari, Suvi; Cenko, Brad; Blagorodnova, Nadia; Hung, Tiara

    2017-12-01

    Zwicky Transient Facility (ZTF) saw its first light (press release on Nov 14, 2017) and is currently in the commissioning phase. The science operation is scheduled to start on Feb 1, 2018. Based on the data from Palomar Transient Factory (PTF), ZTF is expected to discover 30 new tidal disruption events (TDE) in the centers of galaxies containing supermassive blackholes. TDEs are rare transient events, and have only been discovered in recent years by large area transient surveys. Observations of optically discovered TDEs appear to show common characteristics, including blackbody temperatures of a few 10,000K, derived bolometric peak luminosities of several 10^43 - 10^44 erg/s, and photospheric radius of 10^15 - 10^16 cm. These properties are in conflict with the classic TDE model predictions, which suggest an order of magnitude higher temperature and peak luminosity. One proposed explanation is the possible existence of a reprocessing gas layer which absorbs X-ray, UV/optical photons and produces a cooler spectral energy distribution (SED). So far, there are only two published mid-IR light curves of TDEs, each with two epochal data. To solve this mystery, we require higher cadence Spitzer observations of a sample of uniformly selected TDEs. Next year is the only opportunity to obtain the critical observations because Spitzer is expected to operate only to March 2019. We request 24.1 hours of Spitzer time to observe 7 ZTF TDEs. This will produce a unique legacy dataset for many future studies of physics of TDEs.

  6. ARIEL - The Atmospheric Remote-sensing Infrared Exoplanet Large-survey

    Science.gov (United States)

    Eccleston, P.; Tinetti, G.

    2015-10-01

    More than 1,000 extrasolar systems have been discovered, hosting nearly 2,000 exoplanets. Ongoing and planned ESA and NASA missions from space such as GAIA, Cheops, PLATO, K2 and TESS, plus ground based surveys, will increase the number of known systems to tens of thousands. Of all these exoplanets we know very little; i.e. their orbital data and, for some of these, their physical parameters such as their size and mass. In the past decade, pioneering results have been obtained using transit spectroscopy with Hubble, Spitzer and ground-based facilities, enabling the detection of a few of the most abundant ionic, atomic and molecular species and to constrain the planet's thermal structure. Future general purpose facilities with large collecting areas will allow the acquisition of better exoplanet spectra, compared to the currently available, especially from fainter targets. A few tens of planets will be observed with JWST and E-ELT in great detail. A breakthrough in our understanding of planet formation and evolution mechanisms will only happen through the observation of the planetary bulk and atmospheric composition of a statistically large sample of planets. This requires conducting spectroscopic observations covering simultaneously a broad spectral region from the visible to the mid-IR. It also requires a dedicated space mission with the necessary photometric stability to perform these challenging measurements and sufficient agility to observe multiple times ~500 exoplanets over 3.5 years. The ESA Cosmic Vision M4 mission candidate ARIEL is designed to accomplish this goal and will provide a complete, statistically significant sample of gas-giants, Neptunes and super-Earths with temperatures hotter than 600K, as these types of planets will allow direct observation of their bulk properties, enabling us to constrain models of planet formation and evolution. The ARIEL consortium currently includes academic institutes and industry from eleven countries in Europe; the

  7. Sir John Herschel and the Stability of Saturn's Ring

    CERN Document Server

    Whiting, Alan B

    2011-01-01

    In a pioneering exposition of mathematical astronomy for the public, Sir John Herschel attributed the stability of the ring of Saturn to its being eccentric with respect to the planet and lopsided (asymmetric in mass) by a minute amount. Tracing the sources and effects of this error reveals several lessons of general relevance to science: on the formulation and interpretation of calculations, the use of cutting-edge observations and the combining of observations with theory. I emphasise the phenomenon of reinforcing errors.

  8. John Herschel and the Cape flora, 1834 - 1839.

    Science.gov (United States)

    Rourke, J. P.

    John Herschel's interest in botany was stimulated by his contact with the species-rich Cape flora while resident in Cape Town, 1834 - 1838. The comparative study of his extensive living collection of bulbous plants, mainly of the Iridaceae, Liliaceae, Amarayllidaceae and Orchidaceae led him to consider some basic aspects of the origin of species and of taxonomic theory, in letters to colleagues in Europe.

  9. 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.

  10. FAR-INFRARED DUST TEMPERATURES AND COLUMN DENSITIES OF THE MALT90 MOLECULAR CLUMP SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Guzmán, Andrés E.; Smith, Howard A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States); Sanhueza, Patricio [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Contreras, Yanett; Rathborne, Jill M. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping 1710 NSW (Australia); Jackson, James M.; Hoq, Sadia [Institute for Astrophysical Research, Boston University, Boston, MA (United States)

    2015-12-20

    We present dust column densities and dust temperatures for ∼3000 young, high-mass molecular clumps from the Millimeter Astronomy Legacy Team 90 GHz survey, derived from adjusting single-temperature dust emission models to the far-infrared intensity maps measured between 160 and 870 μm from the Herschel/Herschel Infrared Galactic Plane Survey (Hi-Gal) and APEX/APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) surveys. We discuss the methodology employed in analyzing the data, calculating physical parameters, and estimating their uncertainties. The population average dust temperature of the clumps are 16.8 ± 0.2 K for the clumps that do not exhibit mid-infrared signatures of star formation (quiescent clumps), 18.6 ± 0.2 K for the clumps that display mid-infrared signatures of ongoing star formation but have not yet developed an H ii region (protostellar clumps), and 23.7 ± 0.2 and 28.1 ± 0.3 K for clumps associated with H ii and photo-dissociation regions, respectively. These four groups exhibit large overlaps in their temperature distributions, with dispersions ranging between 4 and 6 K. The median of the peak column densities of the protostellar clump population is 0.20 ± 0.02 g cm{sup −2}, which is about 50% higher compared to the median of the peak column densities associated with clumps in the other evolutionary stages. We compare the dust temperatures and column densities measured toward the center of the clumps with the mean values of each clump. We find that in the quiescent clumps, the dust temperature increases toward the outer regions and that these clumps are associated with the shallowest column density profiles. In contrast, molecular clumps in the protostellar or H ii region phase have dust temperature gradients more consistent with internal heating and are associated with steeper column density profiles compared with the quiescent clumps.

  11. Joint US-Japan Observations with the Infrared Space Observatory (ISO): Deep Surveys and Observations of High-Z Objects

    Science.gov (United States)

    Sanders, David B.

    1997-01-01

    Several important milestones were passed during the past year of our ISO observing program: (1) Our first ISO data were successfully obtained. ISOCAM data were taken for our primary deep field target in the 'Lockman Hole'. Thirteen hours of integration (taken over 4 contiguous orbits) were obtained in the LW2 filter of a 3 ft x 3 ft region centered on the position of minimum HI column density in the Lockman Hole. The data were obtained in microscanning mode. This is the deepest integration attempted to date (by almost a factor of 4 in time) with ISOCAM. (2) The deep survey data obtained for the Lockman Hole were received by the Japanese P.I. (Yoshi Taniguchi) in early December, 1996 (following release of the improved pipeline formatted data from Vilspa), and a copy was forwarded to Hawaii shortly thereafter. These data were processed independently by the Japan and Hawaii groups during the latter part of December 1996, and early January, 1997. The Hawaii group made use of the U.S. ISO data center at IPAC/Caltech in Pasadena to carry out their data reduction, while the Japanese group used a copy of the ISOCAM data analysis package made available to them through an agreement with the head of the ISOCAM team, Catherine Cesarsky. (3) Results of our LW2 Deep Survey in the Lockman Hole were first reported at the ISO Workshop "Taking ISO to the Limits: Exploring the Faintest Sources in the Infrared" held at the ISO Science Operations Center in Villafranca, Spain (VILSPA) on 3-4 February, 1997. Yoshi Taniguchi gave an invited presentation summarizing the results of the U.S.-Japan team, and Dave Sanders gave an invited talk summarizing the results of the Workshop at the conclusion of the two day meeting. The text of the talks by Taniguchi and Sanders are included in the printed Workshop Proceedings, and are published in full on the Web. By several independent accounts, the U.S.-Japan Deep Survey results were one of the highlights of the Workshop; these data showed

  12. MOIRCS Deep Survey. VI. Near-infrared Spectroscopy of K-Selected Star-forming Galaxies at z ~ 2

    Science.gov (United States)

    Yoshikawa, Tomohiro; Akiyama, Masayuki; Kajisawa, Masaru; Alexander, David M.; Ohta, Kouji; Suzuki, Ryuji; Tokoku, Chihiro; Uchimoto, Yuka K.; Konishi, Masahiro; Yamada, Toru; Tanaka, Ichi; Omata, Koji; Nishimura, Tetsuo; Koekemoer, Anton M.; Brandt, Niel; Ichikawa, Takashi

    2010-07-01

    We present the results of near-infrared multi-object spectroscopic observations for 37 BzK-color-selected star-forming galaxies conducted with MOIRCS on the Subaru Telescope. The sample is drawn from the Ks -band-selected catalog of the MOIRCS Deep Survey in the GOODS-N region. About half of our samples are selected from the publicly available 24 μm-source catalog of the Multiband Imaging Photometer for Spitzer on board the Spitzer Space Telescope. Hα emission lines are detected from 23 galaxies, of which the median redshift is 2.12. We derived the star formation rates (SFRs) from extinction-corrected Hα luminosities. The extinction correction is estimated from the spectral energy distribution (SED) fitting of multiband photometric data covering UV to near-infrared wavelengths. The Balmer decrement of the stacked emission lines shows that the amount of extinction for the ionized gas is larger than that for the stellar continuum. From a comparison of the extinction-corrected Hα luminosity and other SFR indicators, we found that the relation between the dust properties of stellar continuum and ionized gas is different depending on the intrinsic SFR (differential extinction). We compared SFRs estimated from extinction-corrected Hα luminosities with stellar masses estimated from SED fitting. The comparison shows no correlation between SFR and stellar mass. Some galaxies with stellar mass smaller than ~1010 M sun show SFRs higher than ~100 M sun yr-1. The specific SFRs (SSFRs) of these galaxies are remarkably high; galaxies which have SSFR higher than ~10-8 yr-1 are found in eight of the present sample. From the best-fit parameters of SED fitting for these high-SSFR galaxies, we find that the average age of the stellar population is younger than 100 Myr, which is consistent with the implied high SSFR. The large SFR implies the possibility that the high-SSFR galaxies significantly contribute to the cosmic SFR density of the universe at z ~ 2. When we apply the

  13. HERSCHEL PACS AND SPIRE OBSERVATIONS OF BLAZAR PKS 1510-089: A CASE FOR TWO BLAZAR ZONES

    Energy Technology Data Exchange (ETDEWEB)

    Nalewajko, Krzysztof [University of Colorado, UCB 440, Boulder, CO 80309 (United States); Sikora, Marek [Nicolaus Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw (Poland); Madejski, Greg M.; Szostek, Anna [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road M/S 29, Menlo Park, CA 94025 (United States); Exter, Katrina [Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Szczerba, Ryszard [Nicolaus Copernicus Astronomical Center, Rabianska 8, 87-100, Torun (Poland); Kidger, Mark R.; Lorente, Rosario, E-mail: knalew@colorado.edu [Herschel Science Centre, ESAC, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain)

    2012-11-20

    We present the results of observations of blazar PKS 1510-089 with the Herschel Space Observatory PACS and SPIRE instruments, together with multiwavelength data from Fermi/LAT, Swift, SMARTS, and Submillimeter Array. The source was found in a quiet state, and its far-infrared spectrum is consistent with a power law with a spectral index of {alpha} {approx_equal} 0.7. Our Herschel observations were preceded by two 'orphan' gamma-ray flares. The near-infrared data reveal the high-energy cutoff in the main synchrotron component, which cannot be associated with the main gamma-ray component in a one-zone leptonic model. This is because in such a model the luminosity ratio of the external-Compton (EC) and synchrotron components is tightly related to the frequency ratio of these components, and in this particular case an unrealistically high energy density of the external radiation would be implied. Therefore, we consider a well-constrained two-zone blazar model to interpret the entire data set. In this framework, the observed infrared emission is associated with the synchrotron component produced in the hot-dust region at the supra-parsec scale, while the gamma-ray emission is associated with the EC component produced in the broad-line region at the sub-parsec scale. In addition, the optical/UV emission is associated with the accretion disk thermal emission, with the accretion disk corona likely contributing to the X-ray emission.

  14. Continuum and line modelling of discs around young stars - I. 300000 disc models for HERSCHEL/GASPS

    Science.gov (United States)

    Woitke, P.; Pinte, C.; Tilling, I.; Ménard, F.; Kamp, I.; Thi, W.-F.; Duchêne, G.; Augereau, J.-C.

    2010-06-01

    We have combined the thermo-chemical disc code ProDiMo with the Monte Carlo radiative transfer code MCFOST to calculate a grid of ~300000 circumstellar disc models, systematically varying 11 stellar, disc and dust parameters including the total disc mass, several disc shape parameters and the dust-to-gas ratio. For each model, dust continuum and line radiative transfer calculations are carried out for 29 far-infrared, sub-mm and mm lines of [OI], [CII], 12CO and o/p-H2O under five inclinations. The grid allows us to study the influence of the input parameters on the observables, to make statistical predictions for different types of circumstellar discs and to find systematic trends and correlations between the parameters, the continuum fluxes and the line fluxes. The model grid, comprising the calculated disc temperature and chemical structures, the computed spectral energy distributions, line fluxes and profiles, will be used in particular for the data interpretation of the HERSCHEL open time-key program GASPS. The calculated line fluxes show a strong dependence on the assumed ultraviolet excess of the central star and on the disc flaring. The fraction of models predicting [OI] and [CII] fine-structure lines fluxes above HERSCHEL/PACS and SPICA/SAFARI detection limits is calculated as a function of disc mass. The possibility of deriving the disc gas mass from line observations is discussed.

  15. The accretion/ejection paradigm in young stellar objects: from HST and Herschel to JWST

    Science.gov (United States)

    Podio, Linda

    2012-07-01

    Stellar jets and molecular outflows are observed in association with young accreting stars and are believed to play a key role in the star formation process. In this talk I will show how current and future space missions are of crucial importance to investigate the origin of stellar jets and their link to the accretion process. Thanks to its high angular (˜0.1") resolution, HST has been the first telescope allowing us to investigate the jet physics at optical/UV wavelengths down to the heart of the launching mechanism. We recently analysed a datacube of the jet emitted by the T Tauri star DG Tau obtaining spatio-kinematical maps of the hot atomic gas in the jet and of its physical conditions (Maurri et al., submitted). These data confirm the predictions of theoretical models including the fact that jets may extract the excess angular momentum from the system. In the last two years Herschel has further improved our comprehension of the ejection process observing the far infrared counterpart of fast and collimated atomic jets. PACS and HIFI observations, acquired within the GASPS (GAS in Protoplanetary Systems) Open Time Key Project (PI: B. Dent), show that T Tauri stars driving optical jets are also associated with a warm gas component emitting not only atomic ([OI], [CII]) but also molecular (high-J CO, H_2O, OH) lines. The comparison with Class 0 outflows highlights a clear evolutionary trend: the emission associated with evolved Class I/II sources is fainter and more compact and the estimated mass loss rates and lines cooling are one to two orders of magnitudes lower (Podio et al., to be submitted). The arrival of JWST will fill-in the gap between HST and Herschel opening a new window in the near and mid-infrared range at unprecedented angular resolution (down to 0.03"). This will allow resolving the emission in both atomic (e.g., [FeII]) and molecular (e.g., H_2) lines and understanding if the molecular gas is entrained by the atomic jet or launched with it

  16. Thermal ecology on an exposed algal reef: infrared imagery a rapid tool to survey temperature at local spatial scales

    Science.gov (United States)

    Cox, T. E.; Smith, C. M.

    2011-12-01

    We tested the feasibility of infra-red (IR) thermography as a tool to survey in situ temperatures in intertidal habitats. We employed this method to describe aspects of thermal ecology for an exposed algal reef in the tropics (O`ahu, Hawai`i). In addition, we compared temperatures of the surrounding habitat as determined by IR thermography and traditional waterproof loggers. Images of reef organisms (6 macroalgae, 9 molluscs, 1 anthozoan, and 2 echinoderms), loggers, and landscapes were taken during two diurnal low tides. Analysis of IR thermographs revealed remarkable thermal complexity on a narrow tropical shore, as habitats ranged from 18.1 to 38.3°C and surfaces of organisms that ranged from 21.1 to 33.2°C. The near 20°C difference between abiotic habitats and the mosaic of temperatures experienced by reef organisms across the shore are similar to findings from temperate studies using specialized longterm loggers. Further, IR thermography captured rapid temperature fluctuations that were related to tidal height and cross-correlated to wave action. Finally, we gathered evidence that tidal species were associated with particular temperature ranges and that two species possess morphological characteristics that limit thermal stress. Loggers provided similar results as thermography but lack the ability to resolve variation in fine-scale spatial and temporal patterns. Our results support the utility of IR thermography in exploring thermal ecology, and demonstrate the steps needed to calibrate data leading to establishment of baseline conditions in a changing and heterogeneous environment.

  17. ARIEL: Atmospheric Remote Sensing Infrared Exoplanet Large Survey. A proposal for the ESA Cosmic Vision M4

    Science.gov (United States)

    Pace, E.; Micela, G.; Ariel Team

    The Atmospheric Remote sensing Infrared Exoplanet Large survey (ARIEL) is a proposal in response to the call for a Medium-size mission opportunity in ESA’s Cosmic Vision 2015-2025 Science Programme for a launch in 2025 (M4). This mission will be devoted to observe spectroscopically in the IR a large population (hundreds to one thousand) of known planets in our Galaxy, opening a new discovery space in the field of extrasolar planet exploration and enabling a quantum leap in the understanding of the physics and chemistry of these far away worlds. The population of planets will include warm and hot gas‑giants, Neptunes and large terrestrial planets. The main ARIEL goal is the determination of the composition, formation and history of these planetary systems In order to fulfill the scientific goals of ARIEL, we propose the development of a 1‑meter class aperture space telescope, passively cooled to 70‑80K, to observe the combined light of stars and their planets, building on the current experience of transit and combined light observations with Hubble, Spitzer, and ground-based telescopes. While JWST and EELT will initiate a detailed mid- to high-resolution IR spectroscopic observation of a few tens of planets, this mission will extend the study to a much larger (an order of magnitude difference) representative population of extrasolar planets discovered by ESA GAIA, Cheops, PLATO, NASA Kepler II, TESS and from the ground. The statistical perspective provided by this mission, will allow us to address some of the fundamental questions of the Cosmic Vision programme: What are the conditions for planet formation and the emergence of life? ls our Solar System unique, rare or very common? How does the Solar System work?

  18. Detector Control and Data Acquisition for the Wide-Field Infrared Survey Telescope (WFIRST) with a Custom ASIC

    Science.gov (United States)

    Smith, Brian S.; Loose, Markus; Alkire, Greg; Joshi, Atul; Kelly, Daniel; Siskind, Eric; Rossetti, Dino; Mah, Jonathan; Cheng, Edward; Miko, Laddawan; hide

    2016-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) will have the largest near-IR focal plane ever flown by NASA, a total of 18 4K x 4K devices. The project has adopted a system-level approach to detector control and data acquisition where 1) control and processing intelligence is pushed into components closer to the detector to maximize signal integrity, 2) functions are performed at the highest allowable temperatures, and 3) the electronics are designed to ensure that the intrinsic detector noise is the limiting factor for system performance. For WFIRST, the detector arrays operate at 90 to 100 K, the detector control and data acquisition functions are performed by a custom ASIC at 150 to 180 K, and the main data processing electronics are at the ambient temperature of the spacecraft, notionally approx.300 K. The new ASIC is the main interface between the cryogenic detectors and the warm instrument electronics. Its single-chip design provides basic clocking for most types of hybrid detectors with CMOS ROICs. It includes a flexible but simple-to-program sequencer, with the option of microprocessor control for more elaborate readout schemes that may be data-dependent. All analog biases, digital clocks, and analog-to-digital conversion functions are incorporated and are connected to the nearby detectors with a short cable that can provide thermal isolation. The interface to the warm electronics is simple and robust through multiple LVDS channels. It also includes features that support parallel operation of multiple ASICs to control detectors that may have more capability or requirements than can be supported by a single chip.

  19. NEW MEASUREMENTS OF THE COSMIC INFRARED BACKGROUND FLUCTUATIONS IN DEEP SPITZER/IRAC SURVEY DATA AND THEIR COSMOLOGICAL IMPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kashlinsky, A. [SSAI, Lanham MD 20706 (United States); Arendt, R. G.; Mather, J.; Moseley, S. H. [Observational Cosmology Laboratory, Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ashby, M. L. N.; Fazio, G. G., E-mail: alexander.kashlinsky@nasa.gov [Center for Astrophysics, Cambridge, MA 02138 (United States)

    2012-07-01

    We extend previous measurements of cosmic infrared background (CIB) fluctuations to {approx}< 1 Degree-Sign using new data from the Spitzer Extended Deep Survey. Two fields with depths of {approx_equal} 12 hr pixel{sup -1} over three epochs are analyzed at 3.6 and 4.5 {mu}m. Maps of the fields were assembled using a self-calibration method uniquely suitable for probing faint diffuse backgrounds. Resolved sources were removed from the maps to a magnitude limit of mag{sub AB} {approx_equal} 25, as indicated by the level of the remaining shot noise. The maps were then Fourier transformed and their power spectra were evaluated. Instrumental noise was estimated from the time-differenced data, and subtracting this isolates the spatial fluctuations of the actual sky. The power spectra of the source-subtracted fields remain identical (within the observational uncertainties) for the three epochs indicating that zodiacal light contributes negligibly to the fluctuations. Comparing to 8 {mu}m power spectra shows that Galactic cirrus cannot account for the fluctuations. The signal appears isotropically distributed on the sky as required for an extragalactic origin. The CIB fluctuations continue to diverge to >10 times those of known galaxy populations on angular scales out to {approx}< 1 Degree-Sign . The low shot-noise levels remaining in the diffuse maps indicate that the large-scale fluctuations arise from the spatial clustering of faint sources well below the confusion noise. The spatial spectrum of these fluctuations is in reasonable agreement with an origin in populations clustered according to the standard cosmological model ({Lambda}CDM) at epochs coinciding with the first stars era.

  20. Conceptual model for the use of aerial color infrared photography by mosquito control districts as a survey technique for Psorophora columbiae oviposition habitats in Texas ricelands.

    Science.gov (United States)

    Welch, J B; Olson, J K; Yates, M M; Benton, A R; Baker, R D

    1989-09-01

    Two photographic missions per year are recommended to provide information on land-use and mosquito oviposition habitats. A winter mission, following a rain, will-provide a view of low areas within fields which may be obscured by summer vegetation. A summer mission will provide current land-use and crop distribution information and may show plant stress conditions due to excessive soil moisture. An aerial color infrared photographic survey with directed ground verification should result in a substantial savings in cost and increased efficiency in surveillance of mosquito producing habitats over ground survey techniques currently employed by mosquito control districts.

  1. Probing the cold and warm molecular gas in the Whirlpool Galaxy: Herschel SPIRE-FTS observations of the central region of M51 (NGC 5194)

    Science.gov (United States)

    Schirm, M. R. P.; Wilson, C. D.; Kamenetzky, J.; Parkin, T. J.; Glenn, J.; Maloney, P.; Rangwala, N.; Spinoglio, L.; Baes, M.; Boselli, A.; Cooray, A.; De Looze, I.; Fernández-Ontiveros, J. A.; Karczewski, O. Ł.; Wu, R.

    2017-10-01

    We present Herschel Spectral and Photometric Imaging Receiver (SPIRE)-Fourier Transform Spectrometer (FTS) intermediate-sampled mapping observations of the central ˜8 kpc (˜150 arcsec) of M51, with a spatial resolution of 40 arcsec. We detect four 12CO transitions (J = 4-3 to J = 7-6) and the [C i] 3P2-3P1 and 3P1-3P0 transitions. We supplement these observations with ground-based observations of 12CO J = 1-0 to J = 3-2 and perform a two-component non-local thermodynamic equilibrium analysis. We find that the molecular gas in the nucleus and centre regions has a cool component (Tkin ˜ 10-20 K) with a moderate but poorly constrained density (n(H2) ˜ 103-106 cm-3), as well as significant molecular gas in a warmer (Tkin ˜ 300-3000 K), lower density (n(H2) ˜ 101.6-102.5 cm-3) component. We compare our CO line ratios and calculated densities along with ratios of CO to total infrared luminosity to a grid of photon-dominated region (PDR) models and find that the cold molecular gas likely resides in PDRs with a field strength of G0 ˜ 102. The warm component likely requires an additional source of mechanical heating, from supernovae and stellar winds or possibly shocks produced in the strong spiral density wave. When compared to similar two-component models of other star-forming galaxies published as part of the Very Nearby Galaxies Survey (Arp 220, M82 and NGC 4038/39), M51 has the lowest density for the warm component, while having a warm gas mass fraction that is comparable to those of Arp 220 and M82, and significantly higher than that of NGC 4038/39.

  2. The Host Galaxies of X-Ray Selected Active Galactic Nuclei to z - 2.5: Structure, Star-Formation and Their Relationships from CANDELS and Herschel/Pacs

    Science.gov (United States)

    Rosario, D.J.; McIntosh, D. H.; van der Wel, A.; Kartaltepe, J.; Lang, P.; Santini, P.; Wuyts, S.; Lutz, D.; Rafelski, M.; Villforth, C.; hide

    2014-01-01

    We study the relationship between the structure and star-formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed distributions of structural parameters and FIR luminosities from carefully constructed control samples of galaxies, which we then compare to those of the AGNs. At z is approximately 1, AGNs show slightly diskier light profiles than massive inactive (non-AGN) galaxies, as well as modestly higher levels of gross galaxy disturbance (as measured by visual signatures of interactions and clumpy structure). In contrast, at z 2, AGNs show similar levels of galaxy disturbance as inactive galaxies, but display a red central light enhancement, which may arise due to a more pronounced bulge in AGN hosts or due to extinguished nuclear light. We undertake a number of tests of both these alternatives, but our results do not strongly favour one interpretation over the other. The mean SFR and its distribution among AGNs and inactive galaxies are similar at z greater than 1.5. At z less than 1, however, clear and significant enhancements are seen in the SFRs of AGNs with bulge-dominated light profiles. These trends suggest an evolution in the relation between nuclear activity and host properties with redshift towards a minor role for mergers and interactions at z greater than 15

  3. WHAT DETERMINES THE DENSITY STRUCTURE OF MOLECULAR CLOUDS? A CASE STUDY OF ORION B WITH HERSCHEL

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, N.; Andre, Ph.; Koenyves, V.; Motte, F.; Arzoumanian, D.; Didelon, P.; Hennemann, M.; Hill, T.; Palmeirim, P.; Peretto, N.; Roy, A. [IRFU/SAp CEA/DSM, Laboratoire AIM CNRS, Universite Paris Diderot, F-91191 Gif-sur-Yvette (France); Bontemps, S. [OASU/LAB-UMR5804, CNRS, Universite Bordeaux 1, F-33270 Floirac (France); Federrath, C. [MoCA, School of Mathematical Sciences, Monash University, VIC 3800 (Australia); Ward-Thompson, D. [Jeremiah Horrocks Institute, UCLAN, Preston, Lancashire PR1 2HE (United Kingdom); Benedettini, M.; Pezzuto, S.; Rygl, K. L. J. [IAPS-INAF, Fosso del Cavaliere 100, I-00133 Roma (Italy); Bressert, E. [CSIRO Astronomy and Space Science, Epping (Australia); Di Francesco, J. [NRCC, Herzberg Institute of Astrophysics, University of Victoria (Canada); Griffin, M. [University School of Physics and Astronomy, Cardiff (United Kingdom); and others

    2013-04-01

    A key parameter to the description of all star formation processes is the density structure of the gas. In this Letter, we make use of probability distribution functions (PDFs) of Herschel column density maps of Orion B, Aquila, and Polaris, obtained with the Herschel Gould Belt survey (HGBS). We aim to understand which physical processes influence the PDF shape, and with which signatures. The PDFs of Orion B (Aquila) show a lognormal distribution for low column densities until A{sub V} {approx} 3 (6), and a power-law tail for high column densities, consistent with a {rho}{proportional_to}r {sup -2} profile for the equivalent spherical density distribution. The PDF of Orion B is broadened by external compression due to the nearby OB stellar aggregates. The PDF of a quiescent subregion of the non-star-forming Polaris cloud is nearly lognormal, indicating that supersonic turbulence governs the density distribution. But we also observe a deviation from the lognormal shape at A{sub V} > 1 for a subregion in Polaris that includes a prominent filament. We conclude that (1) the point where the PDF deviates from the lognormal form does not trace a universal A{sub V} -threshold for star formation, (2) statistical density fluctuations, intermittency, and magnetic fields can cause excess from the lognormal PDF at an early cloud formation stage, (3) core formation and/or global collapse of filaments and a non-isothermal gas distribution lead to a power-law tail, and (4) external compression broadens the column density PDF, consistent with numerical simulations.

  4. A Herschel and APEX Census of the Reddest Sources in Orion: Searching for the Youngest Protostars

    Science.gov (United States)

    Stutz, Amelia M.; Tobin, John J.; Stanke, Thomas; Megeath, S. Thomas; Fischer, William J.; Robitaille, Thomas; Henning, Thomas; Ali, Babar; di Francesco, James; Furlan, Elise; Hartmann, Lee; Osorio, Mayra; Wilson, Thomas L.; Allen, Lori; Krause, Oliver; Manoj, P.

    2013-04-01

    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 μm and 160 μm that are either too faint (m 24 > 7 mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS 24 μm band. We find that the 11 reddest protostar candidates with log λF λ70/λF λ24 > 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 μm 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 λF λ70/λF λ24 > 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 bol 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2-2 M ⊙ and luminosities of 0.7-10 L ⊙. 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.

  5. TNOs are Cool: A Survey of the Trans-Neptunian Region: Radiometric properties of Trans-Neptunian Objects

    NARCIS (Netherlands)

    Mommert, Michael; Müller, G.; Bühnhardt, Hermann; Lellouch, Emmanuel; Stansberry, John; Barucci, Antonella; Crovisier, Jacques; Delsanti, Audrey; Dores-Soundiram, Alain; Dotto, Elisabetta; Duffard, René; Fornasier, Sonia; Groussin, Olivier; Gutiérrez Buenestado, Pedro; Hainaut, Olivier; Harris, Alan; Hartogh, Paul; Henry, Florence; Hestroffer, Daniel; Horner, Jonathan; Jewitt, Dave; Kidger, Mark; Kiss, Csaba; Lacerda, Pedro; López, Luisa Lara; Lim, Tanya; Müller, Michael; Moreno, Raphael; Ortiz Moreno, Jose Luis; Protopapa, Silvia; Rengel, Miriam; Santos Sanz, Pablo; Swinyard, Bruce; Thomas, Nicolas; Thirouin, Audrey; Trilling, David

    2010-01-01

    The "TNOs are Cool: A Survey of the Trans-Neptunian Region" project is a Herschel Open Time Key Program awarded some 370 h of Herschel observing time. The observations include PACS and SPIRE point-source photometry on about 140 trans-Neptunian objects with known orbits. The goal is to characterize

  6. 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

  7. LUMINOUS AND HIGH STELLAR MASS CANDIDATE GALAXIES AT z Almost-Equal-To 8 DISCOVERED IN THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Yan Haojing [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Finkelstein, Steven L. [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Huang, Kuang-Han [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Ryan, Russell E.; Ferguson, Henry C.; Koekemoer, Anton M.; Grogin, Norman A. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Newman, Jeffrey A. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Somerville, Rachel S. [Physics and Astronomy Department, Rutgers University, Piscataway, NJ 08854 (United States); Dave, Romeel [Astronomy Department, University of Arizona, Tucson, AZ 85721 (United States); Faber, S. M. [University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Papovich, Casey [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States); Guo Yicheng; Giavalisco, Mauro [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Lee, Kyoung-soo [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Reddy, Naveen; Siana, Brian D. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Cooray, Asantha R. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Hathi, Nimish P. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); and others

    2012-12-20

    One key goal of the Hubble Space Telescope Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey is to track galaxy evolution back to z Almost-Equal-To 8. Its two-tiered ''wide and deep'' strategy bridges significant gaps in existing near-infrared surveys. Here we report on z Almost-Equal-To 8 galaxy candidates selected as F105W-band dropouts in one of its deep fields, which covers 50.1 arcmin{sup 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 < 26.2 mag, and are >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 Almost-Equal-To 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 Almost-Equal-To 8. Their derived stellar masses are on the order of a few Multiplication-Sign 10{sup 9} M{sub Sun }, from which we obtain the first measurement of the high-mass end of the galaxy stellar mass function at z Almost-Equal-To 8. The high number density of very luminous and very massive galaxies at z Almost-Equal-To 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.

  8. 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.

  9. 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

  10. The Herschel/SPIRE Spectrometer Phase Correction Data Processing Tasks

    Science.gov (United States)

    Fulton, T.; Naylor, D.; Polehampton, E.; Hopwood, R.; Valtchanov, I.; Lu, N.; Marchili, N.; Zaretski, J.

    2015-09-01

    Asymmetries in the recorded interferograms of Fourier Transform Spectrometers (FTS) can be caused by optical, electronic, and sampling effects. Left uncorrected, these asymmetries will result in a spectrum with both real and imaginary components and thus a non-zero phase. One or more phase correction steps are applied in FTS data processing pipelines to correct for these effects. In this paper we describe the causes of non-zero phase particular to the Herschel/SPIRE FTS and present the two phase correction processing steps employed. The evolution of the phase correction algorithms is also described.

  11. Retrieval of H2O abundance in Titan's stratosphere from CIRS and Herschel disc-averaged observations

    Science.gov (United States)

    Bauduin, S.; Irwin, P. G. J.; Cottini, V.; Lellouch, E.; Moreno, R.; Nixon, C. A.; Teanby, N. A.

    2017-09-01

    Since its first measurement 20 years ago by the Infrared Space Observatory (ISO), the water (H2O) mole fraction in Titan's stratosphere remains uncertain, due to large differences between the determinations from available measurements. This has notably prevented current models from fully constraining the oxygen flux flowing into Titan's atmosphere. In this work, we aim to understand the differences between the H2O mole fractions estimated from Herschel and Cassini/CIRS observations. This is done by (re)analysing disc-averaged observations from both instruments using an identical retrieval scheme. Previous differences in modelling/retrieval methods, along with differing viewing geometries between the two datasets are in this way mainly avoided. The whole methodology will be presented and the comparison between the two sets of H2O mole fractions will be discussed.

  12. The physical properties of the dust in the RCW 120 H II region as seen by Herschel

    Science.gov (United States)

    Anderson, L. D.; Zavagno, A.; Rodón, J. A.; Russeil, D.; Abergel, A.; Ade, P.; André, P.; Arab, H.; Baluteau, J.-P.; Bernard, J.-P.; Blagrave, K.; Bontemps, S.; Boulanger, F.; Cohen, M.; Compiègne, M.; Cox, P.; Dartois, E.; Davis, G.; Emery, R.; Fulton, T.; Gry, C.; Habart, E.; Huang, M.; Joblin, C.; Jones, S. C.; Kirk, J. M.; Lagache, G.; Lim, T.; Madden, S.; Makiwa, G.; Martin, P.; Miville-Deschênes, M.-A.; Molinari, S.; Moseley, H.; Motte, F.; Naylor, D. A.; Okumura, K.; Pinheiro Gonçalves, D.; Polehampton, E.; Saraceno, P.; Sauvage, M.; Sidher, S.; Spencer, L.; Swinyard, B.; Ward-Thompson, D.; White, G. J.

    2010-07-01

    Context. RCW 120 is a well-studied, nearby Galactic H ii region with ongoing star formation in its surroundings. Previous work has shown that it displays a bubble morphology at mid-infrared wavelengths, and has a massive layer of collected neutral material seen at sub-mm wavelengths. Given the well-defined photo-dissociation region (PDR) boundary and collected layer, it is an excellent laboratory to study the “collect and collapse” process of triggered star formation. Using Herschel Space Observatory data at 100, 160, 250, 350, and 500 μm, in combination with Spitzer and APEX-LABOCA data, we can for the first time map the entire spectral energy distribution of an H ii region at high angular resolution. Aims: We seek a better understanding of RCW 120 and its local environment by analysing its dust temperature distribution. Additionally, we wish to understand how the dust emissivity index, β, is related to the dust temperature. Methods: We determine dust temperatures in selected regions of the RCW 120 field by fitting their spectral energy distribution (SED), derived using aperture photometry. Additionally, we fit the SED extracted from a grid of positions to create a temperature map. Results: We find a gradient in dust temperature, ranging from ⪆30 K in the interior of RCW 120, to ~20 K for the material collected in the PDR, to ~10 K toward local infrared dark clouds and cold filaments. There is an additional, hotter (~100 K) component to the dust emission that we do not investigate here. Our results suggest that RCW 120 is in the process of destroying the PDR delineating its bubble morphology. The leaked radiation from its interior may influence the creation of the next generation of stars. We find support for an anti-correlation between the fitted temperature and β, in rough agreement with what has been found previously. The extended wavelength coverage of the Herschel data greatly increases the reliability of this result. Herschel is an ESA space

  13. 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.

  14. Water vapor toward starless cores: The Herschel view

    Science.gov (United States)

    Caselli, P.; Keto, E.; Pagani, L.; Aikawa, Y.; Yıldız, U. A.; van der Tak, F. F. S.; Tafalla, M.; Bergin, E. A.; Nisini, B.; Codella, C.; van Dishoeck, E. F.; Bachiller, R.; Baudry, A.; Benedettini, M.; Benz, A. O.; Bjerkeli, P.; Blake, G. A.; Bontemps, S.; Braine, J.; Bruderer, S.; Cernicharo, J.; Daniel, F.; di Giorgio, A. M.; Dominik, C.; Doty, S. D.; Encrenaz, P.; Fich, M.; Fuente, A.; Gaier, T.; Giannini, T.; Goicoechea, J. R.; de Graauw, Th.; Helmich, F.; Herczeg, G. J.; Herpin, F.; Hogerheijde, M. R.; Jackson, B.; Jacq, T.; Javadi, H.; Johnstone, D.; Jørgensen, J. K.; Kester, D.; Kristensen, L. E.; Laauwen, W.; Larsson, B.; Lis, D.; Liseau, R.; Luinge, W.; Marseille, M.; McCoey, C.; Megej, A.; Melnick, G.; Neufeld, D.; Olberg, M.; Parise, B.; Pearson, J. C.; Plume, R.; Risacher, C.; Santiago-García, J.; Saraceno, P.; Shipman, R.; Siegel, P.; van Kempen, T. A.; Visser, R.; Wampfler, S. F.; Wyrowski, F.

    2010-10-01

    Aims: Previous studies by the satellites SWAS and Odin provided stringent upper limits on the gas phase water abundance of dark clouds (x(H2O) 7000 AU and ≃2 × 10-10 toward the center. The radiative transfer analysis shows that this is consistent with a x(o-H2O) profile peaking at ≃10-8, 0.1 pc away from the core center, where both freeze-out and photodissociation are negligible. Conclusions: Herschel has provided the first measurement of water vapor in dark regions. Column densities of o-H2O are low, but prestellar cores such as L1544 (with their high central densities, strong continuum, and large envelopes) appear to be very promising tools to finally shed light on the solid/vapor balance of water in molecular clouds and oxygen chemistry in the earliest stages of star formation. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  15. 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 ...

  16. Herschel observations of the circumstellar environments of the Herbig Be stars R Mon and PDS 27

    Science.gov (United States)

    Jiménez-Donaire, M. J.; Meeus, G.; Karska, A.; Montesinos, B.; Bouwman, J.; Eiroa, C.; Henning, T.

    2017-09-01

    Context. The circumstellar environments of Herbig Be stars in the far-infrared are poorly characterised, mainly because they are often embedded and rather distant. The analysis of far-infrared spectroscopy allows us to make a major step forward by covering multiple rotational lines of molecules, e.g. CO, that are useful probes of the physical conditions of the gas. Aims: We characterise the gas and dust in the discs and environments of Herbig Be stars, and we compare the results with those of their lower-mass counterparts, the Herbig Ae stars. Methods: We report and analyse far-infrared observations of two Herbig Be stars, R Mon and PDS 27, obtained with the Herschel instruments PACS and SPIRE. We construct spectral energy distributions and derive the infrared excess. We extract line fluxes from the PACS and SPIRE spectra and construct rotational diagrams in order to estimate the excitation temperature of the gas. We derive CO, [O I] and [C I] luminosities to determine the physical conditions of the gas, and the dominant cooling mechanism. Results: We confirm that the Herbig Be stars are surrounded by remnants from their parental clouds, with an IR excess that mainly originates in a disc. In R Mon we detect [O I], [C I], [C II], CO (26 transitions), water and OH, while in PDS 27 we only detect [C I] and CO (8 transitions). We attribute the absence of OH and water in PDS 27 to UV photo-dissociation and photo-evaporation. From the rotational diagrams, we find several components for CO; we derive Trot949 ± 90 K, 358 ± 20 K and 77 ± 12 K for R Mon; 96 ± 12 K and 31 ± 4 K for PDS 27; and 25 ± 8 K and 27 ± 6 K for their respective compact neighbours. The forsterite feature at 69 μm was not detected in either of the sources, probably due to the lack of (warm) crystalline dust in a flat disc. We find that cooling by molecules is dominant in the Herbig Be stars, while this is not the case in Herbig Ae stars where cooling by [O I] dominates. Moreover, we show that in

  17. Herschel observations of the Marco Polo-R asteroid 175706 (1996 FG3).

    Science.gov (United States)

    O'Rourke, L.; Barucci, A.; Gònzalez-Garcìa, B.; Dotto, E.; Küppers, M.

    2012-09-01

    Background: The Marco Polo-R mission has been selected for the assessment study phase of the ESA M3 missions. This ESA-led sample return mission to the binary asteroid 1996 FG3 (launch window between 2020 and 2024) is proposed with a design that allows it to fit within the pre-defined cost cap of a M-class mission. The binary nature of the target will allow more precise measurements of mass, gravity, and density than for a single object, as well as additional insights into the geology and geophysics of the system. The asteroid has been classified by Binzel et al. [1] as a C-type. It is considered to be a typical example of a primitive object [2]. Dynamically, this is an Apollo asteroid with semimajor axis a of 1.054 AU, eccentricity e of 0.35, and and inclination i of 1.98 degrees. Measurements of the albedo derived from thermal infrared observations give a value of pV = 0.042 (+0.035 -0.017), and a combined diameter of D = 1.84 (+0.56 -0.47) km [3]. The Herschel observations : The MACH-11 (Measurements of 11 Asteroids & Comets) Programme observed this binary asteroid in two occasions in November of 2012. The observations performed had a duration of 0.6 hours with the asteroid pair moving rapidly at 6'/hr thus making removal of the background quite straightforward. The observations were performed in two observing blocks; the first block consisted of a 2 repetition blue/red map, the second block consisted of a 2 repetition green/red map, with the intention to observe the target at different phase angles. Our Results : Our measurements will serve to update the known radiometric properties for this binary asteroid through their inclusion into a thermophysical model (TPM) [4] which has been validated against a large database of asteroids including targets of other spacecraft mission e.g. Lutetia [5], Itokawa [6]. Using existing sets of published thermal observations (Spitzer, TNG NICS), combined with our Herschel observations, applied within this thermophysical model

  18. Water in low-mass star-forming regions with Herschel . HIFI spectroscopy of NGC 1333

    Science.gov (United States)

    Kristensen, L. E.; Visser, R.; van Dishoeck, E. F.; Yıldız, U. A.; Doty, S. D.; Herczeg, G. J.; Liu, F.-C.; Parise, B.; Jørgensen, J. K.; van Kempen, T. A.; Brinch, C.; Wampfler, S. F.; Bruderer, S.; Benz, A. O.; Hogerheijde, M. R.; Deul, E.; Bachiller, R.; Baudry, A.; Benedettini, M.; Bergin, E. A.; Bjerkeli, P.; Blake, G. A.; Bontemps, S.; Braine, J.; Caselli, P.; Cernicharo, J.; Codella, C.; Daniel, F.; de Graauw, Th.; di Giorgio, A. M.; Dominik, C.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; Goicoechea, J. R.; Helmich, F.; Herpin, F.; Jacq, T.; Johnstone, D.; Kaufman, M. J.; Larsson, B.; Lis, D.; Liseau, R.; Marseille, M.; McCoey, C.; Melnick, G.; Neufeld, D.; Nisini, B.; Olberg, M.; Pearson, J. C.; Plume, R.; Risacher, C.; Santiago-García, J.; Saraceno, P.; Shipman, R.; Tafalla, M.; Tielens, A. G. G. M.; van der Tak, F.; Wyrowski, F.; Beintema, D.; de Jonge, A.; Dieleman, P.; Ossenkopf, V.; Roelfsema, P.; Stutzki, J.; Whyborn, N.

    2010-10-01

    “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 (HIFI) on the Herschel Space Observatory observed three deeply embedded protostars in the low-mass star-forming region NGC 1333 in several H_216O, H_218O, and CO transitions. Line profiles are resolved for five H_216O transitions in each source, revealing them to be surprisingly complex. The line profiles are decomposed into broad (>20 km s-1), medium-broad (~5-10 km s-1), and narrow (20 km s-1), indicating that its physical origin is the same as for the broad H_216O component. In one of the sources, IRAS4A, an inverse P Cygni profile is observed, a clear sign of infall in the envelope. From the line profiles alone, it is clear that the bulk of emission arises from shocks, both on small (⪉1000 AU) and large scales along the outflow cavity walls (~10 000 AU). The H2O line profiles are compared to CO line profiles to constrain the H2O abundance as a function of velocity within these shocked regions. The H2O/CO abundance ratios are measured to be in the range of ~0.1-1, corresponding to H2O abundances of ~10-5-10-4 with respect to H2. Approximately 5-10% of the gas is hot enough for all oxygen to be driven into water in warm post-shock gas, mostly at high velocities. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Tables 2 and 3 (page 6) are only available in electronic form at http://www.aanda.org

  19. Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?

    Science.gov (United States)

    Krivov, A. V.; Eiroa, C.; Loehne, T.; Marshall, J. P.; Montesinos, B.; DelBurgo, C.; Absil, O.; Ardila, D.; Augereau, J.-C.; Bayo, A.; hide

    2013-01-01

    Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around approx, 100 micron 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 micron, which is larger than the 100 micron 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 micron, 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

  20. William Herschel's 'Hole in the Sky' and the discovery of dark nebulae

    Science.gov (United States)

    Steinicke, Wolfgang

    2016-12-01

    In 1785 William Herschel published a paper in the Philosophical Transactions containing the remarkable section "An opening or hole". It describes an unusual vacant place in Scorpius. This matter falls into oblivion until Caroline Herschel initiated a correspondence with her nephew John in 1833. It contains Herschel's spectacular words "Hier ist wahrhaftig ein Loch im Himmel" ("Here truly is a hole in the sky"). About a hundred years later, Johann Georg Hagen, Director of the Vatican Observatory, presented a spectacular candidate for the 'hole', discovered in 1857 by Angelo Secchi in Sagittarius and later catalogued by Edward E. Barnard as the dark nebula B 86. Hagen's claim initiated a debate, mainly in the Journal of the British Astronomical Association, about the identity of Herschel's 'object'. Though things could be partly cleared up, unjustified claims still remain. This is mainly due to the fact that original sources were not consulted. A comprehensive study of the curious 'hole' is presented here. It covers major parts of the epochal astronomical work of William, Caroline and John Herschel. This includes a general study of 'vacant places', found by William Herschel and others, and the speculations about their nature, eventually leading to the finding that dark nebulae are due to absorbing interstellar matter. Some of the 'vacant places' could be identified in catalogues of dark nebulae and this leads to a 'Herschel Catalogue of Dark Nebulae' - the first historic catalogue of its kind.

  1. Highlights And Shadows Of High Redshift Starbursts: A Herschel­Fmos Joint Effort

    Science.gov (United States)

    Puglisi, Annagrazia

    2017-06-01

    Starburst galaxies represent a critical stage in galaxy evolution as they are the likely progenitors of passively evolving ellipticals. The properties of high-redshift starbursts are however still debated as it is not clear to which extent their vigorous star formation rate is caused by an enhanced gas fraction or an enhanced star formation efficiency, and what physical processes trigger such violent activity. Our study of the rest-frame optical spectra from the FMOS-COSMOS survey of twelve z 1.6 Herschel starbursts combined with a rich ancillary data-set from UV to ALMA, is shedding light on some of these questions. By measuring the nebular extinction from different indicators, we find that 90% of their extreme SFR arises from an heavily obscured component which is thick in the optical. We also measure their gas-phase metallicity, showing that starbursts are metal-rich outliers from the metallicity-SFR anticorrelation observed at fixed stellar mass for the main sequence population. Our findings are consistent with a major merger origin for the starburst event. I will present this study discussing its implications on our interpretation of the high-redshift starbursts physics. I will also briefly discuss possible extensions of this work with the future PFS survey and how we can take advantage of the IFU capabilities of JWST/NIRspec to unveil the complex structure of these elusive systems.

  2. First results from the Herschel Open time Large Program GaS in Protoplanetary Systems (GASPS)

    Science.gov (United States)

    Thi, W.-F.

    2011-11-01

    We summarize the first results from the Herschel Open time Key Program GaS in Protoplanetary Systems (GASPS, P.I.W. Dent). GASPS aims to determine the gas and dust content of ~240 planet-forming discs with ages 1-30 Myrs in a systematic fashion. Photometry in the far-IR and low-resolution spectroscopy of the fine-structure emissions of OI and CII are obtained with the PACS instrument on board the European space telescope Herschel. Initial modelling of the Herschel and complementary observations of the classical T Tauri star TW Hya and of the Herbig Ae star HD 169142 are presented.

  3. Derivation of sideband gain ratio for Herschel/HIFI

    Science.gov (United States)

    Kester, Do; Higgins, Ronan; Teyssier, David

    2017-03-01

    Context. Heterodyne mixers are commonly used for high-resolution spectroscopy at radio telescopes. When used as a double sideband system, the accurate flux calibration of spectral lines acquired by those detectors is highly dependent on the system gains in the respective mixer sidebands via the so-called sideband gain ratio (SBR). As such, the SBR was one of the main contributors to the calibration uncertainty budget of the Herschel/HIFI instrument. Aims: We want to determine the HIFI instrument sideband gain ratio for all bands on a fine frequency grid and within an accuracy of a few percent. Methods: We introduce a novel technique involving in-orbit HIFI data that is bootstrapped onto standard methods involving laboratory data measurements of the SBR. We deconvolved the astronomical data to provide a proxy of the expected signal at every frequency channel, and extracted the sideband gain ratios from the residuals of that process. Results: We determine the HIFI sideband gain ratio to an accuracy varying between 1 and 4%, with degraded accuracy in higher frequency ranges, and at places where the reliability of the technique is lower. These figures were incorporated into the HIFI data processing pipeline and improved the overall flux uncertainty of the legacy data from this instrument. Conclusions: We demonstrate that a modified sideband deconvolution algorithm, using astronomical data in combination with gas cell measurements, can be used to generate an accurate and fine-granularity picture of the sideband gain ratio behaviour of a heterodyne receiver. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  4. The Taiwan ECDFS Near-Infrared Survey: Ultra-deep J and KS Imaging in the Extended Chandra Deep Field-South

    Science.gov (United States)

    Hsieh, Bau-Ching; Wang, Wei-Hao; Hsieh, Chih-Chiang; Lin, Lihwai; Yan, Haojing; Lim, Jeremy; Ho, Paul T. P.

    2012-12-01

    We present ultra-deep J and KS imaging observations covering a 30' × 30' area of the Extended Chandra Deep Field-South (ECDFS) carried out by our Taiwan ECDFS Near-Infrared Survey (TENIS). The median 5σ limiting magnitudes for all detected objects in the ECDFS reach 24.5 and 23.9 mag (AB) for J and KS , respectively. In the inner 400 arcmin2 region where the sensitivity is more uniform, objects as faint as 25.6 and 25.0 mag are detected at 5σ. Thus, this is by far the deepest J and KS 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+KS -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 KS images and the J+KS -selected multi-wavelength catalog.

  5. 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.

  6. First Results from Faint Infrared Grism Survey (Figs): First Simultaneous Detection of Ly Alpha Emission and Lyman Break From a Galaxy at Z =7.51

    Science.gov (United States)

    Tilvi, V.; Pirzkal, N.; Malhotra, S.; Finkelstein, S. L.; Rhoads, J. E.; Windhorst, R.; Grogin, N. A.; Koekemoer, A.; Zakamska, N. L.; Ryan, R.; hide

    2016-01-01

    Galaxies at high redshifts provide a valuable tool to study cosmic dawn, and therefore it is crucial to reliably identify these galaxies. Here, we present an unambiguous and first simultaneous detection of both the Lyman-Alpha emission and the Lyman break from a z = 7.512 +/- 0.004 galaxy, observed in the Faint Infrared Grism Survey (FIGS). These spectra, taken with G102 grism on Hubble SpaceTelescope (HST), show a significant emission line detection (6 Sigma) in two observational position angles (PA), with Lyman-Alpha line flux of 1.06 +/- 0.19 x 10(exp -17) erg s(exp -1) cm(exp -2). The line flux is nearly a factor of four higher than in the archival MOSFIRE spectroscopic observations. This is consistent with other recent observations implying that ground-based near-infrared spectroscopy underestimates total emission line fluxes, and if confirmed, can have strong implications for reionization studies that are based on ground-based Lyman-Alpha measurements. A 4-Alpha detection of the NV line in one PA also suggests a weak Active Galactic Nucleus (AGN), and if confirmed would make this source the highest-redshift AGN yet found.These observations from the Hubble Space Telescope thus clearly demonstrate the sensitivity of the FIGS survey, and the capability of grism spectroscopy to study the epoch of reionization.

  7. On the nature of infrared-faint radio sources in the Subaru X-ray Deep and Very Large Array-VIMOS VLT Deep Survey fields

    Science.gov (United States)

    Singh, Veeresh; Wadadekar, Yogesh; Ishwara-Chandra, C. H.; Sirothia, Sandeep; Sievers, Jonathan; Beelen, Alexandre; Omont, Alain

    2017-10-01

    Infrared-faint radio sources (IFRSs) are an unusual class of objects that are relatively bright at radio wavelengths but have faint or undetected infrared counterparts, even in deep surveys. We identify and investigate the nature of IFRSs using deep radio (S1.4 GHz ˜ 100 μJy beam-1 at 5σ), optical (mr ˜ 26-27.7 at 5σ) and near-infrared (S3.6 μm ˜ 1.3-2.0 μJy beam-1 at 5σ) data that are available in two deep fields: the Subaru X-ray Deep Field (SXDF) and the Very Large Array-VIMOS VLT Deep Survey (VLA-VVDS) field. In 1.8 deg2 of the two fields, we identify a total of nine confirmed and ten candidate IFRSs. We find that our IFRSs are high-redshift radio-loud active galactic nuclei, with 12/19 sources having redshift estimates in the range of z ˜ 1.7-4.3, while a limit of z ≥ 2.0 is placed on the remaining seven sources. Notably, for the first time, our study finds IFRSs with measured redshift >3.0, and also redshift estimates for IFRSs in the faintest 3.6-μm flux regime (i.e. S3.6 μm colour (mr-m24 μm) suggest that a significant fraction of IFRSs are likely to be hosted in dusty obscured galaxies.

  8. VizieR Online Data Catalog: Herschel counterparts of SDC (Peretto+, 2016)

    Science.gov (United States)

    Peretto, N.; Lenfestey, C.; Fuller, G. A.; Traficante, A.; Molinari, S.; Thompson, M. A.; Ward-Thompson, D.

    2016-03-01

    The goal of this paper is to identify which of the clouds from the Spitzer Dark Cloud catalogue (Peretto & Fuller, 2009, Cat. J/A+A/505/405) are real, which are artefacts. For this we used Herschel Hi-GAL (Molinari et al., 2010PASP..122..314M) column density maps and search for spatial associations between Spitzer Dark Cloud and Herschel column density peaks. Description: This table provides some of the key properties of the Spitzer Dark Clouds that we estimated using the Herschel data and used to disentangle between real and spurious clouds. For each cloud of the Peretto & Fuller (2009, Cat. J/A+A/505/405) catalogue we give the cloud name, the cloud equivalent radius, the average Herschel column density within the boundaries of the SDCs, the average Herschel column density immediately outside the boundary of the SDCs, the Herschel column density noise at the position of the SDC, the Herschel column density peak within the boundaries of the SDCs, the value for criterion c1, the value for criterion c2, the value for criterion c3, and a tag that indicates if the cloud has been identified as real by our automated detection scheme based on the values of c1 and c2. This tag can take a number of values. These are: 'y' for yes; n for no; 'sat' for a SDC entirely located in a saturated portion of the Herschel images; 'ysat' for a cloud that is considered real despite being partially saturated; 'out' for a SDC that is not covered by Herschel images; 'yout' for a cloud that is considered real despite being partially covered by Herschel images; 'nout' for a cloud considered spurious despite being partially covered by Herschel images. Also, note that the column referring to the equivalent radius Req is the same quantity as the one quoted in Table 1 column 11 of Peretto & Fuller (2009, Cat. J/A+A/505/405). However, these latter values should be discarded since a mistake has been found in the calculation of the equivalent radius. Only the new values, the ones provided in Table 1

  9. Mid-Infrared Lasers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mid Infrared DIAL systems can provide vital data needed by atmospheric scientists to understand atmospheric chemistry. The Decadal Survey recommended missions, such...

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

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Chen [School of Space Science and Physics, Shandong University, Weihai, Weihai, Shandong 264209 (China); Xu, Cong Kevin; Lu, Nanyao; Mazzarella, Joe [Infrared Processing and Analysis Center, California Institute of Technology 100-22, Pasadena, CA 91125 (United States); Domingue, Donovan; Ronca, Joseph; Jacques, Allison [Georgia College and State University, CBX 82, Milledgeville, GA 31061 (United States); Buat, Veronique [Laboratoire d’Astrophysique de Marseille—LAM, Université d’Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Cheng, Yi-Wen [Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China); Gao, Yu [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); Huang, Jiasheng [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jarrett, Thomas H. [Astronomy Department, University of Cape Town, Rondebosch 7701 (South Africa); Lisenfeld, Ute [Departamento de Fisica Teórica y del Cosmos, Universidad de Granada (Spain); Sun, Wei-Hsin [Institute of Astrophysics, National Taiwan University and The National Museum of Natural Science, Taiwan (China); Wu, Hong [National Astronomical Observatories, Chinese Academy of Sciences, Beijing (China); Yun, Min S., E-mail: caochen@sdu.edu.cn, E-mail: cxu@ipac.caltech.edu [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2016-02-15

    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{sub dust}) are derived from the IR SED fitting. The mass of total gas (M{sub 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{sub 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.

  11. 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.

  12. The HeRSCheL detector: high-rapidity shower counters for LHCb

    CERN Document Server

    Carvalho Akiba, K.; Bondar, N.; Byczynski, W.; Coco, V.; Collins, P.; Dumps, R.; Dzhelyadin, R.; Gandini, P.; Gruberg Cazon, B. R.; Jacobsson, R.; Johnson, D.; Manthey, J.; Mauricio, J.; McNulty, R.; Monteil, S.; Ravonel Salzgeber, M.; Roy, L.; Schindler, H.; Stevenson, S.; Wilkinson, G.

    The HeRSCheL detector consists of a set of scintillating counters, designed to increase the coverage of the LHCb experiment in the high-rapidity regions on either side of the main spectrometer. The new detector improves the capabilities of LHCb for studies of diffractive interactions, most notably Central Exclusive Production. In this paper the construction, installation, commissioning, and performance of HeRSCheL are presented.

  13. Stabilized finite elements for Bingham and Herschel-Bulkley confined flows Part II: Numerical simulations

    OpenAIRE

    Moreno, E.; Cervera, M.

    2016-01-01

    The objective of this work is to model computationally Bingham and Herschel-Bulkley viscoplastic fluids using stabilized mixed velocity/pressure finite elements. Numerical solutions for these viscoplastic flows are presented and assessed. The regularized viscoplastic models due to Papanastasiou is used. In the discrete model, the Orthogonal Subgrid scale (OSS) method is used. In this part II , numerical solutions for two problems of Bingham and Herschel-Bulkley confined flows are presente...

  14. SCUBA-2 follow-up of Herschel-SPIRE observed Planck overdensities

    Science.gov (United States)

    MacKenzie, Todd P.; Scott, Douglas; Bianconi, Matteo; Clements, David L.; Dole, Herve A.; Flores-Cacho, Inés; Guery, David; Kneissl, Ruediger; Lagache, Guilaine; Marleau, Francine R.; Montier, Ludovic; Nesvadba, Nicole P. H.; Pointecouteau, Etienne; Soucail, Genevieve

    2017-07-01

    We present SCUBA-2 follow-up of 61 candidate high-redshift Planck sources. Of these, 10 are confirmed strong gravitational lenses and comprise some of the brightest such submm sources on the observed sky, while 51 are candidate proto-cluster fields undergoing massive starburst events. With the accompanying Herschel-Spectral and Photometric Imaging Receiver observations and assuming an empirical dust temperature prior of 34^{+13}_{-9} K, we provide photometric redshift and far-IR luminosity estimates for 172 SCUBA-2-selected sources within these Planck overdensity fields. The redshift distribution of the sources peak between a redshift of 2 and 4, with one-third of the sources having S500/S350 > 1. For the majority of the sources, we find far-IR luminosities of approximately 1013 L⊙, corresponding to star formation rates of around 1000 M⊙ yr-1. For S850 > 8 mJy sources, we show that there is up to an order of magnitude increase in star formation rate density and an increase in uncorrected number counts of 6 for S850 > 8 mJy when compared to typical cosmological survey fields. The sources detected with SCUBA-2 account for only approximately 5 per cent of the Planck flux at 353 GHz, and thus many more fainter sources are expected in these fields.

  15. Remnant radio-loud AGN in the Herschel-ATLAS field arXiv

    CERN Document Server

    Mahatma, V.H.; 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.

    Only a small fraction of observed Active Galactic Nuclei 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 LOFAR and the VLA, 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 indice...

  16. 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.

    2018-01-01

    Only a small fraction of observed Active Galactic Nuclei 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 LOFAR and the VLA, 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.

  17. 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.

  18. Herschel And Alma Observations Of The Ism In Massive High-Redshift Galaxy Clusters

    Science.gov (United States)

    Wu, John F.; Aguirre, Paula; Baker, Andrew J.; Devlin, Mark J.; Hilton, Matt; Hughes, John P.; Infante, Leopoldo; Lindner, Robert R.; Sifón, Cristóbal

    2017-06-01

    The Sunyaev-Zel'dovich effect (SZE) can be used to select samples of galaxy clusters that are essentially mass-limited out to arbitrarily high redshifts. I will present results from an investigation of the star formation properties of galaxies in four massive clusters, extending to z 1, which were selected on the basis of their SZE decrements in the Atacama Cosmology Telescope (ACT) survey. All four clusters have been imaged with Herschel/PACS (tracing star formation rate) and two with ALMA (tracing dust and cold gas mass); newly discovered ALMA CO(4-3) and [CI] line detections expand an already large sample of spectroscopically confirmed cluster members. Star formation rate appears to anti-correlate with environmental density, but this trend vanishes after controlling for stellar mass. Elevated star formation and higher CO excitation are seen in "El Gordo," a violent cluster merger, relative to a virialized cluster at a similar high (z 1) redshift. Also exploiting ATCA 2.1 GHz observations to identify radio-loud active galactic nuclei (AGN) in our sample, I will use these data to develop a coherent picture of how environment influences galaxies' ISM properties and evolution in the most massive clusters at early cosmic times.

  19. Far-infrared and sub-millimetre imaging of HD 76582's circumstellar disc

    Science.gov (United States)

    Marshall, Jonathan P.; Booth, Mark; Holland, Wayne; Matthews, Brenda C.; Greaves, Jane S.; Zuckerman, Ben

    2016-07-01

    Debris discs, the tenuous rocky and icy remnants of planet formation, are believed to be evidence for planetary systems around other stars. The JCMT/SCUBA-2 debris disc legacy survey `SCUBA-2 Observations of Nearby Stars' (SONS) observed 100 nearby stars, amongst them HD 76582, for evidence of such material. Here, we present imaging observations by JCMT/SCUBA-2 and Herschel/PACS at sub-millimetre and far-infrared wavelengths, respectively. We simultaneously model the ensemble of photometric and imaging data, spanning optical to sub-millimetre wavelengths, in a self-consistent manner. At far-infrared wavelengths, we find extended emission from the circumstellar disc providing a strong constraint on the dust spatial location in the outer system, although the angular resolution is too poor to constrain the interior of the system. In the sub-millimetre, photometry at 450 and 850 μm reveals a steep fall-off that we interpret as a disc dominated by moderately sized dust grains (amin = 36 μm), perhaps indicative of a non-steady-state collisional cascade within the disc. A disc architecture of three distinct annuli, comprising an unresolved component at 20 au and outer components at 80 and 270 au, along with a very steep particle size distribution (γ = 5), is proposed to match the observations.

  20. 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.

  1. Gas in the protoplanetary disc of HD 169142: Herschel's view

    Science.gov (United States)

    Meeus, G.; Pinte, C.; Woitke, P.; Montesinos, B.; Mendigutía, I.; Riviere-Marichalar, P.; Eiroa, C.; Mathews, G. S.; Vandenbussche, B.; Howard, C. D.; Roberge, A.; Sandell, G.; Duchêne, G.; Ménard, F.; Grady, C. A.; Dent, W. R. F.; Kamp, I.; Augereau, J. C.; Thi, W. F.; Tilling, I.; Alacid, J. M.; Andrews, S.; Ardila, D. R.; Aresu, G.; Barrado, D.; Brittain, S.; Ciardi, D. R.; Danchi, W.; Fedele, D.; de Gregorio-Monsalvo, I.; Heras, A.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mora, A.; Morales-Calderon, M.; Nomura, H.; Pantin, E.; Pascucci, I.; Phillips, N.; Podio, L.; Poelman, D. R.; Ramsay, S.; Riaz, B.; Rice, K.; Solano, E.; Walker, H.; White, G. J.; Williams, J. P.; Wright, G.

    2010-07-01

    In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed at studying the evolution of protoplanetary discs. To constrain the gas properties in the outer disc, we observed the star at several key gas-lines, including [OI] 63.2 and 145.5 μm, [CII] 157.7 μm, CO 72.8 and 90.2 μm, and o-H2O 78.7 and 179.5 μm. We only detect the [OI] 63.2 μm line in our spectra, and derive upper limits for the other lines. We complement our data set with PACS photometry and 12/13CO data obtained with the Submillimeter Array. Furthermore, we derive accurate stellar parameters from optical spectra and UV to mm photometry. We model the dust continuum with the 3D radiative transfer code MCFOST and use this model as an input to analyse the gas lines with the thermo-chemical code ProDiMo. Our dataset is consistent with a simple model in which the gas and dust are well-mixed in a disc with a continuous structure between 20 and 200 AU, but this is not a unique solution. Our modelling effort allows us to constrain the gas-to-dust mass ratio as well as the relative abundance of the PAHs in the disc by simultaneously fitting the lines of several species that originate in different regions. Our results are inconsistent with a gas-poor disc with a large UV excess; a gas mass of 5.0 ± 2.0 × 10-3 M⊙ is still present in this disc, in agreement with earlier CO observations. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. THE WIRED SURVEY. III. AN INFRARED EXCESS AROUND THE ECLIPSING POST-COMMON ENVELOPE BINARY SDSS J030308.35+005443.7

    Energy Technology Data Exchange (ETDEWEB)

    Debes, John H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Hoard, D. W. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Farihi, Jay [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Wachter, Stefanie [IPAC, California Institute of Technology, Pasadena, CA (United States); Leisawitz, David T. [Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Cohen, Martin [Monterey Institute for Research in Astronomy, Marina, CA 93933 (United States)

    2012-11-01

    We present the discovery with WISE of a significant infrared excess associated with the eclipsing post-common envelope binary SDSS J030308.35+005443.7, the first excess discovered around a non-interacting white dwarf+main-sequence M dwarf binary. The spectral energy distribution of the white dwarf+M dwarf companion shows significant excess longward of 3 {mu}m. A T {sub eff} of 8940 K for the white dwarf is consistent with a cooling age >2 Gyr, implying that the excess may be due to a recently formed circumbinary dust disk of material that extends from the tidal truncation radius of the binary at 1.96 R {sub Sun} out to <0.8 AU, with a total mass of {approx}10{sup 20} g. We also construct WISE and follow-up ground-based near-infrared light curves of the system and find variability in the K band that appears to be in phase with ellipsoidal variations observed in the visible. The presence of dust might be due to (1) material being generated by the destruction of small rocky bodies that are being perturbed by an unseen planetary system or (2) dust condensing from the companion's wind. The high inclination of this system and the presence of dust make it an attractive target for M dwarf transit surveys and long-term photometric monitoring.

  3. The earliest phases of high-mass star formation, as seen in NGC 6334 by Herschel-HOBYS

    Science.gov (United States)

    Tigé, J.; Motte, F.; Russeil, D.; Zavagno, A.; Hennemann, M.; Schneider, N.; Hill, T.; Nguyen Luong, Q.; Di Francesco, J.; Bontemps, S.; Louvet, F.; Didelon, P.; Könyves, V.; André, Ph.; Leuleu, G.; Bardagi, J.; Anderson, L. D.; Arzoumanian, D.; Benedettini, M.; Bernard, J.-P.; Elia, D.; Figueira, M.; Kirk, J.; Martin, P. G.; Minier, V.; Molinari, S.; Nony, T.; Persi, P.; Pezzuto, S.; Polychroni, D.; Rayner, T.; Rivera-Ingraham, A.; Roussel, H.; Rygl, K.; Spinoglio, L.; White, G. J.

    2017-06-01

    Aims: To constrain models of high-mass star formation, the Herschel-HOBYS key program aims at discovering massive dense cores (MDCs) able to host the high-mass analogs of low-mass prestellar cores, which have been searched for over the past decade. We here focus on NGC 6334, one of the best-studied HOBYS molecular cloud complexes. Methods: We used Herschel/PACS and SPIRE 70-500 μm images of the NGC 6334 complex complemented with (sub)millimeter and mid-infrared data. We built a complete procedure to extract 0.1 pc dense cores with the getsources software, which simultaneously measures their far-infrared to millimeter fluxes. We carefully estimated the temperatures and masses of these dense cores from their spectral energy distributions (SEDs). We also identified the densest pc-scale cloud structures of NGC 6334, one 2 pc × 1 pc ridge and two 0.8 pc × 0.8 pc hubs, with volume-averaged densities of 105 cm-3. Results: A cross-correlation with high-mass star formation signposts suggests a mass threshold of 75 M⊙ for MDCs in NGC 6334. MDCs have temperatures of 9.5-40 K, masses of 75-1000 M⊙, and densities of 1 × 105-7 × 107 cm-3. Their mid-infrared emission is used to separate 6 IR-bright and 10 IR-quiet protostellar MDCs while their 70 μm emission strength, with respect to fitted SEDs, helps identify 16 starless MDC candidates. The ability of the latter to host high-mass prestellar cores is investigated here and remains questionable. An increase in mass and density from the starless to the IR-quiet and IR-bright phases suggests that the protostars and MDCs simultaneously grow in mass. The statistical lifetimes of the high-mass prestellar and protostellar core phases, estimated to be 1-7 × 104 yr and at most 3 × 105 yr respectively, suggest a dynamical scenario of high-mass star formation. Conclusions: The present study provides good mass estimates for a statistically significant sample, covering the earliest phases of high-mass star formation. High

  4. 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

  5. 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.

  6. The JCMT Gould Belt Survey: A First Look at the Auriga–California Molecular Cloud with SCUBA-2

    Science.gov (United States)

    Broekhoven-Fiene, H.; Matthews, B. C.; Harvey, P.; Kirk, H.; Chen, M.; Currie, M. J.; Pattle, K.; Lane, J.; Buckle, J.; Di Francesco, J.; Drabek-Maunder, E.; Johnstone, D.; Berry, D. S.; Fich, M.; Hatchell, J.; Jenness, T.; Mottram, J. C.; Nutter, D.; Pineda, J. E.; Quinn, C.; Salji, C.; Tisi, S.; Hogerheijde, M. R.; Ward-Thompson, D.; Bastien, P.; Bresnahan, D.; Butner, H.; Chrysostomou, A.; Coude, S.; Davis, C. J.; Duarte-Cabral, A.; Fiege, J.; Friberg, P.; Friesen, R.; Fuller, G. A.; Graves, S.; Greaves, J.; Gregson, J.; Holland, W.; Joncas, G.; Kirk, J. M.; Knee, L. B. G.; Mairs, S.; Marsh, K.; Moriarty-Schieven, G.; Mowat, C.; Rawlings, J.; Richer, J.; Robertson, D.; Rosolowsky, E.; Rumble, D.; Sadavoy, S.; Thomas, H.; Tothill, N.; Viti, S.; White, G. J.; Wilson, C. D.; Wouterloot, J.; Yates, J.; Zhu, M.

    2018-01-01

    We present 850 and 450 μm observations of the dense regions within the Auriga–California molecular cloud using SCUBA-2 as part of the JCMT Gould Belt Legacy Survey to identify candidate protostellar objects, measure the masses of their circumstellar material (disk and envelope), and compare the star formation to that in the Orion A molecular cloud. We identify 59 candidate protostars based on the presence of compact submillimeter emission, complementing these observations with existing Herschel/SPIRE maps. Of our candidate protostars, 24 are associated with young stellar objects (YSOs) in the Spitzer and Herschel/PACS catalogs of 166 and 60 YSOs, respectively (177 unique), confirming their protostellar nature. The remaining 35 candidate protostars are in regions, particularly around LkHα 101, where the background cloud emission is too bright to verify or rule out the presence of the compact 70 μm emission that is expected for a protostellar source. We keep these candidate protostars in our sample but note that they may indeed be prestellar in nature. Our observations are sensitive to the high end of the mass distribution in Auriga–Cal. We find that the disparity between the richness of infrared star-forming objects in Orion A and the sparsity in Auriga–Cal extends to the submillimeter, suggesting that the relative star formation rates have not varied over the Class II lifetime and that Auriga–Cal will maintain a lower star formation efficiency.

  7. Thermal-Infrared Surveys of Near-Earth Object Diameters and Albedos with Spitzer and IRTF/MIRSI

    NARCIS (Netherlands)

    Mommert, Michael; Trilling, David; Hora, Joseph L.; Chesley, Steven; Emery, Josh; Fazio, Giovanni; Harris, Alan W.; Moskovitz, Nick; Mueller, Michael; Smith, Howard

    2015-01-01

    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

  8. Automated fibre optic instrumentation for the William Herschel Telescope

    Science.gov (United States)

    Parry, Ian R.; Lewis, Ian J.

    1990-07-01

    The design and operation of the automated optical-fiber positioning system used for spectroscopic observations at the Cassegrain focus of the 4.2-m William Herschel Telescope (WHT) at Observatorio del Roque de los Muchachos are described. The system is a modified version of the Autofib positioner for the AAT and employs 64 spectroscopic fibers and 8 guide fiber bundles arranged to form a 17-arcmin-diameter field. The fibers are 1-m-long polyimide-coated high-OH silica, with core diameter 260 microns and outer diameter 315 microns, and a 1.2-mm side-length microprism is cemented to the end of each fiber or (7-fiber) guide bundle. The fibers are positioned one at a time by a pick-and-place robot assembly, and a viewing head permitting simultaneous observation of the back-illuminated fiber and the object it is trying to acquire is provided. This prototype Cassegrain-focus system is being studied to aid in the development of a more accurate fiber positioner for use at the prime focus of the WHT.

  9. Calibration of Herschel SPIRE FTS observations at different spectral resolutions

    Science.gov (United States)

    Marchili, N.; Hopwood, R.; Fulton, T.; Polehampton, E. T.; Valtchanov, I.; Zaretski, J.; Naylor, D. A.; Griffin, M. J.; Imhof, P.; Lim, T.; Lu, N.; Makiwa, G.; Pearson, C.; Spencer, L.

    2017-01-01

    The SPIRE Fourier Transform Spectrometer on-board the Herschel Space Observatory had two standard spectral resolution modes for science observations: high resolution (HR) and low resolution (LR), which could also be performed in sequence (H+LR). A comparison of the HR and LR resolution spectra taken in this sequential mode revealed a systematic discrepancy in the continuum level. Analysing the data at different stages during standard pipeline processing demonstrates that the telescope and instrument emission affect HR and H+LR observations in a systematically different way. The origin of this difference is found to lie in the variation of both the telescope and instrument response functions, while it is triggered by fast variation of the instrument temperatures. As it is not possible to trace the evolution of the response functions using housekeeping data from the instrument subsystems, the calibration cannot be corrected analytically. Therefore, an empirical correction for LR spectra has been developed, which removes the systematic noise introduced by the variation of the response functions.

  10. The water abundance behind interstellar shocks: results from Herschel/PACS and Spitzer/IRS observations of H{sub 2}O, CO, and H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Neufeld, David A. [Department of Physics and Astronomy, Johns Hopkins University 3400 North Charles Street, Baltimore, MD 21218 (United States); Gusdorf, Antoine [LERMA, UMR 8112 du CNRS, Observatoire de Paris, École Normale Supérieure, 24 rue Lhomond, F-75005, Paris (France); Güsten, Rolf [Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Herczeg, Greg J. [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Hai Dian Qu, 100871 Beijing (China); Kristensen, Lars; Melnick, Gary J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Nisini, Brunella [Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio Catone (Italy); Ossenkopf, Volker [Physikalisches Institut der Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln (Germany); Tafalla, Mario [Observatorio Astronómico Nacional (IGN), Alfonso XII 3, E-28014 Madrid (Spain); Van Dishoeck, Ewine F. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2014-02-01

    We have investigated the water abundance in shock-heated molecular gas, making use of Herschel measurements of far-infrared (IR) CO and H{sub 2}O line emissions in combination with Spitzer measurements of mid-IR H{sub 2} rotational emissions. We present far-IR line spectra obtained with Herschel's Photodetector Array Camera and Spectrometer instrument in range spectroscopy mode toward two positions in the protostellar outflow NGC 2071 and one position each in the supernova remnants W28 and 3C391. These spectra provide unequivocal detections, at one or more positions, of 12 rotational lines of water, 14 rotational lines of CO, 8 rotational lines of OH (4 lambda doublets), and 7 fine-structure transitions of atoms or atomic ions. We first used a simultaneous fit to the CO line fluxes, along with H{sub 2} rotational line fluxes measured previously by Spitzer, to constrain the temperature and density distribution within the emitting gas; we then investigated the water abundances implied by the observed H{sub 2}O line fluxes. The water line fluxes are in acceptable agreement with standard theoretical models for nondissociative shocks that predict the complete vaporization of grain mantles in shocks of velocity v ∼ 25 km s{sup –1}, behind which the characteristic gas temperature is ∼1300 K and the H{sub 2}O/CO ratio is 1.2.

  11. The Water Abundance behind Interstellar Shocks: Results from Herschel/PACS and Spitzer/IRS Observations of H2O, CO, and H2

    Science.gov (United States)

    Neufeld, David A.; Gusdorf, Antoine; Güsten, Rolf; Herczeg, Greg J.; Kristensen, Lars; Melnick, Gary J.; Nisini, Brunella; Ossenkopf, Volker; Tafalla, Mario; van Dishoeck, Ewine F.

    2014-02-01

    We have investigated the water abundance in shock-heated molecular gas, making use of Herschel measurements of far-infrared (IR) CO and H2O line emissions in combination with Spitzer measurements of mid-IR H2 rotational emissions. We present far-IR line spectra obtained with Herschel's Photodetector Array Camera and Spectrometer instrument in range spectroscopy mode toward two positions in the protostellar outflow NGC 2071 and one position each in the supernova remnants W28 and 3C391. These spectra provide unequivocal detections, at one or more positions, of 12 rotational lines of water, 14 rotational lines of CO, 8 rotational lines of OH (4 lambda doublets), and 7 fine-structure transitions of atoms or atomic ions. We first used a simultaneous fit to the CO line fluxes, along with H2 rotational line fluxes measured previously by Spitzer, to constrain the temperature and density distribution within the emitting gas; we then investigated the water abundances implied by the observed H2O line fluxes. The water line fluxes are in acceptable agreement with standard theoretical models for nondissociative shocks that predict the complete vaporization of grain mantles in shocks of velocity v ~ 25 km s-1, behind which the characteristic gas temperature is ~1300 K and the H2O/CO ratio is 1.2

  12. The Warm CO Gas along the UV-heated Outflow Cavity Walls: A Possible Interpretation for the Herschel/PACS CO Spectra of Embedded YSOs

    Science.gov (United States)

    Lee, Seokho; Lee, Jeong-Eun; Bergin, Edwin A.

    2015-04-01

    A fraction of the mid-J (J = 14-13 to J = 24-23) CO emission detected by the Herschel/Photodetector Array Camera and Spectrometer observations of embedded young stellar objects (YSOs) has been attributed to the UV-heated outflow cavity walls. We have applied our newly developed self-consistent models of photon-dominated-region (PDR) and non-local-thermal-equilibrium-line Radiative transfer In general Grid to the Herschel far-infrared observations of 27 low-mass YSOs and one intermediate-mass YSO, NGC 7129-FIRS2. When the contribution of the hot component (traced by transitions of J > 24) is removed, the rotational temperature of the warm component is nearly constant with ˜250 K. This can be reproduced by the outflow cavity wall (n≥slant {{10}6} c{{m}-3}, log {{G}0}/n≥slant -4.5, log {{G}0}≥slant 3, Tgas ≥ 300 K, and X(CO) ≥ 10-5) heated by a UV radiation field with a blackbody temperature of 15,000 or 10,000 K. However, a shock model combined with an internal PDR will be required to determine the quantitative contribution of a PDR relative to a shock to the mid-J CO emission.

  13. Constraints on the Bulk Composition of Uranus from Herschel PACS and ISO LWS Photometry, SOFIA FORCAST Photometry and Spectroscopy, and Ground-Based Photometry of its Thermal Emission

    Science.gov (United States)

    Orton, Glenn; Mueller, Thomas; Burgdorf, Martin; Fletcher, Leigh; de Pater, Imke; Atreya, Sushil; Adams, Joseph; Herter, Terry; Keller, Luke; Sidher, Sunil; Sinclair, James; Fujiyoshi, Takuya

    2016-04-01

    We present thermal infrared observations of the disk of Uranus at 17-200 μm to deduce its global thermal structure and bulk composition. We combine 17-200 μm filtered photometric measurements by the Herschel PACS and ISO LWS instruments and 19-35 μm filtered photometry and spectroscopy by the SOFIA FORCAST instrument, supplemented by 17-25 μm ground-based photometric filtered imaging of Uranus. Previous analysis of infrared spectroscopic measurements of the disk of Uranus made by the Spitzer IRS instrument yielded a model for the disk-averaged temperature profile and stratospheric composition (Orton et al. 2014a Icarus 243,494; 2014b Icarus 243, 471) that were consistent with submillimeter spectroscopy by the Herschel SPIRE instrument (Swinyard et al. 2014, MNRAS 440, 3658). Our motivation to observe the 17-35 μm spectrum was to place more stringent constraints on the global para-H2 / ortho-H2 ratio in the upper troposphere and lower stratosphere than the ISO SWS results of Fouchet et al. (2003, Icarus 161, 127), who examined H2 quadrupole lines. We will discuss the consistency of these observations with a higher para-H2 fraction than implied by local thermal equilibrium, which would resolve a discrepancy between the Spitzer-based model and observations of HD lines by the Herschel PACS experiment (Feuchtgruber et al. 2013 Astron. & Astrophys. 551, A126). Constraints on the global para-H2 fraction allow for more precise analysis of the far-infrared spectrum, which is sensitive to the He:H2 ratio, a quantity that was not constrained by the Spitzer IRS spectra. The derived model, which assumed the ratio derived by the Voyager-2 IRIS/radio-science occultation experiment (Conrath et al. 1987 J. Geophys. Res. 92, 15003), is inconsistent with 70-200 μm PACS photometry (Mueller et al. 2016 Astron. & Astrophys. submittted) and ISO LWS photometric measurements. However, the model can be made consistent with the observations if the fraction of He relative to H2 were

  14. Update On Professionalism And Standards For Infrared Sensing Devices

    Science.gov (United States)

    Kantsios, Andronicos G.; Courville, George E.

    1984-03-01

    Infrared sensing may seem a relatively new scientific discipline but in reality the existence of infrared was noted as early as 1800 when Sir William Herschel wrote on the subject. He discovered the "invisible rays" as he called them while developing filters for protecting his eyes while observing the sun. Herschel described this effect in 1801 in two papers. The term "infrared" was not coined until the 1880's. The author of the term is not known but in Latin infra means below or beneath, possibly implying beneath the red. Using a prism and a sensitive mercury - in glass thermometer, William Herschel measured the radiation from fires, candles, and kitchen stoves demonstrating a detector able to measure radiation in this infrared region and raising questions about the connection between light and heat. In 1840, Herschel's son John developed a radiation detection process based on the differential evaporation of a thin film of oil to form a "heat picture." This process was improved by Czerny in 1929 and is still in use today as the "evaporagraph." In 1843 Becquerel found that certain materials phosphoresced when exposed to infrared radiation. During the 1880's several highly sensitive new detectors were developed most notable being the Langley bolometer. In 1901 Langley and Abbot reported the use of a bolometer that could detect the heat from a cow at a distance of 1/4 mile. Case in 1917 developed the thallous sulfide detector, the first use of the photoconductive effect in the infrared. Development continued in detector technology especially by the Germans during World War II. Following the war the efforts were on,radiometry. During the 1950's non-military applications for these devices grew rapidly'. Now, point radiometry is an established quantitative technology with thousands of units in place for remote temperature measurement and control. The instruments are calibrated for temperature with appropriate scale, emittance correction, voltage output, and internal

  15. 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.

  16. 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.

  17. INFRARED SPECTROSCOPIC SURVEY OF THE QUIESCENT MEDIUM OF NEARBY CLOUDS. I. ICE FORMATION AND GRAIN GROWTH IN LUPUS

    Energy Technology Data Exchange (ETDEWEB)

    Boogert, A. C. A. [IPAC, NASA Herschel Science Center, Mail Code 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Chiar, J. E. [SETI Institute, Carl Sagan Center, 189 Bernardo Avenue, Mountain View, CA 94043 (United States); Knez, C.; Mundy, L. G. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Öberg, K. I. [Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Pendleton, Y. J. [Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Tielens, A. G. G. M.; Van Dishoeck, E. F., E-mail: aboogert@ipac.caltech.edu [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2013-11-01

    Infrared photometry and spectroscopy (1-25 μm) of background stars reddened by the Lupus molecular cloud complex are used to determine the properties of grains and the composition of ices before they are incorporated into circumstellar envelopes and disks. H{sub 2}O ices form at extinctions of A{sub K} = 0.25 ± 0.07 mag (A{sub V} = 2.1 ± 0.6). Such a low ice formation threshold is consistent with the absence of nearby hot stars. Overall, the Lupus clouds are in an early chemical phase. The abundance of H{sub 2}O ice (2.3 ± 0.1 × 10{sup –5} relative to N{sub H}) is typical for quiescent regions, but lower by a factor of three to four compared to dense envelopes of young stellar objects. The low solid CH{sub 3}OH abundance (<3%-8% relative to H{sub 2}O) indicates a low gas phase H/CO ratio, which is consistent with the observed incomplete CO freeze out. Furthermore it is found that the grains in Lupus experienced growth by coagulation. The mid-infrared (>5 μm) continuum extinction relative to A{sub K} increases as a function of A{sub K}. Most Lupus lines of sight are well fitted with empirically derived extinction curves corresponding to R{sub V} ∼ 3.5 (A{sub K} = 0.71) and R{sub V} ∼ 5.0 (A{sub K} = 1.47). For lines of sight with A{sub K} > 1.0 mag, the τ{sub 9.7}/A{sub K} ratio is a factor of two lower compared to the diffuse medium. Below 1.0 mag, values scatter between the dense and diffuse medium ratios. The absence of a gradual transition between diffuse and dense medium-type dust indicates that local conditions matter in the process that sets the τ{sub 9.7}/A{sub K} ratio. This process is likely related to grain growth by coagulation, as traced by the A{sub 7.4}/A{sub K} continuum extinction ratio, but not to ice mantle formation. Conversely, grains acquire ice mantles before the process of coagulation starts.

  18. NEAR-INFRARED IMAGING AND SPECTROSCOPIC SURVEY OF THE SOUTHERN REGION OF THE YOUNG OPEN CLUSTER NGC 2264

    Energy Technology Data Exchange (ETDEWEB)

    Marinas, Naibi; Lada, Elizabeth A. [Astronomy Department, University of Florida, Gainesville, FL 32611 (United States); Teixiera, Paula S. [Department of Astrophysics, University of Vienna, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria); Lada, Charles J. [Harvard-Smithsonian CFA, Cambridge, MA (United States)

    2013-08-01

    We have obtained JHK near-IR images and JH band low-resolution spectra of candidate members of the southern region of the young open cluster NGC 2264. We have determined spectral types from H-band spectra for 54 sources, 25 of which are classified for the first time. The stars in our sample cover a large range of spectral types (A8-M8). Using a cluster distance of 780 pc, we determined a median age of 1 Myr for this region of NGC 2264, with 90% of the stars being 5 Myr or younger. To improve the statistical significance of our sample, we included 66 additional cluster members within our field of view with optical spectral classification in the literature. We derived infrared excesses using stellar properties to model the photospheric emission for each source and the extinction to correct FLAMINGOS near-IR and Spitzer mid-IR photometry, and obtained a disk fraction of 51% {+-} 5% for the region. Binning the stars by stellar mass, we find a disk fraction of 38% {+-} 9% for the 0.1-0.3 solar mass group, 55% {+-} 6% for 0.3-1 solar masses, and 58% {+-} 10% for the higher than 1 solar mass group. The lower disk fraction for the lower mass stars is similar to the results found in non-cluster regions like Taurus and Chamaeleon, but differs from the older 3 Myr cluster IC 348 in which the disk fraction is lower for the higher mass stars. This mass-dependent disk fraction is accentuated in the sample with isochrone ages younger than 2 Myr. Here, we find that 45% {+-} 11% of the 0.1-0.3 solar mass stars have disks, 60% {+-} 7% of the 0.3-1 solar mass stars have disks, and all 1-3 solar mass stars have disks. Stellar masses might be an important factor in the ability of a system to form or retain a disk early on. However, regardless of the stellar mass, the large infrared excesses expected from optically thick disks disappear within the first 2 Myr for all stars in our study and small excesses from optically thin disks are found mostly in sources younger than 4 Myr.

  19. The SXDF-ALMA 2-arcmin2 Deep Survey: Stacking Rest-frame Near-infrared Selected Objects

    NARCIS (Netherlands)

    Wang, Wei-Hao; Kohno, Kotaro; Hatsukade, Bunyo; Umehata, Hideki; Aretxaga, Itziar; Hughes, David; Caputi, Karina I.; Dunlop, James S.; Ikarashi, Soh; Iono, Daisuke; Ivison, Rob J.; Lee, Minju; Makiya, Ryu; Matsuda, Yuichi; Motohara, Kentaro; Nakanish, Kouichiro; Ohta, Kouji; Tadaki, Ken-ichi; Tamura, Yoichi; Kodama, Tadayuki; Rujopakarn, Wiphu; Wilson, Grant W.; Yamaguchi, Yuki; Yun, Min S.; Coupon, Jean; Hsieh, Bau-Ching; Foucaud, Sébastien

    2016-01-01

    We present stacking analyses on our ALMA deep 1.1 mm imaging in the Subaru/XMM-Newton Deep Survey Field using 1.6 and 3.6 μm selected galaxies in the CANDELS WFC3 catalog. We detect a stacked flux of ∼0.03–0.05 mJy, corresponding to {L}{IR}\\lt {10}11 {L}ȯ and a star formation rate (SFR) of ∼ 15 {M}ȯ

  20. '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.

  1. Linking low- to high-mass young stellar objects with Herschel-HIFI observations of water

    Science.gov (United States)

    San José-García, I.; Mottram, J. C.; van Dishoeck, E. F.; Kristensen, L. E.; van der Tak, F. F. S.; Braine, J.; Herpin, F.; Johnstone, D.; van Kempen, T. A.; Wyrowski, F.

    2016-01-01

    , most likely due to pumping by an infrared radiation field. Finally, a strong correlation with slope unity is measured between the logarithms of the total H2O line luminosity, LH2O, and Lbol, which can be extrapolated to extragalactic sources. This linear correlation, also found for CO, implies that both species primarily trace dense gas directly related to star formation activity. Conclusions: The water emission probed by spectrally unresolved data is largely due to shocks. Broad water and high-J CO lines originate in shocks in the outflow cavity walls for both low- and high-mass YSOs, whereas lower-J CO transitions mostly trace entrained outflow gas. The higher UV field and turbulent motions in high-mass objects compared to their low-mass counterparts may explain the slightly different kinematical properties of 12CO J = 10-9 and H2O lines from low- to high-mass YSOs. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. THE COMPLEX PHYSICS OF DUSTY STAR-FORMING GALAXIES AT HIGH REDSHIFTS AS REVEALED BY HERSCHEL AND SPITZER

    Energy Technology Data Exchange (ETDEWEB)

    Lo Faro, B.; Franceschini, A.; Vaccari, M.; Rodighiero, G.; Feltre, A.; Marchetti, L. [Dipartimento di Fisica e Astronomia, Universita di Padova, vicolo Osservatorio, 3, I-35122 Padova (Italy); Silva, L. [INAF-OATs, Via Tiepolo 11, I-34131 Trieste (Italy); Berta, S.; Lutz, D.; Magnelli, B. [MPE, Postfach 1312, D-85741, Garching (Germany); Bock, J. [California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Burgarella, D.; Buat, V. [Laboratoire d' Astrophysique de Marseille, OAMP, Universite Aix-Marseille, CNRS, 38 rue Frederic Joliot-Curie, F-13388 Marseille Cedex 13 (France); Cava, A. [Departamento de Astrofisica, Facultad de CC. Fisicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Clements, D. L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Farrah, D.; Hurley, P. [Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom); Solares, E. A. Gonzalez [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Magdis, G., E-mail: barbara.lofaro@studenti.unipd.it [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); and others

    2013-01-10

    We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared galaxies ((U)LIRGs) at z {approx} 1 and 2 selected in GOODS-S with 24 {mu}m fluxes between 0.2 and 0.5 mJy. We model the data with a self-consistent physical model (GRASIL) which includes a state-of-the-art treatment of dust extinction and reprocessing. We find that all of our galaxies appear to require massive populations of old (>1 Gyr) stars and, at the same time, to host a moderate ongoing activity of star formation (SFR {<=} 100 M {sub Sun} yr{sup -1}). The bulk of the stars appear to have been formed a few Gyr before the observation in essentially all cases. Only five galaxies of the sample require a recent starburst superimposed on a quiescent star formation history. We also find discrepancies between our results and those based on optical-only spectral energy distribution (SED) fitting for the same objects; by fitting their observed SEDs with our physical model we find higher extinctions (by {Delta}A {sub V} {approx} 0.81 and 1.14) and higher stellar masses (by {Delta}log(M {sub *}) {approx} 0.16 and 0.36 dex) for z {approx} 1 and z {approx} 2 (U)LIRGs, respectively. The stellar mass difference is larger for the most dust-obscured objects. We also find lower SFRs than those computed from L {sub IR} using the Kennicutt relation due to the significant contribution to the dust heating by intermediate-age stellar populations through 'cirrus' emission ({approx}73% and {approx}66% of the total L {sub IR} for z {approx} 1 and z {approx} 2 (U)LIRGs, respectively).

  3. A near-infrared interferometric survey of debris-disc stars. VI. Extending the exozodiacal light survey with CHARA/JouFLU

    Science.gov (United States)

    Nuñez, P. D.; Scott, N. J.; Mennesson, B.; Absil, O.; Augereau, J.-C.; Bryden, G.; ten Brummelaar, T.; Ertel, S.; Coudé du Foresto, V.; Ridgway, S. T.; Sturmann, J.; Sturmann, L.; Turner, N. J.; Turner, N. H.

    2017-12-01

    We report the results of high-angular-resolution observations that search for exozodiacal light in a sample of main sequence stars and sub-giants. Using the "jouvence" of the fiber linked unit for optical recombination (JouFLU) at the center for high angular resolution astronomy (CHARA) telescope array, we have observed a total of 44 stars. Out of the 44 stars, 33 are new stars added to the initial, previously published survey of 42 stars performed at CHARA with the fiber linked unit for optical recombination (FLUOR). Since the start of the survey extension, we have detected a K-band circumstellar excess for six new stars at the 1% level or higher, four of which are known or candidate binaries, and two for which the excess could be attributed to exozodiacal dust. We have also performed follow-up observations of 11 of the stars observed in the previously published survey and found generally consistent results. We do however detect a significantly larger excess on three of these follow-up targets: Altair, υ And and κ CrB. Interestingly, the last two are known exoplanet host stars. We perform a statistical analysis of the JouFLU and FLUOR samples combined, which yields an overall exozodi detection rate of . We also find that the K-band excess in FGK-type stars correlates with the existence of an outer reservoir of cold (≲100 K) dust at the 99% confidence level, while the same cannot be said for A-type stars.

  4. 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

  5. The potential of mid- and near-infrared diffuse reflectance spectroscopy for determining major- and trace-element concentrations in soils from a geochemical survey of North America

    Science.gov (United States)

    Reeves, J. B.; Smith, D.B.

    2009-01-01

    In 2004, soils were collected at 220 sites along two transects across the USA and Canada as a pilot study for a planned soil geochemical survey of North America (North American Soil Geochemical Landscapes Project). The objective of the current study was to examine the potential of diffuse reflectance (DR) Fourier Transform (FT) mid-infrared (mid-IR) and near-infrared (NIRS) spectroscopy to reduce the need for conventional analysis for the determination of major and trace elements in such continental-scale surveys. Soil samples (n = 720) were collected from two transects (east-west across the USA, and north-south from Manitoba, Canada to El Paso, Texas (USA), n = 453 and 267, respectively). The samples came from 19 USA states and the province of Manitoba in Canada. They represented 31 types of land use (e.g., national forest, rangeland, etc.), and 123 different land covers (e.g., soybeans, oak forest, etc.). The samples represented a combination of depth-based sampling (0-5 cm) and horizon-based sampling (O, A and C horizons) with 123 different depths identified. The set was very diverse with few samples similar in land use, land cover, etc. All samples were analyzed by conventional means for the near-total concentration of 49 analytes (Ctotal, Ccarbonate and Corganic, and 46 major and trace elements). Spectra were obtained using dried, ground samples using a Digilab FTS-7000 FT spectrometer in the mid- (4000-400 cm-1) and near-infrared (10,000-4000 cm-1) at 4 cm-1 resolution (64 co-added scans per spectrum) using a Pike AutoDIFF DR autosampler. Partial least squares calibrations were develop using: (1) all samples as a calibration set; (2) samples evenly divided into calibration and validation sets based on spectral diversity; and (3) samples divided to have matching analyte concentrations in calibration and validation sets. In general, results supported the conclusion that neither mid-IR nor NIRS would be particularly useful in reducing the need for conventional

  6. Water in Star-forming Regions with the Herschel Space Observatory (WISH) : I. Overview of Key Program and First Results

    NARCIS (Netherlands)

    van Dishoeck, E. F.; Kristensen, L. E.; Benz, A. O.; Bergin, E. A.; Caselli, P.; Cernicharo, J.; Herpin, F.; Hogerheijde, M. R.; Johnstone, D.; Liseau, R.; Nisini, B.; Shipman, R.; Tafalla, M.; van der Tak, F.; Wyrowski, F.; Aikawa, Y.; Bachiller, R.; Baudry, A.; Benedettini, M.; Bjerkeli, P.; Blake, G. A.; Bontemps, S.; Braine, J.; Brinch, C.; Bruderer, S.; Chavarria, L.; Codella, C.; Daniel, F.; de Graauw, Th.; Deul, E.; di Giorgio, A. M.; Dominik, C.; Doty, S. D.; Dubernet, M. L.; Encrenaz, P.; Feuchtgruber, H.; Fich, M.; Frieswijk, W.; Fuente, A.; Giannini, T.; Goicoechea, J. R.; Helmich, F. P.; Herczeg, G. J.; Jacq, T.; Jorgensen, J. K.; Karska, A.; Kaufman, M. J.; Keto, E.; Larsson, B.; Lefloch, B.; Lis, D.; Marseille, M.; McCoey, C.; Melnick, G.; Neufeld, D.; Olberg, M.; Pagani, L.; Panic, O.; Parise, B.; Pearson, J. C.; Plume, R.; Risacher, C.; Salter, D.; Santiago-Garcia, J.; Saraceno, P.; Staeuber, P.; van Kempen, T. A.; Visser, R.; Viti, S.; Walmsley, M.; Wampfler, S. F.; Yildiz, U. A.

    Water In Star-forming regions with Herschel (WISH) is a key program on the Herschel Space Observatory designed to probe the physical and chemical structures of young stellar objects using water and related molecules and to follow the water abundance from collapsing clouds to planet-forming disks.

  7. The MUSCLES Treasury Survey. III. X-Ray to Infrared Spectra of 11 M and K Stars Hosting Planets

    Science.gov (United States)

    Loyd, R. O. P.; France, Kevin; Youngblood, Allison; Schneider, Christian; Brown, Alexander; Hu, Renyu; Linsky, Jeffrey; Froning, Cynthia S.; Redfield, Seth; Rugheimer, Sarah; Tian, Feng

    2016-06-01

    We present a catalog of panchromatic spectral energy distributions (SEDs) for 7 M and 4 K dwarf stars that span X-ray to infrared wavelengths (5 Å -5.5 μm). These SEDs are composites of Chandra or XMM-Newton data from 5-˜50 Å, a plasma emission model from ˜50-100 Å, broadband empirical estimates from 100-1170 Å, Hubble Space Telescope data from 1170-5700 Å, including a reconstruction of stellar Lyα emission at 1215.67 Å, and a PHOENIX model spectrum from 5700-55000 Å. Using these SEDs, we computed the photodissociation rates of several molecules prevalent in planetary atmospheres when exposed to each star’s unattenuated flux (“unshielded” photodissociation rates) and found that rates differ among stars by over an order of magnitude for most molecules. In general, the same spectral regions drive unshielded photodissociations both for the minimally and maximally FUV active stars. However, for O3 visible flux drives dissociation for the M stars whereas near-UV flux drives dissociation for the K stars. We also searched for an far-UV continuum in the assembled SEDs and detected it in 5/11 stars, where it contributes around 10% of the flux in the range spanned by the continuum bands. An ultraviolet continuum shape is resolved for the star ɛ Eri that shows an edge likely attributable to Si ii recombination. The 11 SEDs presented in this paper, available online through the Mikulski Archive for Space Telescopes, will be valuable for vetting stellar upper-atmosphere emission models and simulating photochemistry in exoplanet atmospheres.

  8. Molecules in Protoplanetary HAEBE discs as seen with Herschel.

    Science.gov (United States)

    Meeus, G.

    2011-05-01

    The discovery of planets around other stars has revealed that planet formation is ubiquitous. However, the mechanisms determining planet formation are not (yet) well-understood. Primordial protoplanetary discs consist 99% out of gas, and only 1% out of dust. With time, those discs are believed to evolve from a flaring geometry into a flat geometry, as the initially small dust grains grow to larger sizes and settle towards the mid-plane. In the mean time, the gas will disperse, until so little is left that giant planets no longer can form. It is thus important to understand the chemical composition of the disc and the influence of the gas heating/cooling processes on the disc structure, and finally how gas gets dispersed as a pieces of the puzzle of planet formation. In this contribution, we study the protoplanetary discs around Herbig Ae/Be stars, young objects of intermediate mass, in the context of gas chemistry. We present Herschel PACS spectroscopic observations for a sample that was obtained within the GASPS (Gas in Protoplanetary Systems) Open Time Key Project, concentrating on the detection and characterisation of emission lines of the molecules H20, CO and CH+ (besides [OI] and [CII]), tracing the disc between 5 and 500 AU. We look for correlations between the observed line fluxes and stellar properties such as effective temperature, Halpha emission, accretion rates and UV flux, as well as the disc properties: degree of flaring, presence and strength of PAH emission and disc mass. We will present a few cases to show how simultaneous modeling (using the thermo-chemical disc code ProDiMo) of the atomic fine structure lines and both Space Telescope and ground-based molecular lines can constrain the disc gas mass, once the disc structure is derived (here with the radiative transfer code MCFost). Finally, we compare our gas line observations with those of young debris disc stars, for which the HAEBE stars are thought to be progenitors.

  9. 21 Cataclysmic variables to be observed by William Herschel Telescope

    Science.gov (United States)

    Waagen, Elizabeth O.

    2016-12-01

    Roque Ruiz-Carmona (Ph.D. candidate, Institute of Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, The Netherlands) has requested AAVSO assistance with his campaign to observe a set of 21 cataclysmic variables (CVs) with the William Herschel Telescope (WHT) at La Palma on 2016 December 16. This campaign is essentially identical in format to the ones successfully carried out by the AAVSO on his behalf in 2015 and in May 2016 (AAVSO Alert Notices 524, 527, 543). Ruiz-Carmona writes: "As the end of my PhD is closer now, this is the second-to-last campaign monitoring CVs into outburst. As an update on my research, it seems that unexpectedly spiral density waves can only be detectable in high inclination systems and it seems that the luminosity of the disk in outburst outshines the spiral pattern for the rest of the system. This can also have deep implications: it can be that the spiral density waves are only an effect of the atmospheres of the disks and are therefore unrelated to transport of matter and angular momentum in the disks. In order to investigate this hypothesis, the sample of CVs I would like to monitor contains only eclipsing systems."[As before,] I just need to know if the targets are in outburst or not..." The PI has requested AAVSO observers to obtain one image of each target on each of TWO separate nights so he may analyze them to determine the final observing list for WHT. Links to finder charts as well as reporting instructions and other information may be found in the full Alert Notice.

  10. Systematic characterization of the Herschel SPIRE Fourier Transform Spectrometer

    Science.gov (United States)

    Hopwood, R.; Polehampton, E. T.; Valtchanov, I.; Swinyard, B. M.; Fulton, T.; Lu, N.; Marchili, N.; van der Wiel, M. H. D.; Benielli, D.; Imhof, P.; Baluteau, J.-P.; Pearson, C.; Clements, D. L.; Griffin, M. J.; Lim, T. L.; Makiwa, G.; Naylor, D. A.; Noble, G.; Puga, E.; Spencer, L. D.

    2015-05-01

    A systematic programme of calibration observations was carried out to monitor the performance of the Spectral and Photometric Imaging REceiver (SPIRE) Fourier Transform Spectrometer (FTS) instrument on board the Herschel Space Observatory. Observations of planets (including the prime point-source calibrator, Uranus), asteroids, line sources, dark sky and cross-calibration sources were made in order to monitor repeatability and sensitivity, and to improve FTS calibration. We present a complete analysis of the full set of calibration observations and use them to assess the performance of the FTS. Particular care is taken to understand and separate out the effect of pointing uncertainties, including the position of the internal beam steering mirror for sparse observations in the early part of the mission. The repeatability of spectral-line centre positions is 40, corresponding to <0.5-2.0 per cent of a resolution element. For spectral-line flux, the repeatability is better than 6 per cent, which improves to 1-2 per cent for spectra corrected for pointing offsets. The continuum repeatability is 4.4 per cent for the SPIRE Long Wavelength spectrometer (SLW) band and 13.6 per cent for the SPIRE Short Wavelength spectrometer (SSW) band, which reduces to ˜1 per cent once the data have been corrected for pointing offsets. Observations of dark sky were used to assess the sensitivity and the systematic offset in the continuum, both of which were found to be consistent across the FTS-detector arrays. The average point-source calibrated sensitivity for the centre detectors is 0.20 and 0.21 Jy [1σ; 1 h], for SLW and SSW. The average continuum offset is 0.40 Jy for the SLW band and 0.28 Jy for the SSW band.

  11. A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs

    Science.gov (United States)

    Absil, O.; di Folco, E.; Mérand, A.; Augereau, J.-C.; Coudé du Foresto, V.; Defrère, D.; Kervella, P.; Aufdenberg, J. P.; Desort, M.; Ehrenreich, D.; Lagrange, A.-M.; Montagnier, G.; Olofsson, J.; ten Brummelaar, T. A.; McAlister, H. A.; Sturmann, J.; Sturmann, L.; Turner, N. H.

    2008-09-01

    Aims: We aim at directly detecting the presence of optically thin circumstellar dust emission within the terrestrial planetary zone around main sequence stars known to harbour cold debris discs. The present study focuses on a sample of six bright A- and early F-type stars. Methods: High-precision interferometric observations have been obtained in the near-infrared K band with the FLUOR instrument installed on the CHARA Array. The measured squared visibilities are compared to the expected visibility of the stellar photospheres based on theoretical photospheric models taking into account rotational distortion. We search for potential visibility reduction at short baselines, a direct piece of evidence for resolved circumstellar emission. Results: Our observations bring to light the presence of resolved circumstellar emission around one of the six target stars (ζ Aql) at the 5σ level. The morphology of the emission source cannot be directly constrained because of the sparse spatial frequency sampling of our interferometric data. Using complementary adaptive optics observations and radial velocity measurements, we find that the presence of a low-mass companion is a likely origin for the excess emission. The potential companion is characterised by a K-band contrast of four magnitudes. It has a most probable mass of about 0.6~M⊙ and is expected to orbit between about 5.5 AU and 8 AU from its host star assuming a purely circular orbit. Nevertheless, by adjusting a physical debris disc model to the observed Spectral Energy Distribution of the ζ Aql system, we also show that the presence of hot dust within 10 AU from ζ Aql, producing a total thermal emission equal to 1.69 ± 0.31% of the photospheric flux in the K band, is another viable explanation for the observed near-infrared excess. Our re-interpretation of archival near- to far-infrared photometric measurements shows however that cold dust is not present around ζ Aql at the sensitivity limit of the IRS and MIPS

  12. Water in star-forming regions with Herschel: highly excited molecular emission from the NGC 1333 IRAS 4B outflow

    Science.gov (United States)

    Herczeg, G. J.; Karska, A.; Bruderer, S.; Kristensen, L. E.; van Dishoeck, E. F.; Jørgensen, J. K.; Visser, R.; Wampfler, S. F.; Bergin, E. A.; Yıldız, U. A.; Pontoppidan, K. M.; Gracia-Carpio, J.

    2012-04-01

    During the embedded phase of pre-main sequence stellar evolution, a disk forms from the dense envelope while an accretion-driven outflow carves out a cavity within the envelope. Highly excited (E' = 1000 - 3000 K) H2O emission in spatially unresolved Spitzer/IRS spectra of a low-mass Class 0 object, NGC 1333 IRAS 4B, has previously been attributed to the envelope-disk accretion shock. However, the highly excited H2O emission could instead be produced in an outflow. As part of the survey of low-mass sources in the Water in Star Forming Regions with Herschel (WISH-LM) program, we used Herschel/PACS to obtain a far-IR spectrum and several Nyquist-sampled spectral images to determine the origin of excited H2O emission from NGC 1333 IRAS 4B. The spectrum has high signal-to-noise in a rich forest of H2O, CO, and OH lines, providing a near-complete census of far-IR molecular emission from a Class 0 protostar. The excitation diagrams for the three molecules all require fits with two excitation temperatures. The highly excited component of H2O emission is characterized by subthermal excitation of ~1500 K gas with a density of ~3 × 106 cm-3, conditions that also reproduce the mid-IR H2O emission detected by Spitzer. On the other hand, a high density, low temperature gas can reproduce the H2O spectrum observed by Spitzer but underpredicts the H2O lines seen by Herschel. Nyquist-sampled spectral maps of several lines show two spatial components of H2O emission, one centered at ~5'' (1200 AU) south of the central source at the position of the blueshifted outflow lobe and a heavily extincted component centered on-source. The redshifted outflow lobe is likely completely obscured, even in the far-IR, by the optically thick envelope. Both spatial components of the far-IR H2O emission are consistent with emission from the outflow. In the blueshifted outflow lobe over 90% of the gas-phase O is molecular, with H2O twice as abundant than CO and 10 times more abundant than OH. The gas

  13. 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

  14. Herschel-SPIRE Fourier transform spectroscopy of the nearby spiral galaxy IC 342

    Science.gov (United States)

    Rigopoulou, D.; Hurley, P. D.; Swinyard, B. M.; Virdee, J.; Croxall, K. V.; Hopwood, R. H. B.; Lim, T.; Magdis, G. E.; Pearson, C. P.; Pellegrini, E.; Polehampton, E.; Smith, J.-D.

    2013-09-01

    We present observations of the nearby spiral galaxy IC 342 with the Herschel Spectral and Photometric Imaging Receiver (SPIRE) Fourier transform spectrometer. The spectral range afforded by SPIRE, 196-671 μm, allows us to access a number of 12CO lines from J = 4-3 to J = 13-12 with the highest J transitions observed for the first time. In addition we present measurements of 13CO, [C I] and [N II]. We use a radiative transfer code coupled with Bayesian likelihood analysis to model and constrain the temperature, density and column density of the gas. We find two 12CO components, one at 35 K and one at 400 K with CO column densities of 6.3 × 1017 and 0.4 × 1017 cm-2 and CO gas masses of 1.26 × 107 and 0.15 × 107 M⊙ for the cold and warm components, respectively. The inclusion of the high-J 12CO line observations indicate the existence of a much warmer gas component (˜400 K) confirming earlier findings from H2 rotational line analysis from Infrared Space Observatory and Spitzer. The mass of the warm gas is 10 per cent of the cold gas, but it likely dominates the CO luminosity. In addition, we detect strong emission from [N II] 205 μm and the 3P1 → 3P0 and 3P2 → 3P1 [C I] lines at 370 and 608 μm, respectively. The measured 12CO line ratios can be explained by photon-dominated region (PDR) models although additional heating by e.g. cosmic rays cannot be excluded. The measured [C I] line ratio together with the derived [C] column density of 2.1 × 1017 cm-2 and the fact that [C I] is weaker than CO emission in IC 342 suggests that [C I] likely arises in a thin layer on the outside of the CO emitting molecular clouds consistent with PDRs playing an important role.

  15. BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission

    Science.gov (United States)

    Lamperti, Isabella; Koss, Michael; Trakhtenbrot, Benny; Schawinski, Kevin; Ricci, Claudio; Oh, Kyuseok; Landt, Hermine; Riffel, Rogério; Rodríguez-Ardila, Alberto; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Mushotzky, Richard; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain

    2017-05-01

    We provide a comprehensive census of the near-infrared (NIR, 0.8-2.4 μm) spectroscopic properties of 102 nearby (z X-ray band (14-195 keV) from the Swift-Burst Alert Telescope survey. With the launch of the James Webb Space Telescope, this regime is of increasing importance for dusty and obscured AGN surveys. We measure black hole masses in 68 per cent (69/102) of the sample using broad emission lines (34/102) and/or the velocity dispersion of the Ca II triplet or the CO band-heads (46/102). We find that emission-line diagnostics in the NIR are ineffective at identifying bright, nearby AGN galaxies because [Fe II] 1.257 μm/Paβ and H2 2.12 μm/Brγ identify only 25 per cent (25/102) as AGN with significant overlap with star-forming galaxies and only 20 per cent of Seyfert 2 have detected coronal lines (6/30). We measure the coronal line emission in Seyfert 2 to be weaker than in Seyfert 1 of the same bolometric luminosity suggesting obscuration by the nuclear torus. We find that the correlation between the hard X-ray and the [Si VI] coronal line luminosity is significantly better than with the [O III] λ5007 luminosity. Finally, we find 3/29 galaxies (10 per cent) that are optically classified as Seyfert 2 show broad emission lines in the NIR. These AGN have the lowest levels of obscuration among the Seyfert 2s in our sample (log NH < 22.43 cm-2), and all show signs of galaxy-scale interactions or mergers suggesting that the optical broad emission lines are obscured by host galaxy dust.

  16. WIRED for EC: New White Dwarfs with WISE Infrared Excesses and New Classification Schemes from the Edinburgh-Cape Blue Object Survey

    Science.gov (United States)

    Dennihy, E.; Clemens, J. C.; Debes, John H.; Dunlap, B. H.; Kilkenny, D.; O'Brien, P. C.; Fuchs, J. T.

    2017-11-01

    We present a simple method for identifying candidate white dwarf systems with dusty exoplanetary debris based on a single temperature blackbody model fit to the infrared excess. We apply this technique to a sample of Southern Hemisphere white dwarfs from the recently completed Edinburgh-Cape Blue Object Survey and identify four new promising dusty debris disk candidates. We demonstrate the efficacy of our selection method by recovering three of the four Spitzer confirmed dusty debris disk systems in our sample. Further investigation using archival high-resolution imaging shows that Spitzer data of the unrecovered fourth object is likely contaminated by a line-of-sight object that either led to a misclassification as a dusty disk in the literature or is confounding our method. Finally, in our diagnostic plot, we show that dusty white dwarfs, which also host gaseous debris, lie along a boundary of our dusty debris disk region, providing clues to the origin and evolution of these especially interesting systems.

  17. New Measurements of the Cosmic Infrared Background Fluctuations in Deep SpitzerllRAC Survey Data and their Cosmological Implications

    Science.gov (United States)

    Kashlinsky, A.; Arendt, R. G.; Ashby, M. L. N.; Fazio, G. G.; Mather, J.; Moseley, S. H.

    2012-01-01

    We extend the previous measurements of CIB fluctuations to angular scales of less than or equal to 1 degree new data obtained in the course of the 2,000+ hour Spitzer Extended Deep Survey. Two fields with completed observations of approximately equal to 12 hr/pixel are analyzed for source-subtracted CIB fluctuations at 3.6 and 4.5 micrometers. The fields, EGS and UDS, cover a total area of approximately 0.25 deg and lie at high Galactic and Ecliptic latitudes, thus minimizing cirrus and zodiacal light contributions to the fluctuations. The observations have been conducted at 3 distinct epochs separated by about 6 months. As in our previous studies, the fields were assembled using the self-calibration method which is uniquely suitable for probing faint diffuse backgrounds. The assembled fields were cleaned off the bright sources down to the low shot noise levels corresponding to AB mag approximately equal to 25, Fourier-transformed and their power spectra evaluated. The noise was estimated from the time-differenced data and subtracted from the signal isolating the fluctuations remaining above the noise levels. The power spectra of the source-subtracted fields remain identical (within the observational uncertainties) for the three epochs of observations indicating that zodiacal light contributes negligibly to the fluctuations. By comparing to the measurements for the same regions at 8 micrometers we demonstrate that Galactic cirrus cannot account for the levels of the fluctuations either. The signal appears isotropically distributed on the sky as required by its origin in the CIB fluctuations. This measurement thus extends our earlier results to the important range of sub-degree scales. We find that the CIB fluctuations continue to diverge to more than 10 times those of known galaxy populations on angular scales out to less than or equal to 1 degree. The low shot noise levels remaining in the diffuse maps indicate that the large scale fluctuations arise from spatial

  18. Water in star-forming regions with Herschel (WISH) III

    DEFF Research Database (Denmark)

    Karska, A.; J. Herczeg, G.; F. van Dishoeck, E.

    2013-01-01

    . We also determine the spatial extent of the emission and investigate the underlying excitation conditions. Most of the protostars in our sample show strong atomic and molecular far-infrared emission. Water is detected in 17 objects, including 5 Class I sources. The high-excitation H2O line at 63...

  19. SixPak: a wide-field IFU for the William Herschel Telescope

    NARCIS (Netherlands)

    Venema, Lars B.; Schoenmaker, Ton; Verheijen, Marc; Trager, Scott; Rutten, René; Bershady, Matthew; Larsen, Søren; Peletier, Reynier; Spaans, Marco

    2008-01-01

    We intend to construct SixPak, a wide-field fibre-based IFU for the 4.2-meter William Herschel Telescope on La Palma. The fibre bundle will consist of 238 fibres, each 3.0 arcsec in diameter, piping light from the Nasmyth focal plane of the WHT to the existing WYFFOS bench spectrograph. A total of

  20. 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.

  1. 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

  2. Gas and dust in the TW Hydrae association as seen by the Herschel Space Observatory

    NARCIS (Netherlands)

    Riviere-Marichalar, P.; Pinte, C.; Barrado, D.; Thi, W. F.; Eiroa, C.; Kamp, I.; Montesinos, B.; Donaldson, J.; Augereau, J. C.; Huelamo, N.; Roberge, A.; Ardila, D.; Sandell, G.; Williams, J. P.; Dent, W. R. F.; Menard, F.; Lillo-Box, J.; Duchene, G.

    Context. Circumstellar discs are the places where planets form, therefore knowledge of their evolution is crucial for our understanding of planet formation. The Herschel Space Observatory is providing valuable data for studying disc systems, thanks to its sensitivity and wavelength coverage. This

  3. The WADI key project : New insights to photon-dominated regions from Herschel observations

    NARCIS (Netherlands)

    Ossenkopf, V.; Röllig, M.; Kramer, C.; Okada, Y.; Fuente, A.; Akyilmaz Yabaci, M.; Benz, A. O.; Berné, O.; Boulanger, F.; Bruderer, S.; Dedes, C.; France, K.; Gerin, M.; Goicoechea, J. R.; Gusdorf, A.; Güsten, R.; Harris, A.; Joblin, C.; Klein, T.; Latter, W.; Le Petit, F.; Lord, S.; Martin, P. G.; Pilleri, P.; Martin-Pintado, J.; Mookerjea, B.; Neufeld, D. A.; Phillips, T.; Rizzo, R.; Simon, R.; Stutzki, J.; van der Tak, F. F. S.; Teyssier, D.; Yorke, H.

    2011-01-01

    Within the Herschel key project "The Warm And Dense ISM" (WADI) we systematically observe a number of prominent photon-dominated regions (PDRs) to measure the impact of varying UV fields on the energy balance, the chemical and dynamical structure of heated molecular clouds.

  4. Warm dust and gas of massive young stellar objects revealed by Herschel PACS spectroscopy

    NARCIS (Netherlands)

    Kwon, Woojin; van der Tak, Floris F. S.; Karska, Agata; Herczeg, Gregory J.; Chavarría, Luis; Herpin, Fabrice; Wyrowski, Friedrich; Braine, Jonathan; van Dishoeck, Ewine F.; Jablonka, P.; André, Ph

    2016-01-01

    We present results of Herschel PACS imaging spectroscopy data toward ten massive young stellar objects taken as part of the WISH project. Our sample consists of four high mass protostellar objects (HMPOs), two hot molecular cores (HMCs), and four ultracompact HII regions (UCHIIs), and the spectra

  5. Herschel-PACS high-precision FIR fluxes of NEAs and MBAs

    Science.gov (United States)

    Müller, T.; Kiss, C.; Ali-Lagoa, V.

    2017-09-01

    We present unique and high-precision Herschel-PACS photometer far-IR observations of near-Earth and main-belt asteroids. These measurements are used for radiometric studies of unprecedented accuracy, resulting in sizes, albedos, thermal inertias, emissivities, and surface roughness for six important NEAs and more than 20 large MBAs.

  6. 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....

  7. ISM and dust properties of normal star-forming galaxies at z~2 derived by Herschel and ALMA with the help of gravitational lensing

    Science.gov (United States)

    Schaerer, Daniel; Boone, Frederic; Dessauges-Zavadsky, Miroslava; Sklias, Panos

    2015-08-01

    Using strong gravitational lensing provided by massive galaxy clusters we have studied a sample of normal star-forming galaxies at z~1.5-3 selected from the Herschel Lensing Survey (HLS). The observations include deep ground-based, HST, Spitzer, and Herschel imaging, plus LABOCA/SCUBA2 data, and IRAM CO observations.Targetted [CII] 158 micron observations of one z=2.013 galaxy from this sample were recently obtained with ALMA, resulting in the first detection of this important ISM cooling line in a faint LIRG (with LIR~1.e11 Lsun), which is magnified by a factor ~50.We discuss the behavior of [CII] and CO emission with other physical properties such as IR luminosity, dust temperature, galaxy metallicity, specific star formation rate, and many other quantities which are measured for our lensed galaxies. We also compare the z~2 data to nearby galaxies and to recent detections and upper limits of [CII] in z>6 Lyman break galaxies and Lyman alpha emitters.

  8. Infrared dust bubble CS51 and its interaction with the surrounding interstellar medium

    Science.gov (United States)

    Das, Swagat R.; Tej, Anandmayee; Vig, Sarita; Liu, Hong-Li; Liu, Tie; Ishwara Chandra, C. H.; Ghosh, Swarna K.

    2017-12-01

    A multiwavelength investigation of the southern infrared dust bubble CS51 is presented in this paper. We probe the associated ionized, cold dust, molecular and stellar components. Radio continuum emission mapped at 610 and 1300 MHz, using the Giant Metrewave Radio Telescope, India, reveals the presence of three compact emission components (A, B, and C) apart from large-scale diffuse emission within the bubble interior. Radio spectral index map shows the co-existence of thermal and non-thermal emission components. Modified blackbody fits to the thermal dust emission using Herschel Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging Receiver data is performed to generate dust temperature and column density maps. We identify five dust clumps associated with CS51 with masses and radius in the range 810-4600 M⊙ and 1.0-1.9 pc, respectively. We further construct the column density probability distribution functions of the surrounding cold dust which display the impact of ionization feedback from high-mass stars. The estimated dynamical and fragmentation time-scales indicate the possibility of collect and collapse mechanism in play at the bubble border. Molecular line emission from the Millimeter Astronomy Legacy Team 90 GHz survey is used to understand the nature of two clumps which show signatures of expansion of CS51.

  9. Far-infrared emission in luminous quasars accompanied by nuclear outflows

    Science.gov (United States)

    Maddox, Natasha; Jarvis, M. J.; Banerji, M.; Hewett, P. C.; Bourne, N.; Dunne, L.; Dye, S.; Eales, S.; Furlanetto, C.; Maddox, S. J.; Smith, M. W. L.; Valiante, E.

    2017-09-01

    Combining large-area optical quasar surveys with the new far-infrared (FIR) Herschel-ATLAS Data Release 1, we search for an observational signature associated with the minority of quasars possessing bright FIR luminosities. We find that FIR-bright quasars show broad C IV emission-line blueshifts in excess of that expected from the optical luminosity alone, indicating particularly powerful nuclear outflows. The quasars show no signs of having redder optical colours than the general ensemble of optically selected quasars, ruling out differences in line-of-sight dust within the host galaxies. We postulate that these objects may be caught in a special evolutionary phase, with unobscured, high black hole accretion rates and correspondingly strong nuclear outflows. The high FIR emission found in these objects is then either a result of star formation related to the outflow, or is due to dust within the host galaxy illuminated by the quasar. We are thus directly witnessing coincident small-scale nuclear processes and galaxy-wide activity, commonly invoked in galaxy simulations that rely on feedback from quasars to influence galaxy evolution.

  10. 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

  11. Technology Needs for Far-Infrared, Submillimeter, and Millimeter Missions

    Science.gov (United States)

    Moseley, S. Harvey

    2004-01-01

    SAFIR will: Study the important and relatively unexplored region of the spectrum between 30 and 300 m; Enable the study of galaxy formation and the earliest stage of star formation by revealing regions too enshrouded by dust to be studied by NGST; Be more than 100 times as sensitive as SIRTF or the European [Herschel] mission.SAFIR is projected to cost around $600M total. The decadal review committee recommends that $100M be allocated in this decade to start the SAFIR project, and that additional technology developments be funded separately: Far-Infrared Array Development ($10M ) Refrigerators ($50M ) Large, Lightweight Optics ($80M ). Current developments are also described.

  12. SURVEY

    DEFF Research Database (Denmark)

    SURVEY er en udbredt metode og benyttes inden for bl.a. samfundsvidenskab, humaniora, psykologi og sundhedsforskning. Også uden for forskningsverdenen er der mange organisationer som f.eks. konsulentfirmaer og offentlige institutioner samt marketingsafdelinger i private virksomheder, der arbejder...

  13. A Nonlinear Model for Designing Herschel-Quincke Waveguide Arrays to Attenuate Shock Waves from Transonic Turbofan Engines Project

    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)...

  14. Herschel-PACS observation of the 10 Myr old T Tauri disk TW Hya. Constraining the disk gas mass

    Science.gov (United States)

    Thi, W.-F.; Mathews, G.; Ménard, F.; Woitke, P.; Meeus, G.; Riviere-Marichalar, P.; Pinte, C.; Howard, C. D.; Roberge, A.; Sandell, G.; Pascucci, I.; Riaz, B.; Grady, C. A.; Dent, W. R. F.; Kamp, I.; Duchêne, G.; Augereau, J.-C.; Pantin, E.; Vandenbussche, B.; Tilling, I.; Williams, J. P.; Eiroa, C.; Barrado, D.; Alacid, J. M.; Andrews, S.; Ardila, D. R.; Aresu, G.; Brittain, S.; Ciardi, D. R.; Danchi, W.; Fedele, D.; de Gregorio-Monsalvo, I.; Heras, A.; Huelamo, N.; Krivov, A.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mendigutía, I.; Montesinos, B.; Mora, A.; Morales-Calderon, M.; Nomura, H.; Phillips, N.; Podio, L.; Poelman, D. R.; Ramsay, S.; Rice, K.; Solano, E.; Walker, H.; White, G. J.; Wright, G.

    2010-07-01

    Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one of the nearest T Tauri stars that is still surrounded by a relatively massive disk. In addition a large number of molecules has been found in the TW Hya disk, making TW Hya the perfect test case in a large survey of disks with Herschel-PACS to directly study their gaseous component. We aim to constrain the gas and dust mass of the circumstellar disk around TW Hya. We observed the fine-structure lines of [O i] and [C ii] as part of the open-time large program GASPS. We complement this with continuum data and ground-based 12 CO 3-2 and 13CO 3-2 observations. We simultaneously model the continuum and the line fluxes with the 3D Monte-Carlo code MCFOST and the thermo-chemical code ProDiMo to derive the gas and dust masses. We detect the [O i] line at 63 μm. The other lines that were observed, [O i] at 145 μm and [C ii] at 157 μm, are not detected. No extended emission has been found. Preliminary modeling of the photometric and line data assuming [ 12CO] /[ 13CO] = 69 suggests a dust mass for grains with radius open for proposals for observing time from the worldwide astronomical community.Appendix is only available in electronic form at http://www.aanda.org

  15. 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.

  16. Infrared thermography

    CERN Document Server

    Meola, Carosena

    2012-01-01

    This e-book conveys information about basic IRT theory, infrared detectors, signal digitalization and applications of infrared thermography in many fields such as medicine, foodstuff conservation, fluid-dynamics, architecture, anthropology, condition monitoring, non destructive testing and evaluation of materials and structures.

  17. 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.

  18. 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......, 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 Lbol increased by 1.25 (1.06) and Tbol 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...

  19. Inertia Effects in the Flow of a Herschel-Bulkley ERF between Fixed Surfaces of Revolution

    Directory of Open Access Journals (Sweden)

    A. Walicka

    2013-01-01

    Full Text Available Many electrorheological fluids (ERFs as fluids with microstructure demonstrate viscoplastic behaviours. Rheometric measurements indicate that some flows of these fluids may be modelled as the flows of a Herschel-Bulkley fluid. In this paper, the flow of a Herschel-Bulkley ER fluid—with a fractional power-law exponent—in a narrow clearance between two fixed surfaces of revolution with common axis of symmetry is considered. The flow is externally pressurized, and it is considered with inertia effect. In order to solve this problem, the boundary layer equations are used. The influence of inertia forces on the pressure distribution is examined by using the method of averaged inertia terms of the momentum equation. Numerical examples of externally pressurized ERFs flows in the clearance between parallel disks and concentric spherical surfaces are presented.

  20. Herschel Extreme Lensing Line Observations: [CII] Variations in Galaxies at Redshifts z=1-3

    Science.gov (United States)

    Malhotra, Sangeeta; Rhoads, James E.; Finkelstein, K.; Yang, Huan; Carilli, Chris; Combes, Françoise; Dassas, Karine; Finkelstein, Steven; Frye, Brenda; Gerin, Maryvonne; Guillard, Pierre; Nesvadba, Nicole; 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 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 is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  1. Herschel observations of near-Earth objects: Encounters with the spacecraft and with the Earth

    Science.gov (United States)

    O'Rourke, L.; Müller, T.; Altieri, B.; Kiss, C.; Kùppers, M.; Barucci, M.; Bockelée-Morvan, D.; Gonzalez-Garcia, B.; Dotto, E.; Yoshikawa, M.; Carry, B.; Kidger, M.; Sanchez-Portal, M.; Vavrek, R.; Teyssier, D.; Marston, A.

    2014-07-01

    The Herschel MACH-11 (Measurements of 11 Asteroids & Comets with Herschel) Programme has as its prime goal to observe those asteroids & comets which have been or will be visited by spacecraft or those which are being studied with a similar goal in mind. The following near-Earth asteroids (NEAs) form part of the list of targets making up this program and will be addressed in this analysis: - 1999 JU_3 (Hayabusa 2 mission target) - 1999 RQ_{36} (OSIRIS-REx mission target) - 1996 FG_3 (Marco-Polo R backup mission target) - (99942) Apophis (Study target) An additional NEA (not part of the MACH-11 program) will also be reviewed, namely 2005 YU_{55}. Each target was observed using the PACS Photometer of the Herschel Space Observatory (Pilbratt et al 2010). The extracted fluxes from each observation campaign were fed into a thermophysical model which has been validated against a large database of asteroids including targets of other spacecraft missions. In all cases, radiometric properties of each target have been derived and will be presented, with their impact on already published data being analysed & discussed.

  2. Herschel observations of cold water vapor and ammonia in protoplanetary disks

    Science.gov (United States)

    Hogerheijde, Michiel R.; Bergin, Edwin A.; Brinch, Christian; Cleeves, L. Ilsedore; Fogel, Jeffrey K. J.; Blake, Geoffrey A.; Dominik, Carsten; Lis, Dariusz C.; Melnick, Gary; Neufeld, David; Panić, Olja; Pearson, John C.; Kristensen, Lars; Yíldíz, Umut A.; van Dishoeck, Ewine F.

    2012-03-01

    We present the results of a Herschel/HIFI study into the presence of cold water vapor in a sample of protoplanetary disks, carried out as part of the Guaranteed Time Key Program `Water in Star Forming Regions with Herschel' (WISH). While toward most disks only upper limits are obtained, rotational ground-state emission lines of ortho-H_2O and para-H_2O are clearly detected toward the disk of TW Hya. The detection of cold water vapor, extending to at least 115 AU, in this disk indicates the presence of a vast reservoir of water ice totalling ˜ 1028 g or thousands of Earth Oceans. Photodesorption by stellar ultraviolet radiation likely liberates a small amount of water vapor from icy grains. Significant settling of such icy grains toward the disk midplane is required to match the detected amount of water vapor. The water ortho-to-para ratio of 0.77 is significantly different from that observed in Solar System comets where a range of 1.5--3 is found. If this reflects the temperature regime of the water ice (formation), this finding suggests that long-range mixing of volatiles has occured in the Solar Nebula. The same Herschel/HIFI data also detect the emission of NH_3 in TW Hya's disk, and the implications of this finding are discussed.

  3. Herschel Open Time Key Programme—TNOs are Cool: A Survey of the Transneptunian Region

    NARCIS (Netherlands)

    Müller, Th. G.; Lellouch, E.; Böhnhardt, H.; Stansberry, J.; Barucci, A.; Crovisier, J.; Delsanti, A.; Doressoundiram, A.; Dotto, E.; Duffard, R.; Fornasier, S.; Groussin, O.; Gutierrez, P. J.; Hainaut, O.; Harris, A.; Hartogh, P.; Hestroffer, D.; Horner, J.; Jewitt, D.; Kidger, M.; Kiss, C.; Lacerda, P.; Lara, L.; Lim, T.; Mueller, M.; Moreno, R.; Ortiz, J.-L.; Rengel, M.; Santos-Sanz, P.; Swinyard, B.; Thomas, N.; Trilling, D.

    2008-01-01

    Over one thousand objects have been discovered orbiting beyond Neptune. These trans-Neptunian objects (TNOs) represent the primitive remnants of the planetesimal disk from which the outer planets formed, and is an analog for unseen dust parent-bodies in debris disks observed around other

  4. VizieR Online Data Catalog: Herschel protocluster survey (Kato+, 2016)

    Science.gov (United States)

    Kato, Y.; Matsuda, Y.; Smail, I.; Swinbank, A. M.; Hatsukade, B.; Umehata, H.; Tanaka, I.; Saito, T.; Iono, D.; Tamura, Y.; Kohno, K.; Erb, D. K.; Lehmer, B. D.; Geach, J. E.; Steidel, C. C.; Alexander, D. M.; Yamada, T.; Hayashino, T.

    2017-11-01

    The observations were executed in Large Map mode with a scan rate of 30arcsec/s, repeated 14 times for each field (Nrep=14). The dates of observations are 2012 June 22 (2QZCluster), 2012 March 4 (HS1700), and 2012 May 10 (SSA22). The coverage of the maps are ~23-arcminx23-arcmin (2QZCluster), ~22-arcminx22-arcmin (HS1700), and ~33-arcminx33-arcmin (SSA22) corresponding to ~40-60 comoving Mpc at the protocluster redshifts, which are sufficient to search for concentration of DSFGs around the density peak of protocluster members. The integration times are 1.8, 1.5, and 3.7h for 2QZCluster, HS1700, and SSA22, respectively. (5 data files).

  5. AGN and Starbursts in Dusty Galaxy Mergers: Insights from the Great Observatories All-sky LIRG Survey

    Science.gov (United States)

    Mazzarella, Joseph M.

    2014-07-01

    The Great Observatories All-sky LIRG Survey (GOALS) is combining imaging and spectroscopic data from the Herschel, Spitzer, Hubble, GALEX, Chandra, and XMM-Newton space telescopes augmented with extensive ground-based observations in a multiwavelength study of approximately 180 Luminous Infrared Galaxies (LIRGs) and 20 Ultraluminous Infrared Galaxies (ULIRGs) that comprise a statistically complete subset of the 60μm-selected IRAS Revised Bright Galaxy Sample. The objects span the full range of galaxy environments (giant isolated spirals, wide and close pairs, minor and major mergers, merger remnants) and nuclear activity types (Seyfert 1, Seyfert 2, LINER, starburst/HII), with proportions that depend strongly on the total infrared luminosity. I will review the science motivations and present highlights of recent results selected from over 25 peer-reviewed journal articles published recently by the GOALS Team. Statistical investigations include detection of high-ionization Fe K emission indicative of deeply embedded AGN, comparison of UV and far-IR properties, investigations of the fraction of extended emission as a function of wavelength derived from mid-IR spectroscopy, mid-IR spectral diagnostics and spectral energy distributions revealing the relative contributions of AGN and starbursts to powering the bolometric luminosity, and quantitative structure analyses that delineate the evolution of stellar bars and nuclear stellar cusps during the merger process. Multiwavelength dissections of individual systems have unveiled large populations of young star clusters and heavily obscured AGN in early-stage (II Zw 96), intermediate-stage (Mrk 266, Mrk 273), and late-stage (NGC 2623, IC 883) mergers. A recently published study that matches numerical simulations to the observed morphology and gas kinematics in mergers has placed four systems on a timeline spanning 175-260 million years after their first passages, and modeling of additional (U)LIRGs is underway. A very

  6. Origin of warm and hot gas emission from low-mass protostars: Herschel-HIFI observations of CO J = 16-15. I. Line profiles, physical conditions, and H2O abundance

    Science.gov (United States)

    Kristensen, L. E.; van Dishoeck, E. F.; Mottram, J. C.; Karska, A.; Yıldız, U. A.; Bergin, E. A.; Bjerkeli, P.; Cabrit, S.; Doty, S.; Evans, N. J.; Gusdorf, A.; Harsono, D.; Herczeg, G. J.; Johnstone, D.; Jørgensen, J. K.; van Kempen, T. A.; Lee, J.-E.; Maret, S.; Tafalla, M.; Visser, R.; Wampfler, S. F.

    2017-09-01

    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 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 line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs. Results: The spectrally resolved line profiles typically show two distinct velocity components: a broad Gaussian component with an average FWHM of 20 km s-1 containing the bulk of the flux, and a narrower Gaussian component with a FWHM of 5 km s-1 that is often offset from the source velocity. Some sources show other velocity components such as extremely-high-velocity features or "bullets". All these velocity components were first detected in H2O line profiles. The average rotational temperature over the entire profile, as measured from comparison between CO J = 16-15 and 10-9 emission, is 300 K. A radiative-transfer analysis shows that the average H2O/CO column-density ratio is 0.02, suggesting a total H2O abundance of 2 × 10-6, independent of velocity. Conclusions: Two distinct velocity profiles observed in the HIFI line profiles suggest that the high-J CO ladder observed with PACS consists of two excitation components. The warm PACS component (300 K) is associated with the broad HIFI component, and the hot PACS component (700 K) is associated with the offset HIFI

  7. The Herschel Exploitation of Local Galaxy Andromeda (HELGA). IV. Dust scaling relations at sub-kpc resolution

    Science.gov (United States)

    Viaene, S.; Fritz, J.; Baes, M.; Bendo, G. J.; Blommaert, J. A. D. L.; Boquien, M.; Boselli, A.; Ciesla, L.; Cortese, L.; De Looze, I.; Gear, W. K.; Gentile, G.; Hughes, T. M.; Jarrett, T.; Karczewski, O. Ł.; Smith, M. W. L.; Spinoglio, L.; Tamm, A.; Tempel, E.; Thilker, D.; Verstappen, J.

    2014-07-01

    Context. Dust and stars play a complex game of interactions in the interstellar medium and around young stars. The imprints of these processes are visible in scaling relations between stellar characteristics, star formation parameters, and dust properties. Aims: In the present work, we aim to examine dust scaling relations on a sub-kpc resolution in the Andromeda galaxy (M 31). The goal is to investigate the properties of M 31 on both a global and local scale and compare them to other galaxies of the local universe. Methods: New Herschel observations are combined with available data from GALEX, SDSS, WISE, and Spitzer to construct a dataset covering UV to submm wavelengths. All images were brought to the beam size and pixel grid of the SPIRE 500 μm frame. This divides M 31 in 22 437 pixels of 36 arcseconds in size on the sky, corresponding to physical regions of 137 × 608 pc in the galaxy's disk. A panchromatic spectral energy distribution was modelled for each pixel and maps of the physical quantities were constructed. Several scaling relations were investigated, focussing on the interactions of dust with starlight. Results: We find, on a sub-kpc scale, strong correlations between Mdust/M⋆ and NUV-r, and between Mdust/M⋆ and μ⋆ (the stellar mass surface density). Striking similarities with corresponding relations based on integrated galaxies are found. We decompose M 31 in four macro-regions based on their far-infrared morphology; the bulge, inner disk, star forming ring, and the outer disk region. In the scaling relations, all regions closely follow the galaxy-scale average trends and behave like galaxies of different morphological types. The specific star formation characteristics we derive for these macro-regions give strong hints of an inside-out formation of the bulge-disk geometry, as well as an internal downsizing process. Within each macro-region, however, a great diversity in individual micro-regions is found, regardless of the properties of the

  8. Three New Cool Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer (WISE) and an Improved Spectrum of the Y0 Dwarf WISE J041022.71+150248.4

    Science.gov (United States)

    Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Skrutskie, Michael F.; Gould, Andrew

    2014-05-01

    As part of a larger search of Wide-field Infrared Survey Explorer (WISE) data for cool brown dwarfs with effective temperatures less than 1000 K, we present the discovery of three new cool brown dwarfs with spectral types later than T7. Using low-resolution, near-infrared spectra obtained with the NASA Infrared Telescope Facility and the Hubble Space Telescope, we derive spectral types of T9.5 for WISE J094305.98+360723.5, T8 for WISE J200050.19+362950.1, and Y0: for WISE J220905.73+271143.9. The identification of WISE J220905.73+271143.9 as a Y dwarf brings the total number of spectroscopically confirmed Y dwarfs to 17. In addition, we present an improved spectrum (i.e., higher signal-to-noise ratio) of the Y0 dwarf WISE J041022.71+150248.4 that confirms the Cushing et al. classification of Y0. Spectrophotometric distance estimates place all three new brown dwarfs at distances less than 12 pc, with WISE J200050.19+362950.1 lying at a distance of only 3.9-8.0 pc. Finally, we note that brown dwarfs like WISE J200050.19+362950.1 that lie in or near the Galactic plane offer an exciting opportunity to directly measure the mass of a brown dwarf via astrometric microlensing.

  9. Three new cool brown dwarfs discovered with the wide-field infrared survey explorer (WISE) and an improved spectrum of the Y0 dwarf wise J041022.71+150248.4

    Energy Technology Data Exchange (ETDEWEB)

    Cushing, Michael C. [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Kirkpatrick, J. Davy; Gelino, Christopher R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Mace, Gregory N. [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Skrutskie, Michael F. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Gould, Andrew, E-mail: michael.cushing@utoledo.edu [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2014-05-01

    As part of a larger search of Wide-field Infrared Survey Explorer (WISE) data for cool brown dwarfs with effective temperatures less than 1000 K, we present the discovery of three new cool brown dwarfs with spectral types later than T7. Using low-resolution, near-infrared spectra obtained with the NASA Infrared Telescope Facility and the Hubble Space Telescope, we derive spectral types of T9.5 for WISE J094305.98+360723.5, T8 for WISE J200050.19+362950.1, and Y0: for WISE J220905.73+271143.9. The identification of WISE J220905.73+271143.9 as a Y dwarf brings the total number of spectroscopically confirmed Y dwarfs to 17. In addition, we present an improved spectrum (i.e., higher signal-to-noise ratio) of the Y0 dwarf WISE J041022.71+150248.4 that confirms the Cushing et al. classification of Y0. Spectrophotometric distance estimates place all three new brown dwarfs at distances less than 12 pc, with WISE J200050.19+362950.1 lying at a distance of only 3.9-8.0 pc. Finally, we note that brown dwarfs like WISE J200050.19+362950.1 that lie in or near the Galactic plane offer an exciting opportunity to directly measure the mass of a brown dwarf via astrometric microlensing.

  10. DIAGNOSTICS OF AGN-DRIVEN MOLECULAR OUTFLOWS IN ULIRGs FROM HERSCHEL-PACS OBSERVATIONS OF OH AT 119 μm

    Energy Technology Data Exchange (ETDEWEB)

    Spoon, H. W. W.; Lebouteiller, V. [Cornell University, CRSR, Space Sciences Building, Ithaca, NY 14853 (United States); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); González-Alfonso, E. [Departamento de Física y Matemáticas, Universidad de Alcalá, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Bernard-Salas, J. [Department of Physical Sciences, Milton Keynes MK7 6AA (United Kingdom); Urrutia, T. [Leibniz Institut für Astrophysik, Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany); Rigopoulou, D.; Verma, A. [Department of Physics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Westmoquette, M. S. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany); Smith, H. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Afonso, J. [Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisbon (Portugal); Pearson, C. [RAL Space, Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX (United Kingdom); Cormier, D. [Institut für theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Efstathiou, A. [School of Sciences, European University Cyprus, Diogenes Street, Engomi, 1516 Nicosia (Cyprus); Borys, C. [Infrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125 (United States); Etxaluze, M. [Departamento de Astrofísica. Centro de Astrobiología. CSIC-INTA. Torrejón de Ardoz, E-28850 Madrid (Spain); Clements, D. L., E-mail: spoon@isc.astro.cornell.edu [Physics Department, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2013-10-01

    We report on our observations of the 79 and 119 μm doublet transitions of OH for 24 local (z < 0.262) ULIRGs observed with Herschel-PACS as part of the Herschel ULIRG Survey (HERUS). Some OH 119 μm profiles display a clear P-Cygni shape and therefore imply outflowing OH gas, while other profiles are predominantly in absorption or are completely in emission. We find that the relative strength of the OH emission component decreases as the silicate absorption increases. This result locates the OH outflows inside the obscured nuclei. The maximum outflow velocities for our sources range from less than 100 to ∼2000 km s{sup –1}, with 15/24 (10/24) sources showing OH absorption at velocities exceeding 700 km s{sup –1} (1000 km s{sup –1}). Three sources show maximum OH outflow velocities exceeding that of Mrk231. Since outflow velocities above 500-700 km s{sup –1} are thought to require an active galactic nucleus (AGN) to drive them, about two-thirds of our ULIRG sample may host AGN-driven molecular outflows. This finding is supported by the correlation we find between the maximum OH outflow velocity and the IR-derived bolometric AGN luminosity. No such correlation is found with the IR-derived star formation rate. The highest outflow velocities are found among sources that are still deeply embedded. We speculate that the molecular outflows in these sources may be in an early phase of disrupting the nuclear dust veil before these sources evolve into less-obscured AGNs. Four of our sources show high-velocity wings in their [C II] fine-structure line profiles, implying neutral gas outflow masses of at least (2-4.5) × 10{sup 8} M{sub ☉}.

  11. Infrared Camera

    Science.gov (United States)

    1997-01-01

    A sensitive infrared camera that observes the blazing plumes from the Space Shuttle or expendable rocket lift-offs is capable of scanning for fires, monitoring the environment and providing medical imaging. The hand-held camera uses highly sensitive arrays in infrared photodetectors known as quantum well infrared photo detectors (QWIPS). QWIPS were developed by the Jet Propulsion Laboratory's Center for Space Microelectronics Technology in partnership with Amber, a Raytheon company. In October 1996, QWIP detectors pointed out hot spots of the destructive fires speeding through Malibu, California. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the duties for which the camera is suited. Medical applications are also expected.

  12. The CHESS spectral survey of star forming regions : Peering into the protostellar shock L1157-B1. II. Shock dynamics

    NARCIS (Netherlands)

    Codella, C.; Lefloch, B.; Ceccarelli, C.; Cernicharo, J.; Caux, E.; Lorenzani, A.; Viti, S.; Hily-Blant, P.; Parise, B.; Maret, S.; Nisini, B.; Caselli, P.; Cabrit, S.; Pagani, L.; Benedettini, M.; Boogert, A.; Gueth, F.; Melnick, G.; Neufeld, D.; Pacheco, S.; Salez, M.; Schuster, K.; Bacmann, A.; Baudry, A.; Bell, T.; Bergin, E. A.; Blake, G.; Bottinelli, S.; Castets, A.; Comito, C.; Coutens, A.; Crimier, N.; Dominik, C.; Demyk, K.; Encrenaz, P.; Falgarone, E.; Fuente, A.; Gerin, M.; Goldsmith, P.; Helmich, F.; Hennebelle, P.; Henning, Th.; Herbst, E.; Jacq, T.; Kahane, C.; Kama, M.; Klotz, A.; Langer, W.; Lis, D.; Lord, S.; Pearson, J.; Phillips, T.; Saraceno, P.; Schilke, P.; Tielens, X.; van der Tak, F.; van der Wiel, M.; Vastel, C.; Wakelam, V.; Walters, A.; Wyrowski, F.; Yorke, H.; Borys, C.; Delorme, Y.; Kramer, C.; Larsson, B.; Mehdi, I.; Ossenkopf, V.; Stutzki, J.; Pardo, J. R.; Bachiller, R.; De lange, G.; Lai, R.; Maiwald, F. W.; Martin-Pintado, J.; Siegel, P.; Wunsch, J. H.

    2010-01-01

    We present the first results of the unbiased survey of the L1157-B1 bow shock, obtained with HIFI in the framework of the key program Chemical HErschel Survey of Star forming regions (CHESS). The L1157 outflow is driven by a low-mass Class 0 protostar and is considered the prototype of the so-called

  13. Infrared photoretinoscope.

    Science.gov (United States)

    Schaeffel, F; Farkas, L; Howland, H C

    1987-04-15

    A modification of the technique of photoretinoscopy is presented which allows measurement of the refractive state of the eye in noncooperative subjects and in very small eyes. Infrared light provided by high-output infrared LEDs permits measurement at large pupil sizes and thereby better resolution. Arrangement of the IR LEDs at different eccentricities from the optical axis of the video camera markedly increases the range of measurement. The current sensitivity for a measurement distance of 1.5 m in a human eye is +/- 0.3 diopter or better over a range of +/-5 diopters. Higher amounts of defocus can be better determined at shorter distances.

  14. Water abundances in high-mass protostellar envelopes: Herschel observations with HIFI

    Science.gov (United States)

    Marseille, M. G.; van der Tak, F. F. S.; Herpin, F.; Wyrowski, F.; Chavarría, L.; Pietropaoli, B.; Baudry, A.; Bontemps, S.; Cernicharo, J.; Jacq, T.; Frieswijk, W.; Shipman, R.; van Dishoeck, E. F.; Bachiller, R.; Benedettini, M.; Benz, A. O.; Bergin, E.; Bjerkeli, P.; Blake, G. A.; Braine, J.; Bruderer, S.; Caselli, P.; Caux, E.; Codella, C.; Daniel, F.; Dieleman, P.; di Giorgio, A. M.; Dominik, C.; Doty, S. D.; Encrenaz, P.; Fich, M.; Fuente, A.; Gaier, T.; Giannini, T.; Goicoechea, J. R.; de Graauw, Th.; Helmich, F.; Herczeg, G. J.; Hogerheijde, M. R.; Jackson, B.; Javadi, H.; Jellema, W.; Johnstone, D.; Jørgensen, J. K.; Kester, D.; Kristensen, L. E.; Larsson, B.; Laauwen, W.; Lis, D.; Liseau, R.; Luinge, W.; McCoey, C.; Megej, A.; Melnick, G.; Neufeld, D.; Nisini, B.; Olberg, M.; Parise, B.; Pearson, J. C.; Plume, R.; Risacher, C.; Roelfsema, P.; Santiago-García, J.; Saraceno, P.; Siegel, P.; Stutzki, J.; Tafalla, M.; van Kempen, T. A.; Visser, R.; Wampfler, S. F.; Yıldız, U. A.

    2010-10-01

    Aims: We derive the dense core structure and the water abundance in four massive star-forming regions in the hope of understanding the earliest stages of massive star formation. Methods: We present Herschel/HIFI observations of the para-H2O 111-000 and 202-111 and the para-H_218O 111-000 transitions. The envelope contribution to the line profiles is separated from contributions by outflows and foreground clouds. The envelope contribution is modeled with Monte-Carlo radiative transfer codes for dust and molecular lines (MC3D and RATRAN), and the water abundance and the turbulent velocity width as free parameters. Results: While the outflows are mostly seen in emission in high-J lines, envelopes are seen in absorption in ground-state lines, which are almost saturated. The derived water abundances range from 5×10-10 to 4×10-8 in the outer envelopes. We detect cold clouds surrounding the protostar envelope, thanks to the very high quality of the Herschel/HIFI data and the unique ability of water to probe them. Several foreground clouds are also detected along the line of sight. Conclusions: The low H2O abundances in massive dense cores are in accordance with the expectation that high densities and low temperatures lead to freeze-out of water on dust grains. The spread in abundance values is not clearly linked to physical properties of the sources. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation of NASA.Appendix (pages 6 to 7) is only available in electronic form at http://www.aanda.org

  15. Feasibility and performances of compressed sensing and sparse map-making with Herschel/PACS data

    Science.gov (United States)

    Barbey, N.; Sauvage, M.; Starck, J.-L.; Ottensamer, R.; Chanial, P.

    2011-03-01

    The Herschel Space Observatory of ESA was launched in May 2009 and has been in operation ever since. From its distant orbit around L2, it needs to transmit a huge quantity of information through a very limited bandwidth. This is especially true for the PACS imaging camera, which needs to compress its data far more than what can be achieved with lossless compression. This is currently solved by including lossy averaging and rounding steps onboard. Recently, a new theory called compressed sensing has emerged from the statistics community. This theory makes use of the sparsity of natural (or astrophysical) images to optimize the acquisition scheme of the data needed to estimate those images. Thus, it can lead to high compression factors. A previous article by Bobin et al. (2008, IEEE J. Selected Topics Signal Process., 2, 718) has shown how the new theory could be applied to simulated Herschel/PACS data to solve the compression requirement of the instrument. In this article, we show that compressed sensing theory can indeed be successfully applied to actual Herschel/PACS data and significantly improves over the standard pipeline. To fully use the redundancy present in the data, we perform a full sky-map estimation and decompression at the same time, which cannot be done in most other compression methods. We also demonstrate that the various artifacts affecting the data (pink noise and glitches, whose behavior is a priori not very compatible with compressed sensing) can also be handled in this new framework. Finally, we compare the methods from the compressed sensing scheme and data acquired with the standard compression scheme. We discuss improvements that can be made on Earth for the creation of sky maps from the data.

  16. Herschel-PACS observation of gas lines from the disc around HD141569A

    OpenAIRE

    Thi, Wing-Fai; Pinte, Christophe; Pantin, Eric; Augereau, Jean-Charles; Meeus, Gwendolyn; Ménard, Francois; Martin-Zaidi, Claire; Woitke, Peter; Riviere-Marichalar, Pablo; Kamp, Inga; Carmona, Andres; Sandell, Goran; Eiroa, Carlos; Dent, William; Montesinos, Benjamin

    2013-01-01

    At the distance of ˜ 99-116 pc, HD141569A is one of the nearest HerbigAe stars that is surrounded by a tenuous disc, probably in transition between a massive primordial disc and a debris disc. We observed the fine-structure lines of O I at 63 and 145 μm , and the C II line at 157 μm with the PACS instrument on board the Herschel Space Telescope as part of the open-time large programme GASPS. We complemented the atomic line observations with Spitzer spectroscopic and photometric continuum data...

  17. Temporal stereophotogrammetric analysis of retrogressive thaw slumps on Herschel Island, Yukon Territory

    Directory of Open Access Journals (Sweden)

    H. Lantuit

    2005-01-01

    Full Text Available The western Canadian Arctic is identified as an area of potentially significant global warming. Thawing permafrost, sea level rise, changing sea ice conditions and increased wave activity will result in accelerated rates of coastal erosion and thermokarst activity in areas of ice-rich permafrost. The Yukon Coastal Plain is widely recognized as one of the most ice-rich and thaw-sensitive areas in the Canadian Arctic. In particular, Herschel Island displays extensive coastal thermokarst. Retrogressive thaw slumps are a common thermokarst landform along the Herschel Island coast that have been increasing in both frequency and extent have in recent years due to increased thawing of massive ground ice and coastal erosion. The volume of sediment and ground ice eroded by retrogressive slump activity and the potential release of climate change related materials like organic carbon, carbon dioxide and methane are largely unknown. The remote setting of Herschel Island, and the Arctic in general, make direct observation of this type of erosion and the analysis of potential climate feedbacks extremely problematic. Remote sensing provides possibly the best solution to this problem. This study looks at two retrogressive thaw slumps located on the western shore of Herschel Island and using stereophotogrammetric methods attempts to (1 develop the first three-dimensional geomorphic analysis of this type of landform, and (2 provide an estimation of the volume of sediment/ground ice eroded through back wasting thermokarst activity. Digital Elevation Models were extracted for the years 1952, 1970 and 2004 and validated using data collected in the field using Kinematic Differential Global Positioning System. Estimates of sediment volumes eroded from retrogressive thaw slumps were found to vary greatly. In one case the total volume of material lost for the 1970–2004 period was approximately 1560000m3. The estimated volume of sediment alone was 360000m3. The

  18. VizieR Online Data Catalog: Draco nebula Herschel 250um map (Miville-Deschenes+, 2017)

    Science.gov (United States)

    Miville-Deschenes, M.-A.; Salome, 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

    Draco was observed with Herschel PACS (110 and 170um) and SPIRE (250, 350 and 500um) as part of the open-time program "First steps toward star formation: unveiling the atomic to molecular transition in the diffuse interstellar medium" (P.I. M-A Miville-Deschenes). A field of 3.85x3.85 was observed in parallel mode. Unfortunately, an error occurred during the acquisition of the PACS data making them unusable. Therefore, the results presented here are solely based on SPIRE data, especially the 250um map that has the highest angular resolution. (2 data files).

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

    Science.gov (United States)

    De Buizer, James M.; Liu, Mengyao; Tan, Jonathan C.; Zhang, Yichen; Beltrán, Maria T.; Shuping, Ralph; Staff, Jan E.; Tanaka, Kei E. I.; Whitney, Barbara

    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 μm. 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 * ˜ 10-50 M ⊙ accreting at ˜10-4-10-3 M ⊙ yr-1 inside cores of initial masses M c ˜ 30-500 M ⊙ embedded in clumps with mass surface densities Σcl ˜ 0.1-3 g cm-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.

  20. 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.

    2018-01-01

    We perform lens modelling and source reconstruction of Submillimeter 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 dataset 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 star formation rate surface density ΣSFR ˜ 132 M⊙yr-1 kpc-2 (or ˜218 M⊙yr-1 kpc-2 for the Gaussian fit). This is consistent with what observed for other star forming galaxies at similar redshifts, and is significantly below the Eddington limit for a radiation pressure regulated starburst.

  1. Infrared Thermometers

    Science.gov (United States)

    Schaefers, John

    2006-01-01

    An infrared (IR) thermometer lab offers the opportunity to give science students a chance to measure surface temperatures, utilizing off-the-shelf technology. Potential areas of study include astronomy (exoplanets), electromagnetic spectrum, chemistry, evaporation rates, anatomy, crystal formation, and water or liquids. This article presents one…

  2. A near-infrared interferometric survey of debris-disc stars. III. First statistics based on 42 stars observed with CHARA/FLUOR

    Science.gov (United States)

    Absil, O.; Defrère, D.; Coudé du Foresto, V.; Di Folco, E.; Mérand, A.; Augereau, J.-C.; Ertel, S.; Hanot, C.; Kervella, P.; Mollier, B.; Scott, N.; Che, X.; Monnier, J. D.; Thureau, N.; Tuthill, P. G.; ten Brummelaar, T. A.; McAlister, H. A.; Sturmann, J.; Sturmann, L.; Turner, N.

    2013-07-01

    Context. Dust is expected to be ubiquitous in extrasolar planetary systems owing to the dynamical activity of minor bodies. Inner dust populations are, however, still poorly known because of the high contrast and small angular separation with respect to their host star, and yet, a proper characterisation of exozodiacal dust is mandatory for the design of future Earth-like planet imaging missions. Aims: We aim to determine the level of near-infrared exozodiacal dust emission around a sample of 42 nearby main sequence stars with spectral types ranging from A to K and to investigate its correlation with various stellar parameters and with the presence of cold dust belts. Methods: We use high-precision K-band visibilities obtained with the FLUOR interferometer on the shortest baseline of the CHARA array. The calibrated visibilities are compared with the expected visibility of the stellar photosphere to assess whether there is an additional, fully resolved circumstellar emission source. Results: Near-infrared circumstellar emission amounting to about 1% of the stellar flux is detected around 13 of our 42 target stars. Follow-up observations showed that one of them (eps Cep) is associated with a stellar companion, while another one was detected around what turned out to be a giant star (kap CrB). The remaining 11 excesses found around single main sequence stars are most probably associated with hot circumstellar dust, yielding an overall occurrence rate of 28+8-6 for our (biased) sample. We show that the occurrence rate of bright exozodiacal discs correlates with spectral type, K-band excesses being more frequent around A-type stars. It also correlates with the presence of detectable far-infrared excess emission in the case of solar-type stars. Conclusions: This study provides new insight into the phenomenon of bright exozodiacal discs, showing that hot dust populations are probably linked to outer dust reservoirs in the case of solar-type stars. For A-type stars, no

  3. Herschel/PACS observations of young sources in Taurus : The far-infrared counterpart of optical jets

    NARCIS (Netherlands)

    Podio, L.; Kamp, I.; Flower, D.; Howard, C.; Sandell, G.; Mora, A.; Aresu, G.; Brittain, S.; Dent, W. R. F.; Pinte, C.; White, G. J.

    Context. Observations of the atomic and molecular line emission associated with jets and outflows emitted by young stellar objects provide sensitive diagnostics of the excitation conditions, and can be used to trace the various evolutionary stages they pass through as they evolve to become main

  4. New constraints on the CH4 vertical profile in Uranus and Neptune from Herschel observations

    Science.gov (United States)

    Lellouch, E.; Moreno, R.; Orton, G. S.; Feuchtgruber, H.; Cavalié, T.; Moses, J. I.; Hartogh, P.; Jarchow, C.; Sagawa, H.

    2015-07-01

    Dedicated line observations of CH4 rotational lines performed with Herschel/PACS and HIFI in 2009-2011 provide new inferences of the mean methane profile in the upper tropospheres and stratospheres of Uranus and Neptune. At Uranus, CH4 is found to be near saturation, with a ~9 × 10-4 tropopause/lower stratosphere mole fraction. This is nominally six times larger than inferred from Spitzer in 2007, although reconciliation may be possible if the CH4 abundance decreases sharply from ~100 to 2 mbar. This unexpected situation might reflect heterogeneous conditions in Uranus' stratosphere, with local CH4 depletions and heating associated with downwelling motions. Higher CH4 abundances compared to values inferred under solstitial conditions by Voyager in 1989 suggest that atmospheric mixing is effectively subdued at high latitudes and/or is time-variable. At Neptune, the mid-stratosphere CH4 abundance is (1.15 ± 0.10) × 10-3, in agreement with earlier determinations and indicative of either leakage through a warmer polar region or upwelling at low or middle latitudes. On both planets, spatially resolved observations of temperature and methane in the stratosphere are needed to further identify the physical processes at work. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  5. 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.

  6. The data processing pipeline for the Herschel SPIRE Fourier Transform Spectrometer

    Science.gov (United States)

    Fulton, T.; Naylor, D. A.; Polehampton, E. T.; Valtchanov, I.; Hopwood, R.; Lu, N.; Baluteau, J.-P.; Mainetti, G.; Pearson, C.; Papageorgiou, A.; Guest, S.; Zhang, L.; Imhof, P.; Swinyard, B. M.; Griffin, M. J.; Lim, T. L.

    2016-05-01

    We present the data processing pipeline to generate calibrated data products from the Spectral and Photometric Imaging Receiver (SPIRE) imaging Fourier Transform Spectrometer on the Herschel Space Observatory. The pipeline processes telemetry from SPIRE observations and produces calibrated spectra for all resolution modes. The spectrometer pipeline shares some elements with the SPIRE photometer pipeline, including the conversion of telemetry packets into data timelines and calculation of bolometer voltages. We present the following fundamental processing steps unique to the spectrometer: temporal and spatial interpolation of the scan mechanism and detector data to create interferograms; Fourier transformation; apodization; and creation of a data cube. We also describe the corrections for various instrumental effects including first- and second-level glitch identification and removal, correction of the effects due to emission from the Herschel telescope and from within the spectrometer instrument, interferogram baseline correction, temporal and spatial phase correction, non-linear response of the bolometers, and variation of instrument performance across the focal plane arrays. Astronomical calibration is based on combinations of observations of standard astronomical sources and regions of space known to contain minimal emission.

  7. The VLTI/MIDI view on the inner mass loss of evolved stars from the Herschel MESS sample

    Science.gov (United States)

    Paladini, C.; Klotz, D.; Sacuto, S.; Lagadec, E.; Wittkowski, M.; Richichi, A.; Hron, J.; Jorissen, A.; Groenewegen, M. A. T.; Kerschbaum, F.; Verhoelst, T.; Rau, G.; Olofsson, H.; Zhao-Geisler, R.; Matter, A.

    2017-04-01

    Context. The mass-loss process from evolved stars is a key ingredient for our understanding of many fields of astrophysics, including stellar evolution and the chemical enrichment of the interstellar medium (ISM) via stellar yields. Nevertheless, many questions are still unsolved, one of which is the geometry of the mass-loss process. Aims: Taking advantage of the results from the Herschel Mass loss of Evolved StarS (MESS) programme, we initiated a coordinated effort to characterise the geometry of mass loss from evolved red giants at various spatial scales. Methods: For this purpose we used the MID-infrared interferometric Instrument (MIDI) to resolve the inner envelope of 14 asymptotic giant branch stars (AGBs) in the MESS sample. In this contribution we present an overview of the interferometric data collected within the frame of our Large Programme, and we also add archive data for completeness. We studied the geometry of the inner atmosphere by comparing the observations with predictions from different geometric models. Results: Asymmetries are detected for the following five stars: R Leo, RT Vir, π1Gruis, omi Ori, and R Crt. All the objects are O-rich or S-type, suggesting that asymmetries in the N band are more common among stars with such chemistry. We speculate that this fact is related to the characteristics of the dust grains. Except for one star, no interferometric variability is detected, i.e. the changes in size of the shells of non-mira stars correspond to changes of the visibility of less than 10%. The observed spectral variability confirms previous findings from the literature. The detection of dust in our sample follows the location of the AGBs in the IRAS colour-colour diagram: more dust is detected around oxygen-rich stars in region II and in the carbon stars in region VII. The SiC dust feature does not appear in the visibility spectrum of the U Ant and S Sct, which are two carbon stars with detached shells. This finding has implications for

  8. Observations of Herbig Ae/Be Stars with Herschel/PACS: The Atomic and Molecular Contents of Their Protoplanetary Discs

    Science.gov (United States)

    Meeus, G.; Montesinos, B.; Mendigutia, I.; Kamp, I.; Thi, W. F.; Eiroa, C.; Grady, C. A.; Mathews, G.; Sandell, G.; Martin-Zaidi, C.; hide

    2012-01-01

    We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part of the GAS in Protoplanetary Systems (GASPS) project. The observations were done in spectroscopic mode, and cover the far-infrared lines of [OI], [CII], CO, CH+, H20, and OH. We have a [OI]63 micro/ detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. The [OI] 145 micron line is only detected in 25% and CO J = 18-17 in 45% (and fewer cases for higher J transitions) of the Herbig Ae/Be stars, while for [CII] 157 micron, we often find spatially variable background contamination. We show the first detection of water in a Herbig Ae disc, HD 163296, which has a settled disc. Hydroxyl is detected as well in this disc. First seen in HD 100546, CH+ emission is now detected for the second time in a Herbig Ae star, HD 97048. We report fluxes for each line and use the observations as line diagnostics of the gas properties. Furthermore, we look for correlations between the strength of the emission lines and either the stellar or disc parameters, such as stellar luminosity, ultraviolet and X-ray flux. accretion rate, polycyclic aromatic hydrocarbon (PAH) band strength, and flaring. We find that the stellar ultraviolet flux is the dominant excitation mechanism of [OI] 63 micron, with the highest line fluxes being found in objects with a large amount of flaring and among the largest PAH strengths. Neither the amount of accretion nor the X-ray luminosity has an influence on the line strength. We find correlations between the line flux of [OI]63 micron and [OI] 145 micron, CO J = IS-17 and [OI] 6300 A, and between the continuum flux at 63 micron and at 1.3 mm, while we find weak correlations between the line flux. of [OI] 63 micron and the PAH luminosity, the line flux of CO J = 3-2, the continuum flux at 63 pm, the stellar effective temperature, and the Br-gamma luminosity. Finally, we use a combination of the [OI] 63 micron and C(12)O J

  9. CHIMPS: the 13CO/C18O (J = 3 → 2) Heterodyne Inner Milky Way Plane Survey

    Science.gov (United States)

    Rigby, A. J.; Moore, T. J. T.; Plume, R.; Eden, D. J.; Urquhart, J. S.; Thompson, M. A.; Mottram, J. C.; Brunt, C. M.; Butner, H. M.; Dempsey, J. T.; Gibson, S. J.; Hatchell, J.; Jenness, T.; Kuno, N.; Longmore, S. N.; Morgan, L. K.; Polychroni, D.; Thomas, H.; White, G. J.; Zhu, M.

    2016-03-01

    We present the 13CO/C18O (J = 3 → 2) Heterodyne Inner Milky Way Plane Survey (CHIMPS) which has been carried out using the Heterodyne Array Receiver Program on the 15 m James Clerk Maxwell Telescope (JCMT) in Hawaii. The high-resolution spectral survey currently covers |b| ≤ 0.5° and 28° ≲ l ≲ 46°, with an angular resolution of 15 arcsec in 0.5 km s-1 velocity channels. The spectra have a median rms of ˜0.6 K at this resolution, and for optically thin gas at an excitation temperature of 10 K, this sensitivity corresponds to column densities of NH2 ˜ 3 × 1020 cm-2 and NH2 ˜ 4 × 1021 cm-2 for 13CO and C18O, respectively. The molecular gas that CHIMPS traces is at higher column densities and is also more optically thin than in other publicly available CO surveys due to its rarer isotopologues, and thus more representative of the three-dimensional structure of the clouds. The critical density of the J = 3 → 2 transition of CO is ≳104 cm-3 at temperatures of ≤20 K, and so the higher density gas associated with star formation is well traced. These data complement other existing Galactic plane surveys, especially the JCMT Galactic Plane Survey which has similar spatial resolution and column density sensitivity, and the Herschel infrared Galactic Plane Survey. In this paper, we discuss the observations, data reduction and characteristics of the survey, presenting integrated-emission maps for the region covered. Position-velocity diagrams allow comparison with Galactic structure models of the Milky Way, and while we find good agreement with a particular four-arm model, there are some significant deviations.

  10. 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 extende