Mid-Infrared Spectral Properties of IR QSOs

International Nuclear Information System (INIS)

Xia, X. Y.; Cao, C.; Mao, S.; Deng, Z. G.

2008-01-01

We analyse mid-infrared (MIR) spectroscopic properties for 19 ultra-luminous infrared quasars (IR QSOs) in the local universe based on the spectra from the Infrared Spectrograph on board the Spitzer Space Telescope. The MIR properties of IR QSOs are compared with those of optically-selected Palomar-Green QSOs (PG QSOs) and ultra-luminous infrared galaxies (ULIRGs). The average MIR spectral features from ∼5 to 30 μm, including the spectral slopes, 6.2 μm PAH emission strengths and [NeII] 12.81 μm luminosities of IR QSOs, differ from those of PG QSOs. In contrast, IR QSOs and ULIRGs have comparable PAH and [NeII] luminosities. These results are consistent with IR QSOs being at a transitional stage from ULIRGs to classical QSOs. We also find the correlation between the EW (PAH 6.2 μm) and outflow velocities suggests that star formation activities are suppressed by feedback from AGNs and/or supernovae.

THE CONTRIBUTION OF TP-AGB STARS TO THE MID-INFRARED COLORS OF NEARBY GALAXIES

International Nuclear Information System (INIS)

Chisari, Nora E.; Kelson, Daniel D.

2012-01-01

We study the mid-infrared color space of 30 galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) survey for which Sloan Digital Sky Survey data are also available. We construct two-color maps for each galaxy and compare them to results obtained from combining Maraston evolutionary synthesis models, galactic thermally pulsating asymptotic giant branch (TP-AGB) colors, and smooth star formation histories. For most of the SINGS sample, the spatially extended mid-IR emission seen by Spitzer in normal galaxies is consistent with our simple model in which circumstellar dust from TP-AGB stars dominates at 8 and 24 μm. There is a handful of exceptions that we identify as galaxies that have high star formation rates presumably with star formation histories that cannot be assumed to be smooth, or anemic galaxies, which were depleted of their H I at some point during their evolution and have very low ongoing star formation rates.

THE CONTRIBUTION OF TP-AGB STARS TO THE MID-INFRARED COLORS OF NEARBY GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Chisari, Nora E. [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Kelson, Daniel D., E-mail: nchisari@astro.princeton.edu [Observatories of the Carnegie Institution of Science, 813 Santa Barbara St., Pasadena, CA 91101 (United States)

2012-07-10

We study the mid-infrared color space of 30 galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) survey for which Sloan Digital Sky Survey data are also available. We construct two-color maps for each galaxy and compare them to results obtained from combining Maraston evolutionary synthesis models, galactic thermally pulsating asymptotic giant branch (TP-AGB) colors, and smooth star formation histories. For most of the SINGS sample, the spatially extended mid-IR emission seen by Spitzer in normal galaxies is consistent with our simple model in which circumstellar dust from TP-AGB stars dominates at 8 and 24 {mu}m. There is a handful of exceptions that we identify as galaxies that have high star formation rates presumably with star formation histories that cannot be assumed to be smooth, or anemic galaxies, which were depleted of their H I at some point during their evolution and have very low ongoing star formation rates.

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Mid-infrared followup of cold brown dwarfs: diversity in age, mass and metallicity

Energy Technology Data Exchange (ETDEWEB)

Saumon, Didier [Los Alamos National Laboratory; Leggett, Sandy K [GEMINI OBSERVATORY; Burningham, Ben [HERTFORDSHITE UNIV; Marley, Mark S [NASA AMES; Waren, S J [IMPERIAL COLLEGE LONDON; Jones, H R A [HERTFORDSHIRE U; Pinfield, D J [HERTFORDSHIRE U; Smart, R L [ASTRONOMICAL OBS

2009-01-01

We present new Spitzer IRAC [3.6], [4.5], [5.8] and [8.0] photometry of nine very late-type T dwarfs. Combining this with previously published photometry, we investigate trends with type and color that are useful for both the planning and interpretation of infrared surveys designed to discover the coldest T or Y dwarfs. Brown dwarfs with effective temperature (T{sub eff}) below 700 K emit more than half their flux at wavelengths longer than 3 {micro}m, and the ratio of the mid-infrared flux to the near-infrared flux becomes very sensitive to T{sub eff} at these low temperatures. We confirm that the color H (1.6 {micro}m) - [4.5] is a good indicator of T{sub eff} with a relatively weak dependence on metallicity and gravity. Conversely, the colors H - K (2.2 {micro}m) and [4.5] - [5.8] are sensitive to metallicity and gravity. Thus near- and mid-infrared photometry provide useful indicators of the fundamental properties of brown dwarfs, and if temperature and gravity are known, then mass and age can be reliably determined from evolutionary models. There are twelve dwarfs currently known with H - [4.5] > 3.0, and {approx} 500 < T{sub eff} K {approx}< 800, which we examine in detail. The ages of the dwarfs in the sample range from very young (0.1 - 1.0 Gyr) to relatively old (3 - 12 Gyr). The mass range is possibly as low as 5 Jupiter masses to up to 70 Jupiter masses, i.e. near the hydrogen burning limit. The metallicities also span a large range, from [m/H]= -0.3 to [m/H]= +0.2. The small number of T8 - T9 dwarfs found in the UKIRT Infrared Deep Sky Survey to date appear to be predominantly young low-mass dwarfs. Accurate mid-infrared photometry of cold brown dwarfs is essentially impossible from the ground, and extensions to the mid-infrared space missions warm-Spitzer and WISE are desirable in order to obtain the vital mid-infrared data for cold brown dwarfs, and to discover more of these rare objects.

SPIRITS: Uncovering Unusual Infrared Transients with Spitzer

International Nuclear Information System (INIS)

Kasliwal, Mansi M.; Jencson, Jacob E.; Tinyanont, Samaporn; Cao, Yi; Cook, David; Bally, John; Masci, Frank; Armus, Lee; Cody, Ann Marie; Bond, Howard E.; Contreras, Carlos; Dykhoff, Devin A.; Amodeo, Samuel; Carlon, Robert L.; Cass, Alexander C.; Corgan, David T.; Faella, Joseph; Boyer, Martha; Cantiello, Matteo; Fox, Ori D.

2017-01-01

We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS—SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer /IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between −11 and −14 (Vega-mag) and [3.6]–[4.5] colors between 0.3 mag and 1.6 mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1 mag yr −1 to >7 mag yr −1 . SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.

SPIRITS: Uncovering Unusual Infrared Transients with Spitzer

Energy Technology Data Exchange (ETDEWEB)

Kasliwal, Mansi M.; Jencson, Jacob E.; Tinyanont, Samaporn; Cao, Yi; Cook, David [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Bally, John [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Masci, Frank; Armus, Lee [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Cody, Ann Marie [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Bond, Howard E. [Dept. of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Contreras, Carlos [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Dykhoff, Devin A.; Amodeo, Samuel; Carlon, Robert L.; Cass, Alexander C.; Corgan, David T.; Faella, Joseph [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States); Boyer, Martha [NASA Goddard Space Flight Center, MC 665, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Cantiello, Matteo [Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Avenue, New York, NY 10010 (United States); Fox, Ori D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

2017-04-20

We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS—SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer /IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between −11 and −14 (Vega-mag) and [3.6]–[4.5] colors between 0.3 mag and 1.6 mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1 mag yr{sup −1} to >7 mag yr{sup −1}. SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.

MID-INFRARED PHOTOMETRY OF COLD BROWN DWARFS: DIVERSITY IN AGE, MASS, AND METALLICITY

International Nuclear Information System (INIS)

Leggett, S. K.; Burningham, Ben; Jones, H. R. A.; Lucas, P. W.; Pinfield, D. J.; Saumon, D.; Marley, M. S.; Warren, S. J.; Smart, R. L.; Tamura, Motohide

2010-01-01

We present new Spitzer Infrared Array Camera (IRAC) photometry of 12 very late-type T dwarfs: nine have [3.6], [4.5], [5.8], and [8.0] photometry and three have [3.6] and [4.5] photometry only. Combining this with previously published photometry, we investigate trends with type and color that are useful for both the planning and interpretation of infrared surveys designed to discover the coldest T or Y dwarfs. The online appendix provides a collation of MKO-system YJHKL'M' and IRAC photometry for a sample of M, L, and T dwarfs. Brown dwarfs with effective temperature (T eff ) below 700 K emit more than half their flux at wavelengths longer than 3 μm, and the ratio of the mid-infrared flux to the near-infrared flux becomes very sensitive to T eff at these low temperatures. We confirm that the color H (1.6 μm) - [4.5] is a good indicator of T eff with a relatively weak dependence on metallicity and gravity. Conversely, the colors H - K (2.2 μm) and [4.5] - [5.8] are sensitive to metallicity and gravity. Thus, near- and mid-infrared photometry provide useful indicators of the fundamental properties of brown dwarfs, and if temperature and gravity are known, then mass and age can be reliably determined from evolutionary models. There are 12 dwarfs currently known with H- [4.5] >3.0, and 500 K ∼ eff ∼<800 K, which we examine in detail. The ages of the dwarfs in the sample range from very young (0.1-1.0 Gyr) to relatively old (3-12 Gyr). The mass range is possibly as low as 5 Jupiter masses to up to 70 Jupiter masses, i.e., near the hydrogen burning limit. The metallicities also span a large range, from [m/H] = -0.3 to [m/H] = +0.3. The small number of T8-T9 dwarfs found in the UK Infrared Telescope Infrared Deep Sky Survey to date appear to be predominantly young low-mass dwarfs. Accurate mid-infrared photometry of cold brown dwarfs is essentially impossible from the ground, and extensions to the mid-infrared space missions, warm-Spitzer and Wide-Field Infrared

Mid-Infrared Observations of Possible Intergalactic Star Forming Regions in the Leo Ring

Science.gov (United States)

Giroux, Mark; Smith, B.; Struck, C.

2011-05-01

Within the Leo group of galaxies lies a gigantic loop of intergalactic gas known as the Leo Ring. Not clearly associated with any particular galaxy, its origin remains uncertain. It may be a primordial intergalactic cloud alternatively, it may be a collision ring, or have a tidal origin. Combining archival Spitzer images of this structure with published UV and optical data, we investigate the mid-infrared properties of possible knots of star formation in the ring. These sources are very faint in the mid-infrared compared to star forming regions in the tidal features of interacting galaxies. This suggests they are either deficient in dust, or they may not be associated with the ring.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-10-01

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

A Cometary Bow Shock and Mid-Infrared Emission Variations Revealed in Spitzer Observations of HD 34078 and IC 405

OpenAIRE

France, Kevin; McCandliss, Stephan R.; Lupu, Roxana E.

2006-01-01

We present new infrared observations of the emission/reflection nebula IC 405 obtained with the Spitzer Space Telescope. Infrared images in the four IRAC bands (3.6, 4.5, 5.8, and 8.0 um) and two MIPS bands (24 and 70 um) are complemented by IRS spectroscopy (5-30 um) of two nebular filaments. The IRAC (8.0 um) and MIPS imaging shows evidence of a bow shock associated with the runaway O9.5V star, HD 34078, created by the interaction between the star and nebular material. The ratio of emission...

EVIDENCE FOR DYNAMICAL CHANGES IN A TRANSITIONAL PROTOPLANETARY DISK WITH MID-INFRARED VARIABILITY

International Nuclear Information System (INIS)

Muzerolle, James; Flaherty, Kevin; Balog, Zoltan; Smith, Paul S.; Rieke, George H.; Furlan, Elise; Allen, Lori; Muench, August; Calvet, Nuria; D'Alessio, Paola; Megeath, S. Thomas; Sherry, William H.

2009-01-01

We present multi-epoch Spitzer Space Telescope observations of the transitional disk LRLL 31 in the 2-3 Myr old star-forming region IC 348. Our measurements show remarkable mid-infrared variability on timescales as short as one week. The infrared continuum emission exhibits systematic wavelength-dependent changes that suggest corresponding dynamical changes in the inner disk structure and variable shadowing of outer disk material. We propose several possible sources for the structural changes, including a variable accretion rate or a stellar or planetary companion embedded in the disk. Our results indicate that variability studies in the infrared can provide important new constraints on protoplanetary disk behavior.

THE ORIGIN OF THE INFRARED EMISSION IN RADIO GALAXIES. II. ANALYSIS OF MID- TO FAR-INFRARED SPITZER OBSERVATIONS OF THE 2JY SAMPLE

International Nuclear Information System (INIS)

Dicken, D.; Tadhunter, C.; Axon, D.; Morganti, R.; Inskip, K. J.; Holt, J.; Groves, B.; Delgado, R. Gonzalez

2009-01-01

We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05 < z < 0.7), conducting a statistical investigation of the links between radio jet, active galactic nucleus (AGN), starburst activity and MFIR properties. This is part of an ongoing extensive study of powerful radio galaxies that benefits from both complete optical emission line information and a uniquely high detection rate in the far-infrared (far-IR). We find tight correlations between the MFIR and [O III]λ5007 emission luminosities, which are significantly better than those between MFIR and extended radio luminosities, or between radio and [O III] luminosities. Since [O III] is a known indicator of intrinsic AGN power, these correlations confirm AGN illumination of the circumnuclear dust as the primary heating mechanism for the dust producing thermal MFIR emission at both 24 and 70 μm. We demonstrate that AGN heating is energetically feasible, and identify the narrow-line region clouds as the most likely location of the cool, far-IR emitting dust. Starbursts make a major contribution to the heating of the cool dust in only 15%-28% of our targets. We also investigate the orientation dependence of the continuum properties, finding that the broad- and narrow-line objects in our sample with strong emission lines have similar distributions of MFIR luminosities and colors. Therefore our results are entirely consistent with the orientation-based unified schemes for powerful radio galaxies. However, the weak line radio galaxies form a separate class of objects with intrinsically low-luminosity AGNs in which both the optical emission lines and the MFIR continuum are weak.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

THE SPITZER-WISE SURVEY OF THE ECLIPTIC POLES

International Nuclear Information System (INIS)

Jarrett, T. H.; Masci, F.; Cutri, R. M.; Marsh, K.; Padgett, D.; Tsai, C. W.; Cohen, M.; Wright, E.; Petty, S.; Stern, D.; Eisenhardt, P.; Mainzer, A.; Ressler, M.; Benford, D.; Blain, A.; Carey, S.; Surace, J.; Lonsdale, C.; Skrutskie, M.; Stanford, S.

2011-01-01

We have carried out a survey of the north and south ecliptic poles, EP-N and EP-S, respectively, with the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer (WISE). The primary objective was to cross-calibrate WISE with the Spitzer and Midcourse Space Experiment (MSX) photometric systems by developing a set of calibration stars that are common to these infrared missions. The ecliptic poles were continuous viewing zones for WISE due to its polar-crossing orbit, making these areas ideal for both absolute and internal calibrations. The Spitzer IRAC and MIPS imaging survey covers a complete area of 0.40 deg 2 for the EP-N and 1.28 deg 2 for the EP-S. WISE observed the whole sky in four mid-infrared bands, 3.4, 4.6, 12, and 22 μm, during its eight-month cryogenic mission, including several hundred ecliptic polar passages; here we report on the highest coverage depths achieved by WISE, an area of ∼1.5 deg 2 for both poles. Located close to the center of the EP-N, the Sy-2 galaxy NGC 6552 conveniently functions as a standard calibrator to measure the red response of the 22 μm channel of WISE. Observations from Spitzer-IRAC/MIPS/IRS-LL and WISE show that the galaxy has a strong red color in the mid-infrared due to star-formation and the presence of an active galactic nucleus (AGN), while over a baseline >1 year the mid-IR photometry of NGC 6552 is shown to vary at a level less than 2%. Combining NGC 6552 with the standard calibrator stars, the achieved photometric accuracy of the WISE calibration, relative to the Spitzer and MSX systems, is 2.4%, 2.8%, 4.5%, and 5.7% for W1 (3.4 μm), W2 (4.6 μm), W3 (12 μm), and W4 (22 μm), respectively. The WISE photometry is internally stable to better than 0.1% over the cryogenic lifetime of the mission. The secondary objective of the Spitzer-WISE Survey was to explore the poles at greater flux-level depths, exploiting the higher angular resolution Spitzer observations and the exceptionally deep (in total

Broadband integrated mid infrared light sources as enabling technology for point of care mid-infrared spectroscopy

Science.gov (United States)

2017-08-20

AFRL-AFOSR-JP-TR-2017-0061 Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy Alex...mid-infrared light sources as enabling technology for point-of-care mid-infrared spectroscopy 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-16-1-4037...Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy ” Date: 16th August 2017 Name

SPITZER SPACE TELESCOPE MID-IR LIGHT CURVES OF NEPTUNE

Energy Technology Data Exchange (ETDEWEB)

Stauffer, John; Rebull, Luisa; Carey, Sean J.; Krick, Jessica; Ingalls, James G.; Lowrance, Patrick; Glaccum, William [Spitzer Science Center (SSC), California Institute of Technology, Pasadena, CA 91125 (United States); Marley, Mark S. [NASA Ames Research Center, Space Sciences and Astrobiology Division, MS245-3, Moffett Field, CA 94035 (United States); Gizis, John E. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Kirkpatrick, J. Davy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Simon, Amy A. [NASA Goddard Space Flight Center, Solar System Exploration Division (690.0), 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Wong, Michael H. [University of California, Department of Astronomy, Berkeley CA 94720-3411 (United States)

2016-11-01

We have used the Spitzer Space Telescope in 2016 February to obtain high cadence, high signal-to-noise, 17 hr duration light curves of Neptune at 3.6 and 4.5 μ m. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1 mag at 3.6 μ m and 0.6 mag at 4.5 μ m. We have also extracted sparsely sampled 18 hr light curves of Neptune at W1 (3.4 μ m) and W2 (4.6 μ m) from the Wide-feld Infrared Survey Explorer ( WISE )/ NEOWISE archive at six epochs in 2010–2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler / K 2 in the visible (amplitude ∼0.02 mag) or at 845 nm with the Hubble Space Telescope ( HST ) in 2015 and at 763 nm in 2016 (amplitude ∼0.2 mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune’s atmosphere than for K 2. Methane gas is the dominant opacity source in Neptune’s atmosphere, and methane absorption bands are present in the HST 763 and 845 nm, WISE W1, and Spitzer 3.6 μ m filters.

Mid-Infrared Silicate Dust Features in Seyfert 1 Spectra

Science.gov (United States)

Thompson, Grant D.; Levenson, N. A.; Sirocky, M. M.; Uddin, S.

2007-12-01

Silicate dust emission dominates the mid-infrared spectra of galaxies, and the dust produces two spectral features, at 10 and 18 μm. These features' strengths (in emission or absorption) and peak wavelengths reveal the geometry of the dust distribution, and they are sensitive to the dust composition. We examine mid-infrared spectra of 32 Seyfert 1 active galactic nuclei (AGN), observed with the Infrared Spectrograph aboard the Spitzer Space Telescope. In the spectra, we typically find the shorter-wavelength feature in emission, at an average peak wavelength of 10.0 μm, although it is known historically as the "9.7 μm" feature. In addition, peak wavelength increases with feature strength. The 10 and 18 μm feature strengths together are sensitive to the dust geometry surrounding the central heating engine. Numerical calculations of radiative transfer distinguish between clumpy and smooth distributions, and we find that the surroundings of these AGN (the obscuring "tori" of unified AGN schemes) are clumpy. Polycyclic aromatic hydrocarbon (PAH) features are associated with star formation, and we find strong PAH emission (luminosity ≥ 1042 erg/s) in only four sources, three of which show independent evidence for starbursts. We will explore the effects of luminosity on dust geometry and chemistry in a comparison sample of quasars. We acknowledge work supported by the NSF under grant number 0237291.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-02-20

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

Nonlinear optics in germanium mid-infrared fiber material: Detuning oscillations in femtosecond mid-infrared spectroscopy

Directory of Open Access Journals (Sweden)

M. Ordu

2017-09-01

Full Text Available Germanium optical fibers hold great promise in extending semiconductor photonics into the fundamentally important mid-infrared region of the electromagnetic spectrum. The demonstration of nonlinear response in fabricated Ge fiber samples is a key step in the development of mid-infrared fiber materials. Here we report the observation of detuning oscillations in a germanium fiber in the mid-infrared region using femtosecond dispersed pump-probe spectroscopy. Detuning oscillations are observed in the frequency-resolved response when mid-infrared pump and probe pulses are overlapped in a fiber segment. The oscillations arise from the nonlinear frequency resolved nonlinear (χ(3 response in the germanium semiconductor. Our work represents the first observation of coherent oscillations in the emerging field of germanium mid-infrared fiber optics.

Spitzer Digs Up Galactic Fossil

Science.gov (United States)

2004-01-01

with stars, infrared images (middle and right), reveal a never-before-seen bundle of stars, called a globular cluster. The left panel is from the California Institute of Technology's Digitized Sky Survey; the middle panel includes images from the NASA-funded Two Micron All-Sky Survey and the University of Wyoming Infrared Observatory (circle inset); and the right panel is from NASA's Spitzer Space Telescope. The Two Micron All-Sky Survey false-color image was obtained using near-infrared wavelengths ranging from 1.3 to 2.2 microns. The University of Wyoming Observatory false-color image was captured on July 31, 2004, at wavelengths ranging from 1.2 to 2.2 microns. The Spitzer false-color image composite was taken on April 21, 2004, by its infrared array camera. It is composed of images obtained at four mid-infrared wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

Towards the mid-infrared optical biopsy

DEFF Research Database (Denmark)

Seddon, Angela B.; Benson, Trevor M.; Sujecki, Slawomir

2016-01-01

We are establishing a new paradigm in mid-infrared molecular sensing, mapping and imaging to open up the mid-infrared spectral region for in vivo (i.e. in person) medical diagnostics and surgery. Thus, we are working towards the mid-infrared optical biopsy ('opsy' look at, bio the biology) in situ...... in the body for real-time diagnosis. This new paradigm will be enabled through focused development of devices and systems which are robust, functionally designed, safe, compact and cost effective and are based on active and passive mid-infrared optical fibers. In particular, this will enable early diagnosis...... of a bright mid-infrared wideband source in a portable package as a first step for medical fiber-based systems operating in the mid-infrared. Moreover, mid-infrared molecular mapping and imaging is potentially a disruptive technology to give improved monitoring of the environment, energy efficiency, security...

The NASA Spitzer Space Telescope.

Science.gov (United States)

Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

2007-01-01

The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

THE MID-INFRARED EXTINCTION LAW AND ITS VARIATION IN THE COALSACK NEBULA

Energy Technology Data Exchange (ETDEWEB)

Wang Shu; Gao Jian; Jiang, B. W.; Chen Yang [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Li Aigen, E-mail: shuwang@mail.bnu.edu.cn, E-mail: jiangao@bnu.edu.cn, E-mail: bjiang@bnu.edu.cn, E-mail: cheny@bnu.edu.cn, E-mail: lia@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

2013-08-10

In recent years, the wavelength dependence of interstellar extinction from the ultraviolet (UV) to the near- and mid-infrared (IR) has been studied extensively. Although it is well established that the UV/optical extinction law varies significantly among the different lines of sight, it is not clear how IR extinction varies among various environments. In this work, using the color-excess method and taking red giants as the extinction tracer, we determine interstellar extinction A{sub {lambda}} in the four Spitzer/IRAC bands in [3.6], [4.5], [5.8], [8.0] {mu}m (relative to A{sub K{sub s}}, extinction in the Two Micron All Sky Survey (2MASS) K{sub s} band at 2.16 {mu}m) of the Coalsack nebula, a nearby starless dark cloud, based on the data obtained from the 2MASS and Spitzer/GLIMPSE surveys. We select five individual regions across the nebula that span a wide variety of physical conditions ranging from diffuse and translucent to dense environments, as traced by the visual extinction, the Spitzer/MIPS 24 {mu}m emission, and CO emission. We find that A{sub {lambda}}/A{sub K{sub s}}, mid-IR extinction relative to A{sub K{sub s}}, decreases from diffuse to dense environments, which may be explained in terms of ineffective dust growth in dense regions. The mean extinction (relative to A{sub K{sub s}}) is calculated for the four IRAC bands as well and exhibits a flat mid-IR extinction law consistent with previous determinations for other regions. Extinction in the IRAC 4.5 {mu}m band is anomalously high, much higher than that of the other three IRAC bands, and cannot be explained in terms of CO and CO{sub 2} ice. Mid-IR extinction in the four IRAC bands has also been derived for four representative regions in the Coalsack Globule 2, which respectively exhibit strong ice absorption, moderate or weak ice absorption, and very weak or no ice absorption. The derived mid-IR extinction curves are all flat, with A{sub {lambda}}/A{sub K{sub s}} increasing with the decrease of the

THE MID-INFRARED EXTINCTION LAW AND ITS VARIATION IN THE COALSACK NEBULA

International Nuclear Information System (INIS)

Wang Shu; Gao Jian; Jiang, B. W.; Chen Yang; Li Aigen

2013-01-01

In recent years, the wavelength dependence of interstellar extinction from the ultraviolet (UV) to the near- and mid-infrared (IR) has been studied extensively. Although it is well established that the UV/optical extinction law varies significantly among the different lines of sight, it is not clear how IR extinction varies among various environments. In this work, using the color-excess method and taking red giants as the extinction tracer, we determine interstellar extinction A λ in the four Spitzer/IRAC bands in [3.6], [4.5], [5.8], [8.0] μm (relative to A K s , extinction in the Two Micron All Sky Survey (2MASS) K s band at 2.16 μm) of the Coalsack nebula, a nearby starless dark cloud, based on the data obtained from the 2MASS and Spitzer/GLIMPSE surveys. We select five individual regions across the nebula that span a wide variety of physical conditions ranging from diffuse and translucent to dense environments, as traced by the visual extinction, the Spitzer/MIPS 24 μm emission, and CO emission. We find that A λ /A K s , mid-IR extinction relative to A K s , decreases from diffuse to dense environments, which may be explained in terms of ineffective dust growth in dense regions. The mean extinction (relative to A K s ) is calculated for the four IRAC bands as well and exhibits a flat mid-IR extinction law consistent with previous determinations for other regions. Extinction in the IRAC 4.5 μm band is anomalously high, much higher than that of the other three IRAC bands, and cannot be explained in terms of CO and CO 2 ice. Mid-IR extinction in the four IRAC bands has also been derived for four representative regions in the Coalsack Globule 2, which respectively exhibit strong ice absorption, moderate or weak ice absorption, and very weak or no ice absorption. The derived mid-IR extinction curves are all flat, with A λ /A K s increasing with the decrease of the 3.1 μm H 2 O ice absorption optical depth τ ice

Hunting Elusive SPRITEs with Spitzer

Science.gov (United States)

Kohler, Susanna

2017-05-01

In recent years, astronomers have developed many wide-field imaging surveys in which the same targets are observed again and again. This new form of observing has allowed us to discover optical and radio transients explosive or irregular events with durations ranging from seconds to years. The dynamic infrared sky, however, has remained largely unexplored until now.Infrared ExplorationExample of a transient: SPIRITS 14ajc was visible when imaged by SPIRITS in 2014 (left) but it wasnt there during previous imaging between 2004 and 2008 (right). The bottom frame shows the difference between the two images. [Adapted from Kasliwal et al. 2017]Why hunt for infrared transients? Optical wavelengths dont allow us to observe events that are obscured, such that their own structure or their surroundings hide them from our view. Both supernovae and luminous red novae (associated with stellar mergers) are discoverable as infrared transients, and there may well be new types of transients in infrared that we havent seen before!To explore this uncharted territory, a team of scientists developed SPIRITS, the Spitzer Infrared Intensive Transients Survey. Begun in 2014, SPIRITS is a five-year long survey that uses the Spitzer Space Telescope to conduct a systematic search for mid-infrared transients in nearby galaxies.In a recent publication led by Mansi Kasliwal (Caltech and the Carnegie Institution for Science), the SPIRITS team has now detailed how their survey works and what theyve discovered in its first year.The light curves of SPRITEs (red stars) lie in the mid-infared luminosity gap between novae (orange) and supernovae (blue). [Kasliwal et al. 2017]Mystery TransientsKasliwal and collaborators used Spitzer to monitor 190 nearby galaxies. In SPIRITS first year, they found over 1958 variable stars and 43 infrared transient sources. Of these 43 transients, 21 were known supernovae, 4 were in the luminosity range of novae, and 4 had optical counterparts. The remaining 14 events

Spitzer Photometry of WISE-Selected Brown Dwarf and Hyper-Lumninous Infrared Galaxy Candidates

Science.gov (United States)

Griffith, Roger L.; Kirkpatrick, J. Davy; Eisenhardt, Peter R. M.; Gelino, Christopher R.; Cushing, Michael C.; Benford, Dominic; Blain, Andrew; Bridge, Carrie R.; Cohen, Martin; Cutri, Roc M.;

NEAR-INFRARED SPECTRA OF GALACTIC STELLAR CLUSTERS DETECTED ON SPITZER/GLIMPSE IMAGES

International Nuclear Information System (INIS)

Messineo, Maria; Davies, Ben; Figer, Donald F.; Ivanov, Valentin D.; Schuller, Frederic; Menten, Karl M.; Habing, Harm J.; Petr-Gotzens, Monika G.

2009-01-01

We present near-infrared spectroscopic observations of massive stars in three stellar clusters located in the direction of the inner Galaxy. One of them, the Quartet, is a new discovery while the other two were previously reported as candidate clusters identified on mid-infrared Spitzer images (GLIMPSE20 and GLIMPSE13). Using medium-resolution (R = 900-1320) H and K spectroscopy, we firmly establish the nature of the brightest stars in these clusters, yielding new identifications of an early WC and two Ofpe/WN9 stars in the Quartet and an early WC star in GLIMPSE20. We combine this information with the available photometric measurements from Two Micron All Sky Survey, to estimate cluster masses, ages, and distances. The presence of several massive stars places the Quartet and GLIMPSE20 among the small sample of known Galactic stellar clusters with masses of a few 10 3 M sun , and ages from 3 to 8 Myr. We estimate a distance of about 3.5 kpc for GLIMPSE20 and 6.0 kpc for Quartet. The large number of giant stars identified in GLIMPSE13 indicates that it is another massive (∼6500 M sun ) cluster, but older, with an age between 30 and 100 Myr, at a distance of about 3 kpc.

RESOLVING THE ACTIVE GALACTIC NUCLEUS AND HOST EMISSION IN THE MID-INFRARED USING A MODEL-INDEPENDENT SPECTRAL DECOMPOSITION

Energy Technology Data Exchange (ETDEWEB)

Hernán-Caballero, Antonio; Alonso-Herrero, Almudena [Instituto de Física de Cantabria, CSIC-UC, Avenida de los Castros s/n, E-39005, Santander (Spain); Hatziminaoglou, Evanthia [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Spoon, Henrik W. W. [Cornell University, CRSR, Space Sciences Building, Ithaca, NY 14853 (United States); Almeida, Cristina Ramos [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Santos, Tanio Díaz [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Hönig, Sebastian F. [School of Physics and Astronomy, University of Southampton, Southampton SO18 1BJ (United Kingdom); González-Martín, Omaira [Centro de Radioastronomía y Astrofísica (CRyA-UNAM), 3-72 (Xangari), 8701, Morelia (Mexico); Esquej, Pilar, E-mail: ahernan@ifca.unican.es [Departamento de Astrofísica, Facultad de CC. Físicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

2015-04-20

We present results on the spectral decomposition of 118 Spitzer Infrared Spectrograph (IRS) spectra from local active galactic nuclei (AGNs) using a large set of Spitzer/IRS spectra as templates. The templates are themselves IRS spectra from extreme cases where a single physical component (stellar, interstellar, or AGN) completely dominates the integrated mid-infrared emission. We show that a linear combination of one template for each physical component reproduces the observed IRS spectra of AGN hosts with unprecedented fidelity for a template fitting method with no need to model extinction separately. We use full probability distribution functions to estimate expectation values and uncertainties for observables, and find that the decomposition results are robust against degeneracies. Furthermore, we compare the AGN spectra derived from the spectral decomposition with sub-arcsecond resolution nuclear photometry and spectroscopy from ground-based observations. We find that the AGN component derived from the decomposition closely matches the nuclear spectrum with a 1σ dispersion of 0.12 dex in luminosity and typical uncertainties of ∼0.19 in the spectral index and ∼0.1 in the silicate strength. We conclude that the emission from the host galaxy can be reliably removed from the IRS spectra of AGNs. This allows for unbiased studies of the AGN emission in intermediate- and high-redshift galaxies—currently inaccesible to ground-based observations—with archival Spitzer/IRS data and in the future with the Mid-InfraRed Instrument of the James Webb Space Telescope. The decomposition code and templates are available at http://denebola.org/ahc/deblendIRS.

A SPITZER SURVEY OF PROTOPLANETARY DISK DUST IN THE YOUNG SERPENS CLOUD : HOW DO DUST CHARACTERISTICS EVOLVE WITH TIME?

NARCIS (Netherlands)

Oliveira, Isa; Pontoppidan, Klaus M.; Merin, Bruno; van Dishoeck, Ewine F.; Lahuis, Fred; Geers, Vincent C.; Jorgensen, Jes K.; Olofsson, Johan; Augereau, Jean-Charles; Brown, Joanna M.

2010-01-01

We present Spitzer InfraRed Spectrograph (IRS) mid-infrared (5-35 mu m) spectra of a complete flux-limited sample (>= 3 mJy at 8 mu m) of young stellar object (YSO) candidates selected on the basis of their infrared colors in the Serpens Molecular Cloud. Spectra of 147 sources are presented and

THE SPITZER DEEP, WIDE-FIELD SURVEY

International Nuclear Information System (INIS)

Ashby, M. L. N.; Brodwin, M.; Stern, D.; Griffith, R.; Eisenhardt, P.; Gorjian, V.; Kozlowski, S.; Kochanek, C. S.; Bock, J. J.; Borys, C.; Brand, K.; Grogin, N. A.; Brown, M. J. I.; Cool, R.; Cooray, A.; Croft, S.; Dey, A.; Eisenstein, D.; Gonzalez, A. H.; Ivison, R. J.

2009-01-01

The Spitzer Deep, Wide-Field Survey (SDWFS) is a four-epoch infrared survey of 10 deg. 2 in the Booetes field of the NOAO Deep Wide-Field Survey using the IRAC instrument on the Spitzer Space Telescope. SDWFS, a Spitzer Cycle 4 Legacy project, occupies a unique position in the area-depth survey space defined by other Spitzer surveys. The four epochs that make up SDWFS permit-for the first time-the selection of infrared-variable and high proper motion objects over a wide field on timescales of years. Because of its large survey volume, SDWFS is sensitive to galaxies out to z ∼ 3 with relatively little impact from cosmic variance for all but the richest systems. The SDWFS data sets will thus be especially useful for characterizing galaxy evolution beyond z ∼ 1.5. This paper explains the SDWFS observing strategy and data processing, presents the SDWFS mosaics and source catalogs, and discusses some early scientific findings. The publicly released, full-depth catalogs contain 6.78, 5.23, 1.20, and 0.96 x 10 5 distinct sources detected to the average 5σ, 4''-diameter, aperture-corrected limits of 19.77, 18.83, 16.50, and 15.82 Vega mag at 3.6, 4.5, 5.8, and 8.0 μm, respectively. The SDWFS number counts and color-color distribution are consistent with other, earlier Spitzer surveys. At the 6 minute integration time of the SDWFS IRAC imaging, >50% of isolated Faint Images of the Radio Sky at Twenty cm radio sources and >80% of on-axis XBooetes sources are detected out to 8.0 μm. Finally, we present the four highest proper motion IRAC-selected sources identified from the multi-epoch imaging, two of which are likely field brown dwarfs of mid-T spectral class.

PLANETARY NEBULAE DETECTED IN THE SPITZER SPACE TELESCOPE GLIMPSE II LEGACY SURVEY

International Nuclear Information System (INIS)

Zhang Yong; Sun Kwok

2009-01-01

We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of these PNs at 3.6, 4.5, 5.8, 8.0, and 24 μm, taken through the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS), are presented. Most of these nebulae are very red and compact in the IRAC bands, and are found to be bright and extended in the 24 μm band. The infrared morphology of these objects are compared with Hα images of the Macquarie-AAO-Strasbourg (MASH) and MASH II PNs. The implications for morphological difference in different wavelengths are discussed. The IRAC data allow us to differentiate between PNs and H II regions and be able to reject non-PNs from the optical catalog (e.g., PNG 352.1 - 00.0). Spectral energy distributions are constructed by combing the IRAC and MIPS data with existing near-, mid-, and far-IR photometry measurements. The anomalous colors of some objects allow us to infer the presence of aromatic emission bands. These multi-wavelength data provide useful insights into the nature of different nebular components contributing to the infrared emission of PNs.

Spitzer deep and wide legacy mid- and far-infrared number counts and lower limits of cosmic infrared background

Science.gov (United States)

Béthermin, M.; Dole, H.; Beelen, A.; Aussel, H.

2010-03-01

Aims: We aim to place stronger lower limits on the cosmic infrared background (CIB) brightness at 24 μm, 70 μm and 160 μm and measure the extragalactic number counts at these wavelengths in a homogeneous way from various surveys. Methods: Using Spitzer legacy data over 53.6 deg2 of various depths, we build catalogs with the same extraction method at each wavelength. Completeness and photometric accuracy are estimated with Monte-Carlo simulations. Number count uncertainties are estimated with a counts-in-cells moment method to take galaxy clustering into account. Furthermore, we use a stacking analysis to estimate number counts of sources not detected at 70 μm and 160 μm. This method is validated by simulations. The integration of the number counts gives new CIB lower limits. Results: Number counts reach 35 μJy, 3.5 mJy and 40 mJy at 24 μm, 70 μm, and 160 μm, respectively. We reach deeper flux densities of 0.38 mJy at 70, and 3.1 at 160 μm with a stacking analysis. We confirm the number count turnover at 24 μm and 70 μm, and observe it for the first time at 160 μm at about 20 mJy, together with a power-law behavior below 10 mJy. These mid- and far-infrared counts: 1) are homogeneously built by combining fields of different depths and sizes, providing a legacy over about three orders of magnitude in flux density; 2) are the deepest to date at 70 μm and 160 μm; 3) agree with previously published results in the common measured flux density range; 4) globally agree with the Lagache et al. (2004) model, except at 160 μm, where the model slightly overestimates the counts around 20 and 200 mJy. Conclusions: These counts are integrated to estimate new CIB firm lower limits of 2.29-0.09+0.09 nW m-2 sr-1, 5.4-0.4+0.4 nW m-2 sr-1, and 8.9-1.1+1.1 nW m-2 sr-1 at 24 μm, 70 μm, and 160 μm, respectively, and extrapolated to give new estimates of the CIB due to galaxies of 2.86-0.16+0.19 nW m-2 sr-1, 6.6-0.6+0.7 nW m-2 sr-1, and 14.6-2.9+7.1 nW m-2 sr-1

Spitzer Infrared Spectrograph Observations of the Galactic Center: Quantifying the Extreme Ultraviolet/Soft X-ray Fluxes

Science.gov (United States)

Simpson, Janet P.

2018-04-01

It has long been shown that the extreme ultraviolet spectrum of the ionizing stars of H II regions can be estimated by comparing the observed line emission to detailed models. In the Galactic Center (GC), however, previous observations have shown that the ionizing spectral energy distribution (SED) of the local photon field is strange, producing both very low excitation ionized gas (indicative of ionization by late O stars) and also widespread diffuse emission from atoms too highly ionized to be found in normal H II regions. This paper describes the analysis of all GC spectra taken by Spitzer's Infrared Spectrograph and downloaded from the Spitzer Heritage Archive. In it, H II region densities and abundances are described, and serendipitously discovered candidate planetary nebulae, compact shocks, and candidate young stellar objects are tabulated. Models were computed with Cloudy, using SEDs from Starburst99 plus additional X-rays, and compared to the observed mid-infrared forbidden and recombination lines. The ages inferred from the model fits do not agree with recent proposed star formation sequences (star formation in the GC occurring along streams of gas with density enhancements caused by close encounters with the black hole, Sgr A*), with Sgr B1, Sgr C, and the Arches Cluster being all about the same age, around 4.5 Myr old, with similar X-ray requirements. The fits for the Quintuplet Cluster appear to give a younger age, but that could be caused by higher-energy photons from shocks from stellar winds or from a supernova.

Next-generation mid-infrared sources

Science.gov (United States)

Jung, D.; Bank, S.; Lee, M. L.; Wasserman, D.

2017-12-01

The mid-infrared (mid-IR) is a wavelength range with a variety of technologically vital applications in molecular sensing, security and defense, energy conservation, and potentially in free-space communication. The recent development and rapid commercialization of new coherent mid-infrared sources have spurred significant interest in the development of mid-infrared optical systems for the above applications. However, optical systems designers still do not have the extensive optical infrastructure available to them that exists at shorter wavelengths (for instance, in the visible and near-IR/telecom wavelengths). Even in the field of optoelectronic sources, which has largely driven the growing interest in the mid-infrared, the inherent limitations of state-of-the-art sources and the gaps in spectral coverage offer opportunities for the development of new classes of lasers, light emitting diodes and emitters for a range of potential applications. In this topical review, we will first present an overview of the current state-of-the-art mid-IR sources, in particular thermal emitters, which have long been utilized, and the relatively new quantum- and interband-cascade lasers, as well as the applications served by these sources. Subsequently, we will discuss potential mid-infrared applications and wavelength ranges which are poorly served by the current stable of mid-IR sources, with an emphasis on understanding the fundamental limitations of the current source technology. The bulk of the manuscript will then explore both past and recent developments in mid-infrared source technology, including narrow bandgap quantum well lasers, type-I and type-II quantum dot materials, type-II superlattices, highly mismatched alloys, lead-salts and transition-metal-doped II-VI materials. We will discuss both the advantages and limitations of each of the above material systems, as well as the potential new applications which they might serve. All in all, this topical review does not aim

Mid-infrared spectroscopic investigation

International Nuclear Information System (INIS)

Walter, L.; Vergo, N.; Salisbury, J.W.

1987-01-01

Mid-infrared spectroscopic research efforts are discussed. The development of a new instrumentation to permit advanced measurements in the mid-infrared region of the spectrum, the development of a special library of well-characterized mineral and rock specimens for interpretation of remote sensing data, and cooperative measurements of the spectral signatures of analogues of materials that may be present on the surfaces of asteroids, planets or their Moons are discussed

A Multiwavelength Study of Cygnus X-1: The First Mid-Infrared Spectroscopic Detection of Compact Jets

Science.gov (United States)

Rahoui, Farid; Lee, Julia C.; Heinz, Sebastian; Hines, Dean C.; Pottschmidt, Katja; Wilms, Joern

2011-01-01

We report on a Spitzer/IRS (mid-infrared), RXTE /PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multi-wavelength study of the micro quasar Cygnus X-I, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break - where the transition from the optically thick to the optically thin regime takes place - at about 2.9 x 10(exp 13) Hz. We then show that the jet's optically thin synchrotron emission accounts for the Cygnus X-1's emission beyond 400 keY, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 micron mid-infrared continuum of Cygnus X-I stems from the blue supergiant companion star HD 226868. Indeed, the emission can then be understood as the combination of the photospheric Raleigh-Jeans tail and the bremsstrahlung from the expanding stellar wind. Moreover, the stellar wind is found to be clumpy, with a filling factor f(sub infinity) approx.= 0.09-0.10. Its bremsstrahlung emission is likely anti-correlated to the soft X-ray emission, suggesting an anticorrelation between the mass-loss and mass-accretion rates. Nevertheless, we do not detect any mid-infrared spectroscopic evidence of interaction between the jets and the Cygnus X-1's environment and/or companion star's stellar wind.

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

International Nuclear Information System (INIS)

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

2011-01-01

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

The gas-rich circumbinary disk of HR 4049. I. A detailed study of the mid-infrared spectrum

Energy Technology Data Exchange (ETDEWEB)

Malek, S. E.; Cami, J., E-mail: sarahemalek@gmail.com, E-mail: jcami@uwo.ca [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada)

2014-01-01

We present a detailed analysis of the mid-infrared spectrum of the peculiar evolved object HR 4049. The full Spitzer-IRS high-resolution spectrum shows a wealth of emission with prominent features from CO{sub 2} and H{sub 2}O and possible contributions from HCN and OH. We model the molecular emission and find that it originates from a massive (M ≳ 8 × 10{sup –3} M {sub ☉}), warm (T {sub ex} ≈ 500 K) and radially extended gas disk that is optically thick at infrared wavelengths. We also report less enrichment in {sup 17}O and {sup 18}O than previously found and a comparison of the Spitzer observations to earlier data obtained by the Short Wavelength Spectrometer on board the Infrared Space Observatory reveals that the CO{sub 2} flux has more than doubled in 10 yr time, indicating active and ongoing chemical evolution in the circumbinary disk. If the gas originates from interaction between the stellar wind and the dust, this suggests that the dust could be oxygen-rich in nature. The molecular gas plays a crucial role in the thermal properties of the circumbinary disk by allowing visible light to heat the dust and then trapping the infrared photons emitted by the dust. This results in higher temperatures and a more homogeneous temperature structure in the disk.

THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

International Nuclear Information System (INIS)

Lane, Ryan A.; Shemmer, Ohad; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Anderson, Scott F.; Brandt, W. N.; Schneider, Donald P.; Plotkin, Richard M.; Richards, Gordon T.; Strauss, Michael A.

2011-01-01

We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 ≤ z ≤ 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame ∼0.1-5 μm spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

Energy Technology Data Exchange (ETDEWEB)

Lane, Ryan A.; Shemmer, Ohad [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Diamond-Stanic, Aleksandar M. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093 (United States); Fan Xiaohui [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Plotkin, Richard M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam (Netherlands); Richards, Gordon T. [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Strauss, Michael A., E-mail: RyanLane@my.unt.edu, E-mail: ohad@unt.edu [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)

2011-12-20

We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 {<=} z {<=} 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame {approx}0.1-5 {mu}m spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

A MID-INFRARED VIEW OF THE HIGH MASS STAR FORMATION REGION W51A

Energy Technology Data Exchange (ETDEWEB)

Barbosa, C. L. [Laboratório Nacional de Astrofísica, R. dos Estados Unidos, Bairro das Nações, CEP 37504-364, Itajubá—MG (Brazil); Blum, R. D. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Damineli, A. [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, R. do Matão, 1226, Cid. Universitária, São Paulo 05508-900 (Brazil); Conti, P. S. [JILA, University of Colorado, Boulder, CO 80309-0440 (United States); Gusmão, D. M., E-mail: cassio.barbosa@pq.cnpq.br, E-mail: rblum@noao.edu, E-mail: augusto.damineli@iag.usp.br, E-mail: pconti@jila.colorado.edu, E-mail: danilo@univap.br [IP and D—Universidade do Vale do Paraíba, Av. Shishima Hifumi, 2911. São José dos Campos, SP, 12244-000 (Brazil)

2016-07-01

In this paper we present the results of a mid-infrared study of G49.5-0.4, or W51A, part of the massive starbirth complex W51. Combining public data from the Spitzer IRAC camera, and Gemini mid-infrared camera T-ReCS at 7.73, 9.69, 12.33, and 24.56 μ m, with a spatial resolution of ∼0.″5, we have identified the mid-infrared counterparts of eight ultracompact H ii regions, showing that two radio sources are deeply embedded in molecular clouds and another is a cloud of ionized gas. From the T-ReCS data we have unveiled the central core of the W51 region, revealing massive young stellar candidates. We modeled the spectral energy distribution of the detected sources. The results suggest that the embedded objects are sources with spectral types ranging from B3 to O5, but the majority of the fits indicate stellar objects with B1 spectral types. We also present an extinction map of IRS 2, showing that a region with lower extinction corresponds to the region where a proposed jet of gas has impacted the foreground cloud. From this map, we also derived the total extinction toward the enigmatic source IRS 2E, which amounts to ∼60 mag in the V band. We calculated the color temperature due to thermal emission of the circumstellar dust of the detected sources; the temperatures are in the interval of ∼100–150 K, which corresponds to the emission of dust located at 0.1 pc from the central source. Finally, we show a possible mid-infrared counterpart of a detected source at millimeter wavelengths that was found by Zapata et al. to be a massive young stellar object undergoing a high accretion rate.

Carnegie Hubble Program: A Mid-Infrared Calibration of the Hubble Constant

Science.gov (United States)

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Victoria; Burns, Chris; Monson, Andy; Persson, S. Eric; Seibert, Mark; Rigby, Jane

2012-01-01

Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 micrometers with the Spitzer Space Telescope, we have obtained a new, high-accuracy calibration of the Hubble constant. We have established the mid-IR zero point of the Leavitt law (the Cepheid period-luminosity relation) using time-averaged 3.6 micrometers data for 10 high-metallicity, MilkyWay Cepheids having independently measured trigonometric parallaxes. We have adopted the slope of the PL relation using time-averaged 3.6micrometers data for 80 long-period Large Magellanic Cloud (LMC) Cepheids falling in the period range 0.8 < log(P) < 1.8.We find a new reddening-corrected distance to the LMC of 18.477 +/- 0.033 (systematic) mag. We re-examine the systematic uncertainties in H(sub 0), also taking into account new data over the past decade. In combination with the new Spitzer calibration, the systematic uncertainty in H(sub 0) over that obtained by the Hubble Space Telescope Key Project has decreased by over a factor of three. Applying the Spitzer calibration to the Key Project sample, we find a value of H(sub 0) = 74.3 with a systematic uncertainty of +/-2.1 (systematic) kilometers per second Mpc(sup -1), corresponding to a 2.8% systematic uncertainty in the Hubble constant. This result, in combination with WMAP7measurements of the cosmic microwave background anisotropies and assuming a flat universe, yields a value of the equation of state for dark energy, w(sub 0) = -1.09 +/- 0.10. Alternatively, relaxing the constraints on flatness and the numbers of relativistic species, and combining our results with those of WMAP7, Type Ia supernovae and baryon acoustic oscillations yield w(sub 0) = -1.08 +/- 0.10 and a value of N(sub eff) = 4.13 +/- 0.67, mildly consistent with the existence of a fourth neutrino species.

Mid infrared lasers for remote sensing applications

Energy Technology Data Exchange (ETDEWEB)

Walsh, Brian M., E-mail: brian.m.walsh@nasa.gov [NASA Langley Research Center, Hampton, VA 23681 (United States); Lee, Hyung R. [National Institute of Aerospace, Hampton, VA 23666 (United States); Barnes, Norman P. [Science Systems and Applications, Inc., Hampton, VA 23666 (United States)

2016-01-15

To accurately measure the concentrations of atmospheric gasses, especially the gasses with low concentrations, strong absorption features must be accessed. Each molecular species or constituent has characteristic mid-infrared absorption features by which either column content or range resolved concentrations can be measured. Because of these characteristic absorption features the mid infrared spectral region is known as the fingerprint region. However, as noted by the Decadal Survey, mid-infrared solid-state lasers needed for DIAL systems are not available. The primary reason is associated with short upper laser level lifetimes of mid infrared transitions. Energy gaps between the energy levels that produce mid-infrared laser transitions are small, promoting rapid nonradiative quenching. Nonradiative quenching is a multiphonon process, the more phonons needed, the smaller the effect. More low energy phonons are required to span an energy gap than high energy phonons. Thus, low energy phonon materials have less nonradiative quenching compared to high energy phonon materials. Common laser materials, such as oxides like YAG, are high phonon energy materials, while fluorides, chlorides and bromides are low phonon materials. Work at NASA Langley is focused on a systematic search for novel lanthanide-doped mid-infrared solid-state lasers using both quantum mechanical models (theoretical) and spectroscopy (experimental) techniques. Only the best candidates are chosen for laser studies. The capabilities of modeling materials, experimental challenges, material properties, spectroscopy, and prospects for lanthanide-doped mid-infrared solid-state laser devices will be presented. - Highlights: • We discuss mid infrared lasers and laser materials. • We discuss applications to remote sensing. • We survey the lanthanide ions in low phonon materials for potential. • We present examples of praseodymium mid infrared spectroscopy and laser design.

Serendipitous discovery of an infrared bow shock near PSR J1549–4848 with Spitzer

Energy Technology Data Exchange (ETDEWEB)

Wang, Zhongxiang [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Kaplan, David L. [Physics Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53211 (United States); Slane, Patrick [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Morrell, Nidia [Las Campanas Observatory, Observatories of the Carnegie Institution of Washington, La Serena (Chile); Kaspi, Victoria M. [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada)

2013-06-01

We report on the discovery of an infrared cometary nebula around PSR J1549–4848 in our Spitzer survey of a few middle-aged radio pulsars. Following the discovery, multi-wavelength imaging and spectroscopic observations of the nebula were carried out. We detected the nebula in Spitzer Infrared Array Camera 8.0, Multiband Imaging Photometer for Spitzer 24 and 70 μm imaging, and in Spitzer IRS 7.5-14.4 μm spectroscopic observations, and also in the Wide-field Infrared Survey Explorer all-sky survey at 12 and 22 μm. These data were analyzed in detail, and we find that the nebula can be described with a standard bow shock shape, and that its spectrum contains polycyclic aromatic hydrocarbon and H{sub 2} emission features. However, it is not certain which object drives the nebula. We analyze the field stars and conclude that none of them can be the associated object because stars with a strong wind or mass ejection that usually produce bow shocks are much brighter than the field stars. The pulsar is approximately 15'' away from the region in which the associated object is expected to be located. In order to resolve the discrepancy, we suggest that a highly collimated wind could be emitted from the pulsar and produce the bow shock. X-ray imaging to detect the interaction of the wind with the ambient medium- and high-spatial resolution radio imaging to determine the proper motion of the pulsar should be carried out, which will help verify the association of the pulsar with the bow shock nebula.

Mid-Infrared Lasers

Data.gov (United States)

National Aeronautics and Space Administration — Mid infrared solid state lasers for Differential Absorption Lidar (DIAL) systems required for understanding atmospheric chemistry are not available. This program...

MID-INFRARED PROPERTIES OF THE SWIFT BURST ALERT TELESCOPE ACTIVE GALACTIC NUCLEI SAMPLE OF THE LOCAL UNIVERSE. I. EMISSION-LINE DIAGNOSTICS

International Nuclear Information System (INIS)

Weaver, K. A.; Melendez, M.; Mushotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth, E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

2010-01-01

We compare mid-infrared emission-line properties from high-resolution Spitzer spectra of a hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) active galactic nuclei (AGNs) detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission lines, [O IV] 25.89 μm, [Ne II] 12.81 μm, [Ne III] 15.56 μm, and [Ne V] 14.32/24.32 μm, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations; however, six newly discovered BAT AGNs are under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT fluxes and luminosities suggests that the emission lines primarily arise in gas ionized by the AGNs. We also compare the mid-infrared emission lines in the BAT AGNs with those from published studies of ULIRGs, Palomar-Green quasars, star-forming galaxies, and LINERs. We find that the BAT AGN sample falls into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line ratios are lower in sources that have been previously classified in the mid-infrared/optical as AGNs than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGNs represent the main contribution to the observed line emission. These ratios represent a new emission line diagnostic for distinguishing between AGNs and star-forming galaxies.

Mid-infrared upconversion spectroscopy

DEFF Research Database (Denmark)

Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin; Andersen, H. V.

2016-01-01

Mid-infrared (MIR) spectroscopy is emerging as an attractive alternative to near-infrared or visible spectroscopy. MIR spectroscopy offers a unique possibility to probe the fundamental absorption bands of a large number of gases as well as the vibrational spectra of complex molecules. In this paper...

FAR-INFRARED PROPERTIES OF SPITZER-SELECTED LUMINOUS STARBURSTS

International Nuclear Information System (INIS)

Kovacs, A.; Omont, A.; Fiolet, N.; Beelen, A.; Dole, H.; Lagache, G.; Lonsdale, C.; Polletta, M.; Greve, T. R.; Borys, C.; Dowell, C. D.; Bell, T. A.; Cox, P.; De Breuck, C.; Farrah, D.; Menten, K. M.; Owen, F.

2010-01-01

We present SHARC-2 350 μm data on 20 luminous z ∼ 2 starbursts with S 1.2 m m > 2 mJy from the Spitzer-selected samples of Lonsdale et al. and Fiolet et al. All the sources were detected, with S 350 μ m > 25 mJy for 18 of them. With the data, we determine precise dust temperatures and luminosities for these galaxies using both single-temperature fits and models with power-law mass-temperature distributions. We derive appropriate formulae to use when optical depths are non-negligible. Our models provide an excellent fit to the 6 μm-2 mm measurements of local starbursts. We find characteristic single-component temperatures T 1 ≅ 35.5 ± 2.2 K and integrated infrared (IR) luminosities around 10 12.9±0.1 L sun for the SWIRE-selected sources. Molecular gas masses are estimated at ≅4 x 10 10 M sun , assuming κ 850 μ m = 0.15 m 2 kg -1 and a submillimeter-selected galaxy (SMG)-like gas-to-dust mass ratio. The best-fit models imply ∼>2 kpc emission scales. We also note a tight correlation between rest-frame 1.4 GHz radio and IR luminosities confirming star formation as the predominant power source. The far-IR properties of our sample are indistinguishable from the purely submillimeter-selected populations from current surveys. We therefore conclude that our original selection criteria, based on mid-IR colors and 24 μm flux densities, provides an effective means for the study of SMGs at z ∼ 1.5-2.5.

Spitzer/infrared spectrograph investigation of mipsgal 24 μm compact bubbles: low-resolution observations

Energy Technology Data Exchange (ETDEWEB)

Nowak, M. [Département de Physique, École Normale Supérieure de Cachan, 61 Avenue du Président Wilson, F-94235 Cachan (France); Flagey, N. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Noriega-Crespo, A.; Carey, S. J.; Van Dyk, S. D. [Spitzer Science Center, California Institute of Technology, 1200 East California Boulevard, MC 314-6, Pasadena, CA 91125 (United States); Billot, N. [Instituto de Radio Astronomía Milimétrica, Avenida Divina Pastora, 7, Local 20, E-18012 Granada (Spain); Paladini, R., E-mail: mathias.nowak@ens-cachan.fr [NASA Herschel Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

2014-12-01

We present Spitzer/InfraRed Spectrograph (IRS) low-resolution observations of 11 compact circumstellar bubbles from the MIPSGAL 24 μm Galactic plane survey. We find that this set of MIPSGAL bubbles (MBs) is divided into two categories and that this distinction correlates with the morphologies of the MBs in the mid-infrared (IR). The four MBs with central sources in the mid-IR exhibit dust-rich, low-excitation spectra, and their 24 μm emission is accounted for by the dust continuum. The seven MBs without central sources in the mid-IR have spectra dominated by high-excitation gas lines (e.g., [O IV] 26.0 μm, [Ne V] 14.3 and 24.3 μm, and [Ne III] 15.5 μm), and the [O IV] line accounts for 50% to almost 100% of the 24 μm emission in five of them. In the dust-poor MBs, the [Ne V] and [Ne III] line ratios correspond to high-excitation conditions. Based on comparisons with published IRS spectra, we suggest that the dust-poor MBs are highly excited planetary nebulae (PNs) with peculiar white dwarfs (e.g., Wolf-Rayet [WR] and novae) at their centers. The central stars of the four dust-rich MBs are all massive star candidates. Dust temperatures range from 40 to 100 K in the outer shells. We constrain the extinction along the lines of sight from the IRS spectra. We then derive distance, dust masses, and dust production rate estimates for these objects. These estimates are all consistent with the nature of the central stars. We summarize the identifications of MBs made to date and discuss the correlation between their mid-IR morphologies and natures. Candidate Be/B[e]/luminous blue variable and WR stars are mainly 'rings' with mid-IR central sources, whereas PNs are mostly 'disks' without mid-IR central sources. Therefore we expect that most of the 300 remaining unidentified MBs will be classified as PNs.

RISING FROM THE ASHES: MID-INFRARED RE-BRIGHTENING OF THE IMPOSTOR SN 2010da IN NGC 300

Energy Technology Data Exchange (ETDEWEB)

Lau, Ryan M.; Ressler, Michael E. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Kasliwal, Mansi M.; Jencson, Jacob [California Institute of Technology, Pasadena, CA 91125 (United States); Bond, Howard E.; Monson, Andrew J. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Smith, Nathan [Steward Observatory, University of Arizona, Tuscon, AZ 85721 (United States); Fox, Ori D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Carlon, Robert; Dykhoff, Devin; Gehrz, Robert [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, SE, University of Minnesota, Minneapolis, MN 55455 (United States); Cody, Ann Marie [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Contreras, Carlos [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Hsiao, Eric [Department of Physics, Florida State University, 77 Chieftain Way, Tallahassee, FL 32306 (United States); Khan, Rubab [NASA Goddard Space Flight Center, MC 665, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Masci, Frank [Infrared Processing and Analysis Center, California Institute of Technology, M/S 100-22, Pasadena, CA 91125 (United States); Monard, L. A. G. [Bronberg and Kleinkaroo Observatories, P.O. Box 281, Calitzdorp 6660, Western Cape (South Africa); Morrell, Nidia; Phillips, Mark [Carnegie Institution of Washington, Las Campanas Observatory, Colina el Pino, Casilla 601, La Serena (Chile)

2016-10-20

We present multi-epoch mid-infrared (IR) photometry and the optical discovery observations of the “impostor” supernova (SN) 2010da in NGC 300 using new and archival Spitzer Space Telescope images and ground-based observatories. The mid-infrared counterpart of SN 2010da was detected as Spitzer Infrared Intensive Transient Survey (SPIRITS) 14bme in the SPIRITS, an ongoing systematic search for IR transients. Before erupting on 2010 May 24, the SN 2010da progenitor exhibited a constant mid-IR flux at 3.6 and only a slight ∼10% decrease at 4.5 μ m between 2003 November and 2007 December. A sharp increase in the 3.6 μ m flux followed by a rapid decrease measured ∼150 days before and ∼80 days after the initial outburst, respectively, reveal a mid-IR counterpart to the coincident optical and high luminosity X-ray outbursts. At late times, after the outburst (∼2000 days), the 3.6 and 4.5 μ m emission increased to over a factor of two times the progenitor flux and is currently observed (as of 2016 Feb) to be fading, but still above the progenitor flux. We attribute the re-brightening mid-IR emission to continued dust production and increasing luminosity of the surviving system associated with SN 2010da. We analyze the evolution of the dust temperature ( T {sub d} ∼ 700–1000 K), mass ( M {sub d} ∼ 0.5–3.8 × 10{sup −7} M {sub ⊙}), luminosity ( L {sub IR} ∼ 1.3–3.5 × 10{sup 4} L {sub ⊙}), and the equilibrium temperature radius ( R {sub eq} ∼ 6.4–12.2 au) in order to resolve the nature of SN 2010da. We address the leading interpretation of SN 2010da as an eruption from a luminous blue variable high-mass X-ray binary (HMXB) system. We propose that SN 2010da is instead a supergiant (sg)B[e]-HMXB based on similar luminosities and dust masses exhibited by two other known sgB[e]-HMXB systems. Additionally, the SN 2010da progenitor occupies a similar region on a mid-IR color–magnitude diagram (CMD) with known sgB[e] stars in the Large

A Mid-Infrared Search for Kardashev Civilizations

Science.gov (United States)

Sigurdsson, Steinn; Wright, J.; Griffith, R.; Povich, M. S.

2014-01-01

We are using the WISE all-sky Source Catalog to search for and put upper limits on the existence of extraterrestrial civilizations with large energy supplies. Any galaxy-spanning (Type III) civilization with an energy supply of more than about one percent of its stellar luminosity will have detectable mid-infrared excess, and nearby (extended) galaxies with civilizations with supplies more than about 80% of their stellar luminosity will be well-distinguished from nearly all natural sources in WISE color-color space. Mid-infrared spectra, far-infrared photometry, and radio emission from CO can all be used to distinguish extraterrestrial mid-infrared radiation from dust.

Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the mean temperature structure of the upper troposphere and stratosphere

Science.gov (United States)

Orton, Glenn S.; Fletcher, Leigh N.; Moses, Julianne I.; Mainzer, Amy K.; Hines, Dean; Hammel, Heidi B.; Martin-Torres, F. Javier; Burgdorf, Martin; Merlet, Cecile; Line, Michael R.

2014-11-01

On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS), ten days after the planet's equinox, when its equator was close to the sub-Earth point. This spectrum provides the highest-resolution broad-band spectrum ever obtained for Uranus from space, allowing a determination of the disk-averaged temperature and molecule composition to a greater degree of accuracy than ever before. The temperature profiles derived from the Voyager radio occultation experiment by Lindal et al. (Lindal, G.F., Lyons, J.R., Sweetnam, D.N., Eshleman, V.R., Hinson, D.P. [1987]. J. Geophys. Res. 92, 14987-15001) and revisions suggested by Sromovsky et al. (Sromovsky, L.A., Fry, P.A., Kim, J.H. [2011]. Icarus 215, 292-312) that match these data best are those that assume a high abundance of methane in the deep atmosphere. However, none of these model profiles provides a satisfactory fit over the full spectral range sampled. This result could be the result of spatial differences between global and low-latitudinal regions, changes in time, missing continuum opacity sources such as stratospheric hazes or unknown tropospheric constituents, or undiagnosed systematic problems with either the Voyager radio-occultation or the Spitzer IRS data sets. The spectrum is compatible with the stratospheric temperatures derived from the Voyager ultraviolet occultations measurements by Herbert et al. (Herbert, F. et al. [1987]. J. Geophys. Res. 92, 15093-15109), but it is incompatible with the hot stratospheric temperatures derived from the same data by Stevens et al. (Stevens, M.H., Strobel, D.F., Herbert, F.H. [1993]. Icarus 101, 45-63). Thermospheric temperatures determined from the analysis of the observed H2 quadrupole emission features are colder than those derived by Herbert et al. at pressures less than ∼1 μbar. Extrapolation of the nominal model spectrum to far-infrared through millimeter wavelengths shows that the spectrum arising solely from H2

A SPITZER SURVEY FOR DUST IN TYPE IIn SUPERNOVAE

International Nuclear Information System (INIS)

Fox, Ori D.; Chevalier, Roger A.; Skrutskie, Michael F.; Soderberg, Alicia M.; Filippenko, Alexei V.; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Smith, Nathan; Steele, Thea N.

2011-01-01

Recent observations suggest that Type IIn supernovae (SNe IIn) may exhibit late-time (>100 days) infrared (IR) emission from warm dust more than other types of core-collapse SNe. Mid-IR observations, which span the peak of the thermal spectral energy distribution, provide useful constraints on the properties of the dust and, ultimately, the circumstellar environment, explosion mechanism, and progenitor system. Due to the low SN IIn rate (<10% of all core-collapse SNe), few IR observations exist for this subclass. The handful of isolated studies, however, show late-time IR emission from warm dust that, in some cases, extends for five or six years post-discovery. While previous Spitzer/IRAC surveys have searched for dust in SNe, none have targeted the Type IIn subclass. This paper presents results from a warm Spitzer/IRAC survey of the positions of all 68 known SNe IIn within a distance of 250 Mpc between 1999 and 2008 that have remained unobserved by Spitzer more than 100 days post-discovery. The detection of late-time emission from 10 targets (∼15%) nearly doubles the database of existing mid-IR observations of SNe IIn. Although optical spectra show evidence for new dust formation in some cases, the data show that in most cases the likely origin of the mid-IR emission is pre-existing dust, which is continuously heated by optical emission generated by ongoing circumstellar interaction between the forward shock and circumstellar medium. Furthermore, an emerging trend suggests that these SNe decline at ∼1000-2000 days post-discovery once the forward shock overruns the dust shell. The mass-loss rates associated with these dust shells are consistent with luminous blue variable progenitors.

YSOVAR: Mid-infrared variability in the star-forming region Lynds 1688

Energy Technology Data Exchange (ETDEWEB)

Günther, H. M.; Poppenhaeger, K.; Wolk, S. J.; Hora, J. L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Cody, A. M. [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Covey, K. R. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Plavchan, P. [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Rebull, L. M.; Stauffer, J. R. [Spitzer Science Center/Caltech, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Allen, L. [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Bayo, A. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Meng, H. Y. A. [Infrared Processing and Analysis Center, California Institute of Technology, MC 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Morales-Calderón, M. [Centro de Astrobiología (INTA-CSIC), ESAC Campus, P.O. Box 78, E-28691 Villanueva de la Canada (Spain); Parks, J. R. [Department of Physics and Astronomy, Georgia State University, 25 Park Place South, Atlanta, GA 30303 (United States); Song, Inseok, E-mail: hguenther@cfa.harvard.edu [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States)

2014-12-01

The emission from young stellar objects (YSOs) in the mid-infrared (mid-IR) is dominated by the inner rim of their circumstellar disks. We present IR data from the Young Stellar Object VARiability (YSOVAR) survey of ∼800 objects in the direction of the Lynds 1688 (L1688) star-forming region over four visibility windows spanning 1.6 yr using the Spitzer Space Telescope in its warm mission phase. Among all light curves, 57 sources are cluster members identified based on their spectral energy distribution and X-ray emission. Almost all cluster members show significant variability. The amplitude of the variability is larger in more embedded YSOs. Ten out of 57 cluster members have periodic variations in the light curves with periods typically between three and seven days, but even for those sources, significant variability in addition to the periodic signal can be seen. No period is stable over 1.6 yr. Nonperiodic light curves often still show a preferred timescale of variability that is longer for more embedded sources. About half of all sources exhibit redder colors in a fainter state. This is compatible with time-variable absorption toward the YSO. The other half becomes bluer when fainter. These colors can only be explained with significant changes in the structure of the inner disk. No relation between mid-IR variability and stellar effective temperature or X-ray spectrum is found.

Mid-infrared Semiconductor Optoelectronics

CERN Document Server

Krier, Anthony

2006-01-01

The practical realisation of optoelectronic devices operating in the 2–10 µm (mid-infrared) wavelength range offers potential applications in a variety of areas from environmental gas monitoring around oil rigs and landfill sites to the detection of pharmaceuticals, particularly narcotics. In addition, an atmospheric transmission window exists between 3 µm and 5 µm that enables free-space optical communications, thermal imaging applications and the development of infrared measures for "homeland security". Consequently, the mid-infrared is very attractive for the development of sensitive optical sensor instrumentation. Unfortunately, the nature of the likely applications dictates stringent requirements in terms of laser operation, miniaturisation and cost that are difficult to meet. Many of the necessary improvements are linked to a better ability to fabricate and to understand the optoelectronic properties of suitable high-quality epitaxial materials and device structures. Substantial progress in these m...

Laser-induced filaments in the mid-infrared

International Nuclear Information System (INIS)

Zheltikov, A M

2017-01-01

Laser-induced filamentation in the mid-infrared gives rise to unique regimes of nonlinear wave dynamics and reveals in many ways unusual nonlinear-optical properties of materials in this frequency range. The λ 2 scaling of the self-focusing threshold P cr , with radiation wavelength λ , allows the laser powers transmitted by single mid-IR filaments to be drastically increased without the loss of beam continuity and spatial coherence. When extended to the mid-infrared, laser filamentation enables new methods of pulse compression. Often working around the universal physical limitations, it helps generate few-cycle and subcycle field waveforms within an extraordinarily broad range of peak powers, from just a few up to hundreds of P cr . As a part of a bigger picture, laser-induced filamentation in the mid-infrared offers important physical insights into the general properties of the nonlinear-optical response of matter as a function of the wavelength. Unlike their near-infrared counterparts, which can be accurately described within the framework of perturbative nonlinear optics, mid-infrared filaments often entangle perturbative and nonperturbative nonlinear-optical effects, showing clear signatures of strong-field optical physics. With the role of nonperturbative nonlinear-optical phenomena growing, as a general tendency, with the field intensity and the driver wavelength, extension of laser filamentation to even longer driver wavelengths, toward the long-wavelength infrared, promises a hic sunt dracones land. (topical review)

A Search for Faint, Diffuse Halo Emission in Edge-On Galaxies with Spitzer/IRAC

Science.gov (United States)

Ashby, Matthew; Arendt, R. G.; Pipher, J. L.; Forrest, W. J.; Marengo, M.; Barmby, P.; Willner, S. P.; Stauffer, J. R.; Fazio, G. G.

2006-12-01

We present deep infrared mosaics of the nearby edge-on spiral galaxies NGC 891, 4244, 4565, and 5907. These data were acquired at 3.6, 4.5, 5.8, and 8.0 microns using the Infrared Array Camera aboard Spitzer as part of GTO program number 3. This effort is designed to detect the putative faint, diffuse emission from halos and thick disks of spiral galaxies in the near-mid infrared under the thermally stable, low-background conditions of space. These conditions in combination with the advantageous viewing angles presented by these well-known edge-on spirals provide arguably the best opportunity to characterize the halo/thick disk components of such galaxies in the infrared. In this contribution we describe our observations, data reduction techniques, corrections for artifacts in the data, and the modeling approach we applied to analyze this unique dataset. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

A Spitzer Survey for Dust in Type IIn Supernovae

Science.gov (United States)

Fox, Ori D.; Chevalier, Roger A.; Skrutskie, Michael F.; Soderberg, Alicia M.; Filippenko, Alexei V.; Ganeshalingam, Mohan; Silverman, Jeffrey M.; Smith, Nathan; Steele, Thea N.

2011-01-01

Recent observations suggest that Type IIn supernovae (SNe IIn) may exhibit late-time (greater than 100 days) infrared (IR) emission from warm dust more than other types of core-collapse SNe. Mid-IR observations, which span the peak of the thermal spectral energy distribution, provide useful constraints on the properties of the dust and, ultimately, the circumstellar environment, explosion mechanism, and progenitor system. Due to the low SN IIn rate (less than 10% of all core-collapse SNe), few IR observations exist for this subclass. The handful of isolated studies, however, show late-time IR emission from warm dust that, in some cases, extends for five or six years post-discovery. While previous Spitzer/IRAC surveys have searched for dust in SNe, none have targeted the Type IIn subclass. This article presents results from a warm Spitzer/IRAC survey of the positions of all 68 known SNe IIn within a distance of 250 Mpc between 1999 and 2008 that have remained unobserved by Spitzer more than 100 days postdiscovery. The detection of late-time emission from ten targets (approximately 15%) nearly doubles the database of existing mid-IR observations of SNe IIn. Although optical spectra show evidence for new dust formation in some cases, the data show that in most cases the likely origin of the mid-IR emission is pre-existing dust, which is continuously heated by optical emission generated by ongoing circumstellar interaction between the forward shock and circumstellar medium. Furthermore, an emerging trend suggests that these SNe decline at approximately 1000-2000 days post-discovery once the forward shock overruns the dust shell. The mass-loss rates associated with these dust shells are consistent with luminous blue variable (LBV) progenitors.

On the Nature of Bright Infrared Sources in the Small Magellanic Cloud: Interpreting MSX through the Lens of Spitzer

Science.gov (United States)

Kraemer, Kathleen E.; Sloan, G. C.

2015-01-01

We compare infrared observations of the Small Magellanic Cloud (SMC) by the Midcourse Space Experiment (MSX) and the Spitzer Space Telescope to better understand what components of a metal-poor galaxy dominate radiative processes in the infrared. The SMC, at a distance of ~60 kpc and with a metallicity of ~0.1-0.2 solar, can serve as a nearby proxy for metal-poor galaxies at high redshift. The MSX Point Source Catalog contains 243 objects in the SMC that were detected at 8.3 microns, the most sensitive MSX band. Multi-epoch, multi-band mapping with Spitzer, supplemented with observations from the Two-Micron All-Sky Survey (2MASS) and the Wide-field Infrared Survey Explorer (WISE), provides variability information, and, together with spectra from Spitzer for ~15% of the sample, enables us to determine what these luminous sources are. How many remain simple point sources? What fraction break up into multiple stars? Which are star forming regions, with both bright diffuse emission and point sources? How do evolved stars and stellar remnants contribute at these wavelengths? What role do young stellar objects and HII regions play? Answering these questions sets the stage for understanding what we will see with the James Webb Space Telescope (JWST).

CRYSTALLINE SILICATES IN EVOLVED STARS. I. SPITZER/INFRARED SPECTROGRAPH SPECTROSCOPY OF IRAS 16456-3542, 18354-0638, AND 23239+5754

Energy Technology Data Exchange (ETDEWEB)

Jiang, B. W.; Zhang, Ke [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Li, Aigen [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Lisse, C. M., E-mail: bjiang@bnu.edu.cn, E-mail: kzhang@caltech.edu, E-mail: lia@missouri.edu, E-mail: carey.lisse@jhuapl.edu [Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States)

2013-03-01

We report the Spitzer Infrared Spectrograph (IRS) observations of three evolved stars: IRAS 16456-3542, 18354-0638, and 23239+5754. The 9.9-37.2 {mu}m Spitzer/IRS high-resolution spectra of these three sources exhibit rich sets of enstatite-dominated crystalline silicate emission features. IRAS 16456-3542 is extremely rich in crystalline silicates, with >90% of its silicate mass in crystalline form, the highest to date ever reported for crystalline silicate sources.

VERY LARGE INTERSTELLAR GRAINS AS EVIDENCED BY THE MID-INFRARED EXTINCTION

Energy Technology Data Exchange (ETDEWEB)

Wang, Shu; Jiang, B. W. [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Li, Aigen, E-mail: shuwang@mail.bnu.edu.cn, E-mail: bjiang@bnu.edu.cn, E-mail: wanshu@missouri.edu, E-mail: lia@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

2015-09-20

The sizes of interstellar grains are widely distributed, ranging from a few angstroms to a few micrometers. The ultraviolet (UV) and optical extinction constrains the dust in the size range of a couple hundredths of micrometers to several submicrometers. The near and mid infrared (IR) emission constrains the nanometer-sized grains and angstrom-sized very large molecules. However, the quantity and size distribution of micrometer-sized grains remain unknown because they are gray in the UV/optical extinction and they are too cold and emit too little in the IR to be detected by IRAS, Spitzer, or Herschel. In this work, we employ the ∼3–8 μm mid-IR extinction, which is flat in both diffuse and dense regions to constrain the quantity, size, and composition of the μm-sized grain component. We find that, together with nano- and submicron-sized silicate and graphite (as well as polycyclic aromatic hydrocarbons), μm-sized graphite grains with C/H ≈ 137 ppm and a mean size of ∼1.2 μm closely fit the observed interstellar extinction of the Galactic diffuse interstellar medium from the far-UV to the mid-IR, as well as the near-IR to millimeter thermal emission obtained by COBE/DIRBE, COBE/FIRAS, and Planck up to λ ≲ 1000 μm. The μm-sized graphite component accounts for ∼14.6% of the total dust mass and ∼2.5% of the total IR emission.

SPITZER OBSERVATIONS OF PASSIVE AND STAR-FORMING EARLY-TYPE GALAXIES: AN INFRARED COLOR-COLOR SEQUENCE

International Nuclear Information System (INIS)

Temi, Pasquale; Brighenti, Fabrizio; Mathews, William G.

2009-01-01

We describe the infrared properties of a large sample of early-type galaxies, comparing data from the Spitzer archive with Ks-band emission from the Two Micron All Sky Survey. While most representations of this data result in correlations with large scatter, we find a remarkably tight relation among colors formed by ratios of luminosities in Spitzer-Multiband Imaging Photometer bands (24, 70, and 160 μm) and the Ks band. Remarkably, this correlation among E and S0 galaxies follows that of nearby normal galaxies of all morphological types. In particular, the tight infrared color-color correlation for S0 galaxies alone follows that of the entire Hubble sequence of normal galaxies, roughly in order of galaxy type from ellipticals to spirals to irregulars. The specific star formation rate (SFR) of S0 galaxies estimated from the 24 μm luminosity increases with decreasing K-band luminosity (or stellar mass) from essentially zero, as with most massive ellipticals, to rates typical of irregular galaxies. Moreover, the luminosities of the many infrared-luminous S0 galaxies can significantly exceed those of the most luminous (presumably post-merger) E galaxies. SFRs in the most infrared-luminous S0 galaxies approach 1-10 solar masses per year. Consistently, with this picture we find that while most early-type galaxies populate an infrared red sequence, about 24% of the objects (mostly S0s) are in an infrared blue cloud together with late-type galaxies. For those early-type galaxies also observed at radio frequencies, we find that the far-infrared luminosities correlate with the mass of neutral and molecular hydrogen, but the scatter is large. This scatter suggests that the star formation may be intermittent or that similar S0 galaxies with cold gaseous disks of nearly equal mass can have varying radial column density distributions that alter the local and global SFRs.

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

Science.gov (United States)

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

2015-08-01

More than 12000 Near-Earth Objects (NEOs) have been discovered over the past few decades and current discovery surveys find on average 4 new NEOs every night. In comparison to asteroid discovery, the physical characterization of NEOs lags far behind: measured diameters and albedos exist only for roughly 10% of all known NEOs. We describe a current and a future observing program that provide diameter and albedo measurements of a large number of NEOs.In our Spitzer Space Telescope Exploration Science program 'NEOSurvey', we are performing a fast and efficient flux-limited survey in which we measure the diameters and albedos of ~600 NEOs in a total of 710 hrs of observing time. We measure the thermal emission of our targets at 4.5 micron and combine these measurements with optical data in a thermal model. Our diameters and albedos come with highly realistic uncertainties that account for a wide range of potential asteroid properties. Our primary goal is to create a large and uniform catalog of NEO properties, including diameters, albedos, and flux density data. This catalog is publicly accessible and provides the latest results usually within 2 weeks after the observation.Starting in 2016, we will also make use of the refurbished and recommissioned MIRSI mid-infrared imaging camera on NASA's InfraRed Telescope Facility (IRTF) to derive the diameters and albedos of up to 750 NEOs over a period of 3 yrs. MIRSI will be equipped with an optical camera that will allow for simultaneous optical imaging, which will improve our thermal modeling results. With MIRSI, we will focus on newly discovered NEOs that are close to Earth and hence relatively bright.The results from both programs, together with already exisiting diameter and albedo results from the literature, will form the largest database of NEO physical properties available to date. With this data set, we will be able to refine the size distribution of small NEOs and the corresponding impact frequency, and compare the

Nuclear mid-infrared properties of nearby low-luminosity AGN

International Nuclear Information System (INIS)

Asmus, D; Duschl, W J; Hönig, S F; Gandhi, P; Smette, A

2012-01-01

We present ground-based high-spatial resolution mid-infrared (MIR) observations of 20 nearby low-luminosity AGN (LLAGN) with VLT/VISIR and the preliminary analysis of a new sample of 10 low-luminosity Seyferts observed with Gemini/Michelle. LLAGN are of great interest because these objects are the most common among active galaxies, especially in the nearby universe. Studying them in great detail makes it possible to investigate the AGN evolution over cosmic timescale. Indeed, many LLAGN likely represent the final stage of an AGN's lifetime. We show that even at low luminosities and accretion rates nuclear unresolved MIR emission is present in most objects. Compared to lower spatial resolution Spitzer/IRS spectra, the high-resolution MIR photometry exhibits significantly lower fluxes and different PAH emission feature properties in many cases. By using scaled Spitzer/IRS spectra of typical starburst galaxies, we show that the star formation contribution to the 12 μm emission is minor in the central parsecs of most LLAGN. Therefore, the observed MIR emission in the VISIR and Michelle data is most likely emitted by the AGN itself, which, for higher luminosity AGN, is interpreted as thermal emission from a dusty torus. Furthermore, the 12 /amemission of the LLAGN is strongly correlated with the absorption corrected 2-10 keV luminosity and the MIR- X-ray correlation found previously for AGN is extended to a range from 10 40 to 10 45 erg/s. This correlation is independent of the object type, and in particular the low-luminosity Seyferts observed with Michelle fall exactly on the power-law fit valid for brighter AGN. In addition, no dependency of the MIR-X-ray ratio on the accretion rate is found. These results are consistent with the unification model being applicable even in the probed low-luminosity regime.

On the mid-infrared variability of candidate eruptive variables (exors): A comparison between Spitzer and WISE data

Energy Technology Data Exchange (ETDEWEB)

Antoniucci, S.; Giannini, T.; Li Causi, G.; Lorenzetti, D., E-mail: simone.antoniucci@oa-roma.inaf.it, E-mail: teresa.giannini@oa-roma.inaf.it, E-mail: gianluca.licausi@oa-roma.inaf.it, E-mail: dario.lorenzetti@oa-roma.inaf.it [INAF-Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monte Porzio (Italy)

2014-02-10

Aiming to statistically study the variability in the mid-IR of young stellar objects, we have compared the 3.6, 4.5, and 24 μm Spitzer fluxes of 1478 sources belonging to the C2D (Cores to Disks) legacy program with the WISE fluxes at 3.4, 4.6, and 22 μm. From this comparison, we have selected a robust sample of 34 variable sources. Their variations were classified per spectral Class (according to the widely accepted scheme of Class I/flat/II/III protostars), and per star forming region. On average, the number of variable sources decreases with increasing Class and is definitely higher in Perseus and Ophiuchus than in Chamaeleon and Lupus. According to the paradigm Class ≡ Evolution, the photometric variability can be considered to be a feature more pronounced in less evolved protostars, and, as such, related to accretion processes. Moreover, our statistical findings agree with the current knowledge of star formation activity in different regions. The 34 selected variables were further investigated for similarities with known young eruptive variables, namely the EXors. In particular, we analyzed (1) the shape of the spectral energy distribution, (2) the IR excess over the stellar photosphere, (3) magnitude versus color variations, and (4) output parameters of model fitting. This first systematic search for EXors ends up with 11 bona fide candidates that can be considered as suitable targets for monitoring or future investigations.

A COMPREHENSIVE SEARCH FOR STELLAR BOWSHOCK NEBULAE IN THE MILKY WAY: A CATALOG OF 709 MID-INFRARED SELECTED CANDIDATES

Energy Technology Data Exchange (ETDEWEB)

Kobulnicky, Henry A.; Chick, William T.; Schurhammer, Danielle P.; Andrews, Julian E.; Munari, Stephan A.; Olivier, Grace M.; Sorber, Rebecca L.; Wernke, Heather N.; Dale, Daniel A. [Dept. of Physics and Astronomy, University of Wyoming, Laramie, WY 82070 (United States); Povich, Matthew S.; Dixon, Don M. [Department of Physics and Astronomy, California State Polytechnic University, 3801 West Temple Avenue, Pomona, CA 91768 (United States)

2016-12-01

We identify 709 arc-shaped mid-infrared nebula in 24 μ m Spitzer Space Telescope or 22 μ m Wide Field Infrared Explorer surveys of the Galactic Plane as probable dusty interstellar bowshocks powered by early-type stars. About 20% are visible at 8 μ m or at shorter mid-infrared wavelengths. The vast majority (660) have no previous identification in the literature. These extended infrared sources are strongly concentrated near the Galactic mid-plane, with an angular scale height of ∼0.°6. All host a symmetrically placed star implicated as the source of a stellar wind sweeping up interstellar material. These are candidate “runaway” stars potentially having high velocities in the reference frame of the local medium. Among the 286 objects with measured proper motions, we find an unambiguous excess with velocity vectors aligned with the infrared morphology—kinematic evidence that many of these are “runaway” stars with large peculiar motions responsible for the bowshock signature. We discuss a population of “in situ” bowshocks (∼103 objects) that face giant H ii regions where the relative motions between the star and ISM may be caused by bulk outflows from an overpressured bubble. We also identify ∼58 objects that face 8 μ m bright-rimmed clouds and apparently constitute a sub-class of in situ bowshocks where the stellar wind interacts with a photoevaporative flow (PEF) from an eroding molecular cloud interface (i.e., “PEF bowshocks”). Orientations of the arcuate nebulae exhibit a correlation over small angular scales, indicating that external influences such as H ii regions are responsible for producing some bowshock nebulae. However, the vast majority of the nebulae in this sample appear to be isolated (499 objects) from obvious external influences.

SPITZER INFRARED LOW-RESOLUTION SPECTROSCOPIC STUDY OF BURIED ACTIVE GALACTIC NUCLEI IN A COMPLETE SAMPLE OF NEARBY ULTRALUMINOUS INFRARED GALAXIES

International Nuclear Information System (INIS)

Imanishi, Masatoshi; Maiolino, Roberto; Nakagawa, Takao

2010-01-01

We present the results of Spitzer Infrared Spectrograph low-resolution infrared 5-35 μm spectroscopy of 17 nearby ultraluminous infrared galaxies (ULIRGs) at z 12 L sun , are found in eight sources. We combine these results with those of our previous research to investigate the energy function of buried AGNs in a complete sample of optically non-Seyfert ULIRGs in the local universe at z < 0.3 (85 sources). We confirm a trend that we previously discovered: that buried AGNs are more common in galaxies with higher infrared luminosities. Because optical Seyferts also show a similar trend, we argue more generally that the energetic importance of AGNs is intrinsically higher in more luminous galaxies, suggesting that the AGN-starburst connections are luminosity dependent. This may be related to the stronger AGN feedback scenario in currently more massive galaxy systems, as a possible origin of the galaxy downsizing phenomenon.

THE MID-INFRARED PERIOD-LUMINOSITY RELATIONS FOR THE SMALL MAGELLANIC CLOUD CEPHEIDS DERIVED FROM SPITZER ARCHIVAL DATA

International Nuclear Information System (INIS)

Ngeow, Chow-Choong; Kanbur, Shashi M.

2010-01-01

In this paper, we derive the Spitzer IRAC band period-luminosity (P-L) relations for the Small Magellanic Cloud (SMC) Cepheids, by matching the Spitzer archival SAGE-SMC data with the OGLE-III SMC Cepheids. We find that the 3.6 μm and 4.5 μm band P-L relations can be better described using two P-L relations with a break period at log(P) = 0.4: this is consistent with similar results at optical wavelengths for SMC P-L relations. The 5.8 μm and 8.0 μm band P-L relations do not extend to sufficiently short periods to enable a similar detection of a slope change at log(P) = 0.4. The slopes of the SMC P-L relations, for log(P) > 0.4, are consistent with their Large Magellanic Cloud counterparts that were derived from a similar data set. They are also in agreement with those obtained from a small sample of Galactic Cepheids with parallax measurements.

Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

Science.gov (United States)

Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

2010-02-01

Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

DEEP SPITZER OBSERVATIONS OF INFRARED-FAINT RADIO SOURCES: HIGH-REDSHIFT RADIO-LOUD ACTIVE GALACTIC NUCLEI?

International Nuclear Information System (INIS)

Norris, Ray P.; Mao, Minnie; Afonso, Jose; Cava, Antonio; Farrah, Duncan; Oliver, Seb; Huynh, Minh T.; Mauduit, Jean-Christophe; Surace, Jason; Ivison, R. J.; Jarvis, Matt; Lacy, Mark; Maraston, Claudia; Middelberg, Enno; Seymour, Nick

2011-01-01

Infrared-faint radio sources (IFRSs) are a rare class of objects which are relatively bright at radio wavelengths but very faint at infrared and optical wavelengths. Here we present sensitive near-infrared observations of a sample of these sources taken as part of the Spitzer Extragalactic Representative Volume Survey. Nearly all the IFRSs are undetected at a level of ∼1 μJy in these new deep observations, and even the detections are consistent with confusion with unrelated galaxies. A stacked image implies that the median flux density is S 3.6μm ∼ 0.2 μJy or less, giving extreme values of the radio-infrared flux density ratio. Comparison of these objects with known classes of object suggests that the majority are probably high-redshift radio-loud galaxies, possibly suffering from significant dust extinction.

SPITZER OBSERVATIONS OF GX17+2: CONFIRMATION OF A PERIODIC SYNCHROTRON SOURCE

International Nuclear Information System (INIS)

Harrison, Thomas E.; McNamara, Bernard J.; Bornak, Jillian; Gelino, Dawn M.; Wachter, Stefanie; Rupen, Michael P.; Gelino, Christopher R.

2011-01-01

GX17+2 is a low-mass X-ray binary (LMXB) that is also a member of a small family of LMXBs known as 'Z-sources' that are believed to have persistent X-ray luminosities that are very close to the Eddington limit. GX17+2 is highly variable at both radio and X-ray frequencies, a feature common to Z-sources. What sets GX17+2 apart is its dramatic variability in the near-infrared, where it changes by ΔK ∼ 3 mag. Previous investigations have shown that these brightenings are periodic, recurring every 3.01 days. Given its high extinction (A V ≥ 9 mag), it has not been possible to ascertain the nature of these events with ground-based observations. We report mid-infrared Spitzer observations of GX17+2 which indicate a synchrotron spectrum for the infrared brightenings. In addition, GX17+2 is highly variable in the mid-infrared during these events. The combination of the large-scale outbursts, the presence of a synchrotron spectrum, and the dramatic variability in the mid-infrared suggest that the infrared brightening events are due to the periodic transit of a synchrotron jet across our line of sight. An analysis of both new, and archival, infrared observations has led us to revise the period for these events to 3.0367 days. We also present new Rossi X-Ray Timing Explorer (RXTE) data for GX17+2 obtained during two predicted infrared brightening events. Analysis of these new data, and data from the RXTE archive, indicates that there is no correlation between the X-ray behavior of this source and the observed infrared brightenings. We examine various scenarios that might produce periodic jet emission.

YSOVAR: MID-INFRARED VARIABILITY IN NGC 1333

Energy Technology Data Exchange (ETDEWEB)

Rebull, L. M. [Infrared Science Archive (IRSA), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Stauffer, J. R.; Cody, A. M. [Spitzer Science Center (SSC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Günther, H. M.; Poppenhaeger, K.; Wolk, S. J.; Hora, J.; Forbrich, J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Hernandez, J. [Centro de Investigaciones de Astronomía, Apdo. Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Bayo, A. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Covey, K. [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Gutermuth, R. [Dept. of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Morales-Calderón, M.; Bouy, H. [Depto. Astrofísica, Centro de Astrobiología (INTA-CSIC), ESAC campus, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Plavchan, P. [NASA Exoplanet Science Institute (NExScI), Infrared Processing and Analysis Center (IPAC), 1200 E. California Blvd., California Institute of Technology, Pasadena, CA 91125 (United States); Song, I. [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States); Terebey, S., E-mail: rebull@ipac.caltech.edu [Department of Physics and Astronomy, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States); and others

2015-12-15

As part of the Young Stellar Object VARiability (YSOVAR) program, we monitored NGC 1333 for ∼35 days at 3.6 and 4.5 μm using the Spitzer Space Telescope. We report here on the mid-infrared variability of the point sources in the ∼10′ × ∼20′ area centered on 03:29:06, +31:19:30 (J2000). Out of 701 light curves in either channel, we find 78 variables over the YSOVAR campaign. About half of the members are variable. The variable fraction for the most embedded spectral energy distributions (SEDs) (Class I, flat) is higher than that for less embedded SEDs (Class II), which is in turn higher than the star-like SEDs (Class III). A few objects have amplitudes (10–90th percentile brightness) in [3.6] or [4.5] > 0.2 mag; a more typical amplitude is 0.1–0.15 mag. The largest color change is >0.2 mag. There are 24 periodic objects, with 40% of them being flat SED class. This may mean that the periodic signal is primarily from the disk, not the photosphere, in those cases. We find 9 variables likely to be “dippers,” where texture in the disk occults the central star, and 11 likely to be “bursters,” where accretion instabilities create brightness bursts. There are 39 objects that have significant trends in [3.6]–[4.5] color over the campaign, about evenly divided between redder-when-fainter (consistent with extinction variations) and bluer-when-fainter. About a third of the 17 Class 0 and/or jet-driving sources from the literature are variable over the YSOVAR campaign, and a larger fraction (∼half) are variable between the YSOVAR campaign and the cryogenic-era Spitzer observations (6–7 years), perhaps because it takes time for the envelope to respond to changes in the central source. The NGC 1333 brown dwarfs do not stand out from the stellar light curves in any way except there is a much larger fraction of periodic objects (∼60% of variable brown dwarfs are periodic, compared to ∼30% of the variables overall)

Observations of Hot-Jupiter occultations combining Spitzer and Kepler photometry

Directory of Open Access Journals (Sweden)

Knutson H.

2011-02-01

Full Text Available We present the status of an ongoing program which aim at measuring occultations by their parent stars of transiting hot giant exoplanets discovered recently by Kepler. The observations are obtained in the near infrared with WarmSpitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of measuring the mid-occultation times and the relative occultation depths in each band-passes. Our measurements of occultations depths in the Kepler bandpass is turned into the determination of the optical geometric albedo Ag in this wavelength domain. The brightness temperatures of these planets are deduced from the infrared observations. We combine the optical and near infrared planetary emergent fluxes to obtain broad band emergent spectra of individual planet. We finally compare these spectra to hot Jupiter atmospheric models in order broadly distinguishing these atmospheres between different classes of models.

Mid-infrared photonics in silicon and germanium

Science.gov (United States)

Soref, Richard

2010-08-01

Ingenious techniques are needed to extend group IV photonics from near-infrared to mid-infrared wavelengths. If achieved, the reward could be on-chip CMOS optoelectronic systems for use in spectroscopy, chemical and biological sensing, and free-space communications.

Mid-infrared supercontinuum generation in the fingerprint region

DEFF Research Database (Denmark)

Møller, Uffe Visbech; Petersen, Christian Rosenberg; Kubat, Irnis

The mid-infrared spectral region is of great technical and scientific interest because most molecules display fundamental vibrational absorptions in this region, leaving distinctive spectral fingerprints. Here, we demonstrate experimentally that launching intense ultra-short pulses with a central...... the potential of fibres to emit across the mid-infrared molecular fingerprint region, which is of key importance for applications such as early cancer diagnostics, gas sensing and food quality control....

IRAS 15099-5856: REMARKABLE MID-INFRARED SOURCE WITH PROMINENT CRYSTALLINE SILICATE EMISSION EMBEDDED IN THE SUPERNOVA REMNANT MSH15-52

International Nuclear Information System (INIS)

Koo, Bon-Chul; Kim, Hyun-Jeong; Im, Myungshin; McKee, Christopher F.; Suh, Kyung-Won; Moon, Dae-Sik; Lee, Ho-Gyu; Onaka, Takashi; Burton, Michael G.; Hiramatsu, Masaaki; Bessell, Michael S.; Gaensler, B. M.; Lee, Jae-Joon; Jeong, Woong-Seob; Tatematsu, Ken'ichi; Kawabe, Ryohei; Ezawa, Hajime; Kohno, Kotaro; Wilson, Grant; Yun, Min S.

2011-01-01

We report new mid-infrared (MIR) observations of the remarkable object IRAS 15099-5856 using the space telescopes AKARI and Spitzer, which demonstrate the presence of prominent crystalline silicate emission in this bright source. IRAS 15099-5856 has a complex morphology with a bright central compact source (IRS1) surrounded by knots, spurs, and several extended (∼4') arc-like filaments. The source is seen only at ≥10 μm. The Spitzer mid-infrared spectrum of IRS1 shows prominent emission features from Mg-rich crystalline silicates, strong [Ne II] 12.81 μm, and several other faint ionic lines. We model the MIR spectrum as thermal emission from dust and compare with the Herbig Be star HD 100546 and the luminous blue variable R71, which show very similar MIR spectra. Molecular line observations reveal two molecular clouds around the source, but no associated dense molecular cores. We suggest that IRS1 is heated by UV radiation from the adjacent O star Muzzio 10 and that its crystalline silicates most likely originated in a mass outflow from the progenitor of the supernova remnant (SNR) MSH 15-52. IRS1, which is embedded in the SNR, could have been shielded from the SN blast wave if the progenitor was in a close binary system with Muzzio 10. If MSH 15-52 is a remnant of Type Ib/c supernova (SN Ib/c), as has been previously proposed, this would confirm the binary model for SN Ib/c. IRS1 and the associated structures may be the relics of massive star death, as shaped by the supernova explosion, the pulsar wind, and the intense ionizing radiation of the embedded O star.

Spitzer - Hot & Colorful Student Activities

Science.gov (United States)

McDonald, D.; Rebull, L. M.; DeWolf, C.; Guastella, P.; Johnson, C. H.; Schaefers, J.; Spuck, T.; McDonald, J. G., III; DeWolf, T.; Brock, S.; Boerma, J.; Bemis, G.; Paulsen, K.; Yueh, N.; Peter, A.; Wassmer, W.; Haber, R.; Scaramucci, A.; Butchart, J.; Holcomb, A.; Karns, B.; Kennedy, S.; Siegel, R.; Weiser, S.

2009-01-01

In this poster, we present the results of several activities developed for the general science student to explore infrared light. The first activity involved measuring infrared radiation using an updated version of Newton's experiment of splitting white light and finding IR radiation. The second used Leslie's cube to allow students to observe different radiators, while the third used a modern infrared thermometer to measure and identify IR sources in an enclosed box. The last activity involved students making false-color images from narrow-band filter images from data sets from Spitzer Space Telescope, STScI Digitized Sky Survey and other sources. Using computer programs like Adobe Photoshop and free software such as ds9, Spot and Leopard, poster-like images were created by the students. This research is funded by the Spitzer Science Center (SSC) and the National Optical Astronomy Observatory (NOAO). Please see our companion poster, Johnson et al., on the science aspect of this program, and another poster on the educational aspects, Guastella et al.

Monolithic beam steering in a mid-infrared, surface-emitting, photonic integrated circuit.

Science.gov (United States)

Slivken, Steven; Wu, Donghai; Razeghi, Manijeh

2017-08-16

The mid-infrared (2.5 < λ < 25 μm) spectral region is utilized for many purposes, such as chemical/biological sensing, free space communications, and illuminators/countermeasures. Compared to near-infrared optical systems, however, mid-infrared component technology is still rather crude, with isolated components exhibiting limited functionality. In this manuscript, we make a significant leap forward in mid-infrared technology by developing a platform which can combine functions of multiple mid-infrared optical elements, including an integrated light source. In a single device, we demonstrate wide wavelength tuning (240 nm) and beam steering (17.9 degrees) in the mid-infrared with a significantly reduced beam divergence (down to 0.5 degrees). The architecture is also set up to be manufacturable and testable on a wafer scale, requiring no cleaved facets or special mirror coating to function.

PROPER MOTIONS OF YOUNG STELLAR OUTFLOWS IN THE MID-INFRARED WITH SPITZER (IRAC). I. THE NGC 1333 REGION

International Nuclear Information System (INIS)

Raga, A. C.; Noriega-Crespo, A.; Carey, S. J.; Arce, H. G.

2013-01-01

We use two 4.5 μm Spitzer (IRAC) maps of the NGC 1333 region taken over a ∼7 yr interval to determine proper motions of its associated outflows. This is a first successful attempt at obtaining proper motions of stellars' outflow from Spitzer observations. For the outflow formed by the Herbig-Haro objects HH7, 8, and 10, we find proper motions of ∼9-13 km s –1 , which are consistent with previously determined optical proper motions of these objects. We determine proper motions for a total of eight outflows, ranging from ∼10 to 100 km s –1 . The derived proper motions show that out of these eight outflows, three have tangential velocities ≤20 km s –1 . This result shows that a large fraction of the observed outflows have low intrinsic velocities and that the low proper motions are not merely a projection effect.

SPRITE: the Spitzer proposal review website

Science.gov (United States)

Crane, Megan K.; Storrie-Lombardi, Lisa J.; Silbermann, Nancy A.; Rebull, Luisa M.

2008-07-01

The Spitzer Science Center (SSC), located on the campus of the California Institute of Technology, supports the science operations of NASA's infrared Spitzer Space Telescope. The SSC issues an annual Call for Proposals inviting investigators worldwide to submit Spitzer Space Telescope proposals. The Spitzer Proposal Review Website (SPRITE) is a MySQL/PHP web database application designed to support the SSC proposal review process. Review panel members use the software to view, grade, and write comments about the proposals, and SSC support team members monitor the grading and ranking process and ultimately generate a ranked list of all the proposals. The software is also used to generate, edit, and email award letters to the proposers. This work was performed at the California Institute of Technology under contract to the National Aeronautics and Space Administration.

ENHANCED WARM H2 EMISSION IN THE COMPACT GROUP MID-INFRARED ''GREEN VALLEY''

International Nuclear Information System (INIS)

Cluver, M. E.; Ogle, P.; Guillard, P.; Appleton, P. N.; Jarrett, T. H.; Rasmussen, J.; Lisenfeld, U.; Verdes-Montenegro, L.; Antonucci, R.; Bitsakis, T.; Charmandaris, V.; Boulanger, F.; Egami, E.; Xu, C. K.; Yun, M. S.

2013-01-01

We present results from a Spitzer mid-infrared spectroscopy study of a sample of 74 galaxies located in 23 Hickson Compact Groups (HCGs), chosen to be at a dynamically active stage of H I depletion. We find evidence for enhanced warm H 2 emission (i.e., above that associated with UV excitation in star-forming regions) in 14 galaxies (∼20%), with 8 galaxies having extreme values of L(H 2 S(0)-S(3))/L(7.7 μm polycyclic aromatic hydrocarbon), in excess of 0.07. Such emission has been seen previously in the compact group HCG 92 (Stephan's Quintet), and was shown to be associated with the dissipation of mechanical energy associated with a large-scale shock caused when one group member collided, at high velocity, with tidal debris in the intragroup medium. Similarly, shock excitation or turbulent heating is likely responsible for the enhanced H 2 emission in the compact group galaxies, since other sources of heating (UV or X-ray excitation from star formation or active galactic nuclei) are insufficient to account for the observed emission. The group galaxies fall predominantly in a region of mid-infrared color-color space identified by previous studies as being connected to rapid transformations in HCG galaxy evolution. Furthermore, the majority of H 2 -enhanced galaxies lie in the optical ''green valley'' between the blue cloud and red sequence, and are primarily early-type disk systems. We suggest that H 2 -enhanced systems may represent a specific phase in the evolution of galaxies in dense environments and provide new insight into mechanisms which transform galaxies onto the optical red sequence.

SPITZER SAGE INFRARED PHOTOMETRY OF MASSIVE STARS IN THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Bonanos, A. Z.; Massa, D. L.; Sewilo, M.

2009-01-01

We present a catalog of 1750 massive stars in the Large Magellanic Cloud (LMC), with accurate spectral types compiled from the literature, and a photometric catalog for a subset of 1268 of these stars, with the goal of exploring their infrared properties. The photometric catalog consists of stars with infrared counterparts in the Spitzer SAGE survey database, for which we present uniform photometry from 0.3 to 24 μm in the UBVIJHK s +IRAC+MIPS24 bands. The resulting infrared color-magnitude diagrams illustrate that the supergiant B[e], red supergiant, and luminous blue variable (LBV) stars are among the brightest infrared point sources in the LMC, due to their intrinsic brightness, and at longer wavelengths, due to dust. We detect infrared excesses due to free-free emission among ∼900 OB stars, which correlate with luminosity class. We confirm the presence of dust around 10 supergiant B[e] stars, finding the shape of their spectral energy distributions (SEDs) to be very similar, in contrast to the variety of SED shapes among the spectrally variable LBVs. The similar luminosities of B[e] supergiants (log L/L sun ≥ 4) and the rare, dusty progenitors of the new class of optical transients (e.g., SN 2008S and NGC 300 OT), plus the fact that dust is present in both types of objects, suggests a common origin for them. We find the infrared colors for Wolf-Rayet stars to be independent of spectral type and their SEDs to be flatter than what models predict. The results of this study provide the first comprehensive roadmap for interpreting luminous, massive, resolved stellar populations in nearby galaxies at infrared wavelengths.

Mid-infrared Variability of Changing-look AGNs

International Nuclear Information System (INIS)

Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Peng, Bo; Yan, Lin; Dou, Liming

2017-01-01

It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer ( WISE ) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

Mid-infrared Variability of Changing-look AGNs

Energy Technology Data Exchange (ETDEWEB)

Sheng, Zhenfeng; Wang, Tinggui; Jiang, Ning; Yang, Chenwei; Peng, Bo [CAS Key Laboratory for Researches in Galaxies and Cosmology, University of Sciences and Technology of China, Hefei, Anhui 230026 (China); Yan, Lin [Caltech Optical Observatories, Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Dou, Liming, E-mail: shengzf@mail.ustc.edu.cn, E-mail: twang@ustc.edu.cn [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China)

2017-09-01

It is known that some active galactic nuclei (AGNs) transit from Type 1 to Type 2 or vice versa. There are two explanations for the so-called changing-look AGNs: one is the dramatic change of the obscuration along the line of sight, and the other is the variation of accretion rate. In this Letter, we report the detection of large amplitude variations in the mid-infrared luminosity during the transitions in 10 changing-look AGNs using the Wide-field Infrared Survey Explorer ( WISE ) and newly released Near-Earth Object WISE Reactivation data. The mid-infrared light curves of 10 objects echo the variability in the optical band with a time lag expected for dust reprocessing. The large variability amplitude is inconsistent with the scenario of varying obscuration, rather it supports the scheme of dramatic change in the accretion rate.

Heterogeneously integrated silicon photonics for the mid-infrared and spectroscopic sensing.

Science.gov (United States)

Chen, Yu; Lin, Hongtao; Hu, Juejun; Li, Mo

2014-07-22

Besides being the foundational material for microelectronics, crystalline silicon has long been used for the production of infrared lenses and mirrors. More recently, silicon has become the key material to achieve large-scale integration of photonic devices for on-chip optical interconnect and signal processing. For optics, silicon has significant advantages: it offers a very high refractive index and is highly transparent in the spectral range from 1.2 to 8 μm. To fully exploit silicon’s superior performance in a remarkably broad range and to enable new optoelectronic functionalities, here we describe a general method to integrate silicon photonic devices on arbitrary foreign substrates. In particular, we apply the technique to integrate silicon microring resonators on mid-infrared compatible substrates for operation in the mid-infrared. These high-performance mid-infrared optical resonators are utilized to demonstrate, for the first time, on-chip cavity-enhanced mid-infrared spectroscopic analysis of organic chemicals with a limit of detection of less than 0.1 ng.

Injection-seeded tunable mid-infrared pulses generated by difference frequency mixing

Science.gov (United States)

Miyamoto, Yuki; Hara, Hideaki; Masuda, Takahiko; Hiraki, Takahiro; Sasao, Noboru; Uetake, Satoshi

2017-03-01

We report on the generation of nanosecond mid-infrared pulses having frequency tunability, a narrow linewidth, and a high pulse energy. These pulses are obtained by frequency mixing between injection-seeded near-infrared pulses in potassium titanyl arsenate crystals. A continuous-wave external cavity laser diode or a Ti:sapphire ring laser is used as a tunable seeding source for the near-infrared pulses. The typical energy of the generated mid-infrared pulses is in the range of 0.4-1 mJ/pulse. The tuning wavelength ranges from 3142 to 4806 nm. A narrow linewidth of 1.4 GHz and good frequency reproducibility of the mid-infrared pulses are confirmed by observing a rovibrational absorption line of gaseous carbon monoxide at 4587 nm.

Archival Investigation of Outburst Sites and Progenitors of Extragalactic Intermediate-Luminosity Mid-IR Transients

Science.gov (United States)

Bond, Howard

2017-08-01

Our team is using Spitzer in a long-term search for extragalactic mid-infrared (MIR) variable stars and transients-the SPIRITS project (SPitzer InfraRed Intensive Transients Survey). In this first exploration of luminous astrophysical transients in the infrared, we have discovered a puzzling new class. We call them SPRITEs: eSPecially Red Intermediate-luminosity Transient Events. They have maximum MIR luminosities between supernovae and classical novae, but are not detected in the optical to deep limits. To date, we have discovered more than 50 SPRITEs in galaxies out to 17 Mpc. In this Archival Research proposal, we request support in order to investigate the pre-eruption sites in HST images of some 3 dozen SPRITEs discovered to date, and an additional 2 dozen that we are likely to find until the end of Spitzer observing in late 2018. Our aims are (1) characterize the pre-outburst environments at HST resolution in the visible and near-IR, to understand the stellar populations, stellar ages and masses, and interstellar medium at the outburst sites; (2) search for progenitors; (3) help prepare the way for a better understanding of the nature of extragalactic IR transients that will be investigated by JWST.

Mid-infrared integrated photonics on silicon: a perspective

Directory of Open Access Journals (Sweden)

Lin Hongtao

2017-12-01

Full Text Available The emergence of silicon photonics over the past two decades has established silicon as a preferred substrate platform for photonic integration. While most silicon-based photonic components have so far been realized in the near-infrared (near-IR telecommunication bands, the mid-infrared (mid-IR, 2–20-μm wavelength band presents a significant growth opportunity for integrated photonics. In this review, we offer our perspective on the burgeoning field of mid-IR integrated photonics on silicon. A comprehensive survey on the state-of-the-art of key photonic devices such as waveguides, light sources, modulators, and detectors is presented. Furthermore, on-chip spectroscopic chemical sensing is quantitatively analyzed as an example of mid-IR photonic system integration based on these basic building blocks, and the constituent component choices are discussed and contrasted in the context of system performance and integration technologies.

Mid-infrared-to-mid-ultraviolet supercontinuum enhanced by third-to-fifteenth odd harmonics.

Science.gov (United States)

Mitrofanov, A V; Voronin, A A; Mitryukovskiy, S I; Sidorov-Biryukov, D A; Pugžlys, A; Andriukaitis, G; Flöry, T; Stepanov, E A; Fedotov, A B; Baltuška, A; Zheltikov, A M

2015-05-01

A high-energy supercontinuum spanning 4.7 octaves, from 250 to 6500 nm, is generated using a 0.3-TW, 3.9-μm output of a mid-infrared optical parametric chirped-pulse amplifier as a driver inducing a laser filament in the air. The high-frequency wing of the supercontinuum spectrum is enhanced by odd-order optical harmonics of the mid-infrared driver. Optical harmonics up to the 15th order are observed in supercontinuum spectra as overlapping, yet well-resolved peaks broadened, as verified by numerical modeling, due to spatially nonuniform ionization-induced blue shift.

LUMINOUS BURIED ACTIVE GALACTIC NUCLEI AS A FUNCTION OF GALAXY INFRARED LUMINOSITY REVEALED THROUGH SPITZER LOW-RESOLUTION INFRARED SPECTROSCOPY

International Nuclear Information System (INIS)

Imanishi, Masatoshi

2009-01-01

We present the results of Spitzer Infrared Spectrograph 5-35 μm low-resolution spectroscopic energy diagnostics of ultraluminous infrared galaxies (ULIRGs) at z> 0.15, classified optically as non-Seyferts. Based on the equivalent widths of polycyclic aromatic hydrocarbon emission and the optical depths of silicate dust absorption features, we searched for signatures of intrinsically luminous, but optically elusive, buried active galactic nuclei (AGNs) in these optically non-Seyfert ULIRGs. We then combined the results with those of non-Seyfert ULIRGs at z IR 12 L sun . We found that the energetic importance of buried AGNs clearly increases with galaxy infrared luminosity, becoming suddenly discernible in ULIRGs with L IR > 10 12 L sun . For ULIRGs with buried AGN signatures, a significant fraction of infrared luminosities can be accounted for by the detected buried AGN and modestly obscured (A V < 20 mag) starburst activity. The implied masses of spheroidal stellar components in galaxies for which buried AGNs become important roughly correspond to the value separating red massive and blue less-massive galaxies in the local universe. Our results may support the widely proposed AGN-feedback scenario as the origin of galaxy downsizing phenomena, where galaxies with currently larger stellar masses previously had higher AGN energetic contributions and star formation originating infrared luminosities, and have finished their major star formation more quickly, due to stronger AGN feedback.

Conceptual thermal design and analysis of a far-infrared/mid-infrared remote sensing instrument

Science.gov (United States)

Roettker, William A.

1992-07-01

This paper presents the conceptual thermal design and analysis results for the Spectroscopy of the Atmosphere using Far-Infrared Emission (SAFIRE) instrument. SAFIRE has been proposed for Mission to Planet Earth to study ozone chemistry in the middle atmosphere using remote sensing of the atmosphere in the far-infrared (21-87 microns) and mid-infrared (9-16 microns) spectra. SAFIRE requires that far-IR detectors be cooled to 3-4 K and mid-IR detectors to 80 K for the expected mission lifetime of five years. A superfluid helium dewar and Stirling-cycle cryocoolers provide the cryogenic temperatures required by the infrared detectors. The proposed instrument thermal design uses passive thermal control techniques to reject 465 watts of waste heat from the instrument.

Generation of Mid-Infrared Frequency Combs for Spectroscopic Applications

Science.gov (United States)

Maser, Daniel L.

Mid-infrared laser sources prove to be a valuable tool in exploring a vast array of phenomena, finding their way into applications ranging from trace gas detection to X-ray generation and carbon dating. Mid-infrared frequency combs, in particular, are well-suited for many of these applications, owing to their inherent low-noise and broadband nature. Frequency comb technology is well-developed in the near-infrared as a result of immense technological development by the telecommunication industry in silica fiber and the existence of readily-available glass dopants such as ytterbium and erbium that enable oscillators at 1 and 1.5 ?m. However, options become substantially more limited at longer wavelengths, as silica is no longer transparent and the components required in a mid-infrared frequency comb system (oscillators, fibers, and both fiber and free-space components) are far less technologically mature. This thesis explores several different approaches to generating frequency comb sources in the mid-infrared region, and the development of sources used in the nonlinear processes implemented to reach these wavelengths. An optical parametric oscillator, two approaches to difference frequency generation, and nonlinear spectral broadening in chip-scale waveguides are developed, characterized, and spectroscopic potential for these techniques is demonstrated. The source used for these nonlinear processes, the erbium-doped fiber amplifier, is also studied and discussed throughout the design and optimization process. The nonlinear optical processes critical to this work are numerically modeled and used to confirm and predict experimental behavior.

A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD 209458 b

Science.gov (United States)

Richardson, L. Jeremy; Harrington, Joseph; Seager, Sara; Deming, Drake

2007-01-01

We have measured the infrared transit of the extrasolar planet HD 209458 b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micrometer array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary system, recorded before, during, and after transit. We perform optimal photometry on the images and use the local zodiacal light as a short-term flux reference. At this long wavelength, the transit curve has a simple box-like shape, allowing robust solutions for the stellar and planetary radii independent of stellar limb darkening, which is negligible at 24 micrometers. We derive a stellar radius of R(sub *) = 1.06 plus or minus 0.07 solar radius, a planetary radius of R(sub p) = 1.26 plus or minus 0.08 R(sub J), and a stellar mass of 1.17 solar mass. Within the errors, our results agree with the measurements at visible wavelengths. The 24 micrometer radius of the planet therefore does not differ significantly compared to the visible result. We point out the potential for deriving extrasolar transiting planet radii to high accuracy using transit photometry at slightly shorter IR wavelengths where greater photometric precision is possible.

LOCUSS: THE MID-INFRARED BUTCHER-OEMLER EFFECT

International Nuclear Information System (INIS)

Haines, C. P.; Smith, G. P.; Sanderson, A. J. R.; Egami, E.; Ellis, R. S.; Moran, S. M.; Merluzzi, P.; Busarello, G.; Smith, R. J.

2009-01-01

We study the mid-infrared (MIR) properties of galaxies in 30 massive galaxy clusters at 0.02 ≤ z ≤ 0.40, using panoramic Spitzer/MIPS 24 μm and near-infrared data, including 27 new observations from the LoCuSS and ACCESS surveys. This is the largest sample of clusters to date with such high-quality and uniform MIR data covering not only the cluster cores, but extending into the infall regions. We use these data to revisit the so-called Butcher-Oemler (BO) effect, measuring the fraction of massive infrared luminous galaxies (K IR > 5 x 10 10 L sun ) within r 200 , finding a steady increase in the fraction with redshift from ∼3% at z = 0.02 to ∼10% by z = 0.30, and an rms cluster-to-cluster scatter about this trend of 0.03. The best-fit redshift evolution model of the form f SF ∝ (1 + z) n has n = 5.7 +2.1 -1.8 , which is stronger redshift evolution than that of L* IR in both clusters and the field. We find that, statistically, this excess is associated with galaxies found at large cluster-centric radii, specifically r 500 200 , implying that the MIR BO effect can be explained by a combination of both the global decline in star formation in the universe since z ∼ 1 and enhanced star formation in the infall regions of clusters at intermediate redshifts. This picture is supported by a simple infall model based on the Millennium Simulation semianalytic galaxy catalogs, whereby star formation in infalling galaxies is instantaneously quenched upon their first passage through the cluster, in that the observed radial trends of f SF trace those inferred from the simulations. The observed f SF values, however, lie systematically above the predictions, suggesting an overall excess of star formation, either due to triggering by environmental processes, or a gradual quenching. We also find that f SF does not depend on simple indicators of the dynamical state of clusters, including the offset between the brightest cluster galaxy and the peak of the X-ray emission

Mid-infrared spectroscopy in skin cancer cell type identification

Science.gov (United States)

Kastl, Lena; Kemper, Björn; Lloyd, Gavin R.; Nallala, Jayakrupakar; Stone, Nick; Naranjo, Valery; Penaranda, Francisco; Schnekenburger, Jürgen

2017-07-01

Mid infrared spectroscopy samples were developed for the analysis of skin tumor cell types and three dimensional tissue phantoms towards the application of midIR spectroscopy for fast and reliable skin cancer diagnostics.

The impact of Spitzer infrared data on stellar mass estimates - and a revised galaxy stellar mass function at 0 < z < 5

Science.gov (United States)

Elsner, F.; Feulner, G.; Hopp, U.

2008-01-01

Aims:We estimate stellar masses of galaxies in the high redshift universe with the intention of determining the influence of newly available Spitzer/IRAC infrared data on the analysis. Based on the results, we probe the mass assembly history of the universe. Methods: We use the GOODS-MUSIC catalog, which provides multiband photometry from the U-filter to the 8 μm Spitzer band for almost 15 000 galaxies with either spectroscopic (for ≈7% of the sample) or photometric redshifts, and apply a standard model fitting technique to estimate stellar masses. We than repeat our calculations with fixed photometric redshifts excluding Spitzer photometry and directly compare the outcomes to look for systematic deviations. Finally we use our results to compute stellar mass functions and mass densities up to redshift z = 5. Results: We find that stellar masses tend to be overestimated on average if further constraining Spitzer data are not included into the analysis. Whilst this trend is small up to intermediate redshifts z ⪉ 2.5 and falls within the typical error in mass, the deviation increases strongly for higher redshifts and reaches a maximum of a factor of three at redshift z ≈ 3.5. Thus, up to intermediate redshifts, results for stellar mass density are in good agreement with values taken from literature calculated without additional Spitzer photometry. At higher redshifts, however, we find a systematic trend towards lower mass densities if Spitzer/IRAC data are included.

Femtosecond few-cycle mid-infrared laser pulses

DEFF Research Database (Denmark)

Liu, Xing

The few-cycle pulses of mid-infrared (mid-IR, wavelength 2-10 microns) have attracted increasing attention owing to their great potentials for high order harmonic generation, time-resolved spectroscopy, precision of cutting and biomedical science.In this thesis, mid-IR frequency conversion.......2 - 5.5 μm with only one fixed pump wavelength, a feature absent in Kerr media. Finally, we experimentally observe supercontinuum generation spanning 1.5 octaves, generated in a 10 mm long silicon-rich nitride waveguide pumped by 100 pJ femtosecond pulses from an erbium fiber laser. The waveguide has...

Silicon Based Mid Infrared SiGeSn Heterostructure Emitters and Detectors

Science.gov (United States)

2016-05-16

AFRL-AFOSR-JP-TR-2016-0054 Silicon based mid infrared SiGeSn heterostrcture emitters and detectors Greg Sun UNIVERSITY OF MASSACHUSETTS Final Report... Silicon Based Mid Infrared SiGeSn Heterostructure Emitters and Detectors ” February 10, 2016 Principal Investigator: Greg Sun Engineering...diodes are incompatible with the CMOS process and therefore cannot be easily integrated with Si electronics . The GeSn mid IR detectors developed in

THE MID-INFRARED EXTINCTION LAW IN THE OPHIUCHUS, PERSEUS, AND SERPENS MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Chapman, Nicholas L.; Mundy, Lee G.; Lai, Shih-Ping; Evans, Neal J. II

2009-01-01

We compute the mid-IR extinction law from 3.6 to 24 μm in three molecular clouds-Ophiuchus, Perseus, and Serpens-by combining data from the 'Cores to Disks' Spitzer Legacy Science program with deep JHK s imaging. Using a new technique, we are able to calculate the line-of-sight (LOS) extinction law toward each background star in our fields. With these LOS measurements, we create, for the first time, maps of the χ 2 deviation of the data from two extinction law models. Because our χ 2 maps have the same spatial resolution as our extinction maps, we can directly observe the changing extinction law as a function of the total column density. In the Spitzer Infrared Array Camera (IRAC) bands, 3.6-8 μm, we see evidence for grain growth. Below A K s = 0.5, our extinction law is well fitted by the Weingartner and Draine R V = 3.1 diffuse interstellar-medium dust model. As the extinction increases, our law gradually flattens, and for A K s ≥1, the data are more consistent with the Weingartner and Draine R V = 5.5 model that uses larger maximum dust grain sizes. At 24 μm, our extinction law is 2-4 times higher than the values predicted by theoretical dust models, but is more consistent with the observational results of Flaherty et al. Finally, from our χ 2 maps we identify a region in Perseus where the IRAC extinction law is anomalously high considering its column density. A steeper near-IR extinction law than the one we have assumed may partially explain the IRAC extinction law in this region.

THE SPITZER INFRARED SPECTROGRAPH SURVEY OF T TAURI STARS IN TAURUS

International Nuclear Information System (INIS)

Furlan, E.; Luhman, K. L.; Espaillat, C.

2011-01-01

We present 161 Spitzer Infrared Spectrograph (IRS) spectra of T Tauri stars and young brown dwarfs in the Taurus star-forming region. All of the targets were selected based on their infrared excess and are therefore surrounded by protoplanetary disks; they form the complete sample of all available IRS spectra of T Tauri stars with infrared excesses in Taurus. We also present the IRS spectra of seven Class 0/I objects in Taurus to complete the sample of available IRS spectra of protostars in Taurus. We use spectral indices that are not significantly affected by extinction to distinguish between envelope- and disk-dominated objects. Together with data from the literature, we construct spectral energy distributions for all objects in our sample. With spectral indices derived from the IRS spectra we infer disk properties such as dust settling and the presence of inner disk holes and gaps. We find a transitional disk frequency, which is based on objects with unusually large 13-31 μm spectral indices indicative of a wall surrounding an inner disk hole, of about 3%, and a frequency of about 20% for objects with unusually large 10 μm features, which could indicate disk gaps. The shape and strength of the 10 μm silicate emission feature suggests weaker 10 μm emission and more processed dust for very low mass objects and brown dwarfs (spectral types M6-M9). These objects also display weaker infrared excess emission from their disks, but do not appear to have more settled disks than their higher-mass counterparts. We find no difference for the spectral indices and properties of the dust between single and multiple systems.

THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. I. CONTINUUM ANALYSIS OF UNRESOLVED TARGETS

Energy Technology Data Exchange (ETDEWEB)

Chen, Christine H. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Mittal, Tushar [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720-4767 (United States); Kuchner, Marc [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Forrest, William J.; Watson, Dan M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Lisse, Carey M. [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Manoj, P. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Sargent, Benjamin A., E-mail: cchen@stsci.edu [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

2014-04-01

During the Spitzer Space Telescope cryogenic mission, Guaranteed Time Observers, Legacy Teams, and General Observers obtained Infrared Spectrograph (IRS) observations of hundreds of debris disk candidates. We calibrated the spectra of 571 candidates, including 64 new IRAS and Multiband Imaging Photometer for Spitzer (MIPS) debris disks candidates, modeled their stellar photospheres, and produced a catalog of excess spectra for unresolved debris disks. For 499 targets with IRS excess but without strong spectral features (and a subset of 420 targets with additional MIPS 70 μm observations), we modeled the IRS (and MIPS data) assuming that the dust thermal emission was well-described using either a one- or two-temperature blackbody model. We calculated the probability for each model and computed the average probability to select among models. We found that the spectral energy distributions for the majority of objects (∼66%) were better described using a two-temperature model with warm (T {sub gr} ∼ 100-500 K) and cold (T {sub gr} ∼ 50-150 K) dust populations analogous to zodiacal and Kuiper Belt dust, suggesting that planetary systems are common in debris disks and zodiacal dust is common around host stars with ages up to ∼1 Gyr. We found that younger stars generally have disks with larger fractional infrared luminosities and higher grain temperatures and that higher-mass stars have disks with higher grain temperatures. We show that the increasing distance of dust around debris disks is inconsistent with self-stirred disk models, expected if these systems possess planets at 30-150 AU. Finally, we illustrate how observations of debris disks may be used to constrain the radial dependence of material in the minimum mass solar nebula.

THE MID-INFRARED EXTINCTION LAW IN THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Gao, Jian; Jiang, B. W.; Xue, M. Y.; Li, Aigen

2013-01-01

Based on photometric data from the Spitzer/SAGE survey, using red giants as extinction tracers, the mid-infrared (MIR) extinction laws in the Large Magellanic Cloud (LMC) are derived for the first time in the form of A λ /A K S . This quantity refers to the extinction in the four Infrared Array Camera (IRAC) bands (i.e., [3.6], [4.5], [5.8], and [8.0] μm) relative to the Two Micron All Sky Survey K S band at 2.16 μm. We obtain the near-infrared extinction coefficient to be E(J – H)/E(H – K S ) ≈ 1.29 ± 0.04 and E(J – K S )/E(H – K S ) ≈ 1.94 ± 0.04. The wavelength dependence of the MIR extinction A λ /A K S in the LMC varies from one sightline to another. The overall mean MIR extinction is A [3.6] /A K S ∼0.72±0.03, A [4.5] /A K S ∼0.94±0.03, A [5.8] /A K S ∼0.58±0.04, and A [8.0] /A K S ∼0.62±0.05. Except for the extinction in the IRAC [4.5] μm band, which may be contaminated by the 4.6 μm CO gas absorption of red giants used to trace LMC extinction, the extinction in the other three IRAC bands show a flat curve, close to the Milky Way R V = 5.5 model extinction curve, where R V is the optical total-to-selective extinction ratio. The possible systematic bias caused by the correlated uncertainties of K S – λ and J – K S is explored in terms of Monte Carlo simulations. We find that this bias could lead to an overestimation of A λ /A K S in the MIR

Versatile silicon-waveguide supercontinuum for coherent mid-infrared spectroscopy

Science.gov (United States)

Nader, Nima; Maser, Daniel L.; Cruz, Flavio C.; Kowligy, Abijith; Timmers, Henry; Chiles, Jeff; Fredrick, Connor; Westly, Daron A.; Nam, Sae Woo; Mirin, Richard P.; Shainline, Jeffrey M.; Diddams, Scott

2018-03-01

Laser frequency combs, with their unique combination of precisely defined spectral lines and broad bandwidth, are a powerful tool for basic and applied spectroscopy. Here, we report offset-free, mid-infrared frequency combs and dual-comb spectroscopy through supercontinuum generation in silicon-on-sapphire waveguides. We leverage robust fabrication and geometrical dispersion engineering of nanophotonic waveguides for multi-band, coherent frequency combs spanning 70 THz in the mid-infrared (2.5 μm-6.2 μm). Precise waveguide fabrication provides significant spectral broadening with engineered spectra targeted at specific mid-infrared bands. We characterize the relative-intensity-noise of different bands and show that the measured levels do not pose any limitation for spectroscopy applications. Additionally, we use the fabricated photonic devices to demonstrate dual-comb spectroscopy of a carbonyl sulfide gas sample at 5 μm. This work forms the technological basis for applications such as point sensors for fundamental spectroscopy, atmospheric chemistry, trace and hazardous gas detection, and biological microscopy.

Versatile silicon-waveguide supercontinuum for coherent mid-infrared spectroscopy

Directory of Open Access Journals (Sweden)

Nima Nader

2018-03-01

Full Text Available Laser frequency combs, with their unique combination of precisely defined spectral lines and broad bandwidth, are a powerful tool for basic and applied spectroscopy. Here, we report offset-free, mid-infrared frequency combs and dual-comb spectroscopy through supercontinuum generation in silicon-on-sapphire waveguides. We leverage robust fabrication and geometrical dispersion engineering of nanophotonic waveguides for multi-band, coherent frequency combs spanning 70 THz in the mid-infrared (2.5 μm–6.2 μm. Precise waveguide fabrication provides significant spectral broadening with engineered spectra targeted at specific mid-infrared bands. We characterize the relative-intensity-noise of different bands and show that the measured levels do not pose any limitation for spectroscopy applications. Additionally, we use the fabricated photonic devices to demonstrate dual-comb spectroscopy of a carbonyl sulfide gas sample at 5 μm. This work forms the technological basis for applications such as point sensors for fundamental spectroscopy, atmospheric chemistry, trace and hazardous gas detection, and biological microscopy.

Generation of broadly tunable picosecond mid-infrared laser and sensitive detection of a mid-infrared signal by parametric frequency up-conversion in MgO:LiNbO3 optical parametric amplifiers

International Nuclear Information System (INIS)

Zhang Qiu-Lin; Zhang Jing; Qiu Kang-Sheng; Zhang Dong-Xiang; Feng Bao-Hua; Zhang Jing-Yuan

2012-01-01

Picosecond optical parametric generation and amplification in the near-infrared region within 1.361–1.656 μm and the mid-infrared region within 2.976–4.875 μm is constructed on the basis of bulk MgO:LiNbO 3 crystals pumped at 1.064 μm. The maximum pulse energy reaches 1.3 mJ at 1.464 μm and 0.47 mJ at 3.894 μm, corresponding to a pump-to-idler photon conversion efficiency of 25%. By seeding the hard-to-measure mid-infrared radiation as the idler in the optical parametric amplification and measuring the amplified and frequency up-converted signal in the near-infrared or even visible region, one can measure very week mid-infrared radiation with ordinary detectors, which are insensitive to mid-infrared radiation, with a very high gain. A maximum gain factor of about 7 × 10 7 is achieved at the mid-infrared wavelength of 3.374 μm and the corresponding energy detection limit is as low as about 390 aJ per pulse. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

OPTICAL SPECTROSCOPY AND NEBULAR OXYGEN ABUNDANCES OF THE SPITZER/SINGS GALAXIES

International Nuclear Information System (INIS)

Moustakas, John; Kennicutt, Robert C. Jr.; Tremonti, Christy A.; Dale, Daniel A.; Smith, John-David T.; Calzetti, Daniela

2010-01-01

We present intermediate-resolution optical spectrophotometry of 65 galaxies obtained in support of the Spitzer Infrared Nearby Galaxies Survey (SINGS). For each galaxy we obtain a nuclear, circumnuclear, and semi-integrated optical spectrum designed to coincide spatially with mid- and far-infrared spectroscopy from the Spitzer Space Telescope. We make the reduced, spectrophotometrically calibrated one-dimensional spectra, as well as measurements of the fluxes and equivalent widths of the strong nebular emission lines, publicly available. We use optical emission-line ratios measured on all three spatial scales to classify the sample into star-forming, active galactic nuclei (AGNs), and galaxies with a mixture of star formation and nuclear activity. We find that the relative fraction of the sample classified as star forming versus AGN is a strong function of the integrated light enclosed by the spectroscopic aperture. We supplement our observations with a large database of nebular emission-line measurements of individual H II regions in the SINGS galaxies culled from the literature. We use these ancillary data to conduct a detailed analysis of the radial abundance gradients and average H II-region abundances of a large fraction of the sample. We combine these results with our new integrated spectra to estimate the central and characteristic (globally averaged) gas-phase oxygen abundances of all 75 SINGS galaxies. We conclude with an in-depth discussion of the absolute uncertainty in the nebular oxygen abundance scale.

Spitzer Observations of the X-ray Sources of NGC 4485/90

Science.gov (United States)

Vazquez, Gerardo A.; Colbert, E.; Hornschemeier, A.; Malhotra, S.; Roberts, T.; Ward, M.

2006-06-01

The mechanism for forming (or igniting) so-called Ultra-Luminous X- ray sources (ULXs) is very poorly understood. In order to investigate the stellar and gaseous environment of ULXs, we have observed the nearby starburst galaxy system NGC 4485/90 with Spitzer's IRAC and IRS instruments. High-quality mid-infrared images and spectra are used to characterize the stellar history of stars near the ULXs, and the ionization state of the surrounding gas. NGC 4485/90 fortuitively hosts six ULXs, and we have analyzed IRAC images and IRS spectra of all six regions. We also observed two "comparison" regions with no X-ray sources. Here we present our preliminary findings on the similarities and differences between the stellar and gaseous components near the ULXs.

Efficient Mosaicking of Spitzer Space Telescope Images

Science.gov (United States)

Jacob, Joseph; Makovoz, David; Eisenhardt, Peter

2007-01-01

A parallel version of the MOPEX software, which generates mosaics of infrared astronomical images acquired by the Spitzer Space Telescope, extends the capabilities of the prior serial version. In the parallel version, both the input image space and the output mosaic space are divided among the available parallel processors. This is the only software that performs the point-source detection and the rejection of spurious imaging effects of cosmic rays required by Spitzer scientists. This software includes components that implement outlier-detection algorithms that can be fine-tuned for a particular set of image data by use of a number of adjustable parameters. This software has been used to construct a mosaic of the Spitzer Infrared Array Camera Shallow Survey, which comprises more than 17,000 exposures in four wavelength bands from 3.6 to 8 m and spans a solid angle of about 9 square degrees. When this software was executed on 32 nodes of the 1,024-processor Cosmos cluster computer at NASA s Jet Propulsion Laboratory, a speedup of 8.3 was achieved over the serial version of MOPEX. The performance is expected to improve dramatically once a true parallel file system is installed on Cosmos.

The Carnegie Chicago Hubble Program: The Mid-Infrared Colours of Cepheids and the Effect of Metallicity on the CO Band-Head at 4.6 Micron

Science.gov (United States)

Scowcroft, Victoria; Seibert, Mark; Freedman, Wendy L.; Beaton, Rachael L.; Madore, Barry F.; Monson, Andrew J.; Rich, Jeffery A.; Rigby, Jane R.

2016-01-01

We compare mid-infrared (IR) 3.6 and 4.5 micron Warm Spitzer observations for Cepheids in the Milky Way and the Large and Small Magellanic Clouds. Using models, we explore in detail the effect of the CO rotation-vibration band-head at 4.6 micron on the mid-IR photometry. We confirm the temperature sensitivity of the CO band-head at 4.6 micron and find no evidence for an effect at 3.6 micron. We compare the ([3.6]-[4.5]) period-colour relations in the MW, LMC and SMC. The slopes of the period-colour relations for the three galaxies are in good agreement, but there is a trend in zero-point with metallicity, with the lowest metallicity Cepheids having redder mid-IR colours. Finally, we present a colour-[Fe/H] relation based on published spectroscopic metallicities. This empirical relation, calibrated to the metallicity system of Genovali et al., demonstrates that the ([3.6]-[4.5]) colour provides a reliable metallicity indicator for Cepheids, with a precision comparable to current spectroscopic determinations.

SIBI: A compact hyperspectral camera in the mid-infrared

Science.gov (United States)

Pola Fossi, Armande; Ferrec, Yann; Domel, Roland; Coudrain, Christophe; Guerineau, Nicolas; Roux, Nicolas; D'Almeida, Oscar; Bousquet, Marc; Kling, Emmanuel; Sauer, Hervé

2015-10-01

Recent developments in unmanned aerial vehicles have increased the demand for more and more compact optical systems. In order to bring solutions to this demand, several infrared systems are being developed at ONERA such as spectrometers, imaging devices, multispectral and hyperspectral imaging systems. In the field of compact infrared hyperspectral imaging devices, ONERA and Sagem Défense et Sécurité have collaborated to develop a prototype called SIBI, which stands for "Spectro-Imageur Birefringent Infrarouge". It is a static Fourier transform imaging spectrometer which operates in the mid-wavelength infrared spectral range and uses a birefringent lateral shearing interferometer. Up to now, birefringent interferometers have not been often used for hyperspectral imaging in the mid-infrared because of the lack of crystal manufacturers, contrary to the visible spectral domain where the production of uniaxial crystals like calcite are mastered for various optical applications. In the following, we will present the design and the realization of SIBI as well as the first experimental results.

SPITZER OBSERVATIONS OF YOUNG RED QUASARS

International Nuclear Information System (INIS)

Urrutia, Tanya; Lacy, Mark; Spoon, Henrik; Glikman, Eilat; Petric, Andreea; Schulz, Bernhard

2012-01-01

We present mid-infrared spectra and photometry of 13 redshift 0.4 < z < 1 dust reddened quasars obtained with Spitzer IRS and MIPS. We compare properties derived from their infrared spectral energy distributions (intrinsic active galactic nucleus (AGN) luminosity and far-infrared luminosity from star formation) to the host luminosities and morphologies from Hubble Space Telescope imaging, and black hole masses estimated from optical and/or near-infrared spectroscopy. Our results are broadly consistent with models in which most dust reddened quasars are an intermediate phase between a merger-driven starburst triggering a completely obscured AGN, and a normal, unreddened quasar. We find that many of our objects have high accretion rates, close to the Eddington limit. These objects tend to fall below the black hole mass-bulge luminosity relation as defined by local galaxies, whereas most of our low accretion rate objects are slightly above the local relation, as typical for normal quasars at these redshifts. Our observations are therefore most readily interpreted in a scenario in which galaxy stellar mass growth occurs first by about a factor of three in each merger/starburst event, followed sometime later by black hole growth by a similar amount. We do not, however, see any direct evidence for quasar feedback affecting star formation in our objects, for example, in the form of a relationship between accretion rate and star formation. Five of our objects, however, do show evidence for outflows in the [O III]5007 Å emission line profile, suggesting that the quasar activity is driving thermal winds in at least some members of our sample.

The Origin of the Infrared Emission in Radio Galaxies : III. Analysis of 3CRR Objects

NARCIS (Netherlands)

Dicken, D.; Tadhunter, C.; Axon, D.; Robinson, A.; Morganti, R.; Kharb, P.

2010-01-01

We present Spitzer photometric data for a complete sample of 19 low-redshift (z <0.1) 3CRR radio galaxies as part of our efforts to understand the origin of the prodigious mid-to far-infrared (MFIR) emission from radio-loud active galactic nuclei (AGNs). Our results show a correlation between AGN

The Carnegie Hubble Program: The Distance and Structure of the SMC as Revealed by Mid-Infrared Observations of Cepheids

Science.gov (United States)

Scowcroft, Victoria; Freedman, Wendy L.; Madore, Barry F.; Monson, Andy; Persson, S. E.; Rich, Jeff; Seibert, Mark; Rigby, Jane R.

2016-01-01

Using Spitzer observations of classical Cepheids we have measured the true average distance modulus of the Small Magellanic Cloud (SMC) to be18.96 +/- 0.01 stat +/- 0.03sys mag (corresponding to 62+/- 0.3kpc), which is 0.48 +/- 0.01 mag more distant than the LMC. This is in agreement with previous results from Cepheid observations, as well as with measurements from other indicators such as RR Lyrae stars and the tip of the red giant branch. Utilizing the properties of the mid-infrared Leavitt Law we measured precise distances to individual Cepheids in the SMC, and have confirmed that the galaxy is tilted and elongated such that its eastern side is up to20 kpc closer than its western side. This is in agreement with the results from red clump stars and dynamical simulations of the Magellanic Clouds and Stream.

Towards diode-pumped mid-infrared praseodymium-ytterbium-doped fluoride fiber lasers

Science.gov (United States)

Woodward, R. I.; Hudson, D. D.; Jackson, S. D.

2018-02-01

We explore the potential of a new mid-infrared laser transition in praseodymium-doped fluoride fiber for emission around 3.4 μm, which can be conveniently pumped by 0.975 μm diodes via ytterbium sensitizer co-doping. Optimal cavity designs are determined through spectroscopic measurements and numerical modeling, suggesting that practical diode-pumped watt-level mid-infrared fiber sources beyond 3 μm could be achieved.

THE ATMOSPHERES OF THE HOT-JUPITERS KEPLER-5b AND KEPLER-6b OBSERVED DURING OCCULTATIONS WITH WARM-SPITZER AND KEPLER

Energy Technology Data Exchange (ETDEWEB)

Desert, Jean-Michel; Charbonneau, David; Fressin, Francois; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Madhusudhan, Nikku [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Knutson, Heather A. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Deming, Drake [Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Brown, Timothy M. [Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States); Caldwell, Douglas [SETI Institute, Mountain View, CA 94043 (United States); Ford, Eric B. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Gilliland, Ronald L. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Marcy, Geoffrey W. [Berkeley Astronomy Department, University of California, Berkeley, CA 94720 (United States); Seager, Sara, E-mail: jdesert@cfa.harvard.edu [Massachusetts Institute of Technology, Cambridge, MA 02159 (United States)

2011-11-01

This paper reports the detection and the measurements of occultations of the two transiting hot giant exoplanets Kepler-5b and Kepler-6b by their parent stars. The observations are obtained in the near-infrared with Warm-Spitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of constraining the eccentricities of these systems and of obtaining broadband emergent photometric data for individual planets. For both targets, the occultations are detected at the 3{sigma} level at each wavelength with mid-occultation times consistent with circular orbits. The brightness temperatures of these planets are deduced from the infrared observations and reach T{sub Spitzer} = 1930 {+-} 100 K and T{sub Spitzer} = 1660 {+-} 120 K for Kepler-5b and Kepler-6b, respectively. We measure optical geometric albedos A{sub g} in the Kepler bandpass and find A{sub g} = 0.12 {+-} 0.04 for Kepler-5b and A{sub g} = 0.11 {+-} 0.04 for Kepler-6b, leading to upper an limit for the Bond albedo of A{sub B} {<=} 0.17 in both cases. The observations for both planets are best described by models for which most of the incident energy is redistributed on the dayside, with only less than 10% of the absorbed stellar flux redistributed to the nightside of these planets.

Star Formation In Nearby Clouds (SFiNCs): X-Ray and Infrared Source Catalogs and Membership

Energy Technology Data Exchange (ETDEWEB)

Getman, Konstantin V.; Broos, Patrick S.; Feigelson, Eric D.; Richert, Alexander J. W.; Ota, Yosuke [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Kuhn, Michael A. [Instituto de Fisica y Astronomia, Universidad de Valparaiso, Gran Bretana 1111, Playa Ancha, Valparaiso (Chile); Millennium Institute of Astrophysics, MAS (Chile); Bate, Matthew R. [Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, Devon EX4 4SB (United Kingdom); Garmire, Gordon P. [Huntingdon Institute for X-Ray Astronomy, LLC, 10677 Franks Road, Huntingdon, PA 16652 (United States)

2017-04-01

The Star Formation in Nearby Clouds (SFiNCs) project is aimed at providing a detailed study of the young stellar populations and of star cluster formation in the nearby 22 star-forming regions (SFRs) for comparison with our earlier MYStIX survey of richer, more distant clusters. As a foundation for the SFiNCs science studies, here, homogeneous data analyses of the Chandra X-ray and Spitzer mid-infrared archival SFiNCs data are described, and the resulting catalogs of over 15,300 X-ray and over 1,630,000 mid-infrared point sources are presented. On the basis of their X-ray/infrared properties and spatial distributions, nearly 8500 point sources have been identified as probable young stellar members of the SFiNCs regions. Compared to the existing X-ray/mid-infrared publications, the SFiNCs member list increases the census of YSO members by 6%–200% for individual SFRs and by 40% for the merged sample of all 22 SFiNCs SFRs.

Design of high-efficiency diffractive optical elements towards ultrafast mid-infrared time-stretched imaging and spectroscopy

Science.gov (United States)

Xie, Hongbo; Ren, Delun; Wang, Chao; Mao, Chensheng; Yang, Lei

2018-02-01

Ultrafast time stretch imaging offers unprecedented imaging speed and enables new discoveries in scientific research and engineering. One challenge in exploiting time stretch imaging in mid-infrared is the lack of high-quality diffractive optical elements (DOEs), which encode the image information into mid-infrared optical spectrum. This work reports the design and optimization of mid-infrared DOE with high diffraction-efficiency, broad bandwidth and large field of view. Using various typical materials with their refractive indices ranging from 1.32 to 4.06 in ? mid-infrared band, diffraction efficiencies of single-layer and double-layer DOEs have been studied in different wavelength bands with different field of views. More importantly, by replacing the air gap of double-layer DOE with carefully selected optical materials, one optimized ? triple-layer DOE, with efficiency higher than 95% in the whole ? mid-infrared window and field of view greater than ?, is designed and analyzed. This new DOE device holds great potential in ultrafast mid-infrared time stretch imaging and spectroscopy.

REPEATABILITY OF SPITZER/IRAC EXOPLANETARY ECLIPSES WITH INDEPENDENT COMPONENT ANALYSIS

Energy Technology Data Exchange (ETDEWEB)

Morello, G.; Waldmann, I. P.; Tinetti, G., E-mail: giuseppe.morello.11@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, WC1E6BT (United Kingdom)

2016-04-01

The research of effective and reliable detrending methods for Spitzer data is of paramount importance for the characterization of exoplanetary atmospheres. To date, the totality of exoplanetary observations in the mid- and far-infrared, at wavelengths >3 μm, have been taken with Spitzer. In some cases, in past years, repeated observations and multiple reanalyses of the same data sets led to discrepant results, raising questions about the accuracy and reproducibility of such measurements. Morello et al. (2014, 2015) proposed a blind-source separation method based on the Independent Component Analysis of pixel time series (pixel-ICA) to analyze InfraRed Array Camera (IRAC) data, obtaining coherent results when applied to repeated transit observations previously debated in the literature. Here we introduce a variant to the pixel-ICA through the use of wavelet transform, wavelet pixel-ICA, which extends its applicability to low-signal-to-noise-ratio cases. We describe the method and discuss the results obtained over 12 eclipses of the exoplanet XO3b observed during the “Warm Spitzer” era in the 4.5 μm band. The final results are reported, in part, also in Ingalls et al. (2016), together with results obtained with other detrending methods, and over 10 synthetic eclipses that were analyzed for the “IRAC Data Challenge 2015.” Our results are consistent within 1σ with the ones reported in Wong et al. (2014) and with most of the results reported in Ingalls et al. (2016), which appeared on arXiv while this paper was under review. Based on many statistical tests discussed in Ingalls et al. (2016), the wavelet pixel-ICA method performs as well as or better than other state-of-art methods recently developed by other teams to analyze Spitzer/IRAC data, and, in particular, it appears to be the most repeatable and the most reliable, while reaching the photon noise limit, at least for the particular data set analyzed. Another strength of the ICA approach is its highest

REPEATABILITY OF SPITZER/IRAC EXOPLANETARY ECLIPSES WITH INDEPENDENT COMPONENT ANALYSIS

International Nuclear Information System (INIS)

Morello, G.; Waldmann, I. P.; Tinetti, G.

2016-01-01

The research of effective and reliable detrending methods for Spitzer data is of paramount importance for the characterization of exoplanetary atmospheres. To date, the totality of exoplanetary observations in the mid- and far-infrared, at wavelengths >3 μm, have been taken with Spitzer. In some cases, in past years, repeated observations and multiple reanalyses of the same data sets led to discrepant results, raising questions about the accuracy and reproducibility of such measurements. Morello et al. (2014, 2015) proposed a blind-source separation method based on the Independent Component Analysis of pixel time series (pixel-ICA) to analyze InfraRed Array Camera (IRAC) data, obtaining coherent results when applied to repeated transit observations previously debated in the literature. Here we introduce a variant to the pixel-ICA through the use of wavelet transform, wavelet pixel-ICA, which extends its applicability to low-signal-to-noise-ratio cases. We describe the method and discuss the results obtained over 12 eclipses of the exoplanet XO3b observed during the “Warm Spitzer” era in the 4.5 μm band. The final results are reported, in part, also in Ingalls et al. (2016), together with results obtained with other detrending methods, and over 10 synthetic eclipses that were analyzed for the “IRAC Data Challenge 2015.” Our results are consistent within 1σ with the ones reported in Wong et al. (2014) and with most of the results reported in Ingalls et al. (2016), which appeared on arXiv while this paper was under review. Based on many statistical tests discussed in Ingalls et al. (2016), the wavelet pixel-ICA method performs as well as or better than other state-of-art methods recently developed by other teams to analyze Spitzer/IRAC data, and, in particular, it appears to be the most repeatable and the most reliable, while reaching the photon noise limit, at least for the particular data set analyzed. Another strength of the ICA approach is its highest

Mid-infrared beam splitter for ultrashort pulses.

Science.gov (United States)

Somma, Carmine; Reimann, Klaus; Woerner, Michael; Kiel, Thomas; Busch, Kurt; Braun, Andreas; Matalla, Mathias; Ickert, Karina; Krüger, Olaf

2017-08-01

A design is presented for a beam splitter suitable for ultrashort pulses in the mid-infrared and terahertz spectral range consisting of a structured metal layer on a diamond substrate. Both the theory and experiment show that this beam splitter does not distort the temporal pulse shape.

Mid-Infrared Tunable Resonant Cavity Enhanced Detectors

Directory of Open Access Journals (Sweden)

Hans Zogg

2008-09-01

Full Text Available Mid-infrared detectors that are sensitive only in a tunable narrow spectral band are presented. They are based on the Resonant Cavity Enhanced Detector (RCED principle and employing a thin active region using IV-VI narrow gap semiconductor layers. A Fabry-Pérot cavity is formed by two mirrors. The active layer is grown onto one mirror, while the second mirror can be displaced. This changes the cavity length thus shifting the resonances where the detector is sensitive. Using electrostatically actuated MEMS micromirrors, a very compact tunable detector system has been fabricated. Mirror movements of more than 3 μm at 30V are obtained. With these mirrors, detectors with a wavelength tuning range of about 0.7 μm have been realized. Single detectors can be used in mid-infrared micro spectrometers, while a detector arrangement in an array makes it possible to realize Adaptive Focal Plane Arrays (AFPA.

Radio Galaxy Zoo: Machine learning for radio source host galaxy cross-identification

Science.gov (United States)

Alger, M. J.; Banfield, J. K.; Ong, C. S.; Rudnick, L.; Wong, O. I.; Wolf, C.; Andernach, H.; Norris, R. P.; Shabala, S. S.

2018-05-01

We consider the problem of determining the host galaxies of radio sources by cross-identification. This has traditionally been done manually, which will be intractable for wide-area radio surveys like the Evolutionary Map of the Universe (EMU). Automated cross-identification will be critical for these future surveys, and machine learning may provide the tools to develop such methods. We apply a standard approach from computer vision to cross-identification, introducing one possible way of automating this problem, and explore the pros and cons of this approach. We apply our method to the 1.4 GHz Australian Telescope Large Area Survey (ATLAS) observations of the Chandra Deep Field South (CDFS) and the ESO Large Area ISO Survey South 1 (ELAIS-S1) fields by cross-identifying them with the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. We train our method with two sets of data: expert cross-identifications of CDFS from the initial ATLAS data release and crowdsourced cross-identifications of CDFS from Radio Galaxy Zoo. We found that a simple strategy of cross-identifying a radio component with the nearest galaxy performs comparably to our more complex methods, though our estimated best-case performance is near 100 per cent. ATLAS contains 87 complex radio sources that have been cross-identified by experts, so there are not enough complex examples to learn how to cross-identify them accurately. Much larger datasets are therefore required for training methods like ours. We also show that training our method on Radio Galaxy Zoo cross-identifications gives comparable results to training on expert cross-identifications, demonstrating the value of crowdsourced training data.

THE MID-INFRARED EXTINCTION LAW IN THE LARGE MAGELLANIC CLOUD

Energy Technology Data Exchange (ETDEWEB)

Gao, Jian; Jiang, B. W.; Xue, M. Y. [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Li, Aigen, E-mail: jiangao@bnu.edu.cn, E-mail: bjiang@bnu.edu.cn, E-mail: lia@missouri.edu [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)

2013-10-10

Based on photometric data from the Spitzer/SAGE survey, using red giants as extinction tracers, the mid-infrared (MIR) extinction laws in the Large Magellanic Cloud (LMC) are derived for the first time in the form of A{sub λ}/A{sub K{sub S}}. This quantity refers to the extinction in the four Infrared Array Camera (IRAC) bands (i.e., [3.6], [4.5], [5.8], and [8.0] μm) relative to the Two Micron All Sky Survey K{sub S} band at 2.16 μm. We obtain the near-infrared extinction coefficient to be E(J – H)/E(H – K{sub S} ) ≈ 1.29 ± 0.04 and E(J – K{sub S} )/E(H – K{sub S} ) ≈ 1.94 ± 0.04. The wavelength dependence of the MIR extinction A{sub λ}/A{sub K{sub S}} in the LMC varies from one sightline to another. The overall mean MIR extinction is A{sub [3.6]}/A{sub K{sub S}}∼0.72±0.03, A{sub [4.5]}/A{sub K{sub S}}∼0.94±0.03, A{sub [5.8]}/A{sub K{sub S}}∼0.58±0.04, and A{sub [8.0]}/A{sub K{sub S}}∼0.62±0.05. Except for the extinction in the IRAC [4.5] μm band, which may be contaminated by the 4.6 μm CO gas absorption of red giants used to trace LMC extinction, the extinction in the other three IRAC bands show a flat curve, close to the Milky Way R{sub V} = 5.5 model extinction curve, where R{sub V} is the optical total-to-selective extinction ratio. The possible systematic bias caused by the correlated uncertainties of K{sub S} – λ and J – K{sub S} is explored in terms of Monte Carlo simulations. We find that this bias could lead to an overestimation of A{sub λ}/A{sub K{sub S}} in the MIR.

MID-INFRARED PROPERTIES OF DISK AVERAGED OBSERVATIONS OF EARTH WITH AIRS

International Nuclear Information System (INIS)

Hearty, Thomas; Song, Inseok; Kim, Sam; Tinetti, Giovanna

2009-01-01

We have investigated mid-infrared spectra of Earth obtained by the Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to explore the characteristics that may someday be observed in extrasolar terrestrial planets. We have used the AIRS infrared (R ∼ 1200; 3.75-15.4 μm) spectra to construct directly observed high-resolution spectra of the only known life bearing planet, Earth. The AIRS spectra are the first such spectra that span the seasons. We investigate the rotational and seasonal spectral variations that would arise due to varying cloud amount and viewing geometry and we explore what signatures may be observable in the mid-infrared by the next generation of telescopes capable of observing extrasolar terrestrial planets.

Diagnostic studies of molecular plasmas using mid-infrared semiconductor lasers

NARCIS (Netherlands)

Röpcke, J.; Welzel, S.; Lang, N.; Hempel, F.; Gatilova, L.; Guaitella, O.; Rousseau, A.; Davies, P.B.

2008-01-01

Within the last decade mid-infrared absorption spectroscopy between 3 and 20 µm, known as infrared laser absorption spectroscopy (IRLAS) and based on tuneable semiconductor lasers, namely lead salt diode lasers, often called tuneable diode lasers (TDL), and quantum cascade lasers (QCL) has

TESTING THE HYPOTHESIS THAT METHANOL MASER RINGS TRACE CIRCUMSTELLAR DISKS: HIGH-RESOLUTION NEAR-INFRARED AND MID-INFRARED IMAGING

International Nuclear Information System (INIS)

De Buizer, James M.; Bartkiewicz, Anna; Szymczak, Marian

2012-01-01

Milliarcsecond very long baseline interferometry maps of regions containing 6.7 GHz methanol maser emission have lead to the recent discovery of ring-like distributions of maser spots and the plausible hypothesis that they may be tracing circumstellar disks around forming high-mass stars. We aimed to test this hypothesis by imaging these regions in the near- and mid-infrared at high spatial resolution and compare the observed emission to the expected infrared morphologies as inferred from the geometries of the maser rings. In the near-infrared we used the Gemini North adaptive optics system of ALTAIR/NIRI, while in the mid-infrared we used the combination of the Gemini South instrument T-ReCS and super-resolution techniques. Resultant images had a resolution of ∼150 mas in both the near-infrared and mid-infrared. We discuss the expected distribution of circumstellar material around young and massive accreting (proto)stars and what infrared emission geometries would be expected for the different maser ring orientations under the assumption that the masers are coming from within circumstellar disks. Based upon the observed infrared emission geometries for the four targets in our sample and the results of spectral energy distribution modeling of the massive young stellar objects associated with the maser rings, we do not find compelling evidence in support of the hypothesis that methanol masers rings reside in circumstellar disks.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-06-10

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

Mid-infrared supercontinuum generation in a suspended core chalcogenide fiber

DEFF Research Database (Denmark)

Møller, Uffe Visbech; Yu, Yi; Gai, Xin

The mid-infrared spectral region is of great interest because virtually all organic compounds display distinctive spectral fingerprints herein that reveal chemical information about them [1], and the mid-infrared region is therefore of key importance to many applications, including food quality...... control [2], gas sensing [3] and medical diagnostics [4] . We have used a low-loss suspended core As 38 Se 62 fiber with core diameter of 4.5 μ m and a zero - dispersion wavelength of 3.5 μ m to generate mid-infrared supercontinuum by pumping with an optical parametric amplifier delivering 320 fs pulses...... with a peak power of ~5.5 kW at a repetition rate of 21 MHz at different wavelengths from 3.3 to 4.7 μ m . By pumping at 4.4 μ m with a peak power of 5.2 kW coupled to the fiber a supercontinuum spanning from 1.7 to 7.5 μ m with an average output power of 15.6 mW was obtained. Figure 1 shows the results...

Young Stars in the Camelopardalis Dust and Molecular Clouds. VI. YSOs Verified by Spitzer and Akari Infrared Photometry

Directory of Open Access Journals (Sweden)

Straižys V.

2010-06-01

Full Text Available Using photometric data of infrared surveys, young stellar object (YSO status is verified for 141 objects selected in our previous papers in the Cassiopeia and Camelopardalis segment of the Milky Way bounded by Galactic coordinates (l, b = (132-158°, ±12°. The area includes the known star- forming regions in the emission nebulae W3, W4 and W5 and the massive YSO AFGL490. Spectral energy distribution (SED curves between 700 nm and 160 μm, constructed from the GSC 2, 2MASS, IRAS, MSX, Spitzer and AKARI data, are used to estimate the evolutionary stages of these stars. We confirm the YSO status for most of the objects. If all of the investigated objects were YSOs, 45% of them should belong to Class I, 41% to class II and 14% to Class III. However, SEDs of some of these objects can be affected by nearby extended infrared sources, like compact H II regions, infrared clusters or dusty galaxies.

LIFTING THE DUSTY VEIL WITH NEAR- AND MID-INFRARED PHOTOMETRY. II. A LARGE-SCALE STUDY OF THE GALACTIC INFRARED EXTINCTION LAW

International Nuclear Information System (INIS)

Zasowski, G.; Majewski, S. R.; Indebetouw, R.

2009-01-01

We combine near-infrared (Two Micron All Sky Survey) and mid-infrared (Spitzer-IRAC) photometry to characterize the IR extinction law (1.2-8 μm) over nearly 150 deg. of contiguous Milky Way midplane longitude. The relative extinctions in five passbands across these wavelength and longitude ranges are derived by calculating color excess ratios for G and K giant red clump stars in contiguous midplane regions and deriving the wavelength dependence of extinction in each one. Strong, monotonic variations in the extinction law shape are found as a function of angle from the Galactic center, symmetric on either side of it. These longitudinal variations persist even when dense interstellar regions, known a priori to have a shallower extinction curve, are removed. The increasingly steep extinction curves toward the outer Galaxy indicate a steady decrease in the absolute-to-selective extinction ratio (R V ) and in the mean dust grain size at greater Galactocentric angles. We note an increasing strength of the 8 μm extinction inflection at high Galactocentric angles and, using theoretical dust models, show that this behavior is consistent with the trend in R V . Along several lines of sight where the solution is most feasible, A λ /A K s as a function of Galactic radius (R GC ) is estimated and shown to have a Galactic radial dependence. Our analyses suggest that the observed relationship between extinction curve shape and Galactic longitude is due to an intrinsic dependence of the extinction law on Galactocentric radius.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-02-15

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

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

Science.gov (United States)

Gardner, Jonathan P.

2009-01-01

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z greater than 6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z greater than 10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (less than 50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth-Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems, and discuss recent progress in constructing the observatory.

Broadband mid-infrared superlattice light-emitting diodes

Science.gov (United States)

Ricker, R. J.; Provence, S. R.; Norton, D. T.; Boggess, T. F.; Prineas, J. P.

2017-05-01

InAs/GaSb type-II superlattice light-emitting diodes were fabricated to form a device that provides emission over the entire 3-5 μm mid-infrared transmission window. Variable bandgap emission regions were coupled together using tunnel junctions to emit at peak wavelengths of 3.3 μm, 3.5 μm, 3.7 μm, 3.9 μm, 4.1 μm, 4.4 μm, 4.7 μm, and 5.0 μm. Cascading the structure recycles the electrons in each emission region to emit several wavelengths simultaneously. At high current densities, the light-emitting diode spectra broadened into a continuous, broadband spectrum that covered the entire mid-infrared band. When cooled to 77 K, radiances of over 1 W/cm2 sr were achieved, demonstrating apparent temperatures above 1000 K over the 3-5 μm band. InAs/GaSb type-II superlattices are capable of emitting from 3 μm to 30 μm, and the device design can be expanded to include longer emission wavelengths.

SPITZER IRAC PHOTOMETRY FOR TIME SERIES IN CROWDED FIELDS

Energy Technology Data Exchange (ETDEWEB)

Novati, S. Calchi; Beichman, C. [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Gould, A.; Fausnaugh, M.; Gaudi, B. S.; Pogge, R. W.; Wibking, B.; Zhu, W.; Poleski, R. [Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Bryden, G.; Henderson, C. B.; Shvartzvald, Y. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Carey, S. [Spitzer, Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Udalski, A.; Pawlak, M.; Szymański, M. K.; Skowron, J.; Mróz, P.; Kozłowski, S. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Collaboration: Spitzer team; OGLE group; and others

2015-12-01

We develop a new photometry algorithm that is optimized for the Infrared Array Camera (IRAC) Spitzer time series in crowded fields and that is particularly adapted to faint or heavily blended targets. We apply this to the 170 targets from the 2015 Spitzer microlensing campaign and present the results of three variants of this algorithm in an online catalog. We present detailed accounts of the application of this algorithm to two difficult cases, one very faint and the other very crowded. Several of Spitzer's instrumental characteristics that drive the specific features of this algorithm are shared by Kepler and WFIRST, implying that these features may prove to be a useful starting point for algorithms designed for microlensing campaigns by these other missions.

High-speed high-sensitivity infrared spectroscopy using mid-infrared swept lasers (Conference Presentation)

Science.gov (United States)

Childs, David T. D.; Groom, Kristian M.; Hogg, Richard A.; Revin, Dmitry G.; Cockburn, John W.; Rehman, Ihtesham U.; Matcher, Stephen J.

2016-03-01

Infrared spectroscopy is a highly attractive read-out technology for compositional analysis of biomedical specimens because of its unique combination of high molecular sensitivity without the need for exogenous labels. Traditional techniques such as FTIR and Raman have suffered from comparatively low speed and sensitivity however recent innovations are challenging this situation. Direct mid-IR spectroscopy is being speeded up by innovations such as MEMS-based FTIR instruments with very high mirror speeds and supercontinuum sources producing very high sample irradiation levels. Here we explore another possible method - external cavity quantum cascade lasers (EC-QCL's) with high cavity tuning speeds (mid-IR swept lasers). Swept lasers have been heavily developed in the near-infrared where they are used for non-destructive low-coherence imaging (OCT). We adapt these concepts in two ways. Firstly by combining mid-IR quantum cascade gain chips with external cavity designs adapted from OCT we achieve spectral acquisition rates approaching 1 kHz and demonstrate potential to reach 100 kHz. Secondly we show that mid-IR swept lasers share a fundamental sensitivity advantage with near-IR OCT swept lasers. This makes them potentially able to achieve the same spectral SNR as an FTIR instrument in a time x N shorter (N being the number of spectral points) under otherwise matched conditions. This effect is demonstrated using measurements of a PDMS sample. The combination of potentially very high spectral acquisition rates, fundamental SNR advantage and the use of low-cost detector systems could make mid-IR swept lasers a powerful technology for high-throughput biomedical spectroscopy.

Efficient femtosecond mid-infrared pulse generation by dispersivewave radiation in bulk lithium niobate crystal

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm.......We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8–2.92 µm are generated using the single pump wavelengths from 1.25–1.45 µm....

New Opportunities in Mid-Infrared Emission Control

Directory of Open Access Journals (Sweden)

Peter Geiser

2015-09-01

Full Text Available Tunable laser absorption spectroscopy (TLAS has been well accepted as a preferred measurement technique for many industrial applications in recent years, especially for in situ applications. Previously, mainly near-infrared lasers have been used in TLAS sensors. The advent of compact mid-infrared light sources, like quantum cascade lasers and interband cascade lasers, has made it possible to detect gases with better sensitivity by utilizing fundamental absorption bands and to measure species that do not have any absorption lines in the near-infrared spectral region. This technological advancement has allowed developing new sensors for gases, such as nitric oxide and sulfur dioxide, for industrial applications. Detection limits of better than 1 ppm·m for nitric oxide and better than 10 ppm·m for sulfur dioxide are demonstrated in field experiments.

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies

Science.gov (United States)

Wright, Jason Thomas; Povich, Matthew; Griffith, Roger; Maldonado, Jessica; Sigurdsson, Steinn; Star Cartier, Kimberly

2015-08-01

The WISE and Spitzer large-area surveys of the mid-infrared sky bring a new opportunity to search for evidence of the energy supplies of very large extraterrestrial civilizations. If these energy supplies rival the output of a civilization's parent star (Kardashev Type II), or if a galaxy-spanning supercivilization's use rivals that of the total galactic luminosity (Type III), they would be detectable as anomolously mid-infrared-bright stars and galaxies, respectively. We have already performed the first search for this emission from Type III civilizations using the WISE all-sky survey, and put the first upper limits on them in the local universe, and discuss ways to improve on these limits. We also discuss some detectable forms of and limits on Type II civilizations in the Mliky Way.

Modelling of mid-infrared interferometric signature of hot exozodiacal dust emission

Science.gov (United States)

Kirchschlager, Florian; Wolf, Sebastian; Brunngräber, Robert; Matter, Alexis; Krivov, Alexander V.; Labdon, Aaron

2018-01-01

Hot exozodiacal dust emission was detected in recent surveys around two dozen main-sequence stars at distances of less than 1 au using the H- and K-band interferometry. Due to the high contrast as well as the small angular distance between the circumstellar dust and the star, direct observation of this dust component is challenging. An alternative way to explore the hot exozodiacal dust is provided by mid-infrared interferometry. We analyse the L, M and N bands interferometric signature of this emission in order to find stronger constraints for the properties and the origin of the hot exozodiacal dust. Considering the parameters of nine debris disc systems derived previously, we model the discs in each of these bands. We find that the M band possesses the best conditions to detect hot dust emission, closely followed by L and N bands. The hot dust in three systems - HD 22484 (10 Tau), HD 102647 (β Leo) and HD 177724 (ζ Aql) - shows a strong signal in the visibility functions, which may even allow one to constrain the dust location. In particular, observations in the mid-infrared could help to determine whether the dust piles up at the sublimation radius or is located at radii up to 1 au. In addition, we explore observations of the hot exozodiacal dust with the upcoming mid-infrared interferometer Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE) at the Very Large Telescope Interferometer.

A Mid-IR Census of Dusty Supernovae From the Past Decade In Preparation for JWST

Science.gov (United States)

Fox, Ori; Andrews, Jennifer; Arendt, Rick; Clayton, Geoff; Dwek, Eli; Filippenko, Alex; Johansson, Joel; Kelly, Patrick; Krafton, Kelsie; Marston, Tony; Mauerhan, Jon; Szalai, Tamas; Van Dyk, Schuyler

2018-05-01

Over the past decade, our team has shown that a surprising number of different supernova (SN) subclasses have members that exhibit mid-infrared (mid-IR) emission from warm dust at late times (>100 days post-explosion). This work has used Spitzer 3.6 and 4.5 micron imaging to constrain the dust origin and heating mechanisms, but a number of questions still remain. How much dust can SNe IIP produce in their ejecta? What progenitor can produce such extreme mass-loss events required to form the large, dense, pre-existing dust shells observed in so many cases? Many of these SNe remain bright today, in some cases more than a decade after discovery. Continued mid-IR monitoring is necessary to answer these questions by measuring the full extent of either the newly formed dust mass or pre-existing dust shell. Furthermore, Spitzer observations of both old and new SNe will provide up to date flux estimates as we prepare for continued observations with JWST. This proposal will cap off nearly a decade of work and bridge the gap to the first few cycles of JWST.

Picosecond mid-infrared amplifier for high average power.

CSIR Research Space (South Africa)

Botha, LR

2007-04-01

Full Text Available High pressure CO2 lasers are good candidates for amplifying picosecond mid infrared pulses. High pressure CO2 lasers are notorious for being unreliable and difficult to operate. In this paper a high pressure CO2 laser is presented based on well...

INFRARED CONTINUUM AND LINE EVOLUTION OF THE EQUATORIAL RING AROUND SN 1987A

Energy Technology Data Exchange (ETDEWEB)

Arendt, Richard G. [CRESST/UMBC (United States); Dwek, Eli [Observational Cosmology Lab, Code 665, NASA/GSFC, Greenbelt, MD 20771 (United States); Bouchet, Patrice [Laboratoire AIM Paris-Saclay, CEA-IRFU/SAp, CNRS, Université Paris Diderot, F-91191 Gif-sur-Yvette (France); Danziger, I. John [INAF-Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, I-34143 Trieste (Italy); Frank, Kari A. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Gehrz, Robert D.; Woodward, Charles E. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street, SE, Minneapolis, MN 55455 (United States); Park, Sangwook, E-mail: richard.g.arendt@nasa.gov [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

2016-03-15

Spitzer observations of SN 1987A have now spanned more than a decade. Since day ∼4000, mid-infrared (mid-IR) emission has been dominated by that from shock-heated dust in the equatorial ring (ER). From 6000 to 8000 days after the explosion, Spitzer observations included broadband photometry at 3.6–24 μm, and low and moderate resolution spectroscopy at 5–35 μm. Here we present later Spitzer observations, through day 10,377, which include only the broadband measurements at 3.6 and 4.5 μm. These data show that the 3.6 and 4.5 μm brightness has clearly begun to fade after day ∼8500, and no longer tracks the X-ray emission as well as it did at earlier epochs. This can be explained by the destruction of the dust in the ER on timescales shorter than the cooling time for the shocked gas. We find that the evolution of the late time IR emission is also similar to the now fading optical emission. We provide the complete record of the IR emission lines, as seen by Spitzer prior to day 8000. The past evolution of the gas as seen by the IR emission lines seems largely consistent with the optical emission, although the IR [Fe ii] and [Si ii] lines show different, peculiar velocity structures.

SPITZER SAGE-SMC INFRARED PHOTOMETRY OF MASSIVE STARS IN THE SMALL MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Bonanos, A. Z.; Lennon, D. J.; Massa, D. L.

2010-01-01

We present a catalog of 5324 massive stars in the Small Magellanic Cloud (SMC), with accurate spectral types compiled from the literature, and a photometric catalog for a subset of 3654 of these stars, with the goal of exploring their infrared properties. The photometric catalog consists of stars with infrared counterparts in the Spitzer SAGE-SMC survey database, for which we present uniform photometry from 0.3to24 μm in the UBVIJHK s +IRAC+MIPS24 bands. We compare the color-magnitude diagrams and color-color diagrams to those of stars in the Large Magellanic Cloud (LMC), finding that the brightest infrared sources in the SMC are also the red supergiants, supergiant B[e] (sgB[e]) stars, luminous blue variables, and Wolf-Rayet stars, with the latter exhibiting less infrared excess, the red supergiants being less dusty and the sgB[e] stars being on average less luminous. Among the objects detected at 24 μm in the SMC are a few very luminous hypergiants, four B-type stars with peculiar, flat spectral energy distributions, and all three known luminous blue variables. We detect a distinct Be star sequence, displaced to the red, and suggest a novel method of confirming Be star candidates photometrically. We find a higher fraction of Oe and Be stars among O and early-B stars in our SMC catalog, respectively, when compared to the LMC catalog, and that the SMC Be stars occur at higher luminosities. We estimate mass-loss rates for the red supergiants, confirming the correlation with luminosity even at the metallicity of the SMC. Finally, we confirm the new class of stars displaying composite A and F type spectra, the sgB[e] nature of 2dFS1804 and find the F0 supergiant 2dFS3528 to be a candidate luminous blue variable with cold dust.

The Spitzer Infrared Nearby Galaxies Survey: A High-Resolution Spectroscopy Anthology

Science.gov (United States)

Dale, Daniel A.; SINGS Team

2009-05-01

Results from high resolution mid-infrared spectroscopy are presented for 155 nuclear and extranuclear regions from SINGS. The SINGS sample shows a wide range in the ratio of [SIII]18.71/[SIII]33.48, but the average ratio of the ensemble indicates a typical interstellar electron density of 300--400 cm-3 on 23"x15" scales and 500--600 cm-3 using 11"x9" apertures, independent of whether the region probed is a star-forming nuclear, a star-forming extranuclear, or an AGN environment. Evidence is provided that variations in gas-phase metallicity play an important role in driving variations in radiation field hardness, as indicated by [NeIII]15.56/[NeII]12.81, for regions powered by star formation. Conversely, the radiation hardness for galaxy nuclei powered by accretion around a massive black hole is independent of metal abundance. Furthermore, for metal-rich environments AGN are distinguishable from star-forming regions by significantly larger [NeIII]15.56/[NeII]12.81 ratios. Finally, [FeII]25.99/[NeII]12.81 versus [SiII]34.82/[SIII]33.48 also provides an empirical method for discerning AGN from normal star-forming sources. However, similar to [NeIII]15.56/[NeII]12.81, these mid-infrared line ratios lose their AGN/star-formation diagnostic powers for very low metallicity star-forming systems with hard radiation fields.

HOT-DUST-POOR QUASARS IN MID-INFRARED AND OPTICALLY SELECTED SAMPLES

International Nuclear Information System (INIS)

Hao Heng; Elvis, Martin; Civano, Francesca; Lawrence, Andy

2011-01-01

We show that the hot-dust-poor (HDP) quasars, originally found in the X-ray-selected XMM-COSMOS type 1 active galactic nucleus (AGN) sample, are just as common in two samples selected at optical/infrared wavelengths: the Richards et al. Spitzer/SDSS sample (8.7% ± 2.2%) and the Palomar-Green-quasar-dominated sample of Elvis et al. (9.5% ± 5.0%). The properties of the HDP quasars in these two samples are consistent with the XMM-COSMOS sample, except that, at the 99% (∼ 2.5σ) significance, a larger proportion of the HDP quasars in the Spitzer/SDSS sample have weak host galaxy contributions, probably due to the selection criteria used. Either the host dust is destroyed (dynamically or by radiation) or is offset from the central black hole due to recoiling. Alternatively, the universality of HDP quasars in samples with different selection methods and the continuous distribution of dust covering factor in type 1 AGNs suggest that the range of spectral energy distributions could be related to the range of tilts in warped fueling disks, as in the model of Lawrence and Elvis, with HDP quasars having relatively small warps.

SPITZER IRS SPECTRA OF DEBRIS DISKS IN THE SCORPIUS–CENTAURUS OB ASSOCIATION

Energy Technology Data Exchange (ETDEWEB)

Jang-Condell, Hannah [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Chen, Christine H.; Mittal, Tushar; Lisse, Carey M. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Manoj, P. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Rd., Mumbai 400005 (India); Watson, Dan [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Nesvold, Erika; Kuchner, Marc [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

2015-08-01

We analyze spectra obtained with the Spitzer Infrared Spectrograph (IRS) of 110 B-, A-, F-, and G-type stars with optically thin infrared excess in the Scorpius–Centaurus OB association. The ages of these stars range from 11 to 17 Myr. We fit the infrared excesses observed in these sources by Spitzer IRS and the Multiband Imaging Photometer for Spitzer (MIPS) to simple dust models according to Mie theory. We find that nearly all of the objects in our study can be fit by one or two belts of dust. Dust around lower mass stars appears to be closer in than around higher mass stars, particularly for the warm dust component in the two-belt systems, suggesting a mass-dependent evolution of debris disks around young stars. For those objects with stellar companions, all dust distances are consistent with truncation of the debris disk by the binary companion. The gaps between several of the two-belt systems can place limits on the planets that might lie between the belts, potentially constraining the mass and locations of planets that may be forming around these stars.

Supercontinuum: broad as a lamp, bright as a laser, now in the mid-infrared

Science.gov (United States)

Moselund, Peter M.; Petersen, Christian; Dupont, Sune; Agger, Christian; Bang, Ole; Keiding, Søren R.

2012-06-01

Based on the experience gained developing our market leading visible spectrum supercontinuum sources NKT Photonics has built the first mid-infrared supercontinuum source based on modelocked picosecond fiber lasers. The source is pumped by a ~ 2 um laser based on a combination of erbium and thulium and use ZBLAN fibers to generate a 1.75-4.4 μm spectrum. We will present results obtained by applying the source for mid-infrared microscopy where absorption spectra can be used to identify the chemical nature of different parts of a sample. Subsequently, we discuss the possible application of a mid-IR supercontinuum source in other areas including infrared countermeasures.

SPITZER OBSERVATIONS OF BOW SHOCKS AND OUTFLOWS IN RCW 38

Energy Technology Data Exchange (ETDEWEB)

Winston, E. [ESA-ESTEC (SRE-SA), Keplerlaan 1, 2201 AZ Noordwijk ZH (Netherlands); Wolk, S. J.; Bourke, T. L.; Spitzbart, B. [Harvard Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Megeath, S. T. [Ritter Observatory, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft Ave., Toledo, OH 43606 (United States); Gutermuth, R., E-mail: ewinston@rssd.esa.int [Five Colleges Astronomy Department, Smith College, Northampton, MA 01027 (United States)

2012-01-10

We report Spitzer observations of five newly identified bow shocks in the massive star-forming region RCW 38. Four are visible at Infrared Array Camera (IRAC) wavelengths, the fifth is only visible at 24 {mu}m. Chandra X-ray emission indicates that winds from the central O5.5 binary, IRS 2, have caused an outflow to the northeast and southwest of the central subcluster. The southern lobe of hot ionized gas is detected in X-rays; shocked gas and heated dust from the shock front are detected with Spitzer at 4.5 and 24 {mu}m. The northern outflow may have initiated the present generation of star formation, based on the filamentary distribution of the protostars in the central subcluster. Further, the bow-shock driving star, YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are identified within this pillar at near- to mid-IR wavelengths. We also report on IRAC 3.6 and 5.8 {mu}m observations of the cluster DBS2003-124, northeast of RCW 38, where 33 candidate young stellar objects (YSOs) are identified. One star associated with the cluster drives a parsec-scale jet. Two Herbig-Haro objects associated with the jet are visible at IRAC and Multiband Imaging Photometer for Spitzer (MIPS) wavelengths. The jet extends over a distance of {approx}3 pc. Assuming a velocity of 100 km s{sup -1} for the jet material gives an age of 3 Multiplication-Sign 10{sup 4} yr, indicating that the star (and cluster) are likely to be very young, with a similar or possibly younger age than RCW 38, and that star formation is ongoing in the extended RCW 38 region.

SPITZER OBSERVATIONS OF BOW SHOCKS AND OUTFLOWS IN RCW 38

International Nuclear Information System (INIS)

Winston, E.; Wolk, S. J.; Bourke, T. L.; Spitzbart, B.; Megeath, S. T.; Gutermuth, R.

2012-01-01

We report Spitzer observations of five newly identified bow shocks in the massive star-forming region RCW 38. Four are visible at Infrared Array Camera (IRAC) wavelengths, the fifth is only visible at 24 μm. Chandra X-ray emission indicates that winds from the central O5.5 binary, IRS 2, have caused an outflow to the northeast and southwest of the central subcluster. The southern lobe of hot ionized gas is detected in X-rays; shocked gas and heated dust from the shock front are detected with Spitzer at 4.5 and 24 μm. The northern outflow may have initiated the present generation of star formation, based on the filamentary distribution of the protostars in the central subcluster. Further, the bow-shock driving star, YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are identified within this pillar at near- to mid-IR wavelengths. We also report on IRAC 3.6 and 5.8 μm observations of the cluster DBS2003-124, northeast of RCW 38, where 33 candidate young stellar objects (YSOs) are identified. One star associated with the cluster drives a parsec-scale jet. Two Herbig-Haro objects associated with the jet are visible at IRAC and Multiband Imaging Photometer for Spitzer (MIPS) wavelengths. The jet extends over a distance of ∼3 pc. Assuming a velocity of 100 km s –1 for the jet material gives an age of 3 × 10 4 yr, indicating that the star (and cluster) are likely to be very young, with a similar or possibly younger age than RCW 38, and that star formation is ongoing in the extended RCW 38 region.

Mid-Infrared Frequency-Agile Dual-Comb Spectroscopy

Science.gov (United States)

Luo, Pei-Ling; Yan, Ming; Iwakuni, Kana; Millot, Guy; Hänsch, Theodor W.; Picqué, Nathalie

2016-06-01

We demonstrate a new approach to mid-infrared dual-comb spectroscopy. It opens up new opportunities for accurate real-time spectroscopic diagnostics and it significantly simplifies the technique of dual-comb spectroscopy. Two mid-infrared frequency combs of slightly different repetition frequencies and moderate, but rapidly tunable, spectral span are generated in the 2800-3200 cm-1 region. The generators rely on electro-optic modulators, nonlinear fibers for spectral broadening and difference frequency generation and do not involve mode-locked lasers. Flat-top frequency combs span up to 10 cm-1 with a comb line spacing of 100 MHz (3×10-3 cm-1). The performance of the spectrometer without any phase-lock electronics or correction scheme is illustrated with spectra showing resolved comb lines and Doppler-limited spectra of methane. High precision on the spectroscopic parameter (line positions and intensities) determination is demonstrated for spectra measured on a millisecond time scale and it is validated with comparison with literature data. G. Millot, S. Pitois, M. Yan, T. Hovannysyan, A. Bendahmane, T.W. Hänsch, N. Picqué, Frequency-agile dual-comb spectroscopy, Nature Photonics 10, 27-30 (2016).

CHARACTERIZING THE MID-INFRARED EXTRAGALACTIC SKY WITH WISE AND SDSS

International Nuclear Information System (INIS)

Yan Lin; Donoso, E.; Tsai, Chao-Wei; Cutri, R.; Jarrett, T.; Stern, D.; Assef, R. J.; Eisenhardt, P.; Blain, A. W.; Stanford, S. A.; Wright, E.; Bridge, C.; Riechers, D. A.

2013-01-01

The Wide-field Infrared Survey Explorer (WISE) has completed its all-sky survey in four channels at 3.4-22 μm, detecting hundreds of millions of objects. We merge the WISE mid-infrared data with optical data from the Sloan Digital Sky Survey (SDSS) and provide a phenomenological characterization of WISE extragalactic sources. WISE is most sensitive at 3.4 μm (W1) and least sensitive at 22 μm (W4). The W1 band probes massive early-type galaxies out to z ∼> 1. This is more distant than SDSS identified early-type galaxies, consistent with the fact that 28% of 3.4 μm sources have faint or no r-band counterparts (r > 22.2). In contrast, 92%-95% of 12 μm and 22 μm sources have SDSS optical counterparts with r ≤ 22.2. WISE 3.4 μm detects 89.8% of the entire SDSS QSO catalog at S/N W1 >7σ, but only 18.9% at 22 μm with S/N W4 > 5σ. We show that WISE colors alone are effective in isolating stars (or local early-type galaxies), star-forming galaxies, and strong active galactic nuclei (AGNs)/QSOs at z ∼ 0.8 and W2 –2 . (2) Selection of dust-obscured, type-2 AGN/QSO candidates. We show that WISE W1 – W2 > 0.8, W2 6 (Vega) colors can be used to identify type-2 AGN candidates. The fraction of these type-2 AGN candidates is one-third of all WISE color-selected AGNs. (3) Selection of ultraluminous infrared galaxies (ULIRGs) at z ∼ 2 with extremely red colors, r – W4 > 14 or well-detected 22 μm sources lacking detections in the 3.4 and 4.6 μm bands. The surface density of z ∼ 2 ULIRG candidates selected with r – W4 > 14 is 0.9 ± 0.07 deg –2 at S/N W4 ≥ 5 (the corresponding, lowest flux density of 2.5 mJy), which is consistent with that inferred from smaller area Spitzer surveys. Optical spectroscopy of a small number of these high-redshift ULIRG candidates confirms our selection, and reveals a possible trend that optically fainter or r – W4 redder candidates are at higher redshifts.

Mid-infrared interferometric variability of DG Tauri: Implications for the inner-disk structure

Science.gov (United States)

Varga, J.; Gabányi, K. É.; Ábrahám, P.; Chen, L.; Kóspál, Á.; Menu, J.; Ratzka, Th.; van Boekel, R.; Dullemond, C. P.; Henning, Th.; Jaffe, W.; Juhász, A.; Moór, A.; Mosoni, L.; Sipos, N.

2017-08-01

Context. DG Tau is a low-mass pre-main sequence star, whose strongly accreting protoplanetary disk exhibits a so-far enigmatic behavior: its mid-infrared thermal emission is strongly time-variable, even turning the 10 μm silicate feature from emission to absorption temporarily. Aims: We look for the reason for the spectral variability at high spatial resolution and at multiple epochs. Methods: Infrared interferometry can spatially resolve the thermal emission of the circumstellar disk, also giving information about dust processing. We study the temporal variability of the mid-infrared interferometric signal, observed with the VLTI/MIDI instrument at six epochs between 2011 and 2014. We fit a geometric disk model to the observed interferometric signal to obtain spatial information about the disk. We also model the mid-infrared spectra by template fitting to characterize the profile and time dependence of the silicate emission. We use physically motivated radiative transfer modeling to interpret the mid-infrared interferometric spectra. Results: The inner disk (r 1-3 au) spectra show a crystalline silicate feature in emission, similar to the spectra of comet Hale-Bopp. The striking difference between the inner and outer disk spectral feature is highly unusual among T Tauri stars. The mid-infrared variability is dominated by the outer disk. The strength of the silicate feature changed by more than a factor of two. Between 2011 and 2014 the half-light radius of the mid-infrared-emitting region decreased from 1.15 to 0.7 au. Conclusions: For the origin of the absorption we discuss four possible explanations: a cold obscuring envelope, an accretion heated inner disk, a temperature inversion on the disk surface and a misaligned inner geometry. The silicate emission in the outer disk can be explained by dusty material high above the disk plane, whose mass can change with time, possibly due to turbulence in the disk. Based on observations made with the ESO Very Large

A SYSTEMATIC STUDY OF MID-INFRARED EMISSION FROM CORE-COLLAPSE SUPERNOVAE WITH SPIRITS

International Nuclear Information System (INIS)

Tinyanont, Samaporn; Kasliwal, Mansi M.; Lau, Ryan; Jencson, Jacob; Prince, Thomas; Fox, Ori D.; Williams, Robert; Smith, Nathan; Perley, Daniel; Dykhoff, Devin; Gehrz, Robert; Johansson, Joel; Van Dyk, Schuyler D.; Masci, Frank; Cody, Ann Marie

2016-01-01

We present a systematic study of mid-infrared emission from 141 nearby supernovae (SNe) observed with Spitzer /IRAC as part of the ongoing SPIRITS survey. We detect 8 Type Ia and 36 core-collapse SNe. All Type Ia/Ibc SNe become undetectable within three years of explosion, whereas 22 ± 11% of Type II SNe continue to be detected. Five Type II SNe are detected even two decades after discovery (SN 1974E, 1979C, 1980K, 1986J, and 1993J). Warm dust luminosity, temperature, and a lower limit on mass are obtained by fitting the two IRAC bands, assuming an optically thin dust shell. We derive warm dust masses between 10 −6 and 10 −2 M ⊙ and dust color temperatures between 200 and 1280 K. This observed warm dust could be pre-existing or newly created, but in either case represents a lower limit to the dust mass because cooler dust may be present. We present three case studies of extreme SNe. SN 2011ja (II-P) was over-luminous ([4.5] = −15.6 mag) at 900 days post explosion with increasing hot dust mass, suggesting either an episode of dust formation or intensifying circumstellar material (CSM) interactions heating up pre-existing dust. SN 2014bi (II-P) showed a factor of 10 decrease in dust mass over one month, suggesting either dust destruction or reduced dust heating. The IR luminosity of SN 2014C (Ib) stayed constant over 800 days, possibly due to strong CSM interaction with an H-rich shell, which is rare among stripped-envelope SNe. The observations suggest that this CSM shell originated from an LBV-like eruption roughly 100 years pre-explosion. The observed diversity demonstrates the power of mid-IR observations of a large sample of SNe.

THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. II. SILICATE FEATURE ANALYSIS OF UNRESOLVED TARGETS

Energy Technology Data Exchange (ETDEWEB)

Mittal, Tushar [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720-4767 (United States); Chen, Christine H. [Space Telescope Science Institute, 3700 San Martin Drive Baltimore, MD 21218 (United States); Jang-Condell, Hannah [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Manoj, P. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Sargent, Benjamin A. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Watson, Dan M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Lisse, Carey M., E-mail: cchen@stsci.edu [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States)

2015-01-10

During the Spitzer Space Telescope cryogenic mission, astronomers obtained Infrared Spectrograph (IRS) observations of hundreds of debris disk candidates that have been compiled in the Spitzer IRS Debris Disk Catalog. We have discovered 10 and/or 20 μm silicate emission features toward 120 targets in the catalog and modeled the IRS spectra of these sources, consistent with MIPS 70 μm observations, assuming that the grains are composed of silicates (olivine, pyroxene, forsterite, and enstatite) and are located either in a continuous disk with power-law size and surface density distributions or thin rings that are well-characterized using two separate dust grain temperatures. For systems better fit by the continuous disk model, we find that (1) the dust size distribution power-law index is consistent with that expected from a collisional cascade, q = 3.5-4.0, with a large number of values outside this range, and (2) the minimum grain size, a {sub min}, increases with stellar luminosity, L {sub *}, but the dependence of a {sub min} on L {sub *} is weaker than expected from radiation pressure alone. In addition, we also find that (3) the crystalline fraction of dust in debris disks evolves as a function of time with a large dispersion in crystalline fractions for stars of any particular stellar age or mass, (4) the disk inner edge is correlated with host star mass, and (5) there exists substantial variation in the properties of coeval disks in Sco-Cen, indicating that the observed variation is probably due to stochasticity and diversity in planet formation.

Mid-infrared quantum cascade laser spectroscopy probing of the ...

Indian Academy of Sciences (India)

Aparajeo Chattopadhyay

2018-05-07

May 7, 2018 ... cm3 molecule. −1 s. −1 ... Quantum cascade laser; time-resolved mid-infrared spectroscopy; transient absorption; peroxy radicals .... peak of the laser emission profile. .... cal with O2 is a termolecular reaction (Eq. 3) and the.

Spitzer/IRS Observations Of Multiple Main-Belt And Binary Near-Earth Asteroids

Science.gov (United States)

Enriquez, J. Emilio; Marchis, F.; Emery, J. P.; Im, S.

2010-10-01

Since the discovery of Ida's companion in 1993, 195 companions of asteroids have been discovered. To understand the formation process of these interesting bodies, their physical properties such as their bulk density, size, shape, and surface roughness need to be determined. During the Spitzer Cycle-4, we obtained IRS thermal emission spectra (5-42 um) of 23 known binary systems. The majority of asteroids are from the main-belt (16), while the rest are NEOs (7). After extracting the thermal spectra, we used a modified Standard Thermal Model (STM) to calculate their equivalent diameter (from 0.8 km to 237 km), their albedo (from 0.04 for C-type to 0.394 for a V-type) and their beaming factor related to the surface roughness and thermal inertia. We derive their emissivity spectra, which is useful to detect silicate features. Combining these measurements with 3D-models of these multiple asteroid systems obtained by lightcurve inversion, we should be able to derive an accurate estimate of their bulk-density and contrast them with their taxonomic classes. Preliminary studies by Marchis et al. (2008)1, suggested a relationship between bulk density and the taxonomic class of asteroids, which varies from 0.9 g/cc for C-complex to 2.4 g/cc for S-complex asteroids. The National Science Foundation supported this research under award number AAG-0807468. It was conducted with the Spitzer space telescope, which is operated by JPL under a contract with NASA. 1 Marchis et al. , 2008, "Mid-infrared Spectra of Binary Asteroids With Spitzer/IRS", 40th DPS Meeting, Bulletin of the American Astronomical Society, 40, 508

Interpretive signs designed to trigger naturalist intelligence at two American zoos

Science.gov (United States)

Bryant, Martha

An investigation of interpretive graphics was conducted in 2005 at two mid-sized AZA-accredited zoos, Lowry Park Zoo, Tampa, Florida and Knoxville Zoo, Knoxville, Tennessee. The Lowry Park Zoo study investigated signs at a red-tailed hawk and sandhill crane exhibit. Combination signs and wordless signs were more effective helping visitors see animals, increasing holding time, and number of engagements than treatments of no signs, or signs with words only. A second study, at Knoxville Zoo, tested combination and wordless signs in a children's zoo, investigating 31 signs at a 3.5-acre exhibit. Comparisons of visitors seeing the animals/using interactive exhibit elements, holding time, and engagement activities, showed wordless signs were more effective than combination signs. Differences in gender ratio, age, group size, and other demographics were not significant. Visit motivation differed between zoos, with visitors from Lowry Park Zoo more often articulating reason for a visit as wanting to see animals. Visitors at Knoxville Zoo most often said they wanted to spend time with family and friends. Differences in potential for naturalist intelligence were probably related to local practices rather than to innate differences in naturalist intelligence. The number of communities in Florida that regulate pet ownership and provide lawn service could account for the lower number of people who have pets and plants. At both institutions, behaviors supported educational theories. The importance of signs as advanced organizers was shown where signs were removed at the bird exhibit at Lowry Park Zoo, with fewer visitors seeing the animals. Social interaction was noted at both zoos, with intra- and inter-group conversations observed. If naturalist intelligence is necessary to see animals, visitors run a continuum. Some are unable to see animals with signs and assistance from other visitors; others see animals with little difficulty. The importance of honing naturalist

Herbig-haro objects and mid-infrared outflows in the VELA C molecular cloud

International Nuclear Information System (INIS)

Zhang, Miaomiao; Wang, Hongchi; Henning, Thomas

2014-01-01

We have performed a deep [S II] λλ6717/6731 wide field Herbig-Haro (HH) object survey toward the Vela C molecular cloud with a sky coverage of about 2 deg 2 . In total, 18 new HH objects, HH 1090-1107, are discovered and the two previously known HH objects, HH 73-74, are also detected in our [S II] images. We also present an investigation of mid-infrared outflows in the Vela C molecular cloud using the Wide-field Infrared Survey Explorer images taken from AllWISE data release. Using the method suggested by Zhang and Wang, 11 extended green objects (EGOs) are identified to be the mid-infrared outflows, including 6 new mid-infrared outflows that have not been detected previously at other wavelengths and 5 mid-infrared counterparts of the HH objects detected in this work. Using the AllWISE Source Catalog and the source classification scheme suggested by Koenig et al., we have identified 56 young stellar object (YSO) candidates in the Vela C molecular cloud. The possible driving sources of the HH objects and EGOs are discussed based on the morphology of HH objects and EGOs and the locations of HH objects, EGOs and YSO candidates. Finally we associate 12 HH objects and 5 EGOs with 10 YSOs and YSO candidates. The median length of the outflows in Vela C is 0.35 pc and the outflows seem to be oriented randomly.

A Spectral Survey of Six Comets in the Mid-Infrared.

Science.gov (United States)

Lisse, Carey M.; Sitko, M. L.; Reach, W. T.; Fernandez, Y. R.; Kelley, M. S.

2008-09-01

With the Spitzer Space Telescope (SST) and Infrared Space Observatory (ISO) we are beginning to understand the details of how the composition and formation of our own Solar System compares to those of other stars in our Galaxy. Recent, detailed observations of comets (remnants of the solar system's proto-stellar nebula), protoplanetary disks around young stellar objects (YSOs), and debris disks around moderate-age stars have given us a collection of detailed spectra containing clues about our Galactic context. Here we discuss 5 to 35 micron spectroscopy of the emission from dust grains and gas molecules in the comae of 6 recent comets: C/Hale-Bopp 1995 O1 [1], 29P/SW1 2004 [2], 9P/Tempel 1 2005 (ejecta) [3], 73P/SW3 (fragments B and C) [4], C/McNaught 2006 P1 [5], and 17P/Holmes 2007 [6]. We thank the Spitzer Science Center, the ISO project, and the NASA/IRTF for their support of this work. References: [1] Crovisier, J. et al. 1997, Science 275, 1904. [2] Stansberry, J.A. et al. 2004, ApJ Suppl. 154, 463. [3] Lisse, C.M. et al. 2006, Science 313, 635. [4] Sitko, M.L., et al. 2008, ACM 2008 abstract #8101. [5] Lisse, C.M. et al. 2007, IAUC 8862. [6] Reach, W.T. et al. 2009, in prep.

Dilute bismides for near and mid-infrared applications

DEFF Research Database (Denmark)

Song, Yuxin; Gu, Yi; Ye, Hong

2013-01-01

Dilute bismides are a group of emerging materials with unique properties. Incorporation of a small amount of Bi in common III–V host materials results in large band-gap reduction and strong spin-orbit splitting, leading to potential applications in near-infrared (NIR) and mid-infrared (MIR......) optoelectronics. Recent progresses on molecular beam epitaxy (MBE) of novel III-Sb-Bi, i.e. GaSbBi and InSbBi thin films from our group are summarised in this paper. Quantum well structures based on GaSbBi and InGaAsBi aiming for the optical communication window were grown and characterized....

The star formation history of the universe as viewed in the infrared

International Nuclear Information System (INIS)

Magnelli, Benjamin

2009-01-01

This thesis is devoted to the estimation of the cosmic star formation history of the Universe through the study of spectral properties of galaxies observed by the Spitzer satellite in the mid-and-far- infrared. My work begins with the extraction of sources contained in the Spitzer images and with the creation of multi- wavelengths catalogs. Using those catalogs I study the spectral properties of infrared galaxies and their evolution with redshift. From the comparison of these properties with the predictions of standard spectral libraries, I show that galaxies situated beyond z∼1.3 present significant evolutions in their spectral properties. Based on these spectral properties, I estimate the cosmic star formation history of the Universe from z∼0 to z∼2.3. This history is characterized by a sharp increase of the star formation density of the Universe form z∼0 and z∼1, followed by a stabilisation phase up to z∼2. This star formation density is dominated between z∼0.8 and z∼2 by luminous infrared galaxies with high star formation rate. Finally, I study the presence of the 3.3 um PAH signature in the spectrum of distant galaxies (0.5 3. (author) [fr

Towards supercontinuum-driven hyperspectral microscopy in the mid-infrared

DEFF Research Database (Denmark)

Lindsay, I. D.; Valle, S.; Ward, J.

2016-01-01

The extension of supercontinuum (SC) sources into the mid-infrared, via the use of fluoride and chalcogenide optical fibers, potentially offers the high radiance of a laser combined with spectral coverage far exceeding that of typical tunable lasers and comparable to traditional black-body emitte...

Short pulse mid-infrared amplifier for high average power

CSIR Research Space (South Africa)

Botha, LR

2006-09-01

Full Text Available High pressure CO2 lasers are good candidates for amplifying picosecond mid infrared pulses. High pressure CO2 lasers are notorious for being unreliable and difficult to operate. In this paper a high pressure CO2 laser is presented based on well...

DEEP JHKs AND SPITZER IMAGING OF FOUR ISOLATED MOLECULAR CLOUD CORES

International Nuclear Information System (INIS)

Chapman, Nicholas L.; Mundy, Lee G.

2009-01-01

We present observations in eight wavebands from 1.25 to 24 μm of four dense cores: L204C-2, L1152, L1155C-2, and L1228. Our goals are to study the young stellar object (YSO) population of these cores and to measure the mid-infrared extinction law. With our combined near-infrared and Spitzer photometry, we classify each source in the cores as, among other things, background stars, galaxies, or embedded YSOs. L1152 contains three YSOs and L1228 has seven, but neither L204C-2 nor L1155C-2 appear to contain any YSOs. We estimate an upper limit of 7 x 10 -5 to 5 x 10 -4 L sun for any undiscovered YSOs in our cores. We also compute the line-of-sight extinction law toward each background star. These measurements are averaged spatially, to create χ 2 maps of the changes in the mid-infrared extinction law throughout our cores, and also in different ranges of extinction. From the χ 2 maps, we identify two small regions in L1152 and L1228 where the outflows in those cores appear to be destroying the larger dust grains, thus altering the extinction law in those regions. On average, however, our extinction law is relatively flat from 3.6 to 24 μm for all ranges of extinction and in all four cores. From 3.6 to 8 μm, this law is consistent with a dust model that includes larger dust grains than the diffuse interstellar medium, which suggests grain growth has occurred in our cores. At 24 μm, our extinction law is two to four times higher than predicted by dust models. However, it is similar to other empirical measurements.

How dead are dead galaxies? Mid-infrared fluxes of quiescent galaxies at redshift 0.3 < z < 2.5: implications for star formation rates and dust heating

International Nuclear Information System (INIS)

Fumagalli, Mattia; Labbé, Ivo; Patel, Shannon G.; Franx, Marijn; Van Dokkum, Pieter; Momcheva, Ivelina; Nelson, Erica; Brammer, Gabriel; Da Cunha, Elisabete; Rix, Hans-Walter; Maseda, Michael; Schreiber, Natascha M. Förster; Kriek, Mariska; Quadri, Ryan; Wake, David; Lundgren, Britt; Whitaker, Katherine E.; Marchesini, Danilo; Pacifici, Camilla; Skelton, Rosalind E.

2014-01-01

We investigate star formation rates (SFRs) of quiescent galaxies at high redshift (0.3 < z < 2.5) using 3D-HST WFC3 grism spectroscopy and Spitzer mid-infrared data. We select quiescent galaxies on the basis of the widely used UVJ color-color criteria. Spectral energy distribution (SED) fitting (rest-frame optical and near-IR) indicates very low SFRs for quiescent galaxies (sSFR ∼ 10 –12 yr –1 ). However, SED fitting can miss star formation if it is hidden behind high dust obscuration and ionizing radiation is re-emitted in the mid-infrared. It is therefore fundamental to measure the dust-obscured SFRs with a mid-IR indicator. We stack the MIPS 24 μm images of quiescent objects in five redshift bins centered on z = 0.5, 0.9, 1.2, 1.7, 2.2 and perform aperture photometry. Including direct 24 μm detections, we find sSFR ∼ 10 –11.9 × (1 + z) 4 yr –1 . These values are higher than those indicated by SED fitting, but at each redshift they are 20-40 times lower than those of typical star-forming galaxies. The true SFRs of quiescent galaxies might be even lower, as we show that the mid-IR fluxes can be due to processes unrelated to ongoing star formation, such as cirrus dust heated by old stellar populations and circumstellar dust. Our measurements show that star formation quenching is very efficient at every redshift. The measured SFR values are at z > 1.5 marginally consistent with the ones expected from gas recycling (assuming that mass loss from evolved stars refuels star formation) and well below that at lower redshifts.

How dead are dead galaxies? Mid-infrared fluxes of quiescent galaxies at redshift 0.3 < z < 2.5: implications for star formation rates and dust heating

Energy Technology Data Exchange (ETDEWEB)

Fumagalli, Mattia; Labbé, Ivo; Patel, Shannon G.; Franx, Marijn [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Van Dokkum, Pieter; Momcheva, Ivelina; Nelson, Erica [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Brammer, Gabriel [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago (Chile); Da Cunha, Elisabete; Rix, Hans-Walter; Maseda, Michael [Max Planck Institute for Astronomy (MPIA), Konigstuhl 17, D-69117 Heidelberg (Germany); Schreiber, Natascha M. Förster [Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Kriek, Mariska [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Quadri, Ryan [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States); Wake, David; Lundgren, Britt [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Whitaker, Katherine E. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Pacifici, Camilla [Yonsei University Observatory, Yonsei University, Seoul 120-749 (Korea, Republic of); Skelton, Rosalind E. [South African Astronomical Observatory, Observatory Road, Cape Town (South Africa)

2014-11-20

We investigate star formation rates (SFRs) of quiescent galaxies at high redshift (0.3 < z < 2.5) using 3D-HST WFC3 grism spectroscopy and Spitzer mid-infrared data. We select quiescent galaxies on the basis of the widely used UVJ color-color criteria. Spectral energy distribution (SED) fitting (rest-frame optical and near-IR) indicates very low SFRs for quiescent galaxies (sSFR ∼ 10{sup –12} yr{sup –1}). However, SED fitting can miss star formation if it is hidden behind high dust obscuration and ionizing radiation is re-emitted in the mid-infrared. It is therefore fundamental to measure the dust-obscured SFRs with a mid-IR indicator. We stack the MIPS 24 μm images of quiescent objects in five redshift bins centered on z = 0.5, 0.9, 1.2, 1.7, 2.2 and perform aperture photometry. Including direct 24 μm detections, we find sSFR ∼ 10{sup –11.9} × (1 + z){sup 4} yr{sup –1}. These values are higher than those indicated by SED fitting, but at each redshift they are 20-40 times lower than those of typical star-forming galaxies. The true SFRs of quiescent galaxies might be even lower, as we show that the mid-IR fluxes can be due to processes unrelated to ongoing star formation, such as cirrus dust heated by old stellar populations and circumstellar dust. Our measurements show that star formation quenching is very efficient at every redshift. The measured SFR values are at z > 1.5 marginally consistent with the ones expected from gas recycling (assuming that mass loss from evolved stars refuels star formation) and well below that at lower redshifts.

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

High-coherence mid-infrared dual-comb spectroscopy spanning 2.6 to 5.2 μm

Science.gov (United States)

Ycas, Gabriel; Giorgetta, Fabrizio R.; Baumann, Esther; Coddington, Ian; Herman, Daniel; Diddams, Scott A.; Newbury, Nathan R.

2018-04-01

Mid-infrared dual-comb spectroscopy has the potential to supplant conventional Fourier-transform spectroscopy in applications requiring high resolution, accuracy, signal-to-noise ratio and speed. Until now, mid-infrared dual-comb spectroscopy has been limited to narrow optical bandwidths or low signal-to-noise ratios. Using digital signal processing and broadband frequency conversion in waveguides, we demonstrate a mid-infrared dual-comb spectrometer covering 2.6 to 5.2 µm with comb-tooth resolution, sub-MHz frequency precision and accuracy, and a spectral signal-to-noise ratio as high as 6,500. As a demonstration, we measure the highly structured, broadband cross-section of propane from 2,840 to 3,040 cm-1, the complex phase/amplitude spectra of carbonyl sulfide from 2,000 to 2,100 cm-1, and of a methane, acetylene and ethane mixture from 2,860 to 3,400 cm-1. The combination of broad bandwidth, comb-mode resolution and high brightness will enable accurate mid-infrared spectroscopy in precision laboratory experiments and non-laboratory applications including open-path atmospheric gas sensing, process monitoring and combustion.

The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy

International Nuclear Information System (INIS)

Leggett, S. K.; Tremblin, P.; Esplin, T. L.; Luhman, K. L.; Morley, Caroline V.

2017-01-01

The survey of the mid-infrared sky by the Wide-field Infrared Survey Explorer ( WISE ) led to the discovery of extremely cold, low-mass brown dwarfs, classified as Y dwarfs, which extend the T class to lower temperatures. Twenty-four Y dwarfs are known at the time of writing. Here we present improved parallaxes for four of these, determined using Spitzer images. We give new photometry for four late-type T and three Y dwarfs and new spectra of three Y dwarfs, obtained at Gemini Observatory. We also present previously unpublished photometry taken from HST , ESO, Spitzer , and WISE archives of 11 late-type T and 9 Y dwarfs. The near-infrared data are put onto the same photometric system, forming a homogeneous data set for the coolest brown dwarfs. We compare recent models to our photometric and spectroscopic data set. We confirm that nonequilibrium atmospheric chemistry is important for these objects. Nonequilibrium cloud-free models reproduce well the near-infrared spectra and mid-infrared photometry for the warmer Y dwarfs with 425 ≤ T eff (K) ≤ 450. A small amount of cloud cover may improve the model fits in the near-infrared for the Y dwarfs with 325 ≤ T eff (K) ≤ 375. Neither cloudy nor cloud-free models reproduce the near-infrared photometry for the T eff = 250 K Y dwarf W0855. We use the mid-infrared region, where most of the flux originates, to constrain our models of W0855. We find that W0855 likely has a mass of 1.5–8 Jupiter masses and an age of 0.3–6 Gyr. The Y dwarfs with measured parallaxes are within 20 pc of the Sun and have tangential velocities typical of the thin disk. The metallicities and ages we derive for the sample are generally solar-like. We estimate that the known Y dwarfs are 3 to 20 Jupiter-mass objects with ages of 0.6–8.5 Gyr.

The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Leggett, S. K. [Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Tremblin, P. [Maison de la Simulation, CEA-CNRS-INRIA-UPS-UVSQ, USR 3441, Centre d’étude de Saclay, F-91191 Gif-Sur-Yvette (France); Esplin, T. L.; Luhman, K. L. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Morley, Caroline V., E-mail: sleggett@gemini.edu [Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138 (United States)

2017-06-20

The survey of the mid-infrared sky by the Wide-field Infrared Survey Explorer ( WISE ) led to the discovery of extremely cold, low-mass brown dwarfs, classified as Y dwarfs, which extend the T class to lower temperatures. Twenty-four Y dwarfs are known at the time of writing. Here we present improved parallaxes for four of these, determined using Spitzer images. We give new photometry for four late-type T and three Y dwarfs and new spectra of three Y dwarfs, obtained at Gemini Observatory. We also present previously unpublished photometry taken from HST , ESO, Spitzer , and WISE archives of 11 late-type T and 9 Y dwarfs. The near-infrared data are put onto the same photometric system, forming a homogeneous data set for the coolest brown dwarfs. We compare recent models to our photometric and spectroscopic data set. We confirm that nonequilibrium atmospheric chemistry is important for these objects. Nonequilibrium cloud-free models reproduce well the near-infrared spectra and mid-infrared photometry for the warmer Y dwarfs with 425 ≤ T {sub eff} (K) ≤ 450. A small amount of cloud cover may improve the model fits in the near-infrared for the Y dwarfs with 325 ≤ T {sub eff} (K) ≤ 375. Neither cloudy nor cloud-free models reproduce the near-infrared photometry for the T {sub eff} = 250 K Y dwarf W0855. We use the mid-infrared region, where most of the flux originates, to constrain our models of W0855. We find that W0855 likely has a mass of 1.5–8 Jupiter masses and an age of 0.3–6 Gyr. The Y dwarfs with measured parallaxes are within 20 pc of the Sun and have tangential velocities typical of the thin disk. The metallicities and ages we derive for the sample are generally solar-like. We estimate that the known Y dwarfs are 3 to 20 Jupiter-mass objects with ages of 0.6–8.5 Gyr.

The SAGE-Spec Spitzer Legacy program: the life-cycle of dust and gas in the Large Magellanic Cloud. Point source classification - III

Science.gov (United States)

Jones, O. C.; Woods, P. M.; Kemper, F.; Kraemer, K. E.; Sloan, G. C.; Srinivasan, S.; Oliveira, J. M.; van Loon, J. Th.; Boyer, M. L.; Sargent, B. A.; McDonald, I.; Meixner, M.; Zijlstra, A. A.; Ruffle, P. M. E.; Lagadec, E.; Pauly, T.; Sewiło, M.; Clayton, G. C.; Volk, K.

2017-09-01

The Infrared Spectrograph (IRS) on the Spitzer Space Telescope observed nearly 800 point sources in the Large Magellanic Cloud (LMC), taking over 1000 spectra. 197 of these targets were observed as part of the SAGE-Spec Spitzer Legacy program; the remainder are from a variety of different calibration, guaranteed time and open time projects. We classify these point sources into types according to their infrared spectral features, continuum and spectral energy distribution shape, bolometric luminosity, cluster membership and variability information, using a decision-tree classification method. We then refine the classification using supplementary information from the astrophysical literature. We find that our IRS sample is comprised substantially of YSO and H II regions, post-main-sequence low-mass stars: (post-)asymptotic giant branch stars and planetary nebulae and massive stars including several rare evolutionary types. Two supernova remnants, a nova and several background galaxies were also observed. We use these classifications to improve our understanding of the stellar populations in the LMC, study the composition and characteristics of dust species in a variety of LMC objects, and to verify the photometric classification methods used by mid-IR surveys. We discover that some widely used catalogues of objects contain considerable contamination and others are missing sources in our sample.

Cutting and skin-ablative properties of pulsed mid-infrared laser surgery.

Science.gov (United States)

Kaufmann, R; Hartmann, A; Hibst, R

1994-02-01

Pulsed mid-infrared lasers allow a precise removal of soft tissues with only minimal thermal damage. To study the potential dermatosurgical usefulness of currently available systems at different wavelengths (2010-nm Thulium:YAG laser, 2100-nm Holmium:YAG laser, 2790-nm Erbium:YSGG laser, and 2940-nm Erbium:YAG laser) in vivo on pig skin. Immediate effects and wound healing of superficial laser-abrasions and incisions were compared with those of identical control lesions produced by dermabrasion, scalpel incisions, or laser surgery performed by a 1060-nm Nd:YAG and a 1060-nm CO2 laser (continuous and superpulsed mode). Best efficiency and least thermal injury was found for the pulsed Erbium:YAG laser, leading to ablative and incisional lesions comparable to those obtained by dermabrasion or superficial scalpel incisions, respectively. In contrast to other mid-infrared lasers tested, the 2940-nm Erbium:YAG laser thus provides a potential instrument for future applications in skin surgery, especially when aiming at a careful ablative removal of delicate superficial lesions with maximum sparing of adjacent tissue structures. However, in the purely incisional application mode pulsed mid-infrared lasers, though of potential usefulness in microsurgical indications (eg, surgery of the cornea), do not offer a suggestive alternative to simple scalpel surgery of the skin.

Mid-infrared Spectroscopy/Bioimaging: Moving toward MIR optical biopsy

DEFF Research Database (Denmark)

Seddon, Angela B.; Napier, Bruce; Lindsay, Ian

2016-01-01

), with its ability to enable in vivo medical diagnosis, is particularly interesting. In fact, the European Commission provides support for a major effort to develop the technology through its Framework Seven (FP7) project called MINERVA (MId- to-NEaR- infrared spectroscopy for improVed medical diAgnostics)....

Silicon nitride photonics: from visible to mid-infrared wavelengths

Science.gov (United States)

Micó, Gloria; Bru, Luis A.; Pastor, Daniel; Doménech, David; Fernández, Juan; Sánchez, Ana; Cirera, Josep M.; Domínguez, Carlos; Muñoz, Pascual

2018-02-01

Silicon nitride has received a lot of attention during the last ten years, for applications such as bio-photonics, tele/datacom, optical signal processing and sensing. In this paper, firstly an updated review of the state of the art of silicon nitride photonics integration platforms will be provided. Secondly, our developments on a moderate confinement Si3N4 platform in the near-infrared will be presented. Finally, our steps towards establishing a Si3N4 based platform for broadband operation spanning from visible to mid-infrared wavelengths will be introduced.

Mid-infrared frequency comb via coherent dispersive wave generation in silicon nitride nanophotonic waveguides

Science.gov (United States)

Guo, Hairun; Herkommer, Clemens; Billat, Adrien; Grassani, Davide; Zhang, Chuankun; Pfeiffer, Martin H. P.; Weng, Wenle; Brès, Camille-Sophie; Kippenberg, Tobias J.

2018-06-01

Mid-infrared optical frequency combs are of significant interest for molecular spectroscopy due to the large absorption of molecular vibrational modes on the one hand, and the ability to implement superior comb-based spectroscopic modalities with increased speed, sensitivity and precision on the other hand. Here, we demonstrate a simple, yet effective, method for the direct generation of mid-infrared optical frequency combs in the region from 2.5 to 4.0 μm (that is, 2,500-4,000 cm-1), covering a large fraction of the functional group region, from a conventional and compact erbium-fibre-based femtosecond laser in the telecommunication band (that is, 1.55 μm). The wavelength conversion is based on dispersive wave generation within the supercontinuum process in an unprecedented large-cross-section silicon nitride (Si3N4) waveguide with the dispersion lithographically engineered. The long-wavelength dispersive wave can perform as a mid-infrared frequency comb, whose coherence is demonstrated via optical heterodyne measurements. Such an approach can be considered as an alternative option to mid-infrared frequency comb generation. Moreover, it has the potential to realize compact dual-comb spectrometers. The generated combs also have a fine teeth-spacing, making them suitable for gas-phase analysis.

THE DARKEST SHADOWS: DEEP MID-INFRARED EXTINCTION MAPPING OF A MASSIVE PROTOCLUSTER

Energy Technology Data Exchange (ETDEWEB)

Butler, Michael J. [Institute of Theoretical Physics, University of Zürich, CH-8057 Zürich (Switzerland); Tan, Jonathan C. [Departments of Astronomy and Physics, University of Florida, Gainesville, FL 32611 (United States); Kainulainen, Jouni [Max-Planck-Institute for Astronomy, Königstuhl 17, D-69117, Heidelberg (Germany)

2014-02-20

We use deep 8 μm Spitzer-IRAC imaging of massive Infrared Dark Cloud (IRDC) G028.37+00.07 to construct a mid-infrared (MIR) extinction map that probes mass surface densities up to Σ ∼ 1 g cm{sup –2} (A{sub V} ∼ 200 mag), amongst the highest values yet probed by extinction mapping. Merging with an NIR extinction map of the region creates a high dynamic range map that reveals structures down to A{sub V} ∼ 1 mag. We utilize the map to: (1) measure a cloud mass ∼7 × 10{sup 4} M {sub ☉} within a radius of ∼8 pc. {sup 13}CO kinematics indicate that the cloud is gravitationally bound. It thus has the potential to form one of the most massive young star clusters known in the Galaxy. (2) Characterize the structures of 16 massive cores within the IRDC, finding they can be fit by singular polytropic spheres with ρ∝r{sup −k{sub ρ}} and k {sub ρ} = 1.3 ± 0.3. They have Σ-bar ≃0.1--0.4 g cm{sup −2}—relatively low values that, along with their measured cold temperatures, suggest that magnetic fields, rather than accretion-powered radiative heating, are important for controlling fragmentation of these cores. (3) Determine the Σ (equivalently column density or A{sub V} ) probability distribution function (PDF) for a region that is nearly complete for A{sub V} > 3 mag. The PDF is well fit by a single log-normal with mean A-bar {sub V}≃9 mag, high compared to other known clouds. It does not exhibit a separate high-end power law tail, which has been claimed to indicate the importance of self-gravity. However, we suggest that the PDF does result from a self-similar, self-gravitating hierarchy of structures present over a wide range of scales in the cloud.

Discrete parametric band conversion in silicon for mid-infrared applications.

Science.gov (United States)

Tien, En-Kuang; Huang, Yuewang; Gao, Shiming; Song, Qi; Qian, Feng; Kalyoncu, Salih K; Boyraz, Ozdal

2010-10-11

Silicon photonics has great potential for mid-wave-infrared applications. The dispersion of waveguide can be manipulated by waveguide dimension and cladding materials. Simulation shows that <3 μm wide conversion can be achieved by tuning the pump wavelength.

Generating Efficient Femtosecond Mid-infrared Pulse by Single Near-infrared Pump Wavelength in Bulk Nonlinear Crystal Without Phase-matching

DEFF Research Database (Denmark)

Zhou, Binbin; Guo, Hairun; Bache, Morten

2014-01-01

We experimentally demonstrate efficient mid-infrared pulse generation by dispersive wave radiation in bulk lithium niobate crystal. Femtosecond mid-IR pulses centering from 2.8-2.92 μm are generated using the single pump wavelengths from 1.25-1.45 μm. © 2014 Optical Society of America...

SPITZER survey of dust grain processing in stable discs around binary post-AGB stars

NARCIS (Netherlands)

Gielen, C.; van Winckel, H.; Min, M.; Waters, L.B.F.M.; Lloyd Evans, T.

2008-01-01

Aims. We investigate the mineralogy and dust processing in the circumbinary discs of binary post-AGB stars using high-resolution TIMMI2 and SPITZER infrared spectra. Methods: We perform a full spectral fitting to the infrared spectra using the most recent opacities of amorphous and crystalline dust

SPITZER IRAC COLOR DIAGNOSTICS FOR EXTENDED EMISSION IN STAR-FORMING REGIONS

International Nuclear Information System (INIS)

Ybarra, Jason E.; Tapia, Mauricio; Román-Zúñiga, Carlos G.; Lada, Elizabeth A.

2014-01-01

The infrared data from the Spitzer Space Telescope are an invaluable tool for identifying physical processes in star formation. In this study, we calculate the Infrared Array Camera (IRAC) color space of UV fluorescent H 2 and polycyclic aromatic hydrocarbon (PAH) emission in photodissociation regions (PDRs) using the Cloudy code with PAH opacities from Draine and Li. We create a set of color diagnostics that can be applied to study the structure of PDRs and to distinguish between FUV-excited and shock-excited H 2 emission. To test this method, we apply these diagnostics to Spitzer IRAC data of NGC 2316. Our analysis of the structure of the PDR is consistent with previous studies of the region. In addition to UV excited emission, we identify shocked gas that may be part of an outflow originating from the cluster

SPITZER IRAC COLOR DIAGNOSTICS FOR EXTENDED EMISSION IN STAR-FORMING REGIONS

Energy Technology Data Exchange (ETDEWEB)

Ybarra, Jason E.; Tapia, Mauricio; Román-Zúñiga, Carlos G. [Instituto de Astronomía, Universidad Nacional Autónoma de Mexíco, Unidad Académica en Ensenada, Km 103 Carr. Tijuana-Ensenada, 22860 Ensenada BC (Mexico); Lada, Elizabeth A., E-mail: jybarra@astro.unam.mx [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States)

2014-10-20

The infrared data from the Spitzer Space Telescope are an invaluable tool for identifying physical processes in star formation. In this study, we calculate the Infrared Array Camera (IRAC) color space of UV fluorescent H{sub 2} and polycyclic aromatic hydrocarbon (PAH) emission in photodissociation regions (PDRs) using the Cloudy code with PAH opacities from Draine and Li. We create a set of color diagnostics that can be applied to study the structure of PDRs and to distinguish between FUV-excited and shock-excited H{sub 2} emission. To test this method, we apply these diagnostics to Spitzer IRAC data of NGC 2316. Our analysis of the structure of the PDR is consistent with previous studies of the region. In addition to UV excited emission, we identify shocked gas that may be part of an outflow originating from the cluster.

NEW DEBRIS DISKS AROUND YOUNG, LOW-MASS STARS DISCOVERED WITH THE SPITZER SPACE TELESCOPE

International Nuclear Information System (INIS)

Plavchan, Peter; Werner, M. W.; Stapelfeldt, K. R.; Chen, C. H.; Su, K. Y. L.; Stauffer, J. R.; Song, I.

2009-01-01

We present 24 μm and 70 μm Multiband Imaging Photometer for Spitzer (MIPS) observations of 70 A through M-type dwarfs with estimated ages from 8 Myr to 1.1 Gyr, as part of a Spitzer guaranteed time program, including a re-analysis of some previously published source photometry. Our sample is selected from stars with common youth indicators such as lithium abundance, X-ray activity, chromospheric activity, and rapid rotation. We compare our MIPS observations to empirically derived K s -[24] colors as a function of the stellar effective temperature to identify 24 μm and 70 μm excesses. We place constraints or upper limits on dust temperatures and fractional infrared luminosities with a simple blackbody dust model. We confirm the previously published 70 μm excesses for HD 92945, HD 112429, and AU Mic, and provide updated flux density measurements for these sources. We present the discovery of 70 μm excesses for five stars: HD 7590, HD 10008, HD 59967, HD 73350, and HD 135599. HD 135599 is also a known Spitzer IRS (InfraRed Spectrograph) excess source, and we confirm the excess at 24 μm. We also present the detection of 24 μm excesses for 10 stars: HD 10008, GJ 3400A, HD 73350, HD 112429, HD 123998, HD 175742, AT Mic, BO Mic, HD 358623 and Gl 907.1. We find that large 70 μm excesses are less common around stars with effective temperatures of less than 5000 K (3.7 +7.6 -1.1 %) than around stars with effective temperatures between 5000 K and 6000 K (21.4 +9.5 -5.7 %), despite the cooler stars having a younger median age in our sample (12 Myr vs. 340 Myr). We find that the previously reported excess for TWA 13A at 70 μm is due to a nearby background galaxy, and the previously reported excess for HD 177724 is due to saturation of the near-infrared photometry used to predict the mid-infrared stellar flux contribution. In the Appendix, we present an updated analysis of dust grain removal timescales due to grain-grain collisions and radiation pressure, Poynting

Cosmic Infrared Background Fluctuations in Deep Spitzer Infrared Array Camera Images: Data Processing and Analysis

Science.gov (United States)

Arendt, Richard; Kashlinsky, A.; Moseley, S.; Mather, J.

2010-01-01

This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer Infrared Array Camera observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations that would otherwise corrupt the results. The procedures and results for masking bright sources and modeling faint sources down to levels set by the instrumental noise are presented. Various tests are performed to demonstrate that the resulting power spectra of these fields are not dominated by instrumental or procedural effects. These tests indicate that the large-scale ([greater, similar]30') fluctuations that remain in the deepest fields are not directly related to the galaxies that are bright enough to be individually detected. We provide the parameterization of these power spectra in terms of separate instrument noise, shot noise, and power-law components. We discuss the relationship between fluctuations measured at different wavelengths and depths, and the relations between constraints on the mean intensity of the CIB and its fluctuation spectrum. Consistent with growing evidence that the [approx]1-5 [mu]m mean intensity of the CIB may not be as far above the integrated emission of resolved galaxies as has been reported in some analyses of DIRBE and IRTS observations, our measurements of spatial fluctuations of the CIB intensity indicate the mean emission from the objects producing the fluctuations is quite low ([greater, similar]1 nW m-2 sr-1 at 3-5 [mu]m), and thus consistent with current [gamma]-ray absorption constraints. The source of the fluctuations may be high-z Population III objects, or a more local component of very low luminosity objects with clustering properties that differ from the resolved galaxies. Finally, we discuss the prospects of the upcoming space-based surveys to directly measure the epochs

COSMIC INFRARED BACKGROUND FLUCTUATIONS IN DEEP SPITZER INFRARED ARRAY CAMERA IMAGES: DATA PROCESSING AND ANALYSIS

International Nuclear Information System (INIS)

Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

2010-01-01

This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer Infrared Array Camera observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations that would otherwise corrupt the results. The procedures and results for masking bright sources and modeling faint sources down to levels set by the instrumental noise are presented. Various tests are performed to demonstrate that the resulting power spectra of these fields are not dominated by instrumental or procedural effects. These tests indicate that the large-scale (∼>30') fluctuations that remain in the deepest fields are not directly related to the galaxies that are bright enough to be individually detected. We provide the parameterization of these power spectra in terms of separate instrument noise, shot noise, and power-law components. We discuss the relationship between fluctuations measured at different wavelengths and depths, and the relations between constraints on the mean intensity of the CIB and its fluctuation spectrum. Consistent with growing evidence that the ∼1-5 μm mean intensity of the CIB may not be as far above the integrated emission of resolved galaxies as has been reported in some analyses of DIRBE and IRTS observations, our measurements of spatial fluctuations of the CIB intensity indicate the mean emission from the objects producing the fluctuations is quite low (∼>1 nW m -2 sr -1 at 3-5 μm), and thus consistent with current γ-ray absorption constraints. The source of the fluctuations may be high-z Population III objects, or a more local component of very low luminosity objects with clustering properties that differ from the resolved galaxies. Finally, we discuss the prospects of the upcoming space-based surveys to directly measure the epochs inhabited by the populations producing these

THE SPECTRAL ENERGY DISTRIBUTIONS AND INFRARED LUMINOSITIES OF z ≈ 2 DUST-OBSCURED GALAXIES FROM Herschel AND Spitzer

International Nuclear Information System (INIS)

Melbourne, J.; Soifer, B. T.; Desai, Vandana; Armus, Lee; Pope, Alexandra; Alberts, Stacey; Dey, Arjun; Jannuzi, B. T.; Bussmann, R. S.

2012-01-01

Dust-obscured galaxies (DOGs) are a subset of high-redshift (z ≈ 2) optically-faint ultra-luminous infrared galaxies (ULIRGs, e.g., L IR > 10 12 L ☉ ). We present new far-infrared photometry, at 250, 350, and 500 μm (observed-frame), from the Herschel Space Telescope for a large sample of 113 DOGs with spectroscopically measured redshifts. Approximately 60% of the sample are detected in the far-IR. The Herschel photometry allows the first robust determinations of the total infrared luminosities of a large sample of DOGs, confirming their high IR luminosities, which range from 10 11.6 L ☉ IR (8-1000 μm) 13.6 L ☉ . 90% of the Herschel-detected DOGs in this sample are ULIRGs and 30% have L IR > 10 13 L ☉ . The rest-frame near-IR (1-3 μm) spectral energy distributions (SEDs) of the Herschel-detected DOGs are predictors of their SEDs at longer wavelengths. DOGs with 'power-law' SEDs in the rest-frame near-IR show observed-frame 250/24 μm flux density ratios similar to the QSO-like local ULIRG, Mrk 231. DOGs with a stellar 'bump' in their rest-frame near-IR show observed-frame 250/24 μm flux density ratios similar to local star-bursting ULIRGs like NGC 6240. None show 250/24 μm flux density ratios similar to extreme local ULIRG, Arp 220; though three show 350/24 μm flux density ratios similar to Arp 220. For the Herschel-detected DOGs, accurate estimates (within ∼25%) of total IR luminosity can be predicted from their rest-frame mid-IR data alone (e.g., from Spitzer observed-frame 24 μm luminosities). Herschel-detected DOGs tend to have a high ratio of infrared luminosity to rest-frame 8 μm luminosity (the IR8 = L IR (8-1000 μm)/νL ν (8 μm) parameter of Elbaz et al.). Instead of lying on the z = 1-2 'infrared main sequence' of star-forming galaxies (like typical LIRGs and ULIRGs at those epochs) the DOGs, especially large fractions of the bump sources, tend to lie in the starburst sequence. While, Herschel-detected DOGs are similar to scaled up

Reduced graphene oxide mid-infrared photodetector at 300 K

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Gustavo E.; Kim, Jin Ho; Oller, Declan; Xu, Jimmy [School of Engineering, Brown University, Box D, Providence, Rhode Island 02912 (United States)

2015-09-14

We report on uncooled mid-infrared photovoltaic responses at 300 K arising in heterojunctions of reduced graphene oxide with p-Si. Two major photoresponse spectral peaks are observed, one in the near infrared starting at 1.1 μm corresponding to electron-hole pair generation in the Si substrate, and another at wavelengths below 2.5 μm, arising from properties of the reduced graphene oxide-Si heterojunction. Our analysis of the current-voltage characteristics at various temperatures suggests that the two materials form a type-II (broken-gap) heterojunction, with a characteristic transition between direct tunneling to field emission, to over-the-barrier excitation with increasing reverse voltage. Illumination was found to affect the onset of the transition between direct tunneling and field-emission, suggesting that the mid infrared response results from the excitation of minority carriers (electrons) from the Si and their collection in the reduced graphene oxide contact. The photoresponse near 1.1 μm showed a time constant at least five times faster than the one at 2.5 μm, which points to surface defects as well as high series resistance and capacitance as potentially limiting factors in this mode of operation. With proper device engineering considerations, these devices could be promising as a graphene-based platform for infrared sensing.

Study of GeSn Alloy for Low Cost Monolithic Mid Infrared Quantum Well Sensor

Directory of Open Access Journals (Sweden)

Prakash PAREEK

2017-02-01

Full Text Available This paper focuses on theoretical study of Tin incorporated group IV alloys particularly GeSn and design of quantum well sensor for mid infrared sensing applications. Initially, the physics behind the selection of material for midinfrared sensor is explained. The importance of controlling strain in GeSn alloy is also explained. The physical background and motivation for incorporation of Tin(Sn in Germanium is briefly narrated. Eigen energy states for different Sn concentrations are obtained for strain compensated quantum well in G valley conduction band (GCB, heavy hole (HH band and light hole (LH band by solving coupled Schrödinger and Poisson equations simultaneously. Sn concentration dependent absorption spectra for HH- GCB transition reveals that significant absorption observed in mid infrared range (3-5 µm. So, Ge1-x Snx quantum well can be used for mid infrared sensing applications.

Silicon Photonic Waveguides for Near- and Mid-Infrared Regions

Science.gov (United States)

Stankovic, S.; Milosevic, M.; Timotijevic, B.; Yang, P. Y.; Teo, E. J.; Crnjanski, J.; Matavulj, P.; Mashanovich, G. Z.

2007-11-01

The basic building block of every photonic circuit is a waveguide. In this paper we investigate the most popular silicon waveguide structures in the form of a silicon-on-insulator rib waveguide. We also analyse two structures that can find applications in mid- and long-wave infrared regions: free-standing and hollow core omnidirectional waveguides.

Multi-wavelength study of infrared galaxies

International Nuclear Information System (INIS)

Marcillac, Delphine

2005-01-01

This thesis deals with a panchromatic study of luminous infrared galaxies (LIRGs) detected at 15 microns by ISOCAM (camera aboard ISO) and at 24 microns by MIPS (camera aboard the recently launched Spitzer satellite). These galaxies are today considered to be the Rosetta Stone of galaxy evolution since they are found to be far more numerous at high redshift and it is thought that a large part of stars seen in the local universe are born in such phases. The first part of this thesis presents a new study dedicated to dust emission of distant LIRGs in the mid-infrared range. Their dust emission has been compared to those of a local sample of LIRGs in addition to the prediction of several spectral energy distributions (SEDs) built on data available in the local universe. It has been shown that distant and local LIRGs present similar mid infrared spectral energy distribution: similar PAH bumps are detected in both local and distant LIRGs, however distant LIRGs show evidence of a stronger silicate absorption at 10 microns associated silicate grains. It also shows that distant LIRG mid infrared emission can be used together with local SEDs in order to estimate the total infrared luminosity. The second part of this thesis is dedicated to the burst of star formation and to the recent star formation history of these galaxies, which is responsible for the dust emission. This study was done thanks to a combination of high resolution spectra (R=2000 in the rest frame) obtained at VLT/FORS2 and the stellar population synthesis models called GALAXEV (Bruzual and Charlot, 2003). It has been shown that the burst of star formation has a duration of about 0.1 Gyear. About 10 % of the stellar content is formed during this burst of star formation. (author) [fr

Terahertz and Mid Infrared

CERN Document Server

Shulika, Oleksiy; Detection of Explosives and CBRN (Using Terahertz)

2014-01-01

The reader will find here a timely update on new THz sources and detection schemes as well as concrete applications to the detection of Explosives and CBRN. Included is a method to identify hidden RDX-based explosives (pure and plastic ones) in the frequency domain study by Fourier Transformation, which has been complemented by the demonstration of improvement of the quality of the images captured commercially available THz passive cameras. The presented examples show large potential for the detection of small hidden objects at long distances (6-10 m).  Complementing the results in the short-wavelength range, laser spectroscopy with a mid-infrared, room temperature, continuous wave, DFB laser diode and high performance DFB QCL have been demonstrated to offer excellent enabling sensor technologies for environmental monitoring, medical diagnostics, industrial and security applications.  From the new source point of view a number of systems have been presented - From superconductors to semiconductors, e.g. Det...

Efficient Mid-Infrared Supercontinuum Generation in Tapered Large Mode Area Chalcogenide Photonic Crystal Fibers

DEFF Research Database (Denmark)

Petersen, Christian Rosenberg; Engelsholm, Rasmus Dybbro; Markos, Christos

2017-01-01

Mid-infrared supercontinuum spanning from 1.8-9  μm with an output power of 41.5 mW is demonstrated by pumping tapered large mode area chalcogenide photonic crystal fibers using a 4 μm optical parametric source.......Mid-infrared supercontinuum spanning from 1.8-9  μm with an output power of 41.5 mW is demonstrated by pumping tapered large mode area chalcogenide photonic crystal fibers using a 4 μm optical parametric source....

A SYSTEMATIC STUDY OF MID-INFRARED EMISSION FROM CORE-COLLAPSE SUPERNOVAE WITH SPIRITS

Energy Technology Data Exchange (ETDEWEB)

Tinyanont, Samaporn; Kasliwal, Mansi M.; Lau, Ryan; Jencson, Jacob; Prince, Thomas [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Fox, Ori D.; Williams, Robert [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Smith, Nathan [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Perley, Daniel [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 København Ø (Denmark); Dykhoff, Devin; Gehrz, Robert [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street, S. E., Minneapolis, MN 55455 (United States); Johansson, Joel [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Van Dyk, Schuyler D.; Masci, Frank [Infrared Processing and Analysis Center, California Institute of Technology, M/S 100-22, Pasadena, CA 91125 (United States); Cody, Ann Marie, E-mail: st@astro.caltech.edu [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2016-12-20

We present a systematic study of mid-infrared emission from 141 nearby supernovae (SNe) observed with Spitzer /IRAC as part of the ongoing SPIRITS survey. We detect 8 Type Ia and 36 core-collapse SNe. All Type Ia/Ibc SNe become undetectable within three years of explosion, whereas 22 ± 11% of Type II SNe continue to be detected. Five Type II SNe are detected even two decades after discovery (SN 1974E, 1979C, 1980K, 1986J, and 1993J). Warm dust luminosity, temperature, and a lower limit on mass are obtained by fitting the two IRAC bands, assuming an optically thin dust shell. We derive warm dust masses between 10{sup −6} and 10{sup −2} M {sub ⊙} and dust color temperatures between 200 and 1280 K. This observed warm dust could be pre-existing or newly created, but in either case represents a lower limit to the dust mass because cooler dust may be present. We present three case studies of extreme SNe. SN 2011ja (II-P) was over-luminous ([4.5] = −15.6 mag) at 900 days post explosion with increasing hot dust mass, suggesting either an episode of dust formation or intensifying circumstellar material (CSM) interactions heating up pre-existing dust. SN 2014bi (II-P) showed a factor of 10 decrease in dust mass over one month, suggesting either dust destruction or reduced dust heating. The IR luminosity of SN 2014C (Ib) stayed constant over 800 days, possibly due to strong CSM interaction with an H-rich shell, which is rare among stripped-envelope SNe. The observations suggest that this CSM shell originated from an LBV-like eruption roughly 100 years pre-explosion. The observed diversity demonstrates the power of mid-IR observations of a large sample of SNe.

Optical Activation of Germanium Plasmonic Antennas in the Mid-Infrared

Science.gov (United States)

Fischer, Marco P.; Schmidt, Christian; Sakat, Emilie; Stock, Johannes; Samarelli, Antonio; Frigerio, Jacopo; Ortolani, Michele; Paul, Douglas J.; Isella, Giovanni; Leitenstorfer, Alfred; Biagioni, Paolo; Brida, Daniele

2016-07-01

Impulsive interband excitation with femtosecond near-infrared pulses establishes a plasma response in intrinsic germanium structures fabricated on a silicon substrate. This direct approach activates the plasmonic resonance of the Ge structures and enables their use as optical antennas up to the mid-infrared spectral range. The optical switching lasts for hundreds of picoseconds until charge recombination redshifts the plasma frequency. The full behavior of the structures is modeled by the electrodynamic response established by an electron-hole plasma in a regular array of antennas.

Mid-infrared response of reduced graphene oxide and its high-temperature coefficient of resistance

Directory of Open Access Journals (Sweden)

Haifeng Liang

2014-10-01

Full Text Available Much effort has been made to study the formation mechanisms of photocurrents in graphene and reduced graphene oxide films under visible and near-infrared light irradiation. A built-in field and photo-thermal electrons have been applied to explain the experiments. However, much less attention has been paid to clarifying the mid-infrared response of reduced graphene oxide films at room temperature. Thus, mid-infrared photoresponse and annealing temperature-dependent resistance experiments were carried out on reduced graphene oxide films. A maximum photocurrent of 75 μA was observed at room temperature, which was dominated by the bolometer effect, where the resistance of the films decreased as the temperature increased after they had absorbed light. The electrons localized in the defect states and the residual oxygen groups were thermally excited into the conduction band, forming a photocurrent. In addition, a temperature increase of 2 °C for the films after light irradiation for 2 minutes was observed using absorption power calculations. This work details a way to use reduced graphene oxide films that contain appropriate defects and residual oxygen groups as bolometer-sensitive materials in the mid-infrared range.

SPITZER OBSERVATIONS OF THE λ ORIONIS CLUSTER. II. DISKS AROUND SOLAR-TYPE AND LOW-MASS STARS

International Nuclear Information System (INIS)

Hernandez, Jesus; Morales-Calderon, Maria; Calvet, Nuria; Hartmann, L.; Muzerolle, J.; Gutermuth, R.; Luhman, K. L.; Stauffer, J.

2010-01-01

We present IRAC/MIPS Spitzer Space Telescope observations of the solar-type and the low-mass stellar population of the young (∼5 Myr) λ Orionis cluster. Combining optical and Two Micron All Sky Survey photometry, we identify 436 stars as probable members of the cluster. Given the distance (450 pc) and the age of the cluster, our sample ranges in mass from 2 M sun to objects below the substellar limit. With the addition of the Spitzer mid-infrared data, we have identified 49 stars bearing disks in the stellar cluster. Using spectral energy distribution slopes, we place objects in several classes: non-excess stars (diskless), stars with optically thick disks, stars with 'evolved disks' (with smaller excesses than optically thick disk systems), and 'transitional disk' candidates (in which the inner disk is partially or fully cleared). The disk fraction depends on the stellar mass, ranging from ∼6% for K-type stars (R C - J C - J>4). We confirm the dependence of disk fraction on stellar mass in this age range found in other studies. Regarding clustering levels, the overall fraction of disks in the λ Orionis cluster is similar to those reported in other stellar groups with ages normally quoted as ∼5 Myr.

Mid-infrared pulsed laser ultrasonic testing for carbon fiber reinforced plastics.

Science.gov (United States)

Kusano, Masahiro; Hatano, Hideki; Watanabe, Makoto; Takekawa, Shunji; Yamawaki, Hisashi; Oguchi, Kanae; Enoki, Manabu

2018-03-01

Laser ultrasonic testing (LUT) can realize contactless and instantaneous non-destructive testing, but its signal-to-noise ratio must be improved in order to measure carbon fiber reinforced plastics (CFRPs). We have developed a mid-infrared (mid-IR) laser source optimal for generating ultrasonic waves in CFRPs by using a wavelength conversion device based on an optical parametric oscillator. This paper reports a comparison of the ultrasonic generation behavior between the mid-IR laser and the Nd:YAG laser. The mid-IR laser generated a significantly larger ultrasonic amplitude in CFRP laminates than a conventional Nd:YAG laser. In addition, our study revealed that the surface epoxy matrix of CFRPs plays an important role in laser ultrasonic generation. Copyright © 2017 Elsevier B.V. All rights reserved.

SPITZER SPECTROSCOPY OF CIRCUMSTELLAR DISKS IN THE 5 Myr OLD UPPER SCORPIUS OB ASSOCIATION

International Nuclear Information System (INIS)

Dahm, S. E.; Carpenter, John M.

2009-01-01

We present mid-infrared spectra between 5.2 and 38 μm for 26 disk-bearing members of the ∼5 Myr old Upper Scorpius OB association obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. We find clear evidence for changes in the spectral characteristics of dust emission between the early-type (B+A) and late-type (K+M) infrared excess stars. The early-type members exhibit featureless continuum excesses that become apparent redward of ∼8 μm. In contrast, 10 and 20 μm silicate features or polycyclic aromatic hydrocarbon emission are present in all but one of the late-type excess members of Upper Scorpius. The strength of silicate emission among late-type Upper Scorpius members is spectral-type dependent, with the most prominent features being associated with K5-M2-type stars. By fitting the spectral energy distributions (SED) of a representative sample of low-mass stars with accretion disk models, we find that the SEDs are consistent with models having inner disk radii ranging from ∼0.2 to 1.2 AU. Complementary high-resolution (R ∼ 33, 000) optical (λλ4800-9200) spectra for the Upper Scorpius excess stars were examined for signatures of gaseous accretion. Of the 35 infrared excess stars identified in Upper Scorpius, only seven (all late-type) exhibit definitive signatures of accretion. Mass-accretion rates for these stars were estimated to range from 10 -11 to 10 -8.9 M sun yr -1 . Compared to Class II sources in Taurus-Auriga, the disk population in Upper Scorpius exhibits reduced levels of near- and mid-infrared excess emission and an order of magnitude lower mass-accretion rates. These results suggest that the disk structure has changed significantly over the 2-4 Myr in age separating these two stellar populations. The ubiquity of depleted inner disks in the Upper Scorpius excess sample implies that such disks are a common evolutionary pathway that persists for some time.

Spitzer IRAC Confirmation of z850-Dropout Galaxies in the Hubble Ultra Deep Field: Stellar Masses and Ages at z ~ 7

Science.gov (United States)

Labbé, Ivo; Bouwens, Rychard; Illingworth, G. D.; Franx, M.

2006-10-01

Using Spitzer IRAC mid-infrared imaging from the Great Observatories Origins Deep Survey, we study z850-dropout sources in the Hubble Ultra Deep Field. After carefully removing contaminating flux from foreground sources, we clearly detect two z850 dropouts at 3.6 and 4.5 μm, while two others are marginally detected. The mid-infrared fluxes strongly support their interpretation as galaxies at z~7, seen when the universe was only 750 Myr old. The IRAC observations allow us for the first time to constrain the rest-frame optical colors, stellar masses, and ages of the highest redshift galaxies. Fitting stellar population models to the spectral energy distributions, we find photometric redshifts in the range 6.7-7.4, rest-frame colors U-V=0.2-0.4, V-band luminosities LV=(0.6-3)×1010 Lsolar, stellar masses (1-10)×109 Msolar, stellar ages 50-200 Myr, star formation rates up to ~25 Msolar yr-1, and low reddening AV~8, during the era of cosmic reionization, but the star formation rate density derived from their stellar masses and ages is not nearly sufficient to reionize the universe. The simplest explanation for this deficiency is that lower mass galaxies beyond our detection limit reionized the universe. Based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407. Support for this work was provided by NASA through contract 125790 issued by JPL/Caltech. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Based on service mode observations collected at the European Southern Observatory, Paranal, Chile (ESO program 073.A-0764A).

High energy eye-safe and mid-infrared optical parametric oscillator

International Nuclear Information System (INIS)

Liu, J; Liu, Q; Huang, L; Gong, M

2010-01-01

A high energy eye-safe and mid-infrared optical parametric oscillator (OPO) is demonstrated. The nonlinear media is a Y-cut KTA crystal with the length of 20 mm, which is pumped by a Nd:YAG laser. Both eye-safe and mid-infrared laser are output with high energy. When the pump energy is 1 J and the pulse duration is 10 ns, we get 53 mJ idler at 3.632 μm and 151 mJ signal at 1.505 μm. As we know, the idler energy is the highest at the wavelength beyond 3.5 μm and the signal energy is the highest with Y-cut KTA. The results prove that the Y-cut KTA crystal can produce the signal and idler with the energies as high as these in the paper. We have tested the temperature-tuning characters and the coefficient of the idler is 0.26 nm/°C

SPITZER OBSERVATIONS OF LONG-TERM INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN CHAMAELEON I

Energy Technology Data Exchange (ETDEWEB)

Flaherty, Kevin M.; Herbst, William [Van Vleck Observatory, Astronomy Department, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459 (United States); DeMarchi, Lindsay [Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, NY 13346 (United States); Muzerolle, James [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Balog, Zoltan [Max-Planck-Institut fur Astronomie, Konigstuhl 17, D-69117 Heidelberg (Germany); Megeath, S. Thomas [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Furlan, Elise [Infrared Processing and Analysis Center, California Institute of Technology, 770 S. Wilson Avenue, Pasadena, CA 91125 (United States); Gutermuth, Robert [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

2016-12-10

Infrared variability is common among young stellar objects, with surveys finding daily to weekly fluctuations of a few tenths of a magnitude. Space-based observations can produce highly sampled infrared light curves, but are often limited to total baselines of about 1 month due to the orientation of the spacecraft. Here we present observations of the Chameleon I cluster, whose low declination makes it observable by the Spitzer Space Telescope over a 200-day period. We observe 30 young stellar objects with a daily cadence to better sample variability on timescales of months. We find that such variability is common, occurring in ∼80% of the detected cluster members. The change in [3.6]–[4.5] color over 200 days for many of the sources falls between that expected for extinction and fluctuations in disk emission. With our high cadence and long baseline we can derive power spectral density curves covering two orders of magnitude in frequency and find significant power at low frequencies, up to the boundaries of our 200-day survey. Such long timescales are difficult to explain with variations driven by the interaction between the disk and stellar magnetic field, which has a dynamical timescale of days to weeks. The most likely explanation is either structural or temperature fluctuations spread throughout the inner ∼0.5 au of the disk, suggesting that the intrinsic dust structure is highly dynamic.

THE LAST GASP OF GAS GIANT PLANET FORMATION: A SPITZER STUDY OF THE 5 Myr OLD CLUSTER NGC 2362

International Nuclear Information System (INIS)

Currie, Thayne; Lada, Charles J.; Robitaille, Thomas P.; Irwin, Jonathan; Kenyon, Scott J.; Plavchan, Peter

2009-01-01

Expanding upon the Infrared Array Camera (IRAC) survey from Dahm and Hillenbrand, we describe Spitzer IRAC and Multiband Imaging Photometer for Spitzer observations of the populous, 5 Myr old open cluster NGC 2362. We analyze the mid-IR colors of cluster members and compared their spectral energy distributions (SEDs) to star+circumstellar disk models to constrain the disk morphologies and evolutionary states. Early/intermediate-type confirmed/candidate cluster members either have photospheric mid-IR emission or weak, optically thin IR excess emission at λ ≥ 24 μm consistent with debris disks. Few late-type, solar/subsolar-mass stars have primordial disks. The disk population around late-type stars is dominated by disks with inner holes (canonical 'transition disks') and 'homologously depleted' disks. Both types of disks represent an intermediate stage between primordial disks and debris disks. Thus, in agreement with previous results, we find that multiple paths for the primordial-to-debris disk transition exist. Because these 'evolved primordial disks' greatly outnumber primordial disks, our results undermine standard arguments in favor of a ∼ 5 yr timescale for the transition based on data from Taurus-Auriga. Because the typical transition timescale is far longer than 10 5 yr, these data also appear to rule out standard ultraviolet photoevaporation scenarios as the primary mechanism to explain the transition. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant planet formation. Consistent with Currie et al., the luminosity of 24 μm emission in debris disks due to planet formation peaks at ∼10-20 Myr. If the gas and dust in disks evolve on similar timescales, the formation timescale for gas giant planets surrounding early-type, high/intermediate-mass (∼>1.4 M sun ) stars is likely 1-5 Myr. Most solar/subsolar-mass stars detected by Spitzer

Luminescence from ZnSe excited by picosecond mid-infrared FEL pulses

International Nuclear Information System (INIS)

Mitsuyu, T.; Suzuki, T.; Tomimasu, T.

1998-01-01

We have observed blue band-edge emission from a ZnSe crystal under irradiation of mid-infrared picosecond free electron laser (FEL) pulses. The emission characteristics including spectrum, excitation power dependence, excitation wavelength dependence, and decay time have been investigated. The experimental results have indicated that it is difficult to understand the excitation process by multiphoton excitation, thermal excitation, or excitation through mid-gap levels. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Stellar mass estimation based on IRAC photometry for Spitzer SWIRE-field galaxies

International Nuclear Information System (INIS)

Zhu Yinan; Wu Hong; Li Haining; Cao Chen

2010-01-01

We analyze the feasibility of estimating the stellar mass of galaxies by mid-infrared luminosities based on a large sample of galaxies cross-identified from Spitzer SWIRE fields and the SDSS spectrographic survey. We derived the formulae to calculate the stellar mass by using IRAC 3.6 μm and 4.5 μm luminosities. The mass-to-luminosity ratios of IRAC 3.6 μm and 4.5 μm luminosities are more sensitive to the star formation history of galaxies than to other factors, such as the intrinsic extinction, metallicity and star formation rate. To remove the effect of star formation history, we used g - r color to recalibrate the formulae and obtain a better result. Researchers must be more careful when estimating the stellar mass of low metallicity galaxies using our formulae. Due to the emission from dust heated by the hottest young stars, luminous infrared galaxies present higher IRAC 4.5 μm luminosities compared to IRAC 3.6 μm luminosities. For most of type-II AGNs, the nuclear activity cannot enhance 3.6 μm and 4.5 μm luminosities compared with normal galaxies. Star formation in our AGN-hosting galaxies is also very weak, almost all of which are early-type galaxies.

Athermal design for mid-wave infrared lens with long EFFL

Science.gov (United States)

Bai, Yu; Xing, Tingwen

2016-10-01

When the environment temperature has changed, then each parameter in infrared lens has also changed, thus the image quality became bad, so athermal technology is one of key technology in designing infrared lens. The temperature influence of each parameter in infrared lens is analyzed in the paper. In the paper, an athermal mid-wave infrared optical system with long focal length by Code-v optical design software was presented. The parameters of the athermal infrared system are 4.0 f/number, 704mm effective focal length (EFL) , 1° field of view and 3.7-4.8 μm spectrum region 100% cold shield efficiency. When the spatial frequency is 16lp/mm, the Modulation Transfer Function (MTF) of all the field of view was above 0.5 from the working temperature range -40° to 60°. From the image quality and thermal analysis result, we knew that the lens had good athermal performance.

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

International Nuclear Information System (INIS)

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

2010-01-01

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

SPITZER OBSERVATIONS OF HOTSPOTS IN RADIO LOBES

International Nuclear Information System (INIS)

Werner, Michael W.; Murphy, David W.; Livingston, John H.; Gorjian, Varoujan; Jones, Dayton L.; Meier, David L.; Lawrence, Charles R.

2012-01-01

We have carried out a systematic search with Spitzer Warm Mission and archival data for infrared emission from the hotspots in radio lobes that have been described by Hardcastle et al. These hotspots have been detected with both radio and X-ray observations, but an observation at an intermediate frequency in the infrared can be critical to distinguish between competing models for particle acceleration and radiation processes in these objects. Between the archival and warm mission data, we report detections of 18 hotspots; the archival data generally include detections at all four IRAC bands, the Warm Mission data only at 3.6 μm. Using a theoretical formalism adopted from Godfrey et al., we fit both archival and warm mission spectral energy distributions (SEDs)—including radio, X-ray, and optical data from Hardcastle as well as the Spitzer data—with a synchrotron self-Compton (SSC) model, in which the X-rays are produced by Compton scattering of the radio frequency photons by the energetic electrons which radiate them. With one exception, an SSC model requires that the magnetic field be less or much less than the equipartition value which minimizes total energy and has comparable amounts of energy in the magnetic field and in the energetic particles. This conclusion agrees with those of comparable recent studies of hotspots, and with the analysis presented by Hardcastle et al. We also show that the infrared data rule out the simplest synchrotron-only models for the SEDs. We briefly discuss the implications of these results and of alternate interpretations of the data.

Mid-infrared materials and devices on a Si platform for optical sensing

Science.gov (United States)

Singh, Vivek; Lin, Pao Tai; Patel, Neil; Lin, Hongtao; Li, Lan; Zou, Yi; Deng, Fei; Ni, Chaoying; Hu, Juejun; Giammarco, James; Soliani, Anna Paola; Zdyrko, Bogdan; Luzinov, Igor; Novak, Spencer; Novak, Jackie; Wachtel, Peter; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Kimerling, Lionel C; Agarwal, Anuradha M

2014-01-01

In this article, we review our recent work on mid-infrared (mid-IR) photonic materials and devices fabricated on silicon for on-chip sensing applications. Pedestal waveguides based on silicon are demonstrated as broadband mid-IR sensors. Our low-loss mid-IR directional couplers demonstrated in SiNx waveguides are useful in differential sensing applications. Photonic crystal cavities and microdisk resonators based on chalcogenide glasses for high sensitivity are also demonstrated as effective mid-IR sensors. Polymer-based functionalization layers, to enhance the sensitivity and selectivity of our sensor devices, are also presented. We discuss the design of mid-IR chalcogenide waveguides integrated with polycrystalline PbTe detectors on a monolithic silicon platform for optical sensing, wherein the use of a low-index spacer layer enables the evanescent coupling of mid-IR light from the waveguides to the detector. Finally, we show the successful fabrication processing of our first prototype mid-IR waveguide-integrated detectors. PMID:27877641

Optimum output coupling for a mid-infrared KTiOAsO4 optical parametric oscillator

International Nuclear Information System (INIS)

Li, Guochao; Gao, Yesheng; Zheng, Guangjin; Zhao, Yao; Chen, Kunfeng; Wang, Qingpu; Bai, Fen

2013-01-01

Taking into account the turn off time of the Q-switch, the coupled equations for a mid-infrared KTiOAsO 4 optical parametric oscillator (OPO) are given. These rate equations are solved numerically and some key parameters for designing the laser system are determined. The key parameters include the optimal coupling and nonlinear crystal length which maximize the output power and OPO conversion efficiency. We found that a low-loss singly resonant OPO cavity not only enhances the mid-infrared output but also decreases the optimal OPO crystal length. (paper)

Silicon Nitride Photonic Integration Platforms for Visible, Near-Infrared and Mid-Infrared Applications

Science.gov (United States)

Micó, Gloria; Pastor, Daniel; Pérez, Daniel; Doménech, José David; Fernández, Juan; Baños, Rocío; Alemany, Rubén; Sánchez, Ana M.; Cirera, Josep M.; Mas, Roser

2017-01-01

Silicon nitride photonics is on the rise owing to the broadband nature of the material, allowing applications of biophotonics, tele/datacom, optical signal processing and sensing, from visible, through near to mid-infrared wavelengths. In this paper, a review of the state of the art of silicon nitride strip waveguide platforms is provided, alongside the experimental results on the development of a versatile 300 nm guiding film height silicon nitride platform. PMID:28895906

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-20

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

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.

Mid-IR Properties of an Unbiased AGN Sample of the Local Universe. 1; Emission-Line Diagnostics

Science.gov (United States)

Weaver, K. A.; Melendez, M.; Muhotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth. E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.;

Graphene-based mid-infrared room-temperature pyroelectric bolometers with ultrahigh temperature coefficient of resistance.

Science.gov (United States)

Sassi, U; Parret, R; Nanot, S; Bruna, M; Borini, S; De Fazio, D; Zhao, Z; Lidorikis, E; Koppens, F H L; Ferrari, A C; Colli, A

2017-01-31

There is a growing number of applications demanding highly sensitive photodetectors in the mid-infrared. Thermal photodetectors, such as bolometers, have emerged as the technology of choice, because they do not need cooling. The performance of a bolometer is linked to its temperature coefficient of resistance (TCR, ∼2-4% K -1 for state-of-the-art materials). Graphene is ideally suited for optoelectronic applications, with a variety of reported photodetectors ranging from visible to THz frequencies. For the mid-infrared, graphene-based detectors with TCRs ∼4-11% K -1 have been demonstrated. Here we present an uncooled, mid-infrared photodetector, where the pyroelectric response of a LiNbO 3 crystal is transduced with high gain (up to 200) into resistivity modulation for graphene. This is achieved by fabricating a floating metallic structure that concentrates the pyroelectric charge on the top-gate capacitor of the graphene channel, leading to TCRs up to 900% K -1 , and the ability to resolve temperature variations down to 15 μK.

Diogenite-like Features in the Spitzer IRS (5-35 micrometers) Spectrum of 956 ELISA

Science.gov (United States)

Lim, Lucy F.; Emery, Joshua P.; Moskovitz, Nicholas A.

2009-01-01

We report preliminary results from the Spitzer Infrared Spectrograph (IRS) observations of the V-type asteroid 956 Elisa. Elisa was observed as part of a campaign to measure the 5.2-38 micron spectra of small basaltic asteroids with the Spitzer IRS. Targets include members of the dynamical family of the unique large differentiated asteroid 4 Vesta ("Vesroids"), several outer-main-belt basaltic asteroids whose orbits exclude them from originating on 4 Vesta, and the basaltic near-Earth asteroid 4055 Magellan.

Spectral-temporal composition matters when cascading supercontinua into the mid-infrared

DEFF Research Database (Denmark)

Petersen, Christian Rosenberg; Moselund, Peter M.; Petersen, Christian

2016-01-01

Supercontinuum generation in chalcogenide fibers is a promising technology for broadband spatially coherent sources in the mid-infrared, but it suffers from discouraging commercial prospects, mainly due to a lack of suitable pump lasers. Here, a promising approach is experimentally demonstrated u...

Rugged and compact mid-infrared solid-state laser for avionics applications

CSIR Research Space (South Africa)

Esser, MJD

2009-11-01

Full Text Available In order to demonstrate the feasibility of a helicopter-based application using advanced laser technology, the authors have developed a rugged and compact mid-infrared solid-state laser. The requirement for the laser was to simultaneously emit at 2...

YSOVAR: MID-INFRARED VARIABILITY AMONG YSOs IN THE STAR FORMATION REGION GGD12-15

Energy Technology Data Exchange (ETDEWEB)

Wolk, Scott J.; Günther, H. Moritz; Poppenhaeger, Katja; Forbrich, J. [Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Cody, A. M. [NASA Ames Research Center, M/S 244-5 Moffett Field, CA 94035 (United States); Rebull, L. M.; Stauffer, J. R. [Spitzer Science Center/Caltech, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Hillenbrand, L. A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Plavchan, P. [Department of Physics Astronomy and Materials Science, Missouri State University, Springfield, MO 65897 (United States); Covey, K. R. [Department of Physics and Astronomy, Western Washington Univ., Bellingham, WA 98225-9164 (United States); Song, Inseok, E-mail: swolk@cfa.harvard.edu [Physics and Astronomy Department, University of Georgia, Athens, GA 30602-2451 (United States)

2015-11-15

We present an IR-monitoring survey with the Spitzer Space Telescope of the star-forming region GGD 12-15. More than 1000 objects were monitored, including about 350 objects within the central 5′, which is found to be especially dense in cluster members. The monitoring took place over 38 days and is part of the Young Stellar Object VARiability project. The region was also the subject of a contemporaneous 67 ks Chandra observation. The field includes 119 previously identified pre-main sequence star candidates. X-rays are detected from 164 objects, 90 of which are identified with cluster members. Overall, we find that about half the objects in the central 5′ are young stellar objects (YSOs) based on a combination of their spectral energy distribution, IR variability, and X-ray emission. Most of the stars with IR excess relative to a photosphere show large amplitude (>0.1 mag) mid-infrared (mid-IR) variability. There are 39 periodic sources, and all but one is found to be a cluster member. Almost half of the periodic sources do not show IR excesses. Overall, more than 85% of the Class I, flat spectrum, and Class II sources are found to vary. The amplitude of the variability is larger in more embedded YSOs. Most of the Class I/II objects exhibit redder colors in a fainter state, which is compatible with time-variable extinction. A few become bluer when fainter, which can be explained with significant changes in the structure of the inner disk. A search for changes in the IR due to X-ray events is carried out, but the low number of flares prevented an analysis of the direct impact of X-ray flares on the IR light curves. However, we find that X-ray detected Class II sources have longer timescales for change in the MIR than a similar set of non-X-ray detected Class IIs.

Mid-Infrared Continuously Tunable Single Mode VECSEL

Science.gov (United States)

Khiar, A.; Rahim, M.; Felder, F.; Fill, M.; Zogg, H.

2011-12-01

Tunable mid-infrared vertical external cavity surface emitting lasers were developed for the wavelength range around 3.8-3.9 μm and 3.2-3.3 μm, respectively. The devices are based on lead salt materials epitaxially grown by MBE on a Si substrate. The active part consists of PbSe QW in a PbSrSe host layer. Both devices are operated around -20 °C and have output power of several 10 mW. By changing the cavity length, a single mode hop free tuning range up to 80 cm-1 is achieved.

Optical system design with common aperture for mid-infrared and laser composite guidance

Science.gov (United States)

Zhang, Xuanzhi; Yang, Zijian; Sun, Ting; Yang, Huamei; Han, Kunye; Hu, Bo

2017-02-01

When the field of operation of precision strike missiles is more and more complicated, autonomous seekers will soon encounter serious difficulties, especially with regard to low signature targets and complex scenarios. So the dual-mode sensors combining an imaging sensor with a semi-active laser seeker are conceived to overcome these specific problems. Here the sensors composed a dual field of view mid-infrared thermal imaging camera and a laser range finder have the common optical aperture which produced the minization of seeker construction. The common aperture optical systems for mid-infrared and laser dual-mode guildance have been developed, which could meet the passive middle infrared high-resolution imaging and the active laser high-precision indication and ranging. The optical system had good image quality, and fulfilled the performance requirement of seeker system. The design and expected performance of such a dual-mode optical system will be discussed.

Mid-infrared optical parametric oscillator pumped by an amplified random fiber laser

Science.gov (United States)

Shang, Yaping; Shen, Meili; Wang, Peng; Li, Xiao; Xu, Xiaojun

2017-01-01

Recently, the concept of random fiber lasers has attracted a great deal of attention for its feature to generate incoherent light without a traditional laser resonator, which is free of mode competition and insure the stationary narrow-band continuous modeless spectrum. In this Letter, we reported the first, to the best of our knowledge, optical parametric oscillator (OPO) pumped by an amplified 1070 nm random fiber laser (RFL), in order to generate stationary mid-infrared (mid-IR) laser. The experiment realized a watt-level laser output in the mid-IR range and operated relatively stable. The use of the RFL seed source allowed us to take advantage of its respective stable time-domain characteristics. The beam profile, spectrum and time-domain properties of the signal light were measured to analyze the process of frequency down-conversion process under this new pumping condition. The results suggested that the near-infrared (near-IR) signal light `inherited' good beam performances from the pump light. Those would be benefit for further develop about optical parametric process based on different pumping circumstances.

ULTRAVIOLET+INFRARED STAR FORMATION RATES: HICKSON COMPACT GROUPS WITH SWIFT AND SPITZER

International Nuclear Information System (INIS)

Tzanavaris, P.; Hornschemeier, A. E.; Immler, S.; Gallagher, S. C.; Johnson, K. E.; Reines, A. E.; Gronwall, C.; Hoversten, E.; Charlton, J. C.

2010-01-01

We present Swift UVOT ultraviolet (UV; 1600-3000 A) data with complete three-band UV photometry for a sample of 41 galaxies in 11 nearby ( -1 ) Hickson Compact Groups (HCGs) of galaxies. We use UVOT uvw2-band (2000 A) photometry to estimate the dust-unobscured component, SFR UV , of the total star formation rate, SFR TOTAL . We use Spitzer MIPS 24 μm photometry to estimate SFR IR , the component of SFR TOTAL that suffers dust extinction in the UV and is re-emitted in the IR. By combining the two components, we obtain SFR TOTAL estimates for all HCG galaxies. We obtain total stellar mass, M * , estimates by means of Two Micron All Sky Survey K s -band luminosities, and use them to calculate specific star formation rates, SSFR ≡ SFR TOTAL /M * . SSFR values show a clear and significant bimodality, with a gap between low (∼ -11 yr -1 ) and high-SSFR (∼>1.2 x 10 -10 yr -1 ) systems. We compare this bimodality to the previously discovered bimodality in α IRAC , the MIR activity index from a power-law fit to the Spitzer IRAC 4.5-8 μm data for these galaxies. We find that all galaxies with α IRAC ≤ 0 ( >0) are in the high- (low-) SSFR locus, as expected if high levels of star-forming activity power MIR emission from polycyclic aromatic hydrocarbon molecules and a hot dust continuum. Consistent with this finding, all elliptical/S0 galaxies are in the low-SSFR locus, while 22 out of 24 spirals/irregulars are in the high-SSFR locus, with two borderline cases. We further divide our sample into three subsamples (I, II, and III) according to decreasing H I richness of the parent galaxy group to which a galaxy belongs. Consistent with the SSFR and α IRAC bimodality, 12 out of 15 type I (11 out of 12 type III) galaxies are in the high- (low-) SSFR locus, while type II galaxies span almost the full range of SSFR values. We use the Spitzer Infrared Nearby Galaxy Survey (SINGS) to construct a comparison subsample of galaxies that (1) match HCG galaxies in J-band total

AN IN-DEPTH VIEW OF THE MID-INFRARED PROPERTIES OF POINT SOURCES AND THE DIFFUSE ISM IN THE SMC GIANT H II REGION, N66

International Nuclear Information System (INIS)

Whelan, David G.; Johnson, Kelsey E.; Indebetouw, Rémy; Lebouteiller, Vianney; Galliano, Frédéric; Peeters, Els; Bernard-Salas, Jeronimo; Brandl, Bernhard R.

2013-01-01

The focus of this work is to study mid-infrared point sources and the diffuse interstellar medium (ISM) in the low-metallicity (∼0.2 Z ☉ ) giant H II region N66 in order to determine properties that may shed light on star formation in these conditions. Using the Spitzer Space Telescope's Infrared Spectrograph, we study polycyclic aromatic hydrocarbon (PAH), dust continuum, silicate, and ionic line emission from 14 targeted infrared point sources as well as spectra of the diffuse ISM that is representative of both the photodissociation regions (PDRs) and the H II regions. Among the point source spectra, we spectroscopically confirm that the brightest mid-infrared point source is a massive embedded young stellar object, we detect silicates in emission associated with two young stellar clusters, and we see spectral features of a known B[e] star that are commonly associated with Herbig Be stars. In the diffuse ISM, we provide additional evidence that the very small grain population is being photodestroyed in the hard radiation field. The 11.3 μm PAH complex emission exhibits an unexplained centroid shift in both the point source and ISM spectra that should be investigated at higher signal-to-noise and resolution. Unlike studies of other regions, the 6.2 μm and 7.7 μm band fluxes are decoupled; the data points cover a large range of I 7.7 /I 11.3 PAH ratio values within a narrow band of I 6.2 /I 11.3 ratio values. Furthermore, there is a spread in PAH ionization, being more neutral in the dense PDR where the radiation field is relatively soft, but ionized in the diffuse ISM/PDR. By contrast, the PAH size distribution appears to be independent of local ionization state. Important to unresolved studies of extragalactic low-metallicity star-forming regions, we find that emission from the infrared-bright point sources accounts for only 20%-35% of the PAH emission from the entire region. These results make a comparative data set to other star-forming regions with

BRIGHTNESS AND FLUCTUATION OF THE MID-INFRARED SKY FROM AKARI OBSERVATIONS TOWARD THE NORTH ECLIPTIC POLE

International Nuclear Information System (INIS)

Pyo, Jeonghyun; Jeong, Woong-Seob; Matsumoto, Toshio; Matsuura, Shuji

2012-01-01

We present the smoothness of the mid-infrared sky from observations by the Japanese infrared astronomical satellite AKARI. AKARI monitored the north ecliptic pole (NEP) during its cold phase with nine wave bands covering from 2.4 to 24 μm, out of which six mid-infrared bands were used in this study. We applied power-spectrum analysis to the images in order to search for the fluctuation of the sky brightness. Observed fluctuation is explained by fluctuation of photon noise, shot noise of faint sources, and Galactic cirrus. The fluctuations at a few arcminutes scales at short mid-infrared wavelengths (7, 9, and 11 μm) are largely caused by the diffuse Galactic light of the interstellar dust cirrus. At long mid-infrared wavelengths (15, 18, and 24 μm), photon noise is the dominant source of fluctuation over the scale from arcseconds to a few arcminutes. The residual fluctuation amplitude at 200'' after removing these contributions is at most 1.04 ± 0.23 nW m –2 sr –1 or 0.05% of the brightness at 24 μm and at least 0.47 ± 0.14 nW m –2 sr –1 or 0.02% at 18 μm. We conclude that the upper limit of the fluctuation in the zodiacal light toward the NEP is 0.03% of the sky brightness, taking 2σ error into account.

THE MID-INFRARED AND NEAR-ULTRAVIOLET EXCESS EMISSIONS OF QUIESCENT GALAXIES ON THE RED SEQUENCE

International Nuclear Information System (INIS)

Ko, Jongwan; Lee, Jong Chul; Hwang, Ho Seong; Sohn, Young-Jong

2013-01-01

We study the mid-infrared (IR) and near-ultraviolet (UV) excess emissions of spectroscopically selected quiescent galaxies on the optical red sequence. We use the Wide-field Infrared Survey Explorer mid-IR and Galaxy Evolution Explorer near-UV data for a spectroscopic sample of galaxies in the Sloan Digital Sky Survey Data Release 7 to study the possible connection between quiescent red-sequence galaxies with and without mid-IR/near-UV excess. Among 648 12 μm detected quiescent red-sequence galaxies without Hα emission, 26% and 55% show near-UV and mid-IR excess emissions, respectively. When we consider only bright (M r n 4000 than those without mid-IR and near-UV excess emissions. We also find that mid-IR weighted mean stellar ages of quiescent red-sequence galaxies with mid-IR excess are larger than those with near-UV excess, and smaller than those without mid-IR and near-UV excess. The environmental dependence of the fraction of quiescent red-sequence galaxies with mid-IR and near-UV excess seems strong even though the trends of quiescent red-sequence galaxies with near-UV excess differ from those with mid-IR excess. These results indicate that the recent star formation traced by near-UV (∼< 1 Gyr) and mid-IR (∼< 2 Gyr) excess is not negligible among nearby, quiescent, red, early-type galaxies. We suggest a possible evolutionary scenario of quiescent red-sequence galaxies from quiescent red-sequence galaxies with near-UV excess to those with mid-IR excess to those without near-UV and mid-IR excess.

Apache ZooKeeper essentials

CERN Document Server

Haloi, Saurav

2015-01-01

Whether you are a novice to ZooKeeper or already have some experience, you will be able to master the concepts of ZooKeeper and its usage with ease. This book assumes you to have some prior knowledge of distributed systems and high-level programming knowledge of C, Java, or Python, but no experience with Apache ZooKeeper is required.

Transparency of Semi-Insulating, n-Type, and p-Type Ammonothermal GaN Substrates in the Near-Infrared, Mid-Infrared, and THz Spectral Range

OpenAIRE

Robert Kucharski; Łukasz Janicki; Marcin Zajac; Monika Welna; Marcin Motyka; Czesław Skierbiszewski; Robert Kudrawiec

2017-01-01

GaN substrates grown by the ammonothermal method are analyzed by Fast Fourier Transformation Spectroscopy in order to study the impact of doping (both n- and p-type) on their transparency in the near-infrared, mid-infrared, and terahertz spectral range. It is shown that the introduction of dopants causes a decrease in transparency of GaN substrates in a broad spectral range which is attributed to absorption on free carriers (n-type samples) or dopant ionization (p-type samples). In the mid-in...

ELEMENTAL ABUNDANCES IN THE EJECTA OF OLD CLASSICAL NOVAE FROM LATE-EPOCH SPITZER SPECTRA

International Nuclear Information System (INIS)

Helton, L. Andrew; Vacca, William D.; Gehrz, Robert D.; Woodward, Charles E.; Shenoy, Dinesh P.; Wagner, R. Mark; Evans, Aneurin; Krautter, Joachim; Schwarz, Greg J.; Starrfield, Sumner

2012-01-01

We present Spitzer Space Telescope mid-infrared IRS spectra, supplemented by ground-based optical observations, of the classical novae V1974 Cyg, V382 Vel, and V1494 Aql more than 11, 8, and 4 years after outburst, respectively. The spectra are dominated by forbidden emission from neon and oxygen, though in some cases, there are weak signatures of magnesium, sulfur, and argon. We investigate the geometry and distribution of the late time ejecta by examination of the emission line profiles. Using nebular analysis in the low-density regime, we estimate lower limits on the abundances in these novae. In V1974 Cyg and V382 Vel, our observations confirm the abundance estimates presented by other authors and support the claims that these eruptions occurred on ONe white dwarfs (WDs). We report the first detection of neon emission in V1494 Aql and show that the system most likely contains a CO WD.

ELEMENTAL ABUNDANCES IN THE EJECTA OF OLD CLASSICAL NOVAE FROM LATE-EPOCH SPITZER SPECTRA

Energy Technology Data Exchange (ETDEWEB)

Helton, L. Andrew; Vacca, William D. [SOFIA Science Center, USRA, NASA Ames Research Center, M.S. N232-11, Moffett Field, CA 94035 (United States); Gehrz, Robert D.; Woodward, Charles E.; Shenoy, Dinesh P. [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street S.E., University of Minnesota, Minneapolis, MN 55455 (United States); Wagner, R. Mark [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Evans, Aneurin [Astrophysics Group, Keele University, Keele, Staffordshire ST5 5BG (United Kingdom); Krautter, Joachim [Landessternwarte-Zentrum fuer Astronomie der Universitaet, Koenigstuhl, D-69117 Heidelberg (Germany); Schwarz, Greg J. [American Astronomical Society, 2000 Florida Avenue, NW, Suite 400, Washington, DC 20009 (United States); Starrfield, Sumner, E-mail: ahelton@sofia.usra.edu [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287 (United States)

2012-08-10

We present Spitzer Space Telescope mid-infrared IRS spectra, supplemented by ground-based optical observations, of the classical novae V1974 Cyg, V382 Vel, and V1494 Aql more than 11, 8, and 4 years after outburst, respectively. The spectra are dominated by forbidden emission from neon and oxygen, though in some cases, there are weak signatures of magnesium, sulfur, and argon. We investigate the geometry and distribution of the late time ejecta by examination of the emission line profiles. Using nebular analysis in the low-density regime, we estimate lower limits on the abundances in these novae. In V1974 Cyg and V382 Vel, our observations confirm the abundance estimates presented by other authors and support the claims that these eruptions occurred on ONe white dwarfs (WDs). We report the first detection of neon emission in V1494 Aql and show that the system most likely contains a CO WD.

INFRARED CLASSIFICATION AND LUMINOSITIES FOR DUSTY ACTIVE GALACTIC NUCLEI AND THE MOST LUMINOUS QUASARS

International Nuclear Information System (INIS)

Weedman, Daniel; Sargsyan, Lusine; Houck, James; Barry, Donald; Lebouteiller, Vianney

2012-01-01

Mid-infrared spectroscopic measurements from the Infrared Spectrometer (IRS) on Spitzer are given for 125 hard X-ray active galactic nuclei (AGNs; 14-195 keV) from the Swift Burst Alert Telescope (BAT) sample and for 32 AGNs with black hole masses (BHMs) from reverberation mapping. The 9.7 μm silicate feature in emission or absorption defines an infrared AGN classification describing whether AGNs are observed through dust clouds, indicating that 55% of the BAT AGNs are observed through dust. The mid-infrared dust continuum luminosity is shown to be an excellent indicator of intrinsic AGN luminosity, scaling closely with the hard X-ray luminosity, log νL ν (7.8 μm)/L(X) = –0.31 ± 0.35, and independent of classification determined from silicate emission or absorption. Dust luminosity scales closely with BHM, log νL ν (7.8 μm) = (37.2 ± 0.5) + 0.87 log BHM for luminosity in erg s –1 and BHM in M ☉ . The 100 most luminous type 1 quasars as measured in νL ν (7.8 μm) are found by comparing Sloan Digital Sky Survey (SDSS) optically discovered quasars with photometry at 22 μm from the Wide-Field Infrared Survey Explorer (WISE), scaled to rest frame 7.8 μm using an empirical template determined from IRS spectra. The most luminous SDSS/WISE quasars have the same maximum infrared luminosities for all 1.5 IR = 10 14.4 L ☉ . Comparing with dust-obscured galaxies from Spitzer and WISE surveys, we find no evidence of hyperluminous obscured quasars whose maximum infrared luminosities exceed the maximum infrared luminosities of optically discovered quasars. Bolometric luminosities L bol estimated from rest-frame optical or ultraviolet luminosities are compared to L IR . For the local AGN, the median log L IR /L bol = –0.35, consistent with a covering factor of 45% for the absorbing dust clouds. For the SDSS/WISE quasars, the median log L IR /L bol = 0.1, with extremes indicating that ultraviolet-derived L bol can be seriously underestimated even for type 1

Quantification of SOC and Clay Content Using Visible Near-Infrared Reflectance–Mid-Infrared Reflectance Spectroscopy With Jack-Knifing Partial Least Squares Regression

DEFF Research Database (Denmark)

Peng, Yi; Knadel, Maria; Gislum, René

2014-01-01

A total of 125 soil samples were collected from a Danish field varying in soil texture from sandy to loamy. Visible near-infrared reflectance (Vis-NIR) and mid-infrared reflectance (MIR) spectroscopy combined with chemometric methods were used to predict soil organic carbon (SOC) and clay content...

MAPPING THE SPATIAL DISTRIBUTION OF DUST EXTINCTION IN NGC 959 USING BROADBAND VISIBLE AND MID-INFRARED FILTERS

International Nuclear Information System (INIS)

Tamura, K.; Jansen, R. A.; Windhorst, R. A.

2009-01-01

We present a method to estimate and map the two-dimensional distribution of dust extinction in the late-type spiral galaxy NGC 959 from the theoretical and observed flux ratio of optical V and mid-IR (MIR) 3.6 μm images. Our method is applicable to both young and old stellar populations for a range of metallicities, and is not restricted to lines of sight toward star-formation (SF) regions. We explore this method using a pixel-based analysis on images of NGC 959 obtained in the V band at the Vatican Advanced Technology Telescope and at 3.6 μm (L band) with Spitzer/Infrared Array Camera. We present the original and extinction corrected Galaxy Evolution Explorer (GALEX) far-UV (FUV) and near-UV (NUV) images, as well as optical UBVR images of NGC 959. While the dust lanes are not clearly evident at GALEX resolution, our dust map clearly traces the dust that can be seen silhouetted against the galaxy's disk in the high-resolution Hubble Space Telescope (HST) images of NGC 959. The advantages of our method are (1) it only depends on two relatively common broadband images in the optical V band and in the MIR at 3.6 μm (but adding a near-UV band improves its fidelity); and (2) it is able to map the two-dimensional spatial distribution of dust within a galaxy. This powerful tool could be used to measure the detailed distribution of dust extinction within higher redshift galaxies to be observed with, e.g., the Hubble Space Telescope (HST)/WFC3 (optical near-IR) and James Webb Space Telescope (mid-IR), and to distinguish properties of dust within galaxy bulges, spiral arms, and inter-arm regions.

Conductive Oxides Trench Structures as Hyperbolic Metamaterials in Mid-infrared Range

DEFF Research Database (Denmark)

Takayama, Osamu; Shkondin, Evgeniy; Panah, Mohammad Esmail Aryaee

,2]. Moreover plasmonics for mid-infrared offer unique applications such as bio-sensing, thermal imaging and quest for novel materials and structures has been continuing [3]. In this report we show that vertical trench structures made of, for example, aluminum-doped ZnO (AZO) or other transparent conductive...

Diffuse-reflectance fourier-transform mid-infrared spectroscopy as a method of characterizing changes in soil organic matter

Science.gov (United States)

Diffuse-Reflectance Fourier-Transform Mid-Infrared Spectroscopy (MidIR) can identify the presence of important organic functional groups in soil organic matter (SOM). Soils contain myriad organic and inorganic components that absorb in the MidIR so spectral interpretation needs to be validated in or...

Estimating optical feedback from a chalcogenide fiber in mid-infrared quantum cascade lasers

Directory of Open Access Journals (Sweden)

L. Jumpertz

2016-10-01

Full Text Available The amount of optical feedback originating from a chalcogenide fiber used to couple light from a mid-infrared quantum cascade laser is evaluated experimentally. Threshold reduction measurements on the fibered laser, combined with an analytical study of a rate equations model of the laser under optical feedback, allow estimating the feedback strength between 11% and 15% depending on the fiber cleavage quality. While this remains below the frontier of the chaotic regime, it is sufficient to deeply modify the optical spectrum of a quantum cascade laser. Hence for applications such as gas spectroscopy, where the shape of the optical spectrum is of prime importance, the use of mid-infrared optical isolators may be necessary for fibered quantum cascade lasers to be fully exploited.

Study on the mechanism of human blood glucose concentration measuring using mid-infrared spectral analysis technology

Science.gov (United States)

Li, Xiang

2016-10-01

All forms of diabetes increase the risk of long-term complications. Blood glucose monitoring is of great importance for controlling diabetes procedure, preventing the complications and improving the patient's life quality. At present, the clinical blood glucose concentration measurement is invasive and could be replaced by noninvasive spectroscopy analytical techniques. The mid-infrared spectral region contains strong characteristic and well-defined absorption bands. Therefore, mid-infrared provides an opportunity for monitoring blood glucose invasively with only a few discrete bonds. Although the blood glucose concentration measurement using mid-infrared spectroscopy has a lot of advantages, the disadvantage is also obvious. The absorption in this infrared region is fundamental molecular group vibration. Absorption intensity is very strong, especially for biological molecules. In this paper, it figures out that the osmosis rate of glucose has a certain relationship with the blood glucose concentration. Therefore, blood glucose concentration could be measured indirectly by measuring the glucose exudate in epidermis layer. Human oral glucose tolerance tests were carried out to verify the correlation of glucose exudation in shallow layer of epidermis layer and blood glucose concentration. As it has been explained above, the mid-infrared spectral region contains well-defined absorption bands, the intensity of absorption peak around 1123 cm-1 was selected to measure the glucose and that around 1170 cm-1 was selected as reference. Ratio of absorption peak intensity was recorded for each set of measurement. The effect and importance of the cleaning the finger to be measured before spectrum measuring are discussed and also verified by experiment.

Mid-infrared plasmonic resonances exploiting heavily-doped Ge on Si

Science.gov (United States)

Biagioni, P.; Sakat, E.; Baldassarre, L.; Calandrini, E.; Samarelli, A.; Gallacher, K.; Frigerio, J.; Isella, G.; Paul, D. J.; Ortolani, M.

2015-03-01

We address the behavior of mid-infrared localized plasmon resonances in elongated germanium antennas integrated on silicon substrates. Calculations based on Mie theory and on the experimentally retrieved dielectric constant allow us to study the tunability and the figures of merit of plasmon resonances in heavily-doped germanium and to preliminarily compare them with those of the most established plasmonic material, gold.

ZOO: la piattaforma WPS libera

Directory of Open Access Journals (Sweden)

Luca Delluchi

2010-03-01

Full Text Available ZOO: WPS serverZOO is a WPS server with powered calculus abilities on geospatial data directly in the web, deriving from the international collaboration of French and Japaneseresearchers. ZOO is composed by three main parts: the Kernel, i.e. the core of the software, the Services, i.e. program processes allowing to connect the differentZOO libraries, and the API, Javascript based libraries for creating and managing WPS services. While an exhaustive description of ZOO is beyond the scope of this paper, we do hope to stimulate discussion bout possibilities and challenges of webbased analysis of geospatial data.

High Power Mid-Infrared Generation with a Quasi-Phase Matched GaAs Guided-wave Optical Parametric Oscillator

National Research Council Canada - National Science Library

Harris, J

2000-01-01

...-power coherent mid-infrared sources. Considerable effort has been devoted over the past decade to the development of mid-IR coherent sources based on nonlinear optical frequency conversion, e.g...

On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations

Energy Technology Data Exchange (ETDEWEB)

Neeley, Jillian R.; Marengo, Massimo; Trueba, Nicolas [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Bono, Giuseppe; Braga, Vittorio F.; Magurno, Davide [Department of Physics, Università di Roma Tor Vergara, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Dall’Ora, Massimo; Marconi, Marcella [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiarello 16, I-80131 Napoli (Italy); Tognelli, Emanuele; Moroni, Pier G. Prada [Dipartimento di Fisica, Università di Pisa, Lago Bruno Pontecorvo 3, I-56127, Pisa (Italy); Beaton, Rachael L.; Madore, Barry F.; Seibert, Mark [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Freedman, Wendy L. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Monson, Andrew J. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Scowcroft, Victoria [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Stetson, Peter B., E-mail: jrneeley@iastate.edu [NRC-Herzberg, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria BC V9E 2E7 (Canada)

2017-06-01

We present new theoretical period–luminosity–metallicity (PLZ) relations for RR Lyræ stars (RRLs) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad range of metal abundances ( Z = 0.0001–0.0198). In deriving the light curves, we tested two sets of atmospheric models and found no significant difference between the resulting mean magnitudes. We also compare our theoretical relations to empirical relations derived from RRLs in both the field and in the globular cluster M4. Our theoretical PLZ relations were combined with multi-wavelength observations to simultaneously fit the distance modulus, μ {sub 0}, and extinction, A {sub V}, of both the individual Galactic RRL and of the cluster M4. The results for the Galactic RRL are consistent with trigonometric parallax measurements from Gaia ’ s first data release. For M4, we find a distance modulus of μ {sub 0} = 11.257 ± 0.035 mag with A {sub V}= 1.45 ± 0.12 mag, which is consistent with measurements from other distance indicators. This analysis has shown that, when considering a sample covering a range of iron abundances, the metallicity spread introduces a dispersion in the PL relation on the order of 0.13 mag. However, if this metallicity component is accounted for in a PLZ relation, the dispersion is reduced to ∼0.02 mag at mid-infrared wavelengths.

Bio-analytical applications of mid-infrared spectroscopy using silver halide fiber-optic probes

International Nuclear Information System (INIS)

Heise, H.M.; Kuepper, L.; Butvina, L.N.

2002-01-01

Infrared-spectroscopy has proved to be a powerful method for the study of various biomedical samples, in particular for in-vitro analysis in the clinical laboratory and for non-invasive diagnostics. In general, the analysis of biofluids such as whole blood, urine, microdialysates and bioreactor broth media takes advantage of the fact that a multitude of analytes can be quantified simultaneously and rapidly without the need for reagents. Progress in the quality of infrared silver halide fibers enabled us to construct several flexible fiber-optic probes of different geometries, which are particularly suitable for the measurement of small biosamples. Recent trends show that dry film measurements by mid-infrared spectroscopy could revolutionize analytical tools in the clinical chemistry laboratory, and an example is given. Infrared diagnostic tools show a promising potential for patients, and minimal-invasive blood glucose assays or skin tissue pathology in particular cannot be left out using mid-infrared fiber-based probes. Other applications include the measurement of skin samples including penetration studies of vitamins and constituents of cosmetic cream formulations. A further field is the micro-domain analysis of biopsy samples from bog mummified corpses, and recent results on the chemistry of dermis and hair samples are reported. Another field of application, for which results are reported, is food analysis and bio-reactor monitoring

Fiber Based Mid Infrared Supercontinuum Source for Spectroscopic Analysis in Food Production

DEFF Research Database (Denmark)

Ramsay, Jacob; Dupont, Sune Vestergaard Lund; Keiding, Søren Rud

Optimization of sustainable food production is a worldwide challenge that is undergoing continuous development as new technologies emerge. Applying solutions for food analysis with novel bright and broad mid-infrared (MIR) light sources has the potential to meet the increasing demands for food...

Heuristic modelling of laser written mid-infrared LiNbO3 stressed-cladding waveguides.

Science.gov (United States)

Nguyen, Huu-Dat; Ródenas, Airán; Vázquez de Aldana, Javier R; Martínez, Javier; Chen, Feng; Aguiló, Magdalena; Pujol, Maria Cinta; Díaz, Francesc

2016-04-04

Mid-infrared lithium niobate cladding waveguides have great potential in low-loss on-chip non-linear optical instruments such as mid-infrared spectrometers and frequency converters, but their three-dimensional femtosecond-laser fabrication is currently not well understood due to the complex interplay between achievable depressed index values and the stress-optic refractive index changes arising as a function of both laser fabrication parameters, and cladding arrangement. Moreover, both the stress-field anisotropy and the asymmetric shape of low-index tracks yield highly birefringent waveguides not useful for most applications where controlling and manipulating the polarization state of a light beam is crucial. To achieve true high performance devices a fundamental understanding on how these waveguides behave and how they can be ultimately optimized is required. In this work we employ a heuristic modelling approach based on the use of standard optical characterization data along with standard computational numerical methods to obtain a satisfactory approximate solution to the problem of designing realistic laser-written circuit building-blocks, such as straight waveguides, bends and evanescent splitters. We infer basic waveguide design parameters such as the complex index of refraction of laser-written tracks at 3.68 µm mid-infrared wavelengths, as well as the cross-sectional stress-optic index maps, obtaining an overall waveguide simulation that closely matches the measured mid-infrared waveguide properties in terms of anisotropy, mode field distributions and propagation losses. We then explore experimentally feasible waveguide designs in the search of a single-mode low-loss behaviour for both ordinary and extraordinary polarizations. We evaluate the overall losses of s-bend components unveiling the expected radiation bend losses of this type of waveguides, and finally showcase a prototype design of a low-loss evanescent splitter. Developing a realistic waveguide

Novel mid-infrared imaging system based on single-mode quantum cascade laser illumination and upconversion

DEFF Research Database (Denmark)

Tomko, Jan; Junaid, Saher; Tidemand-Lichtenberg, Peter

2017-01-01

Compared to the visible or near-infrared (NIR) spectral regions, there is a lack of very high sensitivity detectors in the mid-infrared (MIR) that operate near room temperature. Upconversion of the MIR light to NIR light that is imaged using affordable, fast, and sensitive NIR detectors or camera...

LUMINOSITY FUNCTIONS OF SPITZER-IDENTIFIED PROTOSTARS IN NINE NEARBY MOLECULAR CLOUDS

Energy Technology Data Exchange (ETDEWEB)

Kryukova, E.; Megeath, S. T.; Allen, T. S. [Department of Physics and Astronomy, University of Toledo, Toledo, OH (United States); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Pipher, J. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Allen, L. E. [National Optical Astronomy Observatories, Tucson, AZ (United States); Myers, P. C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Muzerolle, J. [Space Telescope Science Institute, Baltimore, MD (United States)

2012-08-15

We identify protostars in Spitzer surveys of nine star-forming (SF) molecular clouds within 1 kpc: Serpens, Perseus, Ophiuchus, Chamaeleon, Lupus, Taurus, Orion, Cep OB3, and Mon R2, which combined host over 700 protostar candidates. These clouds encompass a variety of SF environments, including both low-mass and high-mass SF regions, as well as dense clusters and regions of sparsely distributed star formation. Our diverse cloud sample allows us to compare protostar luminosity functions in these varied environments. We combine near- and mid-infrared photometry from the Two Micron All Sky Survey and Spitzer to create 1-24 {mu}m spectral energy distributions (SEDs). Using protostars from the c2d survey with well-determined bolometric luminosities, we derive a relationship between bolometric luminosity, mid-IR luminosity (integrated from 1-24 {mu}m), and SED slope. Estimations of the bolometric luminosities for protostar candidates are combined to create luminosity functions for each cloud. Contamination due to edge-on disks, reddened Class II sources, and galaxies is estimated and removed from the luminosity functions. We find that luminosity functions for high-mass SF clouds (Orion, Mon R2, and Cep OB3) peak near 1 L{sub Sun} and show a tail extending toward luminosities above 100 L{sub Sun }. The luminosity functions of the low-mass SF clouds (Serpens, Perseus, Ophiuchus, Taurus, Lupus, and Chamaeleon) do not exhibit a common peak, however the combined luminosity function of these regions peaks below 1 L{sub Sun }. Finally, we examine the luminosity functions as a function of the local surface density of young stellar objects. In the Orion molecular clouds, we find a significant difference between the luminosity functions of protostars in regions of high and low stellar density, the former of which is biased toward more luminous sources. This may be the result of primordial mass segregation, although this interpretation is not unique. We compare our luminosity

LUMINOSITY FUNCTIONS OF SPITZER-IDENTIFIED PROTOSTARS IN NINE NEARBY MOLECULAR CLOUDS

International Nuclear Information System (INIS)

Kryukova, E.; Megeath, S. T.; Allen, T. S.; Gutermuth, R. A.; Pipher, J.; Allen, L. E.; Myers, P. C.; Muzerolle, J.

2012-01-01

We identify protostars in Spitzer surveys of nine star-forming (SF) molecular clouds within 1 kpc: Serpens, Perseus, Ophiuchus, Chamaeleon, Lupus, Taurus, Orion, Cep OB3, and Mon R2, which combined host over 700 protostar candidates. These clouds encompass a variety of SF environments, including both low-mass and high-mass SF regions, as well as dense clusters and regions of sparsely distributed star formation. Our diverse cloud sample allows us to compare protostar luminosity functions in these varied environments. We combine near- and mid-infrared photometry from the Two Micron All Sky Survey and Spitzer to create 1-24 μm spectral energy distributions (SEDs). Using protostars from the c2d survey with well-determined bolometric luminosities, we derive a relationship between bolometric luminosity, mid-IR luminosity (integrated from 1-24 μm), and SED slope. Estimations of the bolometric luminosities for protostar candidates are combined to create luminosity functions for each cloud. Contamination due to edge-on disks, reddened Class II sources, and galaxies is estimated and removed from the luminosity functions. We find that luminosity functions for high-mass SF clouds (Orion, Mon R2, and Cep OB3) peak near 1 L ☉ and show a tail extending toward luminosities above 100 L ☉ . The luminosity functions of the low-mass SF clouds (Serpens, Perseus, Ophiuchus, Taurus, Lupus, and Chamaeleon) do not exhibit a common peak, however the combined luminosity function of these regions peaks below 1 L ☉ . Finally, we examine the luminosity functions as a function of the local surface density of young stellar objects. In the Orion molecular clouds, we find a significant difference between the luminosity functions of protostars in regions of high and low stellar density, the former of which is biased toward more luminous sources. This may be the result of primordial mass segregation, although this interpretation is not unique. We compare our luminosity functions to those

Bezoekersprognose Wad & Zoo

NARCIS (Netherlands)

Alsem, Karel Jan; Wever, Jan

Wad & Zoo is een attractie over het natuurlijke leven in de Eems, van bron tot Wad en Noordzee. Oorspronkelijk was de gedachte dat deze attractie in Delfzijl zou komen, maar hij is nu gepland bij de veerboot naar Borkum in de Eemshaven.Marklinq is door het Bestuur van de Stichting Wad & Zoo gevraagd

SPITZER SECONDARY ECLIPSES OF WASP-18b

International Nuclear Information System (INIS)

Nymeyer, Sarah; Harrington, Joseph; Hardy, Ryan A.; Stevenson, Kevin B.; Campo, Christopher J.; Blecic, Jasmina; Bowman, William C.; Britt, Christopher B. T.; Cubillos, Patricio; Madhusudhan, Nikku; Collier-Cameron, Andrew; Maxted, Pierre F. L.; Loredo, Thomas J.; Hellier, Coel; Anderson, David R.; Gillon, Michael; Hebb, Leslie; Wheatley, Peter J.; Pollacco, Don

2011-01-01

The transiting exoplanet WASP-18b was discovered in 2008 by the Wide Angle Search for Planets project. The Spitzer Exoplanet Target of Opportunity Program observed secondary eclipses of WASP-18b using Spitzer's Infrared Array Camera in the 3.6 μm and 5.8 μm bands on 2008 December 20, and in the 4.5 μm and 8.0 μm bands on 2008 December 24. We report eclipse depths of 0.30% ± 0.02%, 0.39% ± 0.02%, 0.37% ± 0.03%, 0.41% ± 0.02%, and brightness temperatures of 3100 ± 90, 3310 ± 130, 3080 ± 140, and 3120 ± 110 K in order of increasing wavelength. WASP-18b is one of the hottest planets yet discovered—as hot as an M-class star. The planet's pressure-temperature profile most likely features a thermal inversion. The observations also require WASP-18b to have near-zero albedo and almost no redistribution of energy from the day side to the night side of the planet.

Early 2017 observations of TRAPPIST-1 with Spitzer

Science.gov (United States)

Delrez, L.; Gillon, M.; Triaud, A. H. M. J.; Demory, B.-O.; de Wit, J.; Ingalls, J. G.; Agol, E.; Bolmont, E.; Burdanov, A.; Burgasser, A. J.; Carey, S. J.; Jehin, E.; Leconte, J.; Lederer, S.; Queloz, D.; Selsis, F.; Van Grootel, V.

2018-04-01

The recently detected TRAPPIST-1 planetary system, with its seven planets transiting a nearby ultracool dwarf star, offers the first opportunity to perform comparative exoplanetology of temperate Earth-sized worlds. To further advance our understanding of these planets' compositions, energy budgets, and dynamics, we are carrying out an intensive photometric monitoring campaign of their transits with the Spitzer Space Telescope. In this context, we present 60 new transits of the TRAPPIST-1 planets observed with Spitzer/Infrared Array Camera (IRAC) in 2017 February and March. We combine these observations with previously published Spitzer transit photometry and perform a global analysis of the resulting extensive data set. This analysis refines the transit parameters and provides revised values for the planets' physical parameters, notably their radii, using updated properties for the star. As part of our study, we also measure precise transit timings that will be used in a companion paper to refine the planets' masses and compositions using the transit timing variations method. TRAPPIST-1 shows a very low level of low-frequency variability in the IRAC 4.5-μm band, with a photometric RMS of only 0.11 per cent at a 123-s cadence. We do not detect any evidence of a (quasi-)periodic signal related to stellar rotation. We also analyse the transit light curves individually, to search for possible variations in the transit parameters of each planet due to stellar variability, and find that the Spitzer transits of the planets are mostly immune to the effects of stellar variations. These results are encouraging for forthcoming transmission spectroscopy observations of the TRAPPIST-1 planets with the James Webb Space Telescope.

Cold disks : Spitzer spectroscopy of disks around young stars with large gaps

NARCIS (Netherlands)

Blake, G. A.; Dullemond, C. P.; Merin, B.; Augereau, J. C.; Boogert, A. C. A.; Evans, N. J.; Geers, V. C.; Lahuis, F.; Kessler-Silacci, J. E.; Pontoppidan, K. M.; van Dishoeck, E. F.; Brown, J.M.

2007-01-01

We have identified four circumstellar disks with a deficit of dust emission from their inner 15-50 AU. All four stars have F-G spectral type and were uncovered as part of the Spitzer Space Telescope "Cores to Disks" Legacy Program Infrared Spectrograph (IRS) first-look survey of similar to 100 pre -

Dielectric properties of vertically aligned multi-walled carbon nanotubes in the terahertz and mid-infrared range

Science.gov (United States)

Thomson, Mark D.; Zouaghi, Wissem; Meng, Fanqi; Wiecha, Matthias M.; Rabia, Kaneez; Heinlein, Thorsten; Hussein, Laith; Babu, Deepu; Yadav, Sandeep; Engstler, Jörg; Schneider, Jörg J.; Nicoloso, Norbert; Rychetský, Ivan; Kužel, Petr; Roskos, Hartmut G.

2018-01-01

We investigate the broadband dielectric properties of vertically aligned, multi-wall carbon nanotubes (VACNT), over both the terahertz (THz) and mid-infrared spectral ranges. The nominally undoped, metallic VACNT samples are probed at normal incidence, i.e. the response is predominantly due to polarisation perpendicular to the CNT axis. A detailed comparison of various conductivity models and previously reported results is presented for the non-Drude behaviour we observe in the conventional THz range (up to 2.5 THz). Extension to the mid-infrared range reveals an absorption peak at \

Modelling the mid-infrared drying of sweet potato: kinetics, mass and heat transfer parameters, and energy consumption

Science.gov (United States)

Onwude, Daniel I.; Hashim, Norhashila; Abdan, Khalina; Janius, Rimfiel; Chen, Guangnan

2018-04-01

This study investigated the drying kinetics, mass and heat transfer characteristics of sweet potato slices (0.4-0.6 cm thickness) during drying based on mid-infrared experimental set-up (intensity of 1100-1400 W/m2). Thin layer drying models were used to evaluate the drying kinetics of sweet potato slices. Two analytical models (Fick's diffusion model, and Dincer and Dost model) were used to study the mass transfer behaviour of sweet potato slices with and without shrinkage during mid-infrared drying. The heat transfer flux between the emitter and sweet potato slices was also investigated. Results demonstrated that an increase in infrared intensity from 1100 W/m2 to 1400 W/m2 resulted in increased in average radiation heat flux by 3.4 times and a 15% reduction in the overall drying time. The two-term exponential model was found to be the best in predicting the drying kinetics of sweet potato slices during mid-infrared drying. The specific heat consumption varied from 0.91-4.82 kWh/kg. The effective moisture diffusivity with and without shrinkage using the Fick's diffusion model varied from 2.632 × 10-9 to 1.596 × 10-8 m2/s, and 1.24 × 10-8 to 2.4 × 10-8 m2/s using Dincer and Dost model, respectively. The obtained values of mass transfer coefficient, Biot number and activation energy varied from 5.99 × 10-6 to 1.17 × 10-5 m/s, 0.53 to 2.62, and 12.83 kJ/mol to 34.64 kJ/mol, respectively. The values obtained for Biot number implied the existence of simultaneous internal and external resistances. The findings further explained that mid-infrared intensity of 1100 W/m2 did not significantly affect the quality of sweet potato during drying, demonstrating a great potential of applying low intensity mid-infrared radiation in the drying of agricultural crops.

GALAXY CLUSTERS IN THE IRAC DARK FIELD. II. MID-INFRARED SOURCES

International Nuclear Information System (INIS)

Krick, J. E.; Surace, J. A.; Yan, L.; Thompson, D.; Ashby, M. L. N.; Hora, J. L.; Gorjian, V.

2009-01-01

We present infrared (IR) luminosities, star formation rates (SFR), colors, morphologies, locations, and active galactic nuclei (AGNs) properties of 24 μm detected sources in photometrically detected high-redshift clusters in order to understand the impact of environment on star formation (SF) and AGN evolution in cluster galaxies. We use three newly identified z = 1 clusters selected from the IRAC dark field; the deepest ever mid-IR survey with accompanying, 14 band multiwavelength data including deep Hubble Space Telescope imaging and deep wide-area Spitzer MIPS 24 μm imaging. We find 90 cluster members with MIPS detections within two virial radii of the cluster centers, of which 17 appear to have spectral energy distributions dominated by AGNs and the rest dominated by SF. We find that 43% of the star-forming sample have IR luminosities L IR > 10 11 L sun (luminous IR galaxies). The majority of sources (81%) are spirals or irregulars. A large fraction (at least 25%) show obvious signs of interactions. The MIPS-detected member galaxies have varied spatial distributions as compared to the MIPS-undetected members with one of the three clusters showing SF galaxies being preferentially located on the cluster outskirts, while the other two clusters show no such trend. Both the AGN fraction and the summed SFR of cluster galaxies increase from redshift zero to one, at a rate that is a few times faster in clusters than over the same redshift range in the field. Cluster environment does have an effect on the evolution of both AGN fraction and SFR from redshift one to the present, but does not affect the IR luminosities or morphologies of the MIPS sample. SF happens in the same way regardless of environment making MIPS sources look the same in the cluster and field, however the cluster environment does encourage a more rapid evolution with time as compared to the field.

Mid-Infrared Emission Features in the ISM: Feature-to-Features Flux Ratios

Science.gov (United States)

Lu, N. Y.

1998-01-01

Using a limited, but representative sample of sources in the ISM of our Galaxy with published spectra from the Infrared Space Observatory, we analyze flux ratios between the major mid-IR emission features (EFs) centered around 6.2, 7.7, 8.6 and 11.3 mu, respectively.

PHOTOMETRIC MONITORING OF THE COLDEST KNOWN BROWN DWARF WITH THE SPITZER SPACE TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Esplin, T. L.; Luhman, K. L. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Cushing, M. C.; Hardegree-Ullman, K. K.; Trucks, J. L.; Schneider, A. C. [Department of Physics and Astronomy, The University of Toledo, OH 43606 (United States); Burgasser, A. J., E-mail: taran.esplin@psu.edu [Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA 92093 (United States)

2016-11-20

Because WISE J085510.83-071442.5 (hereafter WISE 0855-0714) is the coldest known brown dwarf (∼250 K) and one of the Sun’s closest neighbors (2.2 pc), it offers a unique opportunity to study a planet-like atmosphere in an unexplored regime of temperature. To detect and characterize inhomogeneities in its atmosphere (e.g., patchy clouds, hot spots), we have performed time-series photometric monitoring of WISE 0855-0714 at 3.6 and 4.5 μ m with the Spitzer Space Telescope during two 23 hr periods that were separated by several months. For both bands, we have detected variability with peak-to-peak amplitudes of 4%–5% and 3%–4% in the first and second epochs, respectively. The light curves are semiperiodic in the first epoch for both bands, but they are more irregular in the second epoch. Models of patchy clouds have predicted a large increase in mid-infrared (mid-IR) variability amplitudes (for a given cloud covering fraction) with the appearance of water ice clouds at T {sub eff} < 375 K, so if such clouds are responsible for the variability of WISE 0855-0714, then its small amplitudes of variability indicate a very small deviation in cloud coverage between hemispheres. Alternatively, the similarity in mid-IR variability amplitudes between WISE 0855-0714 and somewhat warmer T and Y dwarfs may suggest that they share a common origin for their variability (i.e., not water clouds). In addition to our variability data, we have examined other constraints on the presence of water ice clouds in the atmosphere of WISE 0855-0714, including the recent mid-IR spectrum from Skemer et al. (2016). We find that robust evidence of such clouds is not yet available.

Design analysis of doped-silicon surface plasmon resonance immunosensors in mid-infrared range.

Science.gov (United States)

DiPippo, William; Lee, Bong Jae; Park, Keunhan

2010-08-30

This paper reports the design analysis of a microfabricatable mid-infrared (mid-IR) surface plasmon resonance (SPR) sensor platform. The proposed platform has periodic heavily doped profiles implanted into intrinsic silicon and a thin gold layer deposited on top, making a physically flat grating SPR coupler. A rigorous coupled-wave analysis was conducted to prove the design feasibility, characterize the sensor's performance, and determine geometric parameters of the heavily doped profiles. Finite element analysis (FEA) was also employed to compute the electromagnetic field distributions at the plasmon resonance. Obtained results reveal that the proposed structure can excite the SPR on the normal incidence of mid-IR light, resulting in a large probing depth that will facilitate the study of larger analytes. Furthermore, the whole structure can be microfabricated with well-established batch protocols, providing tunability in the SPR excitation wavelength for specific biosensing needs with a low manufacturing cost. When the SPR sensor is to be used in a Fourier-transform infrared (FTIR) spectroscopy platform, its detection sensitivity and limit of detection are estimated to be 3022 nm/RIU and ~70 pg/mm(2), respectively, at a sample layer thickness of 100 nm. The design analysis performed in the present study will allow the fabrication of a tunable, disposable mid-IR SPR sensor that combines advantages of conventional prism and metallic grating SPR sensors.

Mid infrared MEMS FTIR spectrometer

Science.gov (United States)

Erfan, Mazen; Sabry, Yasser M.; Mortada, Bassem; Sharaf, Khaled; Khalil, Diaa

2016-03-01

In this work we report, for the first time to the best of our knowledge, a bulk-micromachined wideband MEMS-based spectrometer covering both the NIR and the MIR ranges and working from 1200 nm to 4800 nm. The core engine of the spectrometer is a scanning Michelson interferometer micro-fabricated using deep reactive ion etching (DRIE) technology. The spectrum is obtained using the Fourier Transform techniques that allows covering a very wide spectral range limited by the detector responsivity. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator. Zirconium fluoride (ZrF4) multimode optical fibers are used to connect light between the white light source and the interferometer input, as well as the interferometer output to a PbSe photoconductive detector. The recorded signal-to-noise ratio is 25 dB at the wavelength of 3350 nm. The spectrometer is successfully used in measuring the absorption spectra of methylene chloride, quartz glass and polystyrene film. The presented solution provides a low cost method for producing miniaturized spectrometers in the near-/mid-infrared.

Star-forming Galaxies as AGN Imposters? A Theoretical Investigation of the Mid-infrared Colors of AGNs and Extreme Starbursts

Science.gov (United States)

Satyapal, Shobita; Abel, Nicholas P.; Secrest, Nathan J.

2018-05-01

We conduct for the first time a theoretical investigation of the mid-infrared spectral energy distribution (SED) produced by dust heated by an active galactic nucleus (AGN) and an extreme starburst. These models employ an integrated modeling approach using photoionization and stellar population synthesis models in which both the line and emergent continuum is predicted from gas exposed to the ionizing radiation from a young starburst and an AGN. In this work, we focus on the infrared colors from the Wide-field Infrared Survey Explorer, predicting the dependence of the colors on the input radiation field, the interstellar medium conditions, the obscuring column, and the metallicity. We find that an extreme starburst can mimic an AGN in two band mid-infrared color cuts employed in the literature. However, the three-band color cuts employed in the literature require starbursts with extremely high ionization parameters or gas densities. We show that the extreme mid-infrared colors seen in some blue compact dwarf galaxies are not due to metallicity but rather a combination of high ionization parameters and high column densities. Based on our theoretical calculations, we present a theoretical mid-infrared color cut that will exclude even the most extreme starburst that we have modeled in this work. The theoretical AGN demarcation region presented here can be used to identify elusive AGN candidates for future follow-up studies with the James Webb Space Telescope. The full suite of simulated SEDs are available online.

Visible and Mid-Infrared Gypsum Optical Constants for Modeling of Martian Deposits

Science.gov (United States)

Roush, Ted L.; Esposito, Francesca; Rossmann, George R.; Colangeli, Luigi

2007-08-01

Introduction: Recent and on-going remote and in situ observations indicate that sulfates are present in significant abundances at various locations on Mars [1-7]. The Mars Reconnaissance Orbiter (MRO) imaging spectrometer (CRISM) is returning hyperspectral data at higher spatial resolution [8] than the OMEGA instrument on the Mars Express Mission [3]. Data from both OMEGA and CRISM have provided spectral evidence for the presence of gypsum and various hydrated sulfates on the Martian surface [e.g. 3-7] Thus, the optical properties of sulfates, in general, are of interest to quantitative interpretation of this increasing volume of remotely sensed data. This is because optical constants describe how a material interacts with electromagnetic radiation and represent the fundamental values used in radiative transfer calculations describing a variety of physical environments. Such environments include atmospheres where aerosols are present, planetary and satellite regoliths, and circumstellar dust clouds. Here we focus upon gypsum because of its applicability due to its identification on Mars. Also, gypsum is a mineral that is readily available in samples sizes that are suitable for study using a variety of spectral measurements. In the infrared (>5 μm) several studies reporting the optical constants of gypsum can be used in evaluating the approach used here. Most importantly, there is a general lack of data regarding the optical constants for gypsum at visible and mid-infrared wavelengths (0.4-5 μm) that are being observed by OMEGA and CRISM. Background: In the infrared, there have been several studies focused at determining the optical constants of gypsum using classical dispersion models [9-11]. These have used a variety of samples including; crystals, compressed pellets of pure materials, and grains suspended in a KBr matrix. Spectral measurements of gypsum, and other sulfates, have existed for about 100 years at visible and mid-infrared wavelengths (0.4-5 μm) [e

Comment on "A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study" and "Infrared and infrared emission spectroscopic study of typical Chinese kaolinite and halloysite" by Hongfei Cheng et al. (2010).

Science.gov (United States)

Kloprogge, J Theo

2015-02-05

In two papers Cheng et al. (2010) reported in this journal on the mid-infrared, near-infrared and infrared emission spectroscopy of a halloysite from Hunan Xianrenwan, China. This halloysite contains around 8% of quartz (SiO2) and nearly 9% gibbsite (Al(OH)3). In their interpretation of the spectra these impurities were completely ignored. Careful comparison with a phase pure halloysite from Southern Belgium, synthetic gibbsite, gibbsite from Minas Gerais, and quartz show that these impurities do have a marked influence on the mid-infrared and infrared emission spectra. In the near-infrared, the effect is much less pronounced. Quartz does not show bands in this region and the gibbsite bands will be very weak. Comparison still show that the presence of gibbsite does contribute to the overall spectrum and bands that were ascribed to the halloysite alone do coincide with those of gibbsite. Copyright © 2014 Elsevier B.V. All rights reserved.

Mid-infrared pulsed laser ablation of the arterial wall. Mechanical origin of "acoustic" wall damage and its effect on wall healing

NARCIS (Netherlands)

van Erven, L.; van Leeuwen, T. G.; Post, M. J.; van der Veen, M. J.; Velema, E.; Borst, C.

1992-01-01

Pulsed mid-infrared lasers are an alternative to excimer lasers for transluminal angioplasty. The mid-infrared lasers, however, were reported to produce "acoustic" wall damage that might impair the immediate and long-term results. To study the immediate and long-term effects on the arterial wall,

THELI: CONVENIENT REDUCTION OF OPTICAL, NEAR-INFRARED, AND MID-INFRARED IMAGING DATA

International Nuclear Information System (INIS)

Schirmer, M.

2013-01-01

The last 15 years have seen a surge of new multi-chip optical and near-IR imagers. While some of them are accompanied by specific reduction pipelines, user-friendly and generic reduction tools are uncommon. In this paper I introduce THELI, an easy-to-use graphical interface driving an end-to-end pipeline for the reduction of any optical, near-IR, and mid-IR imaging data. The advantages of THELI when compared to other approaches are highlighted. Combining a multitude of processing algorithms and third party software, THELI provides researchers with a single, homogeneous tool. A short learning curve ensures quick success for new and more experienced observers alike. All tasks are largely automated, while at the same time a high level of flexibility and alternative reduction schemes ensure that widely different scientific requirements can be met. Over 90 optical and infrared instruments at observatories world-wide are pre-configured, while more can be added by the user. The Appendices contain three walk-through examples using public data (optical, near-IR, and mid-IR). Additional extensive documentation for training and troubleshooting is available online

Submillisecond mixing in a continuous-flow, microfluidic mixer utilizing mid-infrared hyperspectral imaging detection.

Science.gov (United States)

Kise, Drew P; Magana, Donny; Reddish, Michael J; Dyer, R Brian

2014-02-07

We report a continuous-flow, microfluidic mixer utilizing mid-infrared hyperspectral imaging detection, with an experimentally determined, submillisecond mixing time. The simple and robust mixer design has the microfluidic channels cut through a polymer spacer that is sandwiched between two IR transparent windows. The mixer hydrodynamically focuses the sample stream with two side flow channels, squeezing it into a thin jet and initiating mixing through diffusion and advection. The detection system generates a mid-infrared hyperspectral absorbance image of the microfluidic sample stream. Calibration of the hyperspectral image yields the mid-IR absorbance spectrum of the sample versus time. A mixing time of 269 μs was measured for a pD jump from 3.2 to above 4.5 in a D2O sample solution of adenosine monophosphate (AMP), which acts as an infrared pD indicator. The mixer was further characterized by comparing experimental results with a simulation of the mixing of an H2O sample stream with a D2O sheath flow, showing good agreement between the two. The IR microfluidic mixer eliminates the need for fluorescence labeling of proteins with bulky, interfering dyes, because it uses the intrinsic IR absorbance of the molecules of interest, and the structural specificity of IR spectroscopy to follow specific chemical changes such as the protonation state of AMP.

Laboratory Studies of Solid CO2 Ices at Different Temperatures and Annealing Times in Support of Spitzer Space Telescope Observations

Science.gov (United States)

White, Douglas; Gerakines, P. A.

2007-12-01

The infrared absorption features of solid carbon dioxide have been detected by space observatories in nearly all lines of sight probing the dense interstellar medium (ISM). It has also been shown that the absorption feature of solid CO2 near 658 cm-1 (15.2 μm) should be a sensitive indicator of the physical conditions of the ice (e.g., temperature and composition). However, the profile structure of this feature is not well understood, and previous laboratory studies have concentrated on a limited range of temperatures and compositions for comparisons to observed spectra from both the Infrared Space Observatory and the Spitzer Space Telescope. In the laboratory study described here, the infrared spectra of ices bearing H2O, CH3OH, and CO2 have been measured with systematically varying compositions and temperatures that span the range of the values expected in the interstellar medium. The mid-infrared spectra (λ = 2.5-25 µm) were measured for 47 different ice compositions at temperatures ranging from 5 K to evaporation (at 5 K intervals). Additionally, annealing experiments of some of these ice compositions have been investigated. These data may be used to determine thermal histories of interstellar ices. This research was supported by NASA award NNG05GE44G under the Astronomy and Physics Research & Analysis Program (APRA).

NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

International Nuclear Information System (INIS)

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

2011-01-01

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

Determination of carbohydrates present in Saccharomyces cerevisiae using mid-infrared spectroscopy and partial least squares regression

OpenAIRE

Plata, Maria R.; Koch, Cosima; Wechselberger, Patrick; Herwig, Christoph; Lendl, Bernhard

2013-01-01

A fast and simple method to control variations in carbohydrate composition of Saccharomyces cerevisiae, baker's yeast, during fermentation was developed using mid-infrared (mid-IR) spectroscopy. The method allows for precise and accurate determinations with minimal or no sample preparation and reagent consumption based on mid-IR spectra and partial least squares (PLS) regression. The PLS models were developed employing the results from reference analysis of the yeast cells. The reference anal...

Critical coupling using the hexagonal boron nitride crystals in the mid-infrared range

Energy Technology Data Exchange (ETDEWEB)

Wu, Jipeng; Wang, Hengliang; Wen, Shuangchun [Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082 (China); Jiang, Leyong; Guo, Jun; Dai, Xiaoyu [SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Xiang, Yuanjiang, E-mail: xiangyuanjiang@126.com [Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082 (China); SZU-NUS Collaborative Innovation Center for Optoelectronic Science & Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China)

2016-05-28

We theoretically demonstrate the perfect absorption phenomena in the hexagonal boron nitride (hBN) crystals in the mid-infrared wavelength ranges by means of critical coupling with a one-dimensional photonic crystal spaced by the air. Different from the polymer absorbing layer composed by a metal-dielectric composite film, the hyperbolic dispersion characteristics of hBN can meet the condition of critical coupling and achieve the total absorption in the mid-infrared wavelength ranges. However, the critical coupling phenomenon can only appear in the hBN crystals with the type II dispersion. Moreover, we discuss the influence of the thickness of hBN, the incident angle, and the thickness and permittivity of the space dielectric on the total absorption. Ultimately, the conditions for absorption enhancement and the optimization methods of perfect absorption are proposed, and the design rules for a totally absorbing system under the different conditions are achieved.

Two-octave mid-infrared supercontinuum generation in As-Se suspended core fibers

DEFF Research Database (Denmark)

Møller, Uffe Visbech; Petersen, Christian Rosenberg; Kubat, Irnis

2015-01-01

A more than two-octave mid-infrared supercontinuum with an average output power of 15.6 mW covering 1.7-7.5 μm (1,333-5,900 cm-1) is generated in a low-loss As38Se62 suspended core fiber with core diameter of 4.5 μm....

Modeling of dispersion engineered chalcogenide rib waveguide for ultraflat mid-infrared supercontinuum generation in all-normal dispersion regime

Science.gov (United States)

Ahmad, H.; Karim, M. R.; Rahman, B. M. A.

2018-03-01

A rigorous numerical investigation has been carried out through dispersion engineering of chalcogenide rib waveguide for near-infrared to mid-infrared ultraflat broadband supercontinuum generation in all-normal group-velocity dispersion regime. We propose a novel design of a 1-cm-long air-clad rib waveguide which is made from {Ge}_{11.5} {As}_{24} {Se}_{64.5} chalcogenide glass as the core with either silica or {Ge}_{11.5} {As}_{24} {S}_{64.5} chalcogenide glass as a lower cladding separately. A broadband ultraflat supercontinuum spanning from 1300 to 1900 nm could be generated when pumped at 1.55 μ {m} with a low input peak power of 100 W. Shifting the pump to 2 μ {m}, the supercontinuum spectra extended in the mid-infrared region up to 3400 nm with a moderate-input peak power of 500 W. To achieve further extension in mid-infrared, we excite our optimized rib waveguide in both the anomalous and all-normal dispersion pumping regions at 3.1 μ {m} with a largest input peak power of 3 kW. In the case of anomalous dispersion region pumping, numerical analysis shows that supercontinuum spectrum can be extended in the mid-infrared up to 10 μ {m}, although this contains high spectral amplitude fluctuations over the entire bandwidth which limits the supercontinuum sources in the field of high precision measurement applications. On the other hand, by optimizing a rib waveguide geometry for pumping in all-normal dispersion region, we are able to generate a smooth and flat-top coherent supercontinuum spectrum with a moderate bandwidth spanning the wavelength range 2-5.5 μ {m} with less than 5 dB spectral fluctuation over the entire output bandwidth. Our proposed design is highly suitable for making on-chip SC light sources for a variety of applications such as biomedical imaging, and environmental and industrial sensing in the mid-infrared region.

Teaching Operant Conditioning at the Zoo.

Science.gov (United States)

Lukas, Kristen E.; Marr, M. Jackson; Maple, Terry L.

1998-01-01

Describes a partnership between Zoo Atlanta and the Georgia Institute of Technology in teaching the principles of operant conditioning to students in an experimental psychology class. Maintains that the positive training techniques used in zoos are models of applied operant conditioning. Includes a discussion of zoo training goals. (MJP)

SPITZER SPECTROSCOPY OF THE CIRCUMPRIMARY DISK IN THE BINARY BROWN DWARF 2MASS J04414489+2301513

International Nuclear Information System (INIS)

Adame, Lucia; Calvet, Nuria; McClure, M. K.; Hartmann, Lee; Luhman, K. L.; D'Alessio, Paola; Furlan, Elise; Forrest, William J.; Watson, Dan M.

2011-01-01

Using the Spitzer Infrared Spectrograph, we have performed mid-infrared spectroscopy on the young binary brown dwarf 2MASS J04414489+2301513 (15 AU) in the Taurus star-forming region. The spectrum exhibits excess continuum emission that likely arises from a circumstellar disk around the primary. Silicate emission is not detected in these data, indicating the presence of significant grain growth. This is one of the few brown dwarf disks at such a young age (∼1 Myr) that has been found to lack silicate emission. To quantitatively constrain the properties of the disk, we have compared the spectral energy distribution of 2MASS J04414489+2301513 to the predictions of our vertical structure codes for irradiated accretion disks. Our models suggest that the remaining atmospheric grains of moderately depleted layers may have grown to a size of ∼>5 μm. In addition, our model fits indicate an outer radius of 0.2-0.3 AU for the disk. The small size of this circumprimary disk could be due to truncation by the secondary. The absence of an outer disk containing a reservoir of small, primordial grains, combined with a weak turbulent mechanism, may be responsible for the advanced grain growth in this disk.

FAR-INFRARED EXTINCTION MAPPING OF INFRARED DARK CLOUDS

Energy Technology Data Exchange (ETDEWEB)

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

2014-01-10

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

FAR-INFRARED EXTINCTION MAPPING OF INFRARED DARK CLOUDS

International Nuclear Information System (INIS)

Lim, Wanggi; Tan, Jonathan C.

2014-01-01

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

THE SPITZER -HETDEX EXPLORATORY LARGE-AREA SURVEY

Energy Technology Data Exchange (ETDEWEB)

Papovich, C.; Shipley, H. V.; Mehrtens, N.; Lanham, C.; DePoy, D. L.; Kawinwanichakij, L. [Department of Physics and Astronomy, Texas A and M University, College Station, TX, 77843-4242 (United States); Lacy, M. [North American ALMA Science Center, NRAO Headquarters, Charlottesville, VA 22903 (United States); Ciardullo, R.; Gronwall, C. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Finkelstein, S. L.; Drory, N.; Gebhardt, K.; Hill, G. J.; Jogee, S. [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Bassett, R. [International Centre for Radio Astronomy Research, University of Western Australia, 7 Fairway, Crawley, WA 6009 (Australia); Behroozi, P. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Blanc, G. A. [Departamento de Astronomía, Universidad de Chile, Camino del Observatorio 1515, Las Condes, Santiago (Chile); Jong, R. S. de [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Gawiser, E. [Department of Physics and Astronomy, Rutgers, The State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Hopp, U., E-mail: papovich@physics.tamu.edu, E-mail: papovich@tamu.edu [Max-Planck-Institut für Extraterrestrische Physik, D-85741, Garching (Germany); and others

2016-06-01

We present post-cryogenic Spitzer imaging at 3.6 and 4.5 μ m with the Infrared Array Camera (IRAC) of the Spitzer /HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers ≈24 deg{sup 2} of the Sloan Digital Sky Survey “Stripe 82” region, and falls within the footprints of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) and the Dark Energy Survey. The HETDEX blind R ∼ 800 spectroscopy will produce ∼200,000 redshifts from the Ly α emission for galaxies in the range 1.9 <  z  < 3.5, and an additional ∼200,000 redshifts from the [O ii] emission for galaxies at z  < 0.5. When combined with deep ugriz images from the Dark Energy Camera, K -band images from NEWFIRM, and other ancillary data, the IRAC photometry from Spitzer will enable a broad range of scientific studies of the relationship between structure formation, galaxy stellar mass, halo mass, the presence of active galactic nuclei, and environment over a co-moving volume of ∼0.5 Gpc{sup 3} at 1.9 <  z  < 3.5. Here, we discuss the properties of the SHELA IRAC data set, including the data acquisition, reduction, validation, and source catalogs. Our tests show that the images and catalogs are 80% (50%) complete to limiting magnitudes of 22.0 (22.6) AB mag in the detection image, which is constructed from the weighted sum of the IRAC 3.6 and 4.5 μ m images. The catalogs reach limiting sensitivities of 1.1  μ Jy at both 3.6 and 4.5 μ m (1 σ , for R = 2″ circular apertures). As a demonstration of the science, we present IRAC number counts, examples of highly temporally variable sources, and galaxy surface density profiles of rich galaxy clusters. In the spirit of the Spitzer Exploratory programs, we provide all of the images and catalogs as part of the publication.

THE SPITZER -HETDEX EXPLORATORY LARGE-AREA SURVEY

International Nuclear Information System (INIS)

Papovich, C.; Shipley, H. V.; Mehrtens, N.; Lanham, C.; DePoy, D. L.; Kawinwanichakij, L.; Lacy, M.; Ciardullo, R.; Gronwall, C.; Finkelstein, S. L.; Drory, N.; Gebhardt, K.; Hill, G. J.; Jogee, S.; Bassett, R.; Behroozi, P.; Blanc, G. A.; Jong, R. S. de; Gawiser, E.; Hopp, U.

2016-01-01

We present post-cryogenic Spitzer imaging at 3.6 and 4.5 μ m with the Infrared Array Camera (IRAC) of the Spitzer /HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers ≈24 deg 2 of the Sloan Digital Sky Survey “Stripe 82” region, and falls within the footprints of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) and the Dark Energy Survey. The HETDEX blind R ∼ 800 spectroscopy will produce ∼200,000 redshifts from the Ly α emission for galaxies in the range 1.9 <  z  < 3.5, and an additional ∼200,000 redshifts from the [O ii] emission for galaxies at z  < 0.5. When combined with deep ugriz images from the Dark Energy Camera, K -band images from NEWFIRM, and other ancillary data, the IRAC photometry from Spitzer will enable a broad range of scientific studies of the relationship between structure formation, galaxy stellar mass, halo mass, the presence of active galactic nuclei, and environment over a co-moving volume of ∼0.5 Gpc 3 at 1.9 <  z  < 3.5. Here, we discuss the properties of the SHELA IRAC data set, including the data acquisition, reduction, validation, and source catalogs. Our tests show that the images and catalogs are 80% (50%) complete to limiting magnitudes of 22.0 (22.6) AB mag in the detection image, which is constructed from the weighted sum of the IRAC 3.6 and 4.5 μ m images. The catalogs reach limiting sensitivities of 1.1  μ Jy at both 3.6 and 4.5 μ m (1 σ , for R = 2″ circular apertures). As a demonstration of the science, we present IRAC number counts, examples of highly temporally variable sources, and galaxy surface density profiles of rich galaxy clusters. In the spirit of the Spitzer Exploratory programs, we provide all of the images and catalogs as part of the publication.

Control of Refining Processes on Mid-Distillates by Near Infrared Spectroscopy

Directory of Open Access Journals (Sweden)

Zanier-Szydlowski N.

1999-07-01

Full Text Available The purpose of this paper is to demonstrate the accuracy of physicochemical determinations based on equations calculated by multivariate analysis of near infrared spectra which gives access to simultaneous analyses both on-line and off-line. Detailed results concerning the determination of the refractive index at 20°C, the density, the weight% of hydrogen, the % of aromatic carbon, the weight% of mono-, di- and total aromatics and the cetane number on mid-distillates are given in a shorter time than using the conventional approach by standardized methods. It is shown that near infrared spectroscopy combined with chemometrics should allow detailed and precise comparisons of the hydrotreatment process efficiencies.

The AKARI FU-HYU galaxy evolution program: first results from the GOODS-N field

Science.gov (United States)

Pearson, C. P.; Serjeant, S.; Negrello, M.; Takagi, T.; Jeong, W.-S.; Matsuhara, H.; Wada, T.; Oyabu, S.; Lee, H. M.; Im, M. S.

2010-05-01

The AKARI FU-HYU mission program carried out mid-infrared imaging of several well studied Spitzer fields preferentially selecting fields already rich in multi-wavelength data from radio to X-ray wavelengths filling in the wavelength desert between the Spitzer IRAC and MIPS bands. We present the initial results for the FU-HYU survey in the GOODS-N field. We utilize the supreme multiwavelength coverage in the GOODS-N field to produce a multiwavelength catalogue from infrared to ultraviolet wavelengths, containing more than 4393 sources, including photometric redshifts. Using the FU-HYU catalogue we present colour-colour diagrams that map the passage of PAH features through our observation bands. We find that the longer mid-infrared bands from AKARI (IRC-L18W 18 micron band) and Spitzer (MIPS24 24 micron band) provide an accurate measure of the total MIR emission of the sources and therefore their probable total mid-infrared luminosity. We also find that colours incorporating the AKARI IRC-S11 11 micron band produce a bimodal distribution where an excess at 11 microns preferentially selects moderate redshift star-forming galaxies. These powerful colour-colour diagnostics are further used as tools to extract anomalous colour populations, in particular a population of Silicate Break galaxies from the GOODS-N field showing that dusty starbursts can be selected of specific redshift ranges (z = 1.2-1.6) by mid-infrared drop-out techniques. The FU-HYU catalogue will be made publically available to the astronomical community.

Confronting Standard Models of Proto-planetary Disks with New Mid-infrared Sizes from the Keck Interferometer

OpenAIRE

Millan-Gabet, Rafael; Che, Xiao; Monnier, John D.; Sitko, Michael L.; Russell, Ray W.; Grady, Carol A.; Day, Amanda N.; Perry, R. B.; Harries, Tim J.; Aarnio, Alicia N.; Colavita, Mark M.; Wizinowich, Peter L.; Ragland, Sam; Woillez, Julien

2016-01-01

We present near- and mid-infrared (MIR) interferometric observations made with the Keck Interferometer Nuller and near-contemporaneous spectro-photometry from the infrared telescope facilities (IRTFs) of 11 well-known young stellar objects, several of which were observed for the first time in these spectral and spatial resolution regimes. With au-level spatial resolution, we first establish characteristic sizes of the infrared emission using a simple geometrical model consisting of a hot inne...

Generation of 70-fs pulses at 286 μm from a mid-infrared fiber laser

Science.gov (United States)

Woodward, R. I.; Hudson, D. D.; Fuerbach, A.; Jackson, S. D.

2017-12-01

We propose and demonstrate a simple route to few-optical-cycle pulse generation from a mid-infrared fiber laser through nonlinear compression of pulses from a holmium-doped fiber oscillator using a short length of chalcogenide fiber and a grating pair. Pulses from the oscillator with 265-fs duration at 2.86 {\\mu}m are spectrally broadened through self-phase modulation in step-index As2S3 fiber to 141-nm bandwidth and then re-compressed to 70 fs (7.3 optical cycles). These are the shortest pulses from a mid-infrared fiber system to date, and we note that our system is compact, robust, and uses only commercially available components. The scalability of this approach is also discussed, supported by numerical modeling.

Two-crystal mid-infrared optical parametric oscillator for absorption and dispersion dual-comb spectroscopy.

Science.gov (United States)

Jin, Yuwei; Cristescu, Simona M; Harren, Frans J M; Mandon, Julien

2014-06-01

We present a femtosecond optical parametric oscillator (OPO) containing two magnesium-doped periodically poled lithium niobate crystals in a singly resonant ring cavity, pumped by two mode-locked Yb-fiber lasers. As such, the OPO generates two idler combs (up to 220 mW), covering a wavelength range from 2.7 to 4.2 μm, from which a mid-infrared dual-comb Fourier transform spectrometer is constructed. By detecting the heterodyning signal between the two idler beams a full broadband spectrum of a molecular gas can be observed over 250  cm(-1) within 70 μs with a spectral resolution of 15 GHz. The absorption and dispersion spectra of acetylene and methane have been measured around 3000  cm(-1), indicating that this OPO represents an ideal broadband mid-infrared source for fast chemical sensing.

When zoo became nature. Copenhagen zoo and perceptions of animals and nature around 1900. I: Tidsskrift for Kulturforskning (NORSK)

DEFF Research Database (Denmark)

Gjerløff, Anne Katrine

2010-01-01

This article points out central historical themes in the debates and arguments given by the directors of Copenhagen Zoo for the zoo as an alternative to nature. When Copenhagen Zoo was founded in 1859, itsn purpose was divided equally between entertainment, enlightenment and symbolizing the glory...... of the Danish capital. During this period though, it also became possible for the Zoo to stage itself as a kinder place for animals, than "real" nature. In the early 20th century, the Zoo attracted attention from animal rights movements, wherefore the debates came to be structured around two radically different...

AN ORDERED MAGNETIC FIELD IN THE PROTOPLANETARY DISK OF AB Aur REVEALED BY MID-INFRARED POLARIMETRY

Energy Technology Data Exchange (ETDEWEB)

Li, Dan; Pantin, Eric; Telesco, Charles M.; Zhang, Han; Barnes, Peter J.; Mariñas, Naibí [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, FL 32611 (United States); Wright, Christopher M. [School of Physical, Environmental, and Mathematical Sciences, University of New South Wales, Canberra, ACT 2610 (Australia); Packham, Chris, E-mail: d.li@ufl.edu [Physics and Astronomy Department, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249 (United States)

2016-11-20

Magnetic fields ( B -fields) play a key role in the formation and evolution of protoplanetary disks, but their properties are poorly understood due to the lack of observational constraints. Using CanariCam at the 10.4 m Gran Telescopio Canarias, we have mapped out the mid-infrared polarization of the protoplanetary disk around the Herbig Ae star AB Aur. We detect ∼0.44% polarization at 10.3 μ m from AB Aur's inner disk ( r  < 80 au), rising to ∼1.4% at larger radii. Our simulations imply that the mid-infrared polarization of the inner disk arises from dichroic emission of elongated particles aligned in a disk B -field. The field is well ordered on a spatial scale, commensurate with our resolution (∼50 au), and we infer a poloidal shape tilted from the rotational axis of the disk. The disk of AB Aur is optically thick at 10.3 μ m, so polarimetry at this wavelength is probing the B -field near the disk surface. Our observations therefore confirm that this layer, favored by some theoretical studies for developing magneto-rotational instability and its resultant viscosity, is indeed very likely to be magnetized. At radii beyond ∼80 au, the mid-infrared polarization results primarily from scattering by dust grains with sizes up to ∼1 μ m, a size indicating both grain growth and, probably, turbulent lofting of the particles from the disk mid-plane.

Simultaneous generation of tunable giant dispersive waves in the visible and mid-infrared regions based on photonic crystal fibers

International Nuclear Information System (INIS)

Zhang, Lei; Yang, Si-Gang; Chen, Hong-Wei; Chen, Ming-Hua; Xie, Shi-Zhong; Han, Ying

2013-01-01

Cherenkov radiation (CR) in both the visible and mid-infrared regions is simultaneously generated experimentally based on a photonic crystal fiber with two zero-dispersion wavelengths. The generation of CR in the visible region originates from solitons located in the anomalous group velocity dispersion (GVD) regime which are perturbed by positive third order dispersion. Conversely, the generation of CR in the mid-infrared region requires that the solitons in the anomalous GVD regime are perturbed by negative third order dispersion. The peak wavelength of the CR in the visible region can be tuned from 498 to 425 nm by increasing the average input pump power from 70 to 400 mW, while the peak wavelength of the CR in the mid-infrared region can be tuned from 1986 to 2279 nm by increasing the average input pump power from 70 to 320 mW. (paper)

Asteroid (16) Psyche: Evidence for a silicate regolith from spitzer space telescope spectroscopy

Science.gov (United States)

Landsman, Zoe A.; Emery, Joshua P.; Campins, Humberto; Hanuš, Josef; Lim, Lucy F.; Cruikshank, Dale P.

2018-04-01

Asteroid (16) Psyche is a unique, metal-rich object belonging to the "M" taxonomic class. It may be a remnant protoplanet that has been stripped of most silicates by a hit-and-run collision. Because Psyche offers insight into the planetary formation process, it is the target of NASA's Psyche mission, set to launch in 2023. In order to constrain Psyche's surface properties, we have carried out a mid-infrared (5-14 μm) spectroscopic study using data collected with the Spitzer Space Telescope's Infrared Spectrograph. Our study includes two observations covering different rotational phases. Using thermophysical modeling, we find that Psyche's surface is smooth and likely has a thermal inertia Γ = 5-25 J/m2/K/s1/2 and bolometric emissivity ɛ = 0.9, although a scenario with ɛ = 0.7 and thermal inertia up to 95 J/m2/K/s1/2 is possible if Psyche is somewhat larger than previously determined. The smooth surface is consistent with the presence of a metallic bedrock, which would be more ductile than silicate bedrock, and thus may not readily form boulders upon impact events. From comparisons with laboratory spectra of silicate and meteorite powders, Psyche's 7-14 μm emissivity spectrum is consistent with the presence of fine-grained (Psyche's surface. We conclude that Psyche is likely covered in a fine silicate regolith, which may also contain iron grains, overlying an iron-rich bedrock.

A SPITZER CENSUS OF STAR FORMATION ACTIVITY IN THE PIPE NEBULA

International Nuclear Information System (INIS)

Forbrich, Jan; Lada, Charles J.; Muench, August A.; Alves, Joao; Lombardi, Marco

2009-01-01

The Pipe Nebula, a large nearby molecular cloud, lacks obvious signposts of star formation in all but one of more than 130 dust extinction cores that have been identified within it. In order to quantitatively determine the current level of star formation activity in the Pipe Nebula, we analyzed 13 deg 2 of sensitive mid-infrared maps of the entire cloud, obtained with the Multiband Imaging Photometer for Spitzer at wavelengths of 24 μm and 70 μm, to search for candidate young stellar objects (YSOs) in the high-extinction regions. We argue that our search is complete for class I and typical class II YSOs with luminosities of L bol ∼ 0.2 L sun and greater. We find only 18 candidate YSOs in the high-extinction regions of the entire Pipe cloud. Twelve of these sources are previously known members of a small cluster associated with Barnard 59, the largest and most massive dense core in the cloud. With only six candidate class I and class II YSOs detected toward extinction cores outside of this cluster, our findings emphatically confirm the notion of an extremely low level of star formation activity in the Pipe Nebula. The resulting star formation efficiency for the entire cloud mass is only ∼0.06%.

The contribution of zoos and aquaria to Aichi Biodiversity Target 12: A case study of Canadian zoos

Directory of Open Access Journals (Sweden)

Andrea Olive

2017-04-01

Full Text Available The purpose of Aichi Biodiversity Target 12 is to prevent extinction of known threaten species, and improve the decline of the world’s most imperiled species. Governments and NGOs around the world are actively working toward this goal. This article examines the role of zoos and aquaria in the conservation of species at risk through an in-depth examination of four accredited Canadian zoos and aquaria. Through site visits, interviews with staff, and research into the programs at each institution, this paper demonstrates that captive breeding, reintroductions, and headstarting projects are each a large component of conservation efforts. Interviews with zoo staff reveal strong consensus that zoo offer two critical components for species at risk conservation: space and expertise. Overall, this article calls for greater attention to the types of conservation actives occurring and the ways in which zoos are working together to protect and recover global biodiversity.

V819 TAU: A RARE WEAK-LINED T TAURI STAR WITH A WEAK INFRARED EXCESS

International Nuclear Information System (INIS)

Furlan, E.; Forrest, W. J.; Manoj, P.; Kim, K. H.; Watson, Dan M.; Sargent, B. A.

2009-01-01

We use Spitzer data to infer that the small infrared excess of V819 Tau, a weak-lined T Tauri star in Taurus, is real and not attributable to a 'companion' 10'' to the south. We do not confirm the mid-infrared excess in HBC 427 and V410 X-ray 3, which are also non-accreting T Tauri stars in the same region; instead, for the former object, the excess arises from a red companion 9'' to the east. A single-temperature blackbody fit to the continuum excess of V819 Tau implies a dust temperature of 143 K; however, a better fit is achieved when the weak 10 and 20 μm silicate emission features are also included. We infer a disk of sub-μm silicate grains between about 1 AU and several 100 AU with a constant surface density distribution. The mid-infrared excess of V819 Tau can be successfully modeled with dust composed mostly of small amorphous olivine grains at a temperature of 85 K, and most of the excess emission is optically thin. The disk could still be primordial, but gas-poor and therefore short-lived, or already at the debris disk stage, which would make it one of the youngest debris disk systems known.

The particle zoo

CERN Document Server

AUTHOR|(CDS)2079223

2016-01-01

What is everything really made of? If we split matter down into smaller and infinitesimally smaller pieces, where do we arrive? At the Particle Zoo - the extraordinary subatomic world of antimatter, neutrinos, strange-flavoured quarks and yetis, gravitons, ghosts and glueballs, mindboggling eleven-dimensional strings and the elusive Higgs boson itself. Be guided around this strangest of zoos by Gavin Hesketh, experimental particle physicist at humanity's greatest experiment, the Large Hadron Collider. Concisely and with a rare clarity, he demystifies how we are uncovering the inner workings of the universe and heading towards the next scientific revolution. Why are atoms so small? How did the Higgs boson save the universe? And is there a theory of everything? The Particle Zoo answers these and many other profound questions, and explains the big ideas of Quantum Physics, String Theory, The Big Bang and Dark Matter...and, ultimately, what we know about the true, fundamental nature of reality.

Towards strong light-matter coupling at the single-resonator level with sub-wavelength mid-infrared nano-antennas

Energy Technology Data Exchange (ETDEWEB)

Malerba, M.; De Angelis, F., E-mail: francesco.deangelis@iit.it [Istituto Italiano di Tecnologia, Via Morego, 30, I-16163 Genova (Italy); Ongarello, T.; Paulillo, B.; Manceau, J.-M.; Beaudoin, G.; Sagnes, I.; Colombelli, R., E-mail: raffaele.colombelli@u-psud.fr [Centre for Nanoscience and Nanotechnology (C2N Orsay), CNRS UMR9001, Univ. Paris Sud, Univ. Paris Saclay, 91405 Orsay (France)

2016-07-11

We report a crucial step towards single-object cavity electrodynamics in the mid-infrared spectral range using resonators that borrow functionalities from antennas. Room-temperature strong light-matter coupling is demonstrated in the mid-infrared between an intersubband transition and an extremely reduced number of sub-wavelength resonators. By exploiting 3D plasmonic nano-antennas featuring an out-of-plane geometry, we observed strong light-matter coupling in a very low number of resonators: only 16, more than 100 times better than what reported to date in this spectral range. The modal volume addressed by each nano-antenna is sub-wavelength-sized and it encompasses only ≈4400 electrons.

The Fourier-Kelvin Stellar Interferometer (FKSI): Infrared Detection and Characterization of Exozodiacal Dust to Super-Earths, A Progress Report

Science.gov (United States)

Danchi, W.

2010-01-01

The Fourier-Kelvin Stellar Interferometer (FKSI) is a structurally connected infrared space interferometer with 0.5 m diameter telescopes on a 12.5 m baseline, and is passively cooled to approx.60K. The FKSI operates in the thermal infrared from 3-8 microns in a nulling (or starlight suppressing) mode for the detection and characterization of exoplanets, debris disks, extrasolar zodiacal dust levels. The FKSI will have the highest angular resolution of any infrared space instrument ever made with its nominal resolution of 40 mas at a 5 micron center wavelength. This resolution exceeds that of Spitzer by a factor of 38 and JWST by a factor of 5. The FKSI mission is conceived as a "probe class" or "mid-sized" strategic mission that utilizes technology advances from flagship projects like JWST, SIM, Spitzer, and the technology programs of TPF-I/Darwin. During the past year we began investigating an enhanced version of FKSI with 1-2 m diameter telescopes, passively cooled to 40K, on a 20-m baseline, with a sunshade giving a +/- 45 degree Field-of-Regard. This enhanced design is capable of detecting and characterizing the atmospheres of many 2 Earth-radius super-Earths and a few Earth-twins. We will report progress on the design of the enhanced mission concept and current status of the technologies needed for this mission.

Extraordinary mid-infrared transmission of subwavelength holes in gold films

KAUST Repository

Yue, Weisheng

2014-04-01

Gold (Au) nanoholes are fabricated with electron-beam lithography and used for the investigation of extraordinary transmission in mid-infrared regime. Transmission properties of the nanoholes are studied as the dependence on hole-size. Transmittance spectra are characterized by Fourier transform infrared spectroscopy (FTIR) and enhanced transmittance through the subwavelength holes is observed. The transmission spectra exhibit well-defined maximum and minimum of which the position are determined by the lattice of the hole array. The hole-size primarily influence the transmission intensity and bandwidth of the resonance peak. With an increase of hole-size, while keep lattice constant fixed, the intensity of the resonance peak and the bandwidth increases, which are due to the localized surface plasmons. Numerical simulation for the transmission through the subwavelength holes is performed and the simulated results agree with the experimental observations. Copyright © 2014 American Scientific Publishers.

Extraordinary mid-infrared transmission of subwavelength holes in gold films

KAUST Repository

Yue, Weisheng; Wang, Zhihong; Yang, Yang; Chen, Longqing; Syed, Ahad A.; Wang, Xianbin

2014-01-01

Gold (Au) nanoholes are fabricated with electron-beam lithography and used for the investigation of extraordinary transmission in mid-infrared regime. Transmission properties of the nanoholes are studied as the dependence on hole-size. Transmittance spectra are characterized by Fourier transform infrared spectroscopy (FTIR) and enhanced transmittance through the subwavelength holes is observed. The transmission spectra exhibit well-defined maximum and minimum of which the position are determined by the lattice of the hole array. The hole-size primarily influence the transmission intensity and bandwidth of the resonance peak. With an increase of hole-size, while keep lattice constant fixed, the intensity of the resonance peak and the bandwidth increases, which are due to the localized surface plasmons. Numerical simulation for the transmission through the subwavelength holes is performed and the simulated results agree with the experimental observations. Copyright © 2014 American Scientific Publishers.

Dayside atmospheric structure of HD209458b from Spitzer eclipses

Science.gov (United States)

Reinhard, Matthew; Harrington, Joseph; Challener, Ryan; Cubillos, Patricio; Blecic, Jasmina

2017-10-01

HD209458b is a hot Jupiter with a radius of 1.26 ± 0.08 Jupiter radii (Richardson et al, 2006) and a mass of 0.64 ± 0.09 Jupiter masses (Snellen et al, 2010). The planet orbits a G0 type star with an orbital period of 3.52472 ± 2.81699e-05 days, and a relatively low eccentricity of 0.0082 +0.0078/-0.0082 (Wang and Ford 2013). We report the analysis of observations of HD209458b during eclipse, taken in the 3.6 and 4.5 micron channels by the Spitzer Space Telescope's Infrared Array Camera (Program 90186). We produce a photometric light curve of the eclipses in both channels, using our Photometry for Orbits Eclipses and Transits (POET) code, and calculate the brightness temperatures and eclipse depths. We also present best estimates of the atmospheric parameters of HD209458b using our Bayesian Atmospheric Radiative Transfer (BART) code. These are some preliminary results of what will be an analysis of all available Spitzer data for HD209458b. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

Near-infrared to Mid-infrared Observations of Galaxy Mergers: NGC 2782 and NGC 7727

Science.gov (United States)

Onaka, Takashi; Nakamura, Tomohiko; Sakon, Itsuki; Wu, Ronin; Ohsawa, Ryou; Kaneda, Hidehiro; Lebouteiller, Vianney; Roellig, Thomas L.

2018-01-01

We present the results of near-infrared-to-mid-infrared (NIR-to-MIR) imaging and NIR spectroscopic observations of two galaxy mergers, NGC 2782 (Arp 215) and NGC 7727 (Arp 222), with the Infrared Camera on board AKARI. NGC 2782 shows extended MIR emission in the eastern side of the galaxy, which corresponds to the eastern tidal tail seen in the H I 21 cm map, while NGC 7727 shows extended MIR emission in the north of the galaxy, which is similar to the plumes seen in the residual image at the K-band after subtracting a galaxy model. Both extended structures are thought to have formed in association with their merger events. They show excess emission at 7–15 μm, which can be attributed to emission from polycyclic aromatic hydrocarbons (PAHs), while the observed spectral energy distributions (SEDs) decline longward of 24 μm, suggesting that very small grains (VSGs) are deficient. These characteristics of the observed MIR SED may be explained if PAHs are formed by fragmentation of VSGs during merger events. The star formation rate is estimated from the MIR PAH emission in the eastern tail region of NGC 2782 and it is in fair agreement with those estimated from Hα and [C II] 158 μm. MIR observations are efficient for the study of dust processing and structures formed during merger events.

Mid-Infrared Sensing of Organic Pollutants in Aqueous Environments

Directory of Open Access Journals (Sweden)

Andrew Ross

2009-08-01

Full Text Available The development of chemical sensors for monitoring the levels of organic pollutants in the aquatic environment has received a great deal of attention in recent decades. In particular, the mid-infrared (MIR sensor based on attenuated total reflectance (ATR is a promising analytical tool that has been used to detect a variety of hydrocarbon compounds (i.e., aromatics, alkyl halides, phenols, etc. dissolved in water. It has been shown that under certain conditions the MIR-ATR sensor is capable of achieving detection limits in the 10-100 ppb concentration range. Since the infrared spectral features of every single organic molecule are unique, the sensor is highly selective, making it possible to distinguish between many different analytes simultaneously. This review paper discusses some of the parameters (i.e., membrane type, film thickness, conditioning that dictate MIR ATR sensor response. The performance of various chemoselective membranes which are used in the fabrication of the sensor will be evaluated. Some of the challenges associated with long-term environmental monitoring are also discussed.

Mid-Infrared Sensing of Organic Pollutants in Aqueous Environments

Science.gov (United States)

Pejcic, Bobby; Myers, Matthew; Ross, Andrew

2009-01-01

The development of chemical sensors for monitoring the levels of organic pollutants in the aquatic environment has received a great deal of attention in recent decades. In particular, the mid-infrared (MIR) sensor based on attenuated total reflectance (ATR) is a promising analytical tool that has been used to detect a variety of hydrocarbon compounds (i.e., aromatics, alkyl halides, phenols, etc.) dissolved in water. It has been shown that under certain conditions the MIR-ATR sensor is capable of achieving detection limits in the 10–100 ppb concentration range. Since the infrared spectral features of every single organic molecule are unique, the sensor is highly selective, making it possible to distinguish between many different analytes simultaneously. This review paper discusses some of the parameters (i.e., membrane type, film thickness, conditioning) that dictate MIR-ATR sensor response. The performance of various chemoselective membranes which are used in the fabrication of the sensor will be evaluated. Some of the challenges associated with long-term environmental monitoring are also discussed. PMID:22454582

Mid-Infrared Interferometry on Spectral Lines. II. Continuum (Dust) Emission Around IRC +10216 and VY Canis Majoris

Science.gov (United States)

Monnier, J. D.; Danchi, W. C.; Hale, D. S.; Lipman, E. A.; Tuthill, P. G.; Townes, C. H.

2000-11-01

The University of California Berkeley Infrared Spatial Interferometer has measured the mid-infrared visibilities of the carbon star IRC +10216 and the red supergiant VY CMa. The dust shells around these sources have been previously shown to be time variable, and these new data are used to probe the evolution of the dust shells on a decade timescale, complementing contemporaneous studies at other wavelengths. Self-consistent, spherically symmetric models at maximum and minimum light both show the inner radius of the IRC +10216 dust shell to be much larger (150 mas) than expected from the dust-condensation temperature, implying that dust production has slowed or stopped in recent years. Apparently, dust does not form every pulsational cycle (638 days), and these mid-infrared results are consistent with recent near-infrared imaging, which indicates little or no new dust production in the last 3 yr. Spherically symmetric models failed to fit recent VY CMa data, implying that emission from the inner dust shell is highly asymmetric and/or time variable.

Evaluating children's conservation biology learning at the zoo.

Science.gov (United States)

Jensen, Eric

2014-08-01

Millions of children visit zoos every year with parents or schools to encounter wildlife firsthand. Public conservation education is a requirement for membership in professional zoo associations. However, in recent years zoos have been criticized for failing to educate the public on conservation issues and related biological concepts, such as animal adaptation to habitats. I used matched pre- and postvisit mixed methods questionnaires to investigate the educational value of zoo visits for children aged 7-15 years. The questionnaires gathered qualitative data from these individuals, including zoo-related thoughts and an annotated drawing of a habitat. A content analysis of these qualitative data produced the quantitative data reported in this article. I evaluated the relative learning outcomes of educator-guided and unguided zoo visits at London Zoo, both in terms of learning about conservation biology (measured by annotated drawings) and changing attitudes toward wildlife conservation (measured using thought-listing data). Forty-one percent of educator-guided visits and 34% of unguided visits resulted in conservation biology-related learning. Negative changes in children's understanding of animals and their habitats were more prevalent in unguided zoo visits. Overall, my results show the potential educational value of visiting zoos for children. However, they also suggest that zoos' standard unguided interpretive materials are insufficient for achieving the best outcomes for visiting children. These results support a theoretical model of conservation biology learning that frames conservation educators as toolmakers who develop conceptual resources to enhance children's understanding of science. © 2014 Society for Conservation Biology.

Blood-feeding ecology of mosquitoes in zoos.

Science.gov (United States)

Tuten, H C; Bridges, W C; Paul, K S; Adler, P H

2012-12-01

To determine if the unique host assemblages in zoos influence blood-feeding by mosquitoes (Diptera: Culicidae), a sampling programme was conducted in Greenville and Riverbanks Zoos, South Carolina, U.S.A., from April 2009 to October 2010. A total of 4355 female mosquitoes of 14 species were collected, of which 106 individuals of nine species were blood-fed. The most common taxa were Aedes albopictus (Skuse), Aedes triseriatus (Say), Anopheles punctipennis (Say), Culex erraticus (Dyar & Knab), Culex pipiens complex (L.) and Culex restuans (Theobald). Molecular analyses (cytochrome b) of bloodmeals revealed that mosquitoes fed on captive animals, humans and wildlife, and took mixed bloodmeals. Host species included one amphibian, 16 birds, 10 mammals (including humans) and two reptiles. Minimum dispersal distances after feeding on captive hosts ranged from 15.5 m to 327.0 m. Mosquito-host associations generally conformed to previous accounts, indicating that mosquito behaviour inside zoos reflects that outside zoos. However, novel variation in host use, including new, exotic host records, warrants further investigation. Zoos, thus, can be used as experiment environments in which to study mosquito behaviour, and the findings extrapolated to non-zoo areas, while providing medical and veterinary benefits to zoo animals, employees and patrons. © 2012 The Authors. Medical and Veterinary Entomology © 2012 The Royal Entomological Society.

Visitor interest in zoo animals and the implications for collection planning and zoo education programmes.

Science.gov (United States)

Moss, Andrew; Esson, Maggie

2010-01-01

As zoos have sought to further their conservation missions, they have become powerful providers of environmental education. Outside of "formal" education initiatives, such as those designed for school and other organized groups, or structured public talks programmes, much of the learning potential that the zoo has to offer is around the viewing of animals and the response of visitors to them. In this, zoo learning is a very personal construct, develops from the previous knowledge, and experiences and motivations of each individual. In this article, we make the assertion that learning potential, although difficult to quantify, is very much related to the attractiveness of animal species and the interest that visitors show in them. Using standard behaviorist measures of attraction and interest (the proportion of visitors that stop and for how long), we analyzed the relative interest in 40 zoo species held in a modern UK zoo and the variables that are significant in predicting that popularity. Further to this, the suggestion is made that the zoo collection planning process could use such information to make more informed decisions about which species should be housed for their educational value. Taxonomic grouping was found to be the most significant predictor of visitor interest--that is, visitors were far more interested in mammals than any other group--although body size (length), increasing animal activity and whether the species was the primary or "flagship" species in an exhibit or not, were all found to have a significant bearing on visitor interest. © 2010 Wiley-Liss, Inc.

Supercontinuum - broad as a lamp, bright as a laser, now in the mid-infrared

DEFF Research Database (Denmark)

Moselund, Peter M.; Petersen, Christian; Dupont, Sune

2012-01-01

Based on the experience gained developing our market leading visible spectrum supercontinuum sources NKT Photonics has built the first mid-infrared supercontinuum source based on modelocked picosecond fiber lasers. The source is pumped by a ≈ 2 um laser based on a combination of erbium and thuliu...

Authentication of Whey Protein Powders by Portable Mid-Infrared Spectrometers Combined with Pattern Recognition Analysis.

Science.gov (United States)

Wang, Ting; Tan, Siow Ying; Mutilangi, William; Aykas, Didem P; Rodriguez-Saona, Luis E

2015-10-01

The objective of this study was to develop a simple and rapid method to differentiate whey protein types (WPC, WPI, and WPH) used for beverage manufacturing by combining the spectral signature collected from portable mid-infrared spectrometers and pattern recognition analysis. Whey protein powders from different suppliers are produced using a large number of processing and compositional variables, resulting in variation in composition, concentration, protein structure, and thus functionality. Whey protein powders including whey protein isolates, whey protein concentrates and whey protein hydrolysates were obtained from different suppliers and their spectra collected using portable mid-infrared spectrometers (single and triple reflection) by pressing the powder onto an Attenuated Total Reflectance (ATR) diamond crystal with a pressure clamp. Spectra were analyzed by soft independent modeling of class analogy (SIMCA) generating a classification model showing the ability to differentiate whey protein types by forming tight clusters with interclass distance values of >3, considered to be significantly different from each other. The major bands centered at 1640 and 1580 cm(-1) were responsible for separation and were associated with differences in amide I and amide II vibrations of proteins, respectively. Another important band in whey protein clustering was associated with carboxylate vibrations of acidic amino acids (∼1570 cm(-1)). The use of a portable mid-IR spectrometer combined with pattern recognition analysis showed potential for discriminating whey protein ingredients that can help to streamline the analytical procedure so that it is more applicable for field-based screening of ingredients. A rapid, simple and accurate method was developed to authenticate commercial whey protein products by using portable mid-infrared spectrometers combined with chemometrics, which could help ensure the functionality of whey protein ingredients in food applications. © 2015

SPATIAL VARIATIONS OF PAH PROPERTIES IN M17SW REVEALED BY SPITZER /IRS SPECTRAL MAPPING

Energy Technology Data Exchange (ETDEWEB)

Yamagishi, M. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Chuo-ku, Sagamihara 252-5210 (Japan); Kaneda, H.; Ishihara, D.; Oyabu, S.; Suzuki, T.; Nishimura, A.; Kohno, M. [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Onaka, T.; Ohashi, S. [Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Nagayama, T.; Matsuo, M. [Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065 (Japan); Umemoto, T.; Minamidani, T.; Fujita, S. [Nobeyama Radio Observatory, National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS), 462-2, Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Tsuda, Y., E-mail: yamagish@ir.isas.jaxa.jp [Graduate School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo 191-0042 (Japan)

2016-12-20

We present Spitzer /IRS mid-infrared spectral maps of the Galactic star-forming region M17 as well as IRSF/SIRIUS Br γ and Nobeyama 45 m/FOREST {sup 13}CO ( J = 1–0) maps. The spectra show prominent features due to polycyclic aromatic hydrocarbons (PAHs) at wavelengths of 6.2, 7.7, 8.6, 11.3, 12.0, 12.7, 13.5, and 14.2  μ m. We find that the PAH emission features are bright in the region between the H ii region traced by Br γ and the molecular cloud traced by {sup 13}CO, supporting that the PAH emission originates mostly from photo-dissociation regions. Based on the spatially resolved Spitzer /IRS maps, we examine spatial variations of the PAH properties in detail. As a result, we find that the interband ratio of PAH 7.7  μ m/PAH 11.3  μ m varies locally near M17SW, but rather independently of the distance from the OB stars in M17, suggesting that the degree of PAH ionization is mainly controlled by local conditions rather than the global UV environments determined by the OB stars in M17. We also find that the interband ratios of the PAH 12.0  μ m, 12.7  μ m, 13.5  μ m, and 14.2  μ m features to the PAH 11.3  μ m feature are high near the M17 center, which suggests structural changes of PAHs through processing due to intense UV radiation, producing abundant edgy irregular PAHs near the M17 center.

ZOO: la piattaforma WPS libera

Directory of Open Access Journals (Sweden)

Luca Delluchi

2010-03-01

ZOO libraries, and the API, Javascript based libraries for creating and managing WPS services. While an exhaustive description of ZOO is beyond the scope of this paper, we do hope to stimulate discussion bout possibilities and challenges of webbased analysis of geospatial data.

Mid-infrared, long wave infrared (4-12 μm) molecular emission signatures from pharmaceuticals using laser-induced breakdown spectroscopy (LIBS).

Science.gov (United States)

Yang, Clayton S-C; Brown, Ei E; Kumi-Barimah, Eric; Hommerich, Uwe H; Jin, Feng; Trivedi, Sudhir B; Samuels, Alan C; Snyder, A Peter

2014-01-01

In an effort to augment the atomic emission spectra of conventional laser-induced breakdown spectroscopy (LIBS) and to provide an increase in selectivity, mid-wave to long-wave infrared (IR), LIBS studies were performed on several organic pharmaceuticals. Laser-induced breakdown spectroscopy signature molecular emissions of target organic compounds are observed for the first time in the IR fingerprint spectral region between 4-12 μm. The IR emission spectra of select organic pharmaceuticals closely correlate with their respective standard Fourier transform infrared spectra. Intact and/or fragment sample molecular species evidently survive the LIBS event. The combination of atomic emission signatures derived from conventional ultraviolet-visible-near-infrared LIBS with fingerprints of intact molecular entities determined from IR LIBS promises to be a powerful tool for chemical detection.

Chemical abundances and dust in planetary nebulae in the Galactic bulge

NARCIS (Netherlands)

Gutenkunst, S.; Bernard-Salas, J.; Pottasch, S. R.; Sloan, G. C.; Houck, J. R.

2008-01-01

We present mid-infrared Spitzer spectra of 11 planetary nebulae in the Galactic bulge. We derive argon, neon, sulfur, and oxygen abundances for them using mainly infrared line fluxes combined with some optical line fluxes from the literature. Due to the high extinction toward the bulge, the infrared

Protoplanetary disks around intermediate-mass stars: the asset of imaging in the mid-infrared

International Nuclear Information System (INIS)

Doucet, Coralie

2006-01-01

The accrued efficiency of the instruments in many wavelengths has allowed to show that most young stellar objects were surrounded by circumstellar matter distributed in a disk. Direct imaging of such systems is very difficult because of their narrow angular size and their weak luminosity in comparison with the star. Nowadays, 50 % of low-mass pre-main sequence stars, i.e. T Tauri stars, are surrounded by a disk. This proportion is less obvious for intermediate-mass stars, like Herbig Ae stars, that are less numerous and whose direct disk detection is more difficult. Until now, only the interpretation of the Spectral Energy Distribution (SED) of such objects allows to have access to the geometry of the disk. But the solutions are degenerated and several parameters fit the same SED. It is essential to have direct images of the objects, the only evidence of the presence of disks. This PhD allows to show that mid-infrared imaging could rise a part of the degeneracy of the disk's parameters linked to the fit of the SED for several objects and gives constraints on the minimum external radius and inclination of the disk. We present a new observation mode with VISIR, the mid-infrared imager and spectrometer on the VLT (ESO, Chile): the so-called BURST mode. This mode allows to reach the diffraction limit of the telescope. Thanks to mid-infrared imaging with this instrument, we were able, for the first time, to have access to the geometry of a disk (flared structure) around a massive star that was, until now, only deduced from the SED modelling. (author) [fr

Multi-octave supercontinuum generation from mid-infrared filamentation in a bulk crystal

Directory of Open Access Journals (Sweden)

Faccio D.

2013-03-01

Full Text Available We present supercontinuum generation pumped by femtosecond mid-infrared pulses in a bulk homogeneous material. The spectrum extends from 450 nm into the midinfrared, and carries high spectral energy density (3 pJ/nm–10 nJ/nm. The supercontinuum has high shot-to-shot reproducibility and preserves the carrier-to-envelope phase. Our result paves the way for compact supercontinuum sources with unprecedented bandwidth.

LIFTING THE DUSTY VEIL WITH NEAR- AND MID-INFRARED PHOTOMETRY. I. DESCRIPTION AND APPLICATIONS OF THE RAYLEIGH-JEANS COLOR EXCESS METHOD

International Nuclear Information System (INIS)

Majewski, Steven R.; Zasowski, Gail; Nidever, David L.

2011-01-01

The Milky Way (MW) remains a primary laboratory for understanding the structure and evolution of spiral galaxies, but typically we are denied clear views of MW stellar populations at low Galactic latitudes because of extinction by interstellar dust. However, the combination of Two Micron All-Sky Survey (2MASS) near-infrared (NIR) and Spitzer-IRAC mid-infrared (MIR) photometry enables a powerful method for determining the line-of-sight reddening to any star: the sampled wavelengths lie in the Rayleigh-Jeans part of the spectral energy distribution of most stars, where, to first order, all stars have essentially the same intrinsic color. Thus, changes in stellar NIR-MIR colors due to interstellar reddening are readily apparent, and (under an assumed extinction law) the observed colors and magnitudes of stars can be easily and accurately restored to their intrinsic values, greatly increasing their usefulness for Galactic structure studies. In this paper, we explore this 'Rayleigh-Jeans Color Excess' (RJCE) method and demonstrate that use of even a simple variant of the RJCE method based on a single reference color, (H -[4.5μ]), can rather accurately remove dust effects from previously uninterpretable 2MASS color-magnitude diagrams of stars in fields along the heavily reddened Galactic midplane, with results far superior to those derived from application of other dereddening methods. We also show that 'total' Galactic midplane extinction looks rather different from that predicted using 100μ emission maps from the IRAS/ISSA and COBE/DIRBE instruments as presented by Schlegel et al. Instead, the Galactic midplane extinction strongly resembles the distribution of 13 CO (J = 1→0) emission. Future papers will focus on refining the RJCE method and applying the technique to understand better not only dust and its distribution but also the distribution of stars intermixed with the dust in the low-latitude Galaxy.

Jupiter's Mid-Infrared Aurora: Solar Connection and Minor Constituents

Science.gov (United States)

Kostiuk, Theodore; Livengood, T.A.; Fast, K.E.; Hewagama, T.; Schmilling, F.; Sonnabend, G.; Delgado, J.

2009-01-01

High spectral resolution in the 12 pin region of the polar regions of Jupiter reveal unique information on auroral phenomena and upper stratospheric composition. Polar aurorae in Jupiter's atmosphere radiate; throughout the electromagnetic spectrum from X-ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based. spectroscopic measurements of Jupiter's northern mid-IR aurora acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane, emission brightness and solar 10.7-cm radar flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high scalar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. The spectra measured contain features that cannot be attributed to ethane and are most likely spectra of minor constituents whose molecular bands overlap the v9 band of ethane. Possible candidates are allene, propane, and other higher order hydrocarbons. These features appear to be enhanced in the active polar regions. Laboratory measurements at comparable spectral resolution of spectra of candidate molecules will be used to identify the constituents. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the NASA/ESA Europa Jupiter System Mission.

Effect of preservatives on the accuracy of mid-infrared milk component testing.

Science.gov (United States)

Barbano, D M; Wojciechowski, K L; Lynch, J M

2010-12-01

Our objective was to determine the effect of commonly used milk preservatives on the accuracy of fat, protein, and lactose content determination in milk by mid-infrared (mid-IR) milk analysis. Two producer raw milks (Holstein and Jersey) and 2 pasteurized modified milks, 1 similar to Holstein milk and 1 similar to Jersey milk were used as the 4 different milk sources. Seven different milk preservative approaches (K(2)Cr(2)O(7) and 6 different bronopol-based preservatives) and a portion of unpreserved milk for each of the 4 different milks sources were tested for fat B, lactose, protein, and fat A. The experiment was replicated 3 times (28 d each) for a total of 84 d. Two mid-infrared (mid-IR) transmittance milk analyzers (an optical and a virtual filter instrument) were used. A large batch of pilot milk was prepared from pasteurized, homogenized, unpreserved whole milk, split into vials, quick frozen by immersion in liquid nitrogen, and transferred into a -80 °C freezer. Pilots were thawed and analyzed on each testing day during the study. Significant increases were observed in all uncorrected readings on the pilot milks over the 84 d of the study, but the increases were gradual and small on each instrument for all components. Results from the study were corrected for these changes. A significant difference in mid-IR fat A readings was observed, whereas no differences were detected for fat B, lactose, or protein between unpreserved and preserved milks containing 0.02% K(2)Cr(2)O(7.) Therefore, K(2)Cr(2)O(7) has little or no effect on mid-IR test results. All bronopol-based preservative approaches in this study differed in mid-IR test results compared with K(2)Cr(2)O(7)-preserved and unpreserved milks, with the largest effect on protein results. Mid-IR uncorrected readings increased with time of refrigerated storage at 4°C for all preservative approaches, with the largest increase for protein. The rate of increase in uncorrected readings with time of storage was

Ultrafast Silicon Photonics with Visible to Mid-Infrared Pumping of Silicon Nanocrystals.

Science.gov (United States)

Diroll, Benjamin T; Schramke, Katelyn S; Guo, Peijun; Kortshagen, Uwe R; Schaller, Richard D

2017-10-11

Dynamic optical control of infrared (IR) transparency and refractive index is achieved using boron-doped silicon nanocrystals excited with mid-IR optical pulses. Unlike previous silicon-based optical switches, large changes in transmittance are achieved without a fabricated structure by exploiting strong light coupling of the localized surface plasmon resonance (LSPR) produced from free holes of p-type silicon nanocrystals. The choice of optical excitation wavelength allows for selectivity between hole heating and carrier generation through intraband or interband photoexcitation, respectively. Mid-IR optical pumping heats the free holes of p-Si nanocrystals to effective temperatures greater than 3500 K. Increases of the hole effective mass at high effective hole temperatures lead to a subpicosecond change of the dielectric function, resulting in a redshift of the LSPR, modulating mid-IR transmission by as much as 27%, and increasing the index of refraction by more than 0.1 in the mid-IR. Low hole heat capacity dictates subpicosecond hole cooling, substantially faster than carrier recombination, and negligible heating of the Si lattice, permitting mid-IR optical switching at terahertz repetition frequencies. Further, the energetic distribution of holes at high effective temperatures partially reverses the Burstein-Moss effect, permitting the modulation of transmittance at telecommunications wavelengths. The results presented here show that doped silicon, particularly in micro- or nanostructures, is a promising dynamic metamaterial for ultrafast IR photonics.

Wireless Mid-Infrared Spectroscopy Sensor Network for Automatic Carbon Dioxide Fertilization in a Greenhouse Environment

Directory of Open Access Journals (Sweden)

Jianing Wang

2016-11-01

Full Text Available In this paper, a wireless mid-infrared spectroscopy sensor network was designed and implemented for carbon dioxide fertilization in a greenhouse environment. A mid-infrared carbon dioxide (CO2 sensor based on non-dispersive infrared (NDIR with the functionalities of wireless communication and anti-condensation prevention was realized as the sensor node. Smart transmission power regulation was applied in the wireless sensor network, according to the Received Signal Strength Indication (RSSI, to realize high communication stability and low-power consumption deployment. Besides real-time monitoring, this system also provides a CO2 control facility for manual and automatic control through a LabVIEW platform. According to simulations and field tests, the implemented sensor node has a satisfying anti-condensation ability and reliable measurement performance on CO2 concentrations ranging from 30 ppm to 5000 ppm. As an application, based on the Fuzzy proportional, integral, and derivative (PID algorithm realized on a LabVIEW platform, the CO2 concentration was regulated to some desired concentrations, such as 800 ppm and 1200 ppm, in 30 min with a controlled fluctuation of <±35 ppm in an acre of greenhouse.

Analysis of energy transfer process based emission spectra of erbium doped germanate glasses for mid-infrared laser materials

International Nuclear Information System (INIS)

Cai, Muzhi; Wei, Tao; Zhou, Beier; Tian, Ying; Zhou, Jiajia; Xu, Shiqing; Zhang, Junjie

2015-01-01

Highlights: • Er 3+ doped germanate glass with good thermal stability were prepared. • Ionic boding nature was proved by bonding parameter calculation. • Mid-infrared fluorescent behaviors and energy transfer were investigated. • Rate equation and Dexter’s theory were utilized to elucidate 2.7 μm emission. - Abstract: Er 3+ activated germanate glass with good thermal stability was prepared. Bonding parameters have been calculated and the nature of ionic bonding of the germanate glass has been determined. Mid-infrared fluorescence was observed and corresponding radiative properties were investigated. For Er 3+ : 4 I 11/2 → 4 I 13/2 transition, high spontaneous radiative transition probability (30.09 s −1 ), large emission cross section ((14.84 ± 0.10) × 10 −21 cm 2 ) and superior gain performance were obtained from the prepared glass. Besides, energy transfer processes concerning the 2.7 μm emission were also discussed in detail. According to simplified rate equation and Dexter’s theory, energy transfer microscopic parameters were computed to elucidate observed 2.7 μm emissions. Results demonstrate that the prepared germanate glass possessing excellent spectroscopic properties might be an attractive candidate for mid-infrared laser or amplifier

SPITZER PARALLAX OF OGLE-2015-BLG-0966: A COLD NEPTUNE IN THE GALACTIC DISK

Energy Technology Data Exchange (ETDEWEB)

Street, R. A.; Bachelet, E. [LCOGT, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Novati, S. Calchi [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Hundertmark, M. P. G.; Jørgensen, U. G. [Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Øster Voldgade 5, DK-1350—Copenhagen K (Denmark); Zhu, W.; Gould, A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Yee, J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tsapras, Y. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg (ZAH), D-69120 Heidelberg (Germany); Bennett, D. P. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Dominik, M. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Andersen, M. I. [Niels Bohr Institute and Dark Cosmology Centre, University of Copenhagen, Juliane Mariesvej 30, DK-2100—Copenhagen Ø (Denmark); Bozza, V. [Dipartimento di Fisica “E.R. Caianiello,” Università di Salerno, Via Giovanni Paolo II 132, I-84084, Fisciano (Italy); Bramich, D. M. [Qatar Environment and Energy Research Institute, Qatar Foundation, P.O. Box 5825, Doha (Qatar); Collaboration: RoboNet Project and MiNDSTEp Consortium; OGLE Project; Spitzer Team; MOA Collaboration; KMTNet Modeling Team; and others

2016-03-10

We report the detection of a cold Neptune m{sub planet} = 21 ± 2 M{sub ⊕} orbiting a 0.38 M{sub ⊙} M dwarf lying 2.5–3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations to measure the Galactic distribution of planets. This is the first time that the complex real-time protocols described by Yee et al., which aim to maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey and follow up teams successfully combined their efforts within the framework of these protocols to detect this planet. This is the second planet in the Spitzer Galactic distribution sample. Both are in the near to mid-disk and are clearly not in the Galactic bulge.

Evaluation of detectable angle of mid-infrared slot antennas

Science.gov (United States)

Obara, R.; Horikawa, J.; Shimakage, H.; Kawakami, A.

2017-07-01

For evaluations of a mid-infrared (MIR) detectors with antenna, we constructed an angular dependence measurement system of the antenna properties. The fabricated MIR detector consisted of twin slot antennas and a bolometer. The area of the slot antennas was designed to be 2.6 × 0.2 μm2 as to resonate at 61 THz, and they were located parallel and separated 1.6 μm each other. The bolometer was fabricated using by a 7.0-nm thick NbN thin film, and located at the center of the twin antennas. We measured polarization angle dependence and directivity, and showed that the MIR antennas have polarization dependence and directivity like radiofrequency antennas.

SPITZER OBSERVATIONS OF COMET 67P/CHURYUMOV-GERASIMENKO AT 5.5-4.3 AU FROM THE SUN

International Nuclear Information System (INIS)

Kelley, Michael S.; Wooden, Diane H.; Tubiana, Cecilia; Boehnhardt, Hermann; Woodward, Charles E.; Harker, David E.

2009-01-01

We report Spitzer Space Telescope observations of comet 67P/Churyumov-Gerasimenko at 5.5 and 4.3 AU from the Sun, post-aphelion. Comet 67P is the primary target of the European Space Agency's Rosetta mission. The Rosetta spacecraft will rendezvous with the nucleus at heliocentric distances similar to our observations. Rotationally resolved observations at 8 and 24 μm (at a heliocentric distance, r h , of 4.8 AU) that sample the size and color-temperature of the nucleus are combined with aphelion R-band light curves observed at the Very Large Telescope (VLT) and yield a mean effective radius of 2.04 ± 0.11 km, and an R-band geometric albedo of 0.054 ± 0.006. The amplitudes of the R-band and mid-infrared light curves agree, which suggests that the variability is dominated by the shape of the nucleus. We also detect the dust trail of the comet at 4.8 and 5.5 AU, constrain the grain sizes to be ∼ h = 4 AU in 2014.

AKARI/IRC source catalogues and source counts for the IRAC Dark Field, ELAIS North and the AKARI Deep Field South

Science.gov (United States)

Davidge, H.; Serjeant, S.; Pearson, C.; Matsuhara, H.; Wada, T.; Dryer, B.; Barrufet, L.

2017-12-01

We present the first detailed analysis of three extragalactic fields (IRAC Dark Field, ELAIS-N1, ADF-S) observed by the infrared satellite, AKARI, using an optimized data analysis toolkit specifically for the processing of extragalactic point sources. The InfaRed Camera (IRC) on AKARI complements the Spitzer Space Telescope via its comprehensive coverage between 8-24 μm filling the gap between the Spitzer/IRAC and MIPS instruments. Source counts in the AKARI bands at 3.2, 4.1, 7, 11, 15 and 18 μm are presented. At near-infrared wavelengths, our source counts are consistent with counts made in other AKARI fields and in general with Spitzer/IRAC (except at 3.2 μm where our counts lie above). In the mid-infrared (11 - 18 μm), we find our counts are consistent with both previous surveys by AKARI and the Spitzer peak-up imaging survey with the InfraRed Spectrograph (IRS). Using our counts to constrain contemporary evolutionary models, we find that although the models and counts are in agreement at mid-infrared wavelengths there are inconsistencies at wavelengths shortward of 7 μm, suggesting either a problem with stellar subtraction or indicating the need for refinement of the stellar population models. We have also investigated the AKARI/IRC filters, and find an active galactic nucleus selection criteria out to z < 2 on the basis of AKARI 4.1, 11, 15 and 18 μm colours.

High spatial resolution observations of the T Tau system - II. Interferometry in the mid-infrared

International Nuclear Information System (INIS)

Ratzka, Thorsten

2008-01-01

Each time the resolution was improved, observations of the young low-mass star T Tau led to new insights. Initially classified as the prototype of low-mass pre-main-sequence stars, measurements with high resolution techniques in the near-infrared revealed the existence of a deeply embedded companion only 0.7 arcsec to the south. Later on, this companion itself has been resolved into two sources with a separation of only about 50 mas. We investigated both the optically bright northern component and the embedded southern binary with the MID-infrared Interferometric instrument (MIDI). The resulting visibilities of the northern component decrease with wavelength, independent of the baseline's position angle. This is a clear sign of the large face-on circumstellar disc. With a simultaneous fit of a radiative transfer model to both the interferometric results and the spectral energy distribution, the properties of this disc can be determined without the high degeneracy of fits to the spectral energy distribution alone. Since the visibilities of the southern binary are clearly dominated by the typical sinusoidal binary signal, we could for the first time in the mid-infrared derive separate spectra for both components together with a very precise relative position. This position is in excellent agreement with the orbit found from a fit to the near-infrared adaptive optics measurements. The orbit with its small periastron distance indicates tidally truncated discs, which are consistent with the interferometric measurements. The peculiar properties of the infrared companion can be explained by the model of an intermediate mass star extincted by an almost edge-on disc.

Mid-infrared volume diffraction gratings in IG2 chalcogenide glass: fabrication, characterization, and theoretical verification

Science.gov (United States)

Butcher, Helen L.; MacLachlan, David G.; Lee, David; Brownsword, Richard A.; Thomson, Robert R.; Weidmann, Damien

2018-02-01

Ultrafast laser inscription (ULI) has previously been employed to fabricate volume diffraction gratings in chalcogenide glasses, which operate in transmission mode in the mid-infrared spectral region. Prior gratings were manufactured for applications in astrophotonics, at wavelengths around 2.5 μm. Rugged volume gratings also have potential use in remote atmospheric sensing and molecular spectroscopy; for these applications, longer wavelength operation is required to coincide with atmospheric transparency windows (3-5 μm) and intense ro-vibrational molecular absorption bands. We report on ULI gratings inscribed in IG2 chalcogenide glass, enabling access to the full 3-5 μm window. High-resolution broadband spectral characterization of fabricated gratings was performed using a Fourier transform spectrometer. The zeroth order transmission was characterized to derive the diffraction efficiency into higher orders, up to the fourth orders in the case of gratings optimized for first order diffraction at 3 μm. The outcomes imply that ULI in IG2 is well suited for the fabrication of volume gratings in the mid infrared, providing the impact of the ULI fabrication parameters on the grating properties are well understood. To develop this understanding, grating modeling was conducted. Parameters studied include grating thickness, refractive index modification, and aspect ratio of the modulation achieved by ULI. Knowledge of the contribution and sensitivity of these parameters was used to inform the design of a 4.3 μm grating expected to achieve > 95% first order efficiency. We will also present the characterization of these latest mid-infrared diffraction gratings in IG2.

Welcome to the Twilight Zone: The Mid-infrared Properties of Post-starburst Galaxies

Science.gov (United States)

Alatalo, Katherine; Bitsakis, Theodoros; Lanz, Lauranne; Lacy, Mark; Brown, Michael J. I.; French, K. Decker; Ciesla, Laure; Appleton, Philip N.; Beaton, Rachael L.; Cales, Sabrina L.; Crossett, Jacob; Falcón-Barroso, Jesús; Kelson, Daniel D.; Kewley, Lisa J.; Kriek, Mariska; Medling, Anne M.; Mulchaey, John S.; Nyland, Kristina; Rich, Jeffrey A.; Urry, C. Meg

2017-07-01

We investigate the optical and Wide-field Survey Explorer (WISE) colors of “E+A” identified post-starburst galaxies, including a deep analysis of 190 post-starbursts detected in the 2 μm All Sky Survey Extended Source Catalog. The post-starburst galaxies appear in both the optical green valley and the WISE Infrared Transition Zone. Furthermore, we find that post-starbursts occupy a distinct region of [3.4]-[4.6] versus [4.6]-[12] WISE colors, enabling the identification of this class of transitioning galaxies through the use of broadband photometric criteria alone. We have investigated possible causes for the WISE colors of post-starbursts by constructing a composite spectral energy distribution (SED), finding that the mid-infrared (4-12 μm) properties of post-starbursts are consistent with either 11.3 μm polycyclic aromatic hydrocarbon emission, or thermally pulsating asymptotic giant branch (TP-AGB) and post-AGB stars. The composite SED of extended post-starburst galaxies with 22 μm emission detected with signal-to-noise ratio ≥slant 3 requires a hot dust component to produce their observed rising mid-infrared SED between 12 and 22 μm. The composite SED of WISE 22 μm non-detections (S/N systems. This could mean that including selections capable of identifying AGNs as part of a search for transitioning and post-starburst galaxies would create a more complete census of the transition pathways taken as a galaxy quenches its star formation.

Subwavelength engineered fiber-to-chip silicon-on-sapphire interconnects for mid-infrared applications (Conference Presentation)

Science.gov (United States)

Alonso-Ramos, Carlos; Han, Zhaohong; Le Roux, Xavier; Lin, Hongtao; Singh, Vivek; Lin, Pao Tai; Tan, Dawn; Cassan, Eric; Marris-Morini, Delphine; Vivien, Laurent; Wada, Kazumi; Hu, Juejun; Agarwal, Anuradha; Kimerling, Lionel C.

2016-05-01

The mid-Infrared wavelength range (2-20 µm), so-called fingerprint region, contains the very sharp vibrational and rotational resonances of many chemical and biological substances. Thereby, on-chip absorption-spectrometry-based sensors operating in the mid-Infrared (mid-IR) have the potential to perform high-precision, label-free, real-time detection of multiple target molecules within a single sensor, which makes them an ideal technology for the implementation of lab-on-a-chip devices. Benefiting from the great development realized in the telecom field, silicon photonics is poised to deliver ultra-compact efficient and cost-effective devices fabricated at mass scale. In addition, Si is transparent up to 8 µm wavelength, making it an ideal material for the implementation of high-performance mid-IR photonic circuits. The silicon-on-insulator (SOI) technology, typically used in telecom applications, relies on silicon dioxide as bottom insulator. Unfortunately, silicon dioxide absorbs light beyond 3.6 µm, limiting the usability range of the SOI platform for the mid-IR. Silicon-on-sapphire (SOS) has been proposed as an alternative solution that extends the operability region up to 6 µm (sapphire absorption), while providing a high-index contrast. In this context, surface grating couplers have been proved as an efficient means of injecting and extracting light from mid-IR SOS circuits that obviate the need of cleaving sapphire. However, grating couplers typically have a reduced bandwidth, compared with facet coupling solutions such as inverse or sub-wavelength tapers. This feature limits their feasibility for absorption spectroscopy applications that may require monitoring wide wavelength ranges. Interestingly, sub-wavelength engineering can be used to substantially improve grating coupler bandwidth, as demonstrated in devices operating at telecom wavelengths. Here, we report on the development of fiber-to-chip interconnects to ZrF4 optical fibers and integrated SOS

The UK Infrared Telescope M33 monitoring project - I. Variable red giant stars in the central square kiloparsec

Science.gov (United States)

Javadi, Atefeh; van Loon, Jacco Th.; Mirtorabi, Mohammad Taghi

2011-02-01

We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The most extensive data set was obtained in the K band with the UIST instrument for the central 4 × 4 arcmin2 (1 kpc2) - this contains the nuclear star cluster and inner disc. These data, taken during the period 2003-2007, were complemented by J- and H-band images. Photometry was obtained for 18 398 stars in this region; of these, 812 stars were found to be variable, most of which are asymptotic giant branch (AGB) stars. Our data were matched to optical catalogues of variable stars and carbon stars and to mid-infrared photometry from the Spitzer Space Telescope. In this first of a series of papers, we present the methodology of the variability survey and the photometric catalogue - which is made publicly available at the Centre de Données astronomiques de Strasbourg - and discuss the properties of the variable stars. The most dusty AGB stars had not been previously identified in optical variability surveys, and our survey is also more complete for these types of stars than the Spitzer survey.

Application of mid-infrared tuneable diode laser absorption spectroscopy to plasma diagnostics: a review

International Nuclear Information System (INIS)

Roepcke, J; Lombardi, G; Rousseau, A; Davies, P B

2006-01-01

Within the last decade mid-infrared absorption spectroscopy over a region from 3 to 17μm and based on tuneable lead salt diode lasers, often called tuneable diode laser absorption spectroscopy or TDLAS, has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry in molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has led to further applications of TDLAS because most of these compounds and their decomposition products are infrared active. TDLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetic phenomena. Information about gas temperature and population densities can also be derived from TDLAS measurements. A variety of free radicals and molecular ions have been detected by TDLAS. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of quantum cascade lasers (QCLs) offers an attractive new option for the monitoring and control of industrial plasma processes. The aim of the present paper is threefold: (i) to review recent achievements in our understanding of molecular phenomena in plasmas (ii) to report on selected studies of the spectroscopic properties and kinetic behaviour of radicals and (iii) to describe the current status of advanced instrumentation for TDLAS in the mid-infrared

Mid-infrared GaSb-based resonant tunneling diode photodetectors for gas sensing applications

Science.gov (United States)

Rothmayr, F.; Pfenning, A.; Kistner, C.; Koeth, J.; Knebl, G.; Schade, A.; Krueger, S.; Worschech, L.; Hartmann, F.; Höfling, S.

2018-04-01

We present resonant tunneling diode-photodetectors (RTD-PDs) with GaAs0.15Sb0.85/AlAs0.1Sb0.9 double barrier structures combined with an additional quaternary Ga0.64In0.36As0.33Sb0.67 absorption layer covering the fingerprint absorption lines of various gases in the mid-infrared wavelength spectral region. The absorption layer cut-off wavelength is determined to be 3.5 μm, and the RTD-PDs show peak-to-valley current ratios up to 4.3 with a peak current density of 12 A/cm-2. The incorporation of the quaternary absorption layer enables the RTD-PDs to be sensitive to illumination with light up to the absorption lines of HCl at 3395 nm. At this wavelength, the detector shows a responsivity of 6.3 mA/W. At the absorption lines of CO2 and CO at 2004 nm and 2330 nm, respectively, the RTD-PDs reach responsivities up to 0.97 A/W. Thus, RTD-PDs pave the way towards high sensitive mid-infrared detectors that can be utilized in tunable laser absorption spectroscopy.

Research on propane leak detection system and device based on mid infrared laser

Science.gov (United States)

Jiang, Meng; Wang, Xuefeng; Wang, Junlong; Wang, Yizhao; Li, Pan; Feng, Qiaoling

2017-10-01

Propane is a key component of liquefied petroleum gas (LPG) and crude oil volatile. This issue summarizes the recent progress of propane detection technology. Meanwhile, base on the development trend, our latest progress is also provided. We demonstrated a mid infrared propane sensor system, which is based on wavelength modulation spectroscopy (WMS) technique with a CW interband cascade laser (ICL) emitting at 3370.4nm. The ICL laser scanned over a sharp feature in the broader spectrum of propane, and harmonic signals are obtained by lock-in amplifier for gas concentration deduction. The surrounding gas is extracted into the fine optical absorption cell through the pump to realize online detection. The absorption cell is designed in mid infrared windows range. An example experimental setup is shown. The second harmonic signals 2f and first harmonic signals1f are obtained. We present the sensor performance test data including dynamic precision and temperature stability. The propane detection sensor system and device is portable can carried on the mobile inspection vehicle platforms or intelligent robot inspection platform to realize the leakage monitoring of whole oil gas tank area.

Characterization methods of integrated optics for mid-infrared interferometry

Science.gov (United States)

Labadie, Lucas; Kern, Pierre Y.; Schanen-Duport, Isabelle; Broquin, Jean-Emmanuel

2004-10-01

his article deals with one of the important instrumentation challenges of the stellar interferometry mission IRSI-Darwin of the European Space Agency: the necessity to have a reliable and performant system for beam combination has enlightened the advantages of an integrated optics solution, which is already in use for ground-base interferometry in the near infrared. Integrated optics provides also interesting features in terms of filtering, which is a main issue for the deep null to be reached by Darwin. However, Darwin will operate in the mid infrared range from 4 microns to 20 microns where no integrated optics functions are available on-the-shelf. This requires extending the integrated optics concept and the undergoing technology in this spectral range. This work has started with the IODA project (Integrated Optics for Darwin) under ESA contract and aims to provide a first component for interferometry. In this paper are presented the guidelines of the characterization work that is implemented to test and validate the performances of a component at each step of the development phase. We present also an example of characterization experiment used within the frame of this work, is theoretical approach and some results.

Mid Infrared Instrument cooler subsystem test facility overview

Science.gov (United States)

Moore, B.; Zan, J.; Hannah, B.; Chui, T.; Penanen, K.; Weilert, M.

2017-12-01

The Cryocooler for the Mid Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) provides cooling at 6.2K on the instrument interface. The cooler system design has been incrementally documented in previous publications [1][2][3][4][5]. It has components that traverse three primary thermal regions on JWST: Region 1, approximated by 40K; Region 2, approximated by 100K; and Region 3, which is at the allowable flight temperatures for the spacecraft bus. However, there are several sub-regions that exist in the transition between primary regions and at the heat reject interfaces of the Cooler Compressor Assembly (CCA) and Cooler Control Electronics Assembly (CCEA). The design and performance of the test facility to provide a flight representative thermal environment for acceptance testing and characterization of the complete MIRI cooler subsystem are presented.

Emergent Exoplanet Flux: Review of the Spitzer Results

OpenAIRE

Deming, Drake

2008-01-01

Observations using the Spitzer Space Telescope provided the first detections of photons from extrasolar planets. Spitzer observations are allowing us to infer the temperature structure, composition, and dynamics of exoplanet atmospheres. The Spitzer studies extend from many hot Jupiters, to the hot Neptune orbiting GJ436. Here I review the current status of Spitzer secondary eclipse observations, and summarize the results from the viewpoint of what is robust, what needs more work, and what th...

2 W high efficiency PbS mid-infrared surface emitting laser

Science.gov (United States)

Ishida, A.; Sugiyama, Y.; Isaji, Y.; Kodama, K.; Takano, Y.; Sakata, H.; Rahim, M.; Khiar, A.; Fill, M.; Felder, F.; Zogg, H.

2011-09-01

High efficiency laser operation with output power exceeding 2 W was obtained for vertical external-cavity PbS based IV-VI compound surface emitting quantum-well structures. The laser showed external quantum efficiency as high as 16%. Generally, mid-infrared III-V or II-VI semiconductor laser operation utilizing interband electron transitions are restricted by Auger recombination and free carrier absorption. Auger recombination is much lower in the IV-VI semiconductors, and the free-carrier absorption is significantly reduced by an optically pumped laser structure including multi-step optical excitation layers.

SPITZER IRS SPECTRA OF LUMINOUS 8 μm SOURCES IN THE LARGE MAGELLANIC CLOUD: TESTING COLOR-BASED CLASSIFICATIONS

International Nuclear Information System (INIS)

Buchanan, Catherine L.; Kastner, Joel H.; Hrivnak, Bruce J.; Sahai, Raghvendra

2009-01-01

We present archival Spitzer Infrared Spectrograph (IRS) spectra of 19 luminous 8 μm selected sources in the Large Magellanic Cloud (LMC). The object classes derived from these spectra and from an additional 24 spectra in the literature are compared with classifications based on Two Micron All Sky Survey (2MASS)/MSX (J, H, K, and 8 μm) colors in order to test the 'JHK8' (Kastner et al.) classification scheme. The IRS spectra confirm the classifications of 22 of the 31 sources that can be classified under the JHK8 system. The spectroscopic classification of 12 objects that were unclassifiable in the JHK8 scheme allow us to characterize regions of the color-color diagrams that previously lacked spectroscopic verification, enabling refinements to the JHK8 classification system. The results of these new classifications are consistent with previous results concerning the identification of the most infrared-luminous objects in the LMC. In particular, while the IRS spectra reveal several new examples of asymptotic giant branch (AGB) stars with O-rich envelopes, such objects are still far outnumbered by carbon stars (C-rich AGB stars). We show that Spitzer IRAC/MIPS color-color diagrams provide improved discrimination between red supergiants and oxygen-rich and carbon-rich AGB stars relative to those based on 2MASS/MSX colors. These diagrams will enable the most luminous IR sources in Local Group galaxies to be classified with high confidence based on their Spitzer colors. Such characterizations of stellar populations will continue to be possible during Spitzer's warm mission through the use of IRAC [3.6]-[4.5] and 2MASS colors.

Mid-infrared spectroscopy for characterization of Baltic amber (succinite)

Science.gov (United States)

Wagner-Wysiecka, Ewa

2018-05-01

Natural Baltic amber (succinite) is the most appreciated fossil resin of the rich cultural traditions dating back to prehistoric times. Its unequivocal identification is extremely important in many branches of science and trades including archeology, paleontology, chemistry and finally mineralogical and gemological societies. Current methods of modification of natural succinite are more and more sophisticated making the identification of natural Baltic amber often challenging. In article the systematic analytical approach for identification of natural and modified under different conditions succinite, using mid-infrared spectroscopy (transmission, Drifts and ATR techniques) is presented. The correlation between spectral characteristics and properties of succinite is discussed pointing that the understanding of the nature of changes is the key of identification of this precious material.

Physical Properties of Asteroid (10302) 1989 ML, a Potential Spacecraft Target, from Spitzer Observations

Science.gov (United States)

Mueller, Michael; Harris, A. W.

2006-09-01

We report on results from recent Spitzer observations of near-Earth asteroid (10302) 1989 ML, which is among the lowest-ranking objects in terms of the specific momentum Δv required to reach it from Earth. It was originally considered as a target for Hayabusa and is now under consideration as a target of the planned ESA mission Don Quijote. Unfortunately, little is known about the physical properties of 1989 ML, in particular its size and albedo are unknown. Its exhibits an X type reflection spectrum, so depending on its albedo, 1989 ML may be an E, M, or P type asteroid. Provisional results from thermal-infrared observations carried out with Spitzer indicate that the albedo of 1989 ML is compatible with an M- or E-type classification. We will discuss our results and their implications for the physical properties and the rotation period of 1989 ML, and its importance as a potential spacecraft target. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

Analysis of energy transfer process based emission spectra of erbium doped germanate glasses for mid-infrared laser materials

Energy Technology Data Exchange (ETDEWEB)

Cai, Muzhi; Wei, Tao; Zhou, Beier; Tian, Ying; Zhou, Jiajia; Xu, Shiqing, E-mail: shiqingxu@cjlu.edu.cn; Zhang, Junjie, E-mail: jjzhang@cjlu.edu.cn

2015-03-25

Highlights: • Er{sup 3+} doped germanate glass with good thermal stability were prepared. • Ionic boding nature was proved by bonding parameter calculation. • Mid-infrared fluorescent behaviors and energy transfer were investigated. • Rate equation and Dexter’s theory were utilized to elucidate 2.7 μm emission. - Abstract: Er{sup 3+} activated germanate glass with good thermal stability was prepared. Bonding parameters have been calculated and the nature of ionic bonding of the germanate glass has been determined. Mid-infrared fluorescence was observed and corresponding radiative properties were investigated. For Er{sup 3+}:{sup 4}I{sub 11/2}→{sup 4}I{sub 13/2} transition, high spontaneous radiative transition probability (30.09 s{sup −1}), large emission cross section ((14.84 ± 0.10) × 10{sup −21} cm{sup 2}) and superior gain performance were obtained from the prepared glass. Besides, energy transfer processes concerning the 2.7 μm emission were also discussed in detail. According to simplified rate equation and Dexter’s theory, energy transfer microscopic parameters were computed to elucidate observed 2.7 μm emissions. Results demonstrate that the prepared germanate glass possessing excellent spectroscopic properties might be an attractive candidate for mid-infrared laser or amplifier.

Prospective for graphene based thermal mid-infrared light emitting devices

Science.gov (United States)

Lawton, L. M.; Mahlmeister, N. H.; Luxmoore, I. J.; Nash, G. R.

2014-08-01

We have investigated the spatial and spectral characteristics of mid-infrared thermal emission from large area Chemical Vapor Deposition (CVD) graphene, transferred onto SiO2/Si, and show that the emission is broadly that of a grey-body emitter, with emissivity values of approximately 2% and 6% for mono- and multilayer graphene. For the currents used, which could be sustained for over one hundred hours, the emission peaked at a wavelength of around 4 μm and covered the characteristic absorption of many important gases. A measurable modulation of thermal emission was obtained even when the drive current was modulated at frequencies up to 100 kHz.

Prospective for graphene based thermal mid-infrared light emitting devices

Directory of Open Access Journals (Sweden)

L. M. Lawton

2014-08-01

Full Text Available We have investigated the spatial and spectral characteristics of mid-infrared thermal emission from large area Chemical Vapor Deposition (CVD graphene, transferred onto SiO2/Si, and show that the emission is broadly that of a grey-body emitter, with emissivity values of approximately 2% and 6% for mono- and multilayer graphene. For the currents used, which could be sustained for over one hundred hours, the emission peaked at a wavelength of around 4 μm and covered the characteristic absorption of many important gases. A measurable modulation of thermal emission was obtained even when the drive current was modulated at frequencies up to 100 kHz.

THE INFRARED PROPERTIES OF EMBEDDED SUPER STAR CLUSTERS: PREDICTIONS FROM THREE-DIMENSIONAL RADIATIVE TRANSFER MODELS

International Nuclear Information System (INIS)

Whelan, David G.; Johnson, Kelsey E.; Indebetouw, Remy; Whitney, Barbara A.; Wood, Kenneth

2011-01-01

With high-resolution infrared data becoming available that can probe the formation of high-mass stellar clusters for the first time, appropriate models that make testable predictions of these objects are necessary. We utilize a three-dimensional radiative transfer code, including a hierarchically clumped dusty envelope, to study the earliest stages of super star cluster (SSC) evolution. We explore a range of parameter space in geometric sequences that mimic the hypothesized evolution of an embedded SSC. The inclusion of a hierarchically clumped medium can make the envelope porous, in accordance with previous models and supporting observational evidence. The infrared luminosity inferred from observations can differ by a factor of two from the true value in the clumpiest envelopes depending on the viewing angle. The infrared spectral energy distribution also varies with viewing angle for clumpy envelopes, creating a range in possible observable infrared colors and magnitudes, silicate feature depths, and dust continua. General observable features of cluster evolution differ between envelopes that are relatively opaque or transparent to mid-infrared photons. For optically thick envelopes, evolution is marked by a gradual decline of the 9.8 μm silicate absorption feature depth and a corresponding increase in the visual/ultraviolet flux. For the optically thin envelopes, clusters typically begin with a strong hot dust component and silicates in emission, and these features gradually fade until the mid-infrared polycyclic aromatic hydrocarbon features are predominant. For the models with a smooth dust distribution, the Spitzer MIPS or Herschel PACS [70]-[160] color is a good probe of the stellar mass relative to the total mass or star formation efficiency (SFE). Likewise, the IRAC/MIPS [3.6]-[24] color can be used to constrain the R in and R out values of the envelope. However, clumpiness confuses the general trends seen in the smooth dust distribution models, making it

Sol-gel based mid-infrared evanescent wave sensors for detection of organophosphate pesticides in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Janotta, Markus; Karlowatz, Manfred; Vogt, Frank; Mizaikoff, Boris

2003-10-31

This work demonstrates the application of organically modified sol-gels as recognition layers combined with mid-infrared evanescent wave sensors for in situ detection of nitrated organics in aqueous media. Sol-gels were prepared by acid-catalyzed copolymerization of phenyltrimethoxysilane (PTMOS) and tetramethoxysilane (TMOS) and were spin-coated onto ZnSe attenuated total reflection (ATR) waveguides. These sensors were investigated with respect to their enrichment properties of selected organophosphates, i.e. parathion, fenitrothion and paraoxon, respectively, and their capability of suppressing interfering water background absorptions. Figures of merit are derived from calibration curves determined to assess sensitivity and reproducibility of the applied sensor system. It can be concluded that sol-gel coated infrared optical sensors enable reproducible detection of organophosphates down to the sub-ppm concentration range. Furthermore, measurement of spiked river water samples demonstrates feasibility as remote field sensor system. Once the required sensitivity is achieved, sol-gel based mid-infrared evanescent wave sensors have the potential of being an alternative to commonly applied biosensors for detection of organophosphates in environmental analysis, since they provide superior mechanical and chemical stability during application relevant periods of time.

Infrared Faint Radio Sources in the Extended Chandra Deep Field South

Science.gov (United States)

Huynh, Minh T.

2009-01-01

Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey (ATLAS) which have no observable counterpart in the Spitzer Wide-area Infrared Extragalactic Survey (SWIRE). The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6 to 70 micron) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the SED of these objects shows that they are consistent with high redshift AGN (z > 2).

Potential and limitation of mid-infrared attenuated total reflectance spectroscopy for real time analysis of raw milk in milking lines.

Science.gov (United States)

Linker, Raphael; Etzion, Yael

2009-02-01

Real-time information about milk composition would be very useful for managing the milking process. Mid-infrared spectroscopy, which relies on fundamental modes of molecular vibrations, is routinely used for off-line analysis of milk and the purpose of the present study was to investigate the potential of attenuated total reflectance mid-infrared spectroscopy for real-time analysis of milk in milking lines. The study was conducted with 189 samples from over 70 cows that were collected during an 18 months period. Principal component analysis, wavelets and neural networks were used to develop various models for predicting protein and fat concentration. Although reasonable protein models were obtained for some seasonal sub-datasets (determination errors protein), the models lacked robustness and it was not possible to develop a model suitable for all the data. Determination of fat concentration proved even more problematic and the determination errors remained unacceptably large regardless of the sub-dataset analyzed or of the spectral intervals used. These poor results can be explained by the limited penetration depth of the mid-infrared radiation that causes the spectra to be very sensitive to the presence of fat globules or fat biofilms in the boundary layer that forms at the interface between the milk and the crystal that serves both as radiation waveguide and sensing element. Since manipulations such as homogenisation are not permissible for in-line analysis, these results show that the potential of mid-infrared attenuated total reflectance spectroscopy for in-line milk analysis is indeed quite limited.

Development of integrated platform based on chalcogenides for sensing applications in the mid-infrared

Science.gov (United States)

Gutierrez-Arroyo, Aldo; Bodiou, Loïc.; Lemaitre, Jonathan; Baudet, Emeline; Baillieul, Marion; Hardy, Isabelle; Caillaud, Celine; Colas, Florent; Boukerma, Kada; Rinnert, Emmanuel; Michel, Karine; Bureau, Bruno; Nazabal, Virginie; Charrier, Joël.

2018-03-01

Mid-Infrared (mid-IR) spectral range, spanning from 2 μm to 20 μm, is ideal for chemical sensing using spectroscopy thanks to the presence of vibrational absorption bands of many liquid and gas substances in this wavelength range. Indeed, mid-IR spectroscopy allows simultaneous qualitative and quantitative analysis by, respectively, identifying molecules from their spectral signature and relating the concentrations of different chemical agents to their absorption coefficient according to Beer-Lambert law. In the last years, photonic integrated sensors based on mid-IR spectroscopy have emerged as a cheap, accurate, and compact solution that would enable continuous real-time on-site diagnostics and monitoring of molecular species without the need to collect samples for off-site measurements. Here, we report the design, processing and characterization of a photonic integrated transducer based on selenide ridge waveguides. Evanescent wave detection of chemical substances in liquid phase (isopropyl alcohol, C3H8O, and acetic acid, C2H4O2, both dissolved in cyclohexane) is presented using their absorption at a wavelength of 7.7 μm.

Far-and mid-infrared properties of carbon layers elaborated by plasma sputtering

Energy Technology Data Exchange (ETDEWEB)

Rousseau, Benoit, E-mail: benoit.rousseau@univ-nantes.fr [Université de Nantes, CNRS, LTN UMR6607, La Chantrerie, Rue Christian Pauc, B.P. 50609, F-44306 Nantes Cedex 3 (France); Ammar, Mohamed Ramzi; Bormann, Denis; Simon, Patrick [CNRS, CEMHTI UPR3079, Université d' Orléans, F-55071 (France); Rabat, Hervé; Brault, Pascal [Université d' Orléans, CNRS, GREMI UMR7344, BP 6744, F-45067 Orléans Cedex 2 (France)

2016-12-30

Highlights: • Magnetron sputtering deposition of columnar, disordered carbon films. • Sputtered carbon films infrared properties are dependent on the local order. • Film texture at the micro-nanoscale explains difference of optical properties. - Abstract: The far-and mid-infrared reflectivity spectra of two carbon layers deposited on pure (100) silicon substrates by DC magnetron sputtering were investigated at room temperature in the 10–5000 cm{sup −1} wavenumber range. Their structural and textural features were also studied by combining Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray Reflectivity (XRR) and Rutherford Backscattering Spectroscopy (RBS). The set of results was used to discuss afterwards the influence of the texture on the infrared properties at varying length scale. Thereby, the two layers were found to be heterogeneous as assessed by RBS, XRR and FESEM and their thicknesses had been measured by XRR and FESEM. The information on the structural organization and “crystallite” size was given by Raman spectroscopy. The influence of both the textural and structural parameters on the measured infrared reflectivity spectra was discussed. Finally, a methodology was proposed to recover the intrinsic index of refraction and the intrinsic index of absorption of each layer.

Thermal noise in mid-infrared broadband upconversion detectors

DEFF Research Database (Denmark)

Barh, Ajanta; Tidemand-Lichtenberg, Peter; Pedersen, Christian

2018-01-01

Low noise detection with state-of-the-art mid-infrared (MIR) detectors (e.g., PbS, PbSe, InSb, HgCdTe) is a primary challenge owing to the intrinsic thermal background radiation of the low bandgap detector material itself. However, researchers have employed frequency upconversion based detectors...... of the noise-equivalent power of an UCD system. In this article, we rigorously analyze the optical power generated by frequency upconversion of the intrinsic black-body radiation in the nonlinear material itself due to the crystals residual emissivity, i.e. absorption. The thermal radiation is particularly...... prominent at the optical absorption edge of the nonlinear material even at room temperature. We consider a conventional periodically poled lithium niobate (PPLN) based MIR-UCD for the investigation. The UCD is designed to cover a broad spectral range, overlapping with the entire absorption edge of the PPLN...

IV-VI mid-infrared VECSEL on Si-substrate

Science.gov (United States)

Fill, M.; Felder, F.; Rahim, M.; Khiar, A.; Rodriguez, R.; Zogg, H.; Ishida, A.

2012-03-01

Optically pumped VECSEL (vertical external cavity surface emitting lasers) based on IV-VI semiconductors grown on Si cover the entire wavelength range between 3.0 and 10 μm. Thanks to their simple structure and large wavelength coverage they are an interesting alternative laser technology to access the mid-infrared wavelength region. The active layers consist either of homogeneous "bulk" layers, double heterostructures or quantum well structures of the PbSe, PbTe or PbS material system. Maximum operation temperatures of 325 K are achieved with output powers above 200 mWp. Further, continuously tunable VECSEL are presented, emitting between 3.2 and 5.4 μm. The single emission mode is continuously tunable over 50-100 nm around the center wavelength, yielding an output power > 10 mWp. The axial symmetric emission beam has a half divergence angle of < 3.3°.

Efficient, High-Power Mid-Infrared Laser for National Securityand Scientific Applications

Energy Technology Data Exchange (ETDEWEB)

Kiani, Leily S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-11-02

The LLNL fiber laser group developed a unique short-wave-infrared, high-pulse energy, highaverage- power fiber based laser. This unique laser source has been used in combination with a nonlinear frequency converter to generate wavelengths, useful for remote sensing and other applications in the mid-wave infrared (MWIR). Sources with high average power and high efficiency in this MWIR wavelength region are not yet available with the size, weight, and power requirements or energy efficiency necessary for future deployment. The LLNL developed Fiber Laser Pulsed Source (FiLPS) design was adapted to Erbium doped silica fibers for 1.55 μm pumping of Cadmium Silicon Phosphide (CSP). We have demonstrated, for the first time optical parametric amplification of 2.4 μm light via difference frequency generation using CSP with an Erbium doped fiber source. In addition, for efficiency comparison purposes, we also demonstrated direct optical parametric generation (OPG) as well as optical parametric oscillation (OPO).

SPITZER OBSERVATIONS OF WHITE DWARFS: THE MISSING PLANETARY DEBRIS AROUND DZ STARS

International Nuclear Information System (INIS)

Xu, S.; Jura, M.

2012-01-01

We report a Spitzer/Infrared Array Camera search for infrared excesses around white dwarfs, including 14 newly observed targets and 16 unpublished archived stars. We find a substantial infrared excess around two warm white dwarfs—J220934.84+122336.5 and WD 0843+516, the latter apparently being the hottest white dwarf known to display a close-in dust disk. Extending previous studies, we find that the fraction of white dwarfs with dust disks increases as the star's temperature increases; for stars cooler than 10,000 K, even the most heavily polluted ones do not have ∼1000 K dust. There is tentative evidence that the dust disk occurrence is correlated with the volatility of the accreted material. In the Appendix, we modify a previous analysis to clarify how Poynting-Robertson drag might play an important role in transferring materials from a dust disk into a white dwarf's atmosphere.

Mid-infrared spectroscopic characterisation of an ultra-broadband tunable EC-QCL system intended for biomedical applications

Science.gov (United States)

Vahlsing, T.; Moser, H.; Grafen, M.; Nalpantidis, K.; Brandstetter, M.; Heise, H. M.; Lendl, B.; Leonhardt, S.; Ihrig, D.; Ostendorf, A.

2015-07-01

Mid-infrared spectroscopy has been successfully applied for reagent-free clinical chemistry applications. Our aim is to design a portable bed-side system for ICU patient monitoring, based on mid-infrared absorption spectra of continuously sampled body-fluids. Robust and miniature bed-side systems can be achieved with tunable external cavity quantum cascade lasers (EC-QCL). Previously, single EC-QCL modules covering a wavenumber interval up to 250 cm-1 have been utilized. However, for broader applicability in biomedical research an extended interval around the mid-infrared fingerprint region should be accessible, which is possible with at least three or four EC-QCL modules. For such purpose, a tunable ultra-broadband system (1920 - 780 cm-1, Block Engineering) has been studied with regard to its transient emission characteristics in ns time resolution during different laser pulse widths using a VERTEX 80v FTIR spectrometer with step-scan option. Furthermore, laser emission line profiles of all four incorporated EC-QCL modules have been analysed at high spectral resolution (0.08 cm-1) and beam profiles with few deviations from the TEM 00 spatial mode have been manifested. Emission line reproducibility has been tested for various wavenumbers in step tune mode. The overall accuracy of manufacturer default wavenumber setting has been found between ± 3 cm-1 compared to the FTIR spectrometer scale. With regard to an application in clinical chemistry, theoretically achievable concentration accuracies for different blood substrates based on blood plasma and dialysate spectra previously recorded by FTIRspectrometers have been estimated taking into account the now accessible extended wavenumber interval.

Non-invasive identification of metal-oxalate complexes on polychrome artwork surfaces by reflection mid-infrared spectroscopy.

Science.gov (United States)

Monico, Letizia; Rosi, Francesca; Miliani, Costanza; Daveri, Alessia; Brunetti, Brunetto G

2013-12-01

In this work a reflection mid-infrared spectroscopy study of twelve metal-oxalate complexes, of interest in art conservation science as alteration compounds, was performed. Spectra of the reference materials highlighted the presence of derivative-like and/or inverted features for the fundamental vibrational modes as result of the main contribution from the surface component of the reflected light. In order to provide insights in the interpretation of theses spectral distortions, reflection spectra were compared with conventional transmission ones. The Kramers-Kronig (KK) algorithm, employed to correct for the surface reflection distortions, worked properly only for the derivative-like bands. Therefore, to pay attention to the use of this algorithm when interpreting the reflection spectra is recommended. The outcome of this investigation was exploited to discriminate among different oxalates on thirteen polychrome artworks analyzed in situ by reflection mid-infrared spectroscopy. The visualization of the νs(CO) modes (1400-1200 cm(-1)) and low wavenumber bands (below 900 cm(-1)) in the raw reflection profiles allowed Ca, Cu and Zn oxalates to be identified. Further information about the speciation of different hydration forms of calcium oxalates were obtained by using the KK transform. The work proves reflection mid-infrared spectroscopy to be a reliable and sensitive spectro-analytical method for identifying and mapping different metal-oxalate alteration compounds on the surface of artworks, thus providing conservation scientists with a non-invasive tool to obtain information on the state of conservation and causes of alteration of artworks. Copyright © 2013 Elsevier B.V. All rights reserved.

The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects. III. CH4

NARCIS (Netherlands)

Oberg, Karin I.; Boogert, A. C. Adwin; Pontoppidan, Klaus M.; Blake, Geoffrey A.; Evans, Neal J.; Lahuis, Fred; van Dishoeck, Ewine F.

2008-01-01

CH4 is proposed to be the starting point of a rich organic chemistry. Solid CH4 abundances have previously been determined mostly toward high-mass star-forming regions. Spitzer IRS now provides a unique opportunity to probe solid CH4 toward low-mass star-forming regions as well. Infrared spectra

A Universal Animal Welfare Framework for Zoos

Science.gov (United States)

Kagan, Ron; Carter, Scott; Allard, Stephanie

2015-01-01

The Detroit Zoological Society's (DZS) Center for Zoo Animal Welfare (CZAW) was created to advance the science and policy of the welfare of exotic nonhuman animals in captivity. This important part of the DZS mission is achieved through assessments of, and research on, the welfare of animals in zoos; by recognizing extraordinary achievement in the advancement of animal welfare; by widely sharing knowledge through a bibliographic resource center; by conducting professional training for animal care staff; and by convening important discussions in the form of international symposia. This special issue of the Journal of Applied Animal Welfare Science features selected papers from the most recent international CZAW symposium held at the Detroit Zoo in November 2014, as well as a universal framework for zoo animal welfare developed by the DZS. PMID:26440494

OBSERVATIONAL 5-20 μm INTERSTELLAR EXTINCTION CURVES TOWARD STAR-FORMING REGIONS DERIVED FROM SPITZER IRS SPECTRA

International Nuclear Information System (INIS)

McClure, M.

2009-01-01

Using Spitzer Infrared Spectrograph observations of G0-M4 III stars behind dark clouds, I construct 5-20 μm empirical extinction curves for 0.3 ≤ A K V between ∼3 and 50. For A K K > 1, the curve exhibits lower contrast between the silicate and absorption continuum, develops ice absorption, and lies closer to the Weingartner and Draine R V = 5.5 Case B curve, a result which is consistent with that of Flaherty et al. and Chiar et al. Recently, work using Spitzer Infrared Array Camera data by Chapman et al. independently reaches a similar conclusion that the shape of the extinction curve changes as a function of increasing A K . By calculating the optical depths of the 9.7 μm silicate and 6.0, 6.8, and 15.2 μm ice features, I determine that a process involving ice is responsible for the changing shape of the extinction curve and speculate that this process is a coagulation of ice-mantled grains rather than ice-mantled grains alone.

Black phosphorus saturable absorber for a diode-pumped passively Q-switched Er:CaF2 mid-infrared laser

Science.gov (United States)

Li, Chun; Liu, Jie; Guo, Zhinan; Zhang, Han; Ma, Weiwei; Wang, Jingya; Xu, Xiaodong; Su, Liangbi

2018-01-01

A multilayer black phosphorus, as a novel two dimensional saturable absorber, has superb saturable absorption properties for a Er:CaF2 solid-state pulse laser. The pulse laser is realized at mid-infrared region with the passively Q-switched technology by a diode-pumping. The high-quality black phosphorus saturable absorber is fabricated by liquid phase exfoliation method. The pulse laser generates the pulses operation with the pulse duration of 954.8 ns, the repetition rate of 41.93 kHz, the pulse energy of 4.25 μJ and the peak power of 4.45 W. Our work demonstrates that black phosphorus could be used as a kind of efficient mid-infrared region optical absorber for ultrafast photonics.

A Tunable Mid-Infrared Solid-State Laser with a Compact Thermal Control System

Directory of Open Access Journals (Sweden)

Deyang Yu

2018-05-01

Full Text Available Tunable mid-infrared lasers are widely used in laser spectroscopy, gas sensing and many other related areas. In order to solve heat dissipation problems and improve the environmental temperature adaptability of solid-state laser sources, a tunable all-fiber laser pumped optical parametric oscillator (OPO was established, and a compact thermal control system based on thermoelectric coolers, an automatic temperature control circuit, cooling fins, fans and heat pipes was integrated and designed for the laser. This system is compact, light and air-cooling which satisfies the demand for miniaturization of lasers. A mathematical model and method was established to estimate the cooling capacity of this thermal control system under different ambient environments. A finite-element model was built and simulated to analyze the thermal transfer process. Experiments in room and high temperature environments were carried out and showed that the substrate temperature of a pump module could be maintained at a stable value with controlled precision to 0.2 degrees, while the output power stability of the laser was within ±1%. The experimental results indicate that this compact air-cooling thermal control system could effectively solve the heat dissipation problem of mid-infrared solid-state lasers with a one hundred watts level pump module in room and high temperature environments.

Ultrafast Mid-Infrared Intra-Excitonic Response of Individualized Single-Walled Carbon Nanotubes

International Nuclear Information System (INIS)

Wang, Jigang; Graham, Matt W.; Ma, Yingzhong; Fleming, Graham R.; Kaindl, Robert A.

2009-01-01

The quasi-1D confinement and reduced screening of photoexcited charges in single-walled carbon nanotubes (SWNTs) entails strongly-enhanced Coulomb interactions and exciton binding energies. Such amplified electron-hole (e-h) correlations have important implications for both fundamental physics and optoelectronic applications of nanotubes. The availability of 'individualized' SWNT ensembles with bright and structured luminescence has rendered specific tube chiralities experimentally accessible. In these samples, evidence for excitonic behavior was found in absorption-luminescence maps, two-photon excited luminescence, or ultrafast carrier dynamics. Here, we report ultrafast mid-infrared (mid-IR) studies of individualized SWNTs, evidencing strong photoinduced absorption around 200 meV in semiconducting tubes of (6,5) and (7,5) chiralities. This manifests the observation of quasi-1D intra-excitonic transitions between different relative-momentum states, in agreement with the binding energy and calculated oscillator strength. Our measurements further reveal a saturation of the photoinduced absorption with increasing phase-space filling of the correlated e-h pairs. The transient mid-IR response represents a new tool, unhindered by restrictions of momentum or interband dipole moment, to investigate the density and dynamics of SWNT excitons.

Mid-infrared optical properties of chalcogenide glasses within tin-antimony-selenium ternary system.

Science.gov (United States)

Lin, Ruiqiang; Chen, Feifei; Zhang, Xiaoyu; Huang, Yicong; Song, Baoan; Dai, Shixun; Zhang, Xianghua; Ji, Wei

2017-10-16

In this work, we investigated the mid-infrared (MIR) optical properties of selenide (Se-based) chalcogenide glasses (ChGs) within an As- and Ge-free system, namely the environment-friendly and low-cost tin-antimony-selenium (Sn-Sb-Se, SSS) ternary system, which has not been systematically studied to the best of our knowledge. As compared to ChGs within those conventional Se-based systems, SSS ChGs were found to exhibit extended infrared transmittance range as well as larger linear refractive index (n 0 ). Femtosecond Z-scan measurements show the presence of evident three-photon absorption from Urbach absorption of the SSS ChGs at MIR wavelength, which resonantly enhanced the nonlinear refractive behavior and resulted in large nonlinear refractive index (n 2 ).

[The prevention of distemper in zoo animals].

Science.gov (United States)

Franke, V; Matern, B; Ackermann, O; Danner, K

1989-02-01

The distemper virus infection of different non-domestic carnivorous zoo animals is known since long. All species involved belonged to the suborder Fissipedia. In 1988 a distemper or morbillivirus-like infection occurred in harbour seals, a member of the suborder pinnipedia. For the prophylaxis of distemper in dogs attenuated live vaccines are commonly used. In zoo animals, however, these vaccines caused distemper several times. In contrast, an inactivated virus vaccine proved both its safety and efficacy in more than hundred zoo animals of various species.

CHARACTERIZING THE POPULATION OF BRIGHT INFRARED SOURCES IN THE SMALL MAGELLANIC CLOUD

Energy Technology Data Exchange (ETDEWEB)

Kraemer, K. E. [Institute for Scientific Research, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467 (United States); Sloan, G. C. [Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853-6801 (United States); Wood, P. R. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek ACT 2611 (Australia); Jones, O. C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Egan, M. P., E-mail: kathleen.kraemer@bc.edu, E-mail: sloan@astro.cornell.edu, E-mail: wood@mso.anu.edu.au, E-mail: michael.p.egan@nga.mil [National Geospatial Intelligence Agency, 7500 GEOINT Drive, Springfield, VA 22150 (United States)

2017-01-10

We have used the Infrared Spectrograph (IRS) on the Spitzer Space Telescope to observe stars in the Small Magellanic Cloud (SMC) selected from the Point Source Catalog of the Midcourse Space Experiment (MSX). We concentrate on the dust properties of the oxygen-rich evolved stars. The dust composition has smaller contributions from alumina compared to the Galaxy. This difference may arise from the lower metallicity in the SMC, but it could be a selection effect, as the SMC sample includes more stars that are brighter and thus more massive. The distribution of the SMC stars along the silicate sequence looks more like the Galactic sample of red supergiants than asymptotic giant branch stars (AGBs). While many of the SMC stars are definitively on the AGB, several also show evidence of hot bottom burning. Three of the supergiants show PAH emission at 11.3 μ m. Two other sources show mixed chemistry, with both carbon-rich and oxygen-rich spectral features. One, MSX SMC 134, may be the first confirmed silicate/carbon star in the SMC. The other, MSX SMC 049, is a candidate post-AGB star. MSX SMC 145, previously considered a candidate OH/IR star, is actually an AGB star with a background galaxy at z  = 0.16 along the same line of sight. We consider the overall characteristics of all the MSX sources, the most infrared-bright objects in the SMC, in light of the higher sensitivity and resolution of Spitzer , and compare them with the object types expected from the original selection criteria. This population represents what will be seen in more distant galaxies by the upcoming James Webb Space Telescope ( JWST ). Color–color diagrams generated from the IRS spectra and the mid-infrared filters on JWST show how one can separate evolved stars from young stellar objects (YSOs) and distinguish among different classes of YSOs.

CHARACTERIZING THE POPULATION OF BRIGHT INFRARED SOURCES IN THE SMALL MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Kraemer, K. E.; Sloan, G. C.; Wood, P. R.; Jones, O. C.; Egan, M. P.

2017-01-01

We have used the Infrared Spectrograph (IRS) on the Spitzer Space Telescope to observe stars in the Small Magellanic Cloud (SMC) selected from the Point Source Catalog of the Midcourse Space Experiment (MSX). We concentrate on the dust properties of the oxygen-rich evolved stars. The dust composition has smaller contributions from alumina compared to the Galaxy. This difference may arise from the lower metallicity in the SMC, but it could be a selection effect, as the SMC sample includes more stars that are brighter and thus more massive. The distribution of the SMC stars along the silicate sequence looks more like the Galactic sample of red supergiants than asymptotic giant branch stars (AGBs). While many of the SMC stars are definitively on the AGB, several also show evidence of hot bottom burning. Three of the supergiants show PAH emission at 11.3 μ m. Two other sources show mixed chemistry, with both carbon-rich and oxygen-rich spectral features. One, MSX SMC 134, may be the first confirmed silicate/carbon star in the SMC. The other, MSX SMC 049, is a candidate post-AGB star. MSX SMC 145, previously considered a candidate OH/IR star, is actually an AGB star with a background galaxy at z  = 0.16 along the same line of sight. We consider the overall characteristics of all the MSX sources, the most infrared-bright objects in the SMC, in light of the higher sensitivity and resolution of Spitzer , and compare them with the object types expected from the original selection criteria. This population represents what will be seen in more distant galaxies by the upcoming James Webb Space Telescope ( JWST ). Color–color diagrams generated from the IRS spectra and the mid-infrared filters on JWST show how one can separate evolved stars from young stellar objects (YSOs) and distinguish among different classes of YSOs.

Mid-infrared supercontinuum covering the 1.4–13.3 μm molecular fingerprint region using ultra-high NA chalcogenide step-index fibre

DEFF Research Database (Denmark)

Petersen, Christian Rosenberg; Møller, Uffe Visbech; Kubat, Irnis

2014-01-01

-power laser diodes, quantum cascade lasers and synchrotron radiation have precluded mid-infrared applications where the spatial coherence, broad bandwidth, high brightness and portability of a supercontinuum laser are all required. Here, we demonstrate experimentally that launching intense ultra-short pulses...... the potential of fibres to emit across the mid-infrared molecular ‘fingerprint region’, which is of key importance for applications such as early cancer diagnostics3, gas sensing and food quality control....

Knowledge, Interest, and Value of Youth Zoo Visitors

Science.gov (United States)

Burris, Alexandra M.

In the face of massive global extinction, the mission of zoos for conservation education has increasing importance. Zoos are in a unique position to affect the development of youth in ways that are consistent with cultivating pro-environmental behaviors. The purpose of this study was to examine three intrinsic traits of youth important to the goals of conservation education: knowledge about animals, interest in animals, and value for animals. In particular, I explored the relationship between these three traits and the utterances and behaviors of youth zoo visitors during their visit. Using an embedded correlational data transformation mixed methods design, this study examined the experiences of 37 youth attending the zoo. Data collection sources included a drawing activity meant to assess the knowledge of youth about animals, Likert-type questionnaires meant to assess the youth's interest and value, and a semi-structured interview meant to ascertain critical moments from the youth's visit. The results of these instruments were paired with extensive video data of the youth's entire zoo visit. Results of the study indicated that youth organize their knowledge about animals around ecological and morphological concepts and that this forms the basis for their value of animals. The knowledge, interest, and value of youth zoo visitors did seem to correlate with some utterances and behaviors in the zoo, but learning talk was rare. Results also indicated that certain critical moments during the youth's visit were social in nature and centered on the behaviors of animals. These moments may be the most promising for influencing the development of knowledge, interest, and value. The discussion and implications sections of the study focus on the practical use of the findings for zoo education. The study points to the importance of studying intrinsic traits of youth as well as the important influences of the social and physical context on the development of these traits during

Optical field emission from resonant gold nanorods driven by femtosecond mid-infrared pulses

Energy Technology Data Exchange (ETDEWEB)

Kusa, F. [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei Tokyo 184-8588 (Japan); Institute of Industrial Science, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Echternkamp, K. E.; Herink, G.; Ropers, C. [4th Physical Institute – Solids and Nanostructures, University of Göttingen, 37077 Göttingen (Germany); Ashihara, S., E-mail: ashihara@iis.u-tokyo.ac.jp [Institute of Industrial Science, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

2015-07-15

We demonstrate strong-field photoelectron emission from gold nanorods driven by femtosecond mid-infrared optical pulses. The maximum photoelectron yield is reached at the localized surface plasmon resonance, indicating that the photoemission is governed by the resonantly-enhanced optical near-field. The wavelength- and field-dependent photoemission yield allows for a noninvasive determination of local field enhancements, and we obtain intensity enhancement factors close to 1300, in good agreement with finite-difference time domain computations.

Mid-infrared spectroscopy and multivariate analysis for determination of tetracycline residues in cow's milk

Directory of Open Access Journals (Sweden)

Lizeth Mariel Casarrubias-Torres

2018-01-01

Full Text Available Mid-infrared spectroscopy and chemometric analysis were tested to determine tetracycline's residues in cow's milk. Cow's milk samples (n = 30 were spiked with tetracycline, chlortetracycline, and oxytetracycline in the range of 10-400 µg/l. Chemometric models to quantify each of the tetracycline's residues were developed by applying Partial Components Regression and Partial Least Squares algorithms. The Soft Independent Modeling of Class Analogy model was used to differentiate between pure milk and milk sample with tetracycline residues. The best models for predicting the levels of these antibiotics were obtained using Partial Least Square 1 algorithm (coefficient of determination between 0.997-0.999 and the standard error of calibration from 1.81 to 2.95. The Soft Independent Modeling of Class Analogy model showed well-separated groups allowing classification of milk samples and milk sample with antibiotics. The obtained results demonstrate the great analytical potential of chemometrics coupled with mid-infrared spectroscopy for the prediction of antibiotic in cow's milk at a concentration of microgram per litre (µg/l. This technique can be used to verify the safety of the milk rapidly and reliably.

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.

Infrared galaxies evolution. From cosmological observations with ISO to a mid-infrared to sub-millimetric modeling

International Nuclear Information System (INIS)

Dole, Herve

2000-01-01

This thesis deals with the analysis of the FIRBACK deep survey performed in the far infrared at λ=170 μm with the Infrared Space Observatory whose aim is the study of the galaxies contributing to the Cosmic Infrared Background, and with the modelling of galaxy evolution in the mid-infrared to submillimeter range. The FIRBACK survey covers 3. 89 Sq. Deg. in 3 high galactic latitude and low foreground emission fields (2 of which are in the northern sky). I first present the techniques of reduction, processing and calibration of the ISOPHOT cosmological data. I show that there is a good agreement between PHOT and DIRBE on extended emission, thanks to the derivation of the PHOT footprint. Final maps are created, and the survey is confusion limited at σc=45 mJy. I present then the techniques of source extraction and the simulations for photometry needed to build the final catalog of 106 sources between 180 mJy (4σ) and 2.4 Jy. The complementary catalog is made of 90 sources between 135 and 180 mJy. Galaxy counts show a large excess with respect to local counts or models (with and without evolution), only compatible with strong evolution scenarios. The Cosmic Infrared Background (CIB) is resolved at 4 % at 170 μm. The identifications of the sources at other wavelengths suggest that most of the sources are local, but a non-negligible part lies above redshift 1. I have developed a phenomenological model of galaxy evolution in order to constrain galaxy evolution in the infrared and to have a better understanding of what the FIRBACK sources are. Using the local Luminosity Function (LF), and template spectra of starburst galaxies, it is possible to constrain the evolution of the LF using all the available data: deep source counts at 15, 170 and 850 μm and the CIB spectrum. I show that galaxy evolution is dominated by a high infrared luminosity population, peaking at L=2.0*10"1"1 Redshift distributions are in agreement with available observations. Predictions are

POLYCYCLIC AROMATIC HYDROCARBON EMISSION IN SPITZER/IRS MAPS. I. CATALOG AND SIMPLE DIAGNOSTICS

Energy Technology Data Exchange (ETDEWEB)

Stock, D. J.; Choi, W. D.-Y.; Moya, L. G. V.; Otaguro, J. N.; Sorkhou, S.; Peeters, E. [Department of Physics and Astronomy, University of Western Ontario, London, ON, N6A 3K7 (Canada); Allamandola, L. J. [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-0001 (United States); Tielens, A. G. G. M., E-mail: dstock4@uwo.ca [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA (Netherlands)

2016-03-01

We present a sample of resolved galactic H ii regions and photodissociation regions (PDRs) observed with the Spitzer infrared spectrograph in spectral mapping mode between the wavelengths of 5–15 μm. For each object we have spectral maps at a spatial resolution of ∼4″ in which we have measured all of the mid-infrared emission and absorption features. These include the polycyclic aromatic hydrocarbon (PAH) emission bands, primarily at 6.2, 7.7, 8.6, 11.2, and 12.7 μm, as well as the spectral emission lines of neon and sulfur and the absorption band caused by silicate dust at around 9.8 μm. In this work we describe the data in detail, including the data reduction and measurement strategies, and subsequently present the PAH emission band intensity correlations for each of the objects and the sample as a whole. We find that there are distinct differences between the sources in the sample, with two main groups: the first comprising the H ii regions and the second the reflection nebulae (RNe). Three sources—the reflection nebula NGC 7023, the Horsehead nebula PDR (an interface between the H ii region IC 434 and the Orion B molecular cloud), and M17—resist this categorization, with the Horsehead PDR points mimicking the RNe and the NGC 7023 fluxes displaying a unique bifurcated appearance in our correlation plots. These discrepancies seem to be due to the very low radiation field experienced by the Horsehead PDR and the very clean separation between the PDR environment and a diffuse environment in the NGC 7023 observations.

The Mid-Infrared Instrument for the James Webb Space Telescope, I: Introduction

DEFF Research Database (Denmark)

Rieke, G. H.; Wright, G. S.; Böker, T.

2015-01-01

MIRI (the Mid-Infrared Instrument for the James Webb Space Telescope [JWST]) operates from 5 to 28: 5 μm and combines over this range: (1) unprecedented sensitivity levels; (2) subarcsecond angular resolution; (3) freedom from atmospheric interference; (4) the inherent stability of observing...... in space; and (5) a suite of versatile capabilities including imaging, low- and medium-resolution spectroscopy (with an integral field unit), and coronagraphy. We illustrate the potential uses of this unique combination of capabilities with various science examples: (1) imaging exoplanets; (2) transit...

Fabrication of Shatter-Proof Metal Hollow-Core Optical Fibers for Endoscopic Mid-Infrared Laser Applications

Directory of Open Access Journals (Sweden)

Katsumasa Iwai

2018-04-01

Full Text Available A method for fabricating robust and thin hollow-core optical fibers that carry mid-infrared light is proposed for use in endoscopic laser applications. The fiber is made of stainless steel tubing, eliminating the risk of scattering small glass fragments inside the body if the fiber breaks. To reduce the inner surface roughness of the tubing, a polymer base layer is formed prior to depositing silver and optical-polymer layers that confine light inside the hollow core. The surface roughness is greatly decreased by re-coating thin polymer base layers. Because of this smooth base layer surface, a uniform optical-polymer film can be formed around the core. As a result, clear interference peaks are observed in both the visible and mid-infrared regions. Transmission losses were also low for the carbon dioxide laser used for medical treatments as well as the visible laser diode used for an aiming beam. Measurements of bending losses for these lasers demonstrate the feasibility of the designed fiber for endoscopic applications.

SPECTRAL CHARACTERISTICS OF MID-INFRARED LIGHT-EMITTING DIODES BASED ON InAs (Sb,P

Directory of Open Access Journals (Sweden)

N. K. Zhumashev

2016-01-01

Full Text Available Subject of Study. We consider spectral characteristics of mid-infrared light-emitting diodes with heterostructures based on InAs(Sb,P emitting at T=300 K in the wavelength range 3.4–4.1 micrometers. The aim of the study was to search for the ways of increasing the diode efficiency. Methods. The heterostructures were grown from metal-organic chemical compounds with the use of vapor-phase epitaxial technique. The spectra were recorded under pulse excitation with the use of computer-controlled installation employing MDR-23 grating monochromator and a lock-in amplifier. InSb photodiode was used as a detector. Comparative study of electroluminescence spectra of the diodes was carried out at the temperatures equal to 300 K and 77 K. We compared the obtained data with the calculation results of the band diagrams of the heterostructures. Main Results. As a result of comparative study of the electroluminescence spectra of the diodes recorded at 300 K and 77 K we have established that increasing of their efficiency is hindered by substantial influence of Auger recombination. For the first time at 77 К we have observed the effect of stimulated emission from InAsSb active layer in light-emitting structures made of InAs/InAsSb/InAsSbP. For heterostructures with quantum wells InAs/(InAs/InAsSb/InAsSbP we have found out that at 77 К the carrier recombination occurs outside quantum wells, which points out to the insufficient carrier localization in the active layer. Thus, we have shown that the efficiency of mid-infrared light-emitting diodes based on InAs(Sb,P can be increased via suppression of Auger-recombination and improvement of carrier localization in the active region. Practical Relevance. The results of the study can be used for development of heterostructures for mid-infrared light-emitting diodes.

Mid-infrared mapping of Jupiter's temperatures, aerosol opacity and chemical distributions with IRTF/TEXES

Science.gov (United States)

Fletcher, Leigh N.; Greathouse, T. K.; Orton, G. S.; Sinclair, J. A.; Giles, R. S.; Irwin, P. G. J.; Encrenaz, T.

2016-11-01

Global maps of Jupiter's atmospheric temperatures, gaseous composition and aerosol opacity are derived from a programme of 5-20 μm mid-infrared spectroscopic observations using the Texas Echelon Cross Echelle Spectrograph (TEXES) on NASA's Infrared Telescope Facility (IRTF). Image cubes from December 2014 in eight spectral channels, with spectral resolutions of R ∼2000 - 12 , 000 and spatial resolutions of 2-4° latitude, are inverted to generate 3D maps of tropospheric and stratospheric temperatures, 2D maps of upper tropospheric aerosols, phosphine and ammonia, and 2D maps of stratospheric ethane and acetylene. The results are compared to a re-analysis of Cassini Composite Infrared Spectrometer (CIRS) observations acquired during Cassini's closest approach to Jupiter in December 2000, demonstrating that this new archive of ground-based mapping spectroscopy can match and surpass the quality of previous investigations, and will permit future studies of Jupiter's evolving atmosphere. The visibility of cool zones and warm belts varies from channel to channel, suggesting complex vertical variations from the radiatively-controlled upper troposphere to the convective mid-troposphere. We identify mid-infrared signatures of Jupiter's 5-μm hotspots via simultaneous M, N and Q-band observations, which are interpreted as temperature and ammonia variations in the northern Equatorial Zone and on the edge of the North Equatorial Belt (NEB). Equatorial plumes enriched in NH3 gas are located south-east of NH3-desiccated 'hotspots' on the edge of the NEB. Comparison of the hotspot locations in several channels across the 5-20 μm range indicate that these anomalous regions tilt westward with altitude. Aerosols and PH3 are both enriched at the equator but are not co-located with the NH3 plumes. The equatorial temperature minimum and PH3/aerosol maxima have varied in amplitude over time, possibly as a result of periodic equatorial brightenings and the fresh updrafts of

Innovative mid-infrared detector concepts

Science.gov (United States)

Höfling, Sven; Pfenning, Andreas; Weih, Robert; Ratajczak, Albert; Hartmann, Fabian; Knebl, Georg; Kamp, Martin; Worschech, Lukas

2016-09-01

Gas sensing is a key technology with applications in various industrial, medical and environmental areas. Optical detection mechanisms allow for a highly selective, contactless and fast detection. For this purpose, rotational-vibrational absorption bands within the mid infrared (MIR) spectral region are exploited and probed with appropriate light sources. During the past years, the development of novel laser concepts such as interband cascade lasers (ICLs) and quantum cascade lasers (QCLs) has driven a continuous optimization of MIR laser sources. On the other hand side, there has been relatively little progress on detectors in this wavelength range. Here, we study two novel and promising GaSb-based detector concepts: Interband cascade detectors (ICD) and resonant tunneling diode (RTD) photodetectors. ICDs are a promising approach towards highly sensitive room temperature detection of MIR radiation. They make use of the cascading scheme that is enabled by the broken gap alignment of the two binaries GaSb and InAs. The interband transition in GaSb/InAs-superlattices (SL) allows for normal incidence detection. The cut-off wavelength, which determines the low energy detection limit, can be engineered via the SL period. RTD photodetectors act as low noise and high speed amplifiers of small optically generated electrical signals. In contrast to avalanche photodiodes, where the gain originates from multiplication due to impact ionization, in RTD photodetectors a large tunneling current is modulated via Coulomb interaction by the presence of photogenerated minority charge carriers. For both detector concepts, first devices operational at room temperature have been realized.

Demonstration of a mid-infrared NO molecular Faraday optical filter.

Science.gov (United States)

Wu, Kuijun; Feng, Yutao; Li, Juan; Yu, Guangbao; Liu, Linmei; Xiong, Yuanhui; Li, Faquan

2017-12-11

A molecular Faraday optical filter (MFOF) working in the mid-infrared region is realized for the first time. NO molecule was used as the working material of the MFOF for potential applications in atmospheric remote sensing and combustion diagnosis. We develop a complete theory to describe the performance of MFOF by taking both Zeeman absorption and Faraday rotation into account. We also record the Faraday rotation transmission (FRT) signal using a quantum cascade laser over the range of 1,820 cm -1 to 1,922 cm -1 and calibrate it by using a 101.6 mm long solid germanium etalon with a free spectral range of 0.012 cm -1 . Good agreement between the simulation results and experimental data is achieved. The NO-MFOF's transmission characteristics as a function of magnetic field and pressure are studied in detail. Both Comb-like FRT spectrum and single branch transmission spectrum are obtained by changing the magnetic field. The diversity of FRT spectrum expands the range of potential applications in infrared optical remote sensing. This filtering method can also be extended to the lines of other paramagnetic molecules.

Transparency of Semi-Insulating, n-Type, and p-Type Ammonothermal GaN Substrates in the Near-Infrared, Mid-Infrared, and THz Spectral Range

Directory of Open Access Journals (Sweden)

Robert Kucharski

2017-06-01

Full Text Available GaN substrates grown by the ammonothermal method are analyzed by Fast Fourier Transformation Spectroscopy in order to study the impact of doping (both n- and p-type on their transparency in the near-infrared, mid-infrared, and terahertz spectral range. It is shown that the introduction of dopants causes a decrease in transparency of GaN substrates in a broad spectral range which is attributed to absorption on free carriers (n-type samples or dopant ionization (p-type samples. In the mid-infrared the transparency cut-off, which for a semi-insulating GaN is at ~7 µm due to an absorption on a second harmonic of optical phonons, shifts towards shorter wavelengths due to an absorption on free carriers up to ~1 µm at n ~ 1020 cm−3 doping level. Moreover, a semi-insulating GaN crystal shows good transparency in the 1–10 THz range, while for n-and p-type crystal, the transparency in this spectral region is significantly quenched below 1%. In addition, it is shown that in the visible spectral region n-type GaN substrates with a carrier concentration below 1018 cm−3 are highly transparent with the absorption coefficient below 3 cm−1 at 450 nm, a satisfactory condition for light emitting diodes and laser diodes operating in this spectral range.

Seroepidemiology of Toxoplasma gondii in zoo animals in selected zoos in the midwestern United States.

Science.gov (United States)

de Camps, Silvia; Dubey, J P; Saville, W J A

2008-06-01

Toxoplasma gondii infections in zoo animals are of interest because many captive animals die of clinical toxoplasmosis and because of the potential risk of exposure of children and elderly to T. gondii oocysts excreted by cats in the zoos. Seroprevalence of T. gondii antibodies in wild zoo felids, highly susceptible zoo species, and feral cats from 8 zoos of the midwestern United States was determined by using the modified agglutination test (MAT). A titer of 1:25 was considered indicative of T. gondii exposure. Among wild felids, antibodies to T. gondii were found in 6 (27.3%) of 22 cheetahs (Acynonyx jubatus jubatus), 2 of 4 African lynx (Caracal caracal), 1 of 7 clouded leopards (Neofelis nebulosa), 1 of 5 Pallas cats (Otocolobus manul), 12 (54.5%) of 22 African lions (Panthera leo), 1 of 1 jaguar (Panthera onca), 1 of 1 Amur leopard (Panthera pardus orientalis), 1 of 1 Persian leopard (Panthera pardus saxicolor), 5 (27.8%) of 18 Amur tigers (Panthera tigris altaica), 1 of 4 fishing cats (Prionailurus viverrinus), 3 of 6 pumas (Puma concolor), 2 of 2 Texas pumas (Puma concolor stanleyana), and 5 (35.7%) of 14 snow leopards (Uncia uncia). Antibodies were found in 10 of 34 feral domestic cats (Felis domesticus) trapped in 3 zoos. Toxoplasma gondii oocysts were not found in any of the 78 fecal samples from wild and domestic cats. Among the macropods, antibodies were detected in 1 of 3 Dama wallabies (Macropus eugenii), 1 of 1 western grey kangaroo (Macropus fuliginosus), 1 of 2 wallaroos (Macropus robustus), 6 of 8 Bennett's wallabies (Macropus rufogriseus), 21 (61.8%) of 34 red kangaroos (Macropus rufus), and 1 of 1 dusky pademelon (Thylogale brunii). Among prosimians, antibodies were detected in 1 of 3 blue-eyed black lemurs (Eulemur macaco flavifrons), 1 of 21 ring-tailed lemurs (Lemur catta), 2 of 9 red-ruffed lemurs (Varecia variegata rubra), and 2 of 4 black- and white-ruffed lemurs (Varecia variegata variegata). Among the avian species tested, 2 of 3 bald

Analytical potential of mid-infrared detection in capillary electrophoresis and liquid chromatography: A review

International Nuclear Information System (INIS)

Kuligowski, Julia; Quintas, Guillermo; Guardia, Miguel de la; Lendl, Bernhard

2010-01-01

Literature published in the last decade concerning the use of mid-infrared spectrometry as a detection system in separation techniques employing a liquid mobile phase is reviewed. In addition to the continued use of isocratic liquid chromatographic (LC) techniques, advances in chemometric data evaluation techniques now allow the use of gradient techniques on a routine basis, thus significantly broadening the range of possible applications of LC-IR. The general trend towards miniaturized separation systems was also followed for mid-IR detection where two key developments are of special importance. Firstly, concerning on-line detection the advent of micro-fabricated flow-cells with inner volumes of only a few nL for transmission as well as attenuated total reflection measurements enabled on-line mid-IR detection in capillary LC and opened the path for the first successful realization of on-line mid-IR detection in capillary zone electrophoresis as well as micellar electrokinetic chromatography. Secondly, concerning off-line detection the use of micro-flow through dispensers now enables to concentrate eluting analytes on dried spots sized a few tens of micrometers, thus matching the dimensions for sensitive detection by mid-IR microscopy. Finally in an attempt to increase detection sensitivity of on-line mid-IR detection, mid-IR quantum cascade lasers have been used. Applications cover the field of food analysis, environmental analysis and the characterization of explosives among others. Best detection sensitivities for on-line and off-line detection have been achieved in miniaturized systems and are in the order of 50 ng and 2 ng on column, respectively.

Mineralogy and Thermal Properties of V-Type Asteroid 956 Elisa: Evidence for Diogenitic Material from the Spitzer IRS (5-35 Micrometers) Spectrum

Science.gov (United States)

Lim, Lucy F.; Emery, Joshua P.; Moskovitz, Nicholas A.

2010-01-01

We present the thermal infrared (5-35 micrometer) spectrum of 956 Elisa as measured by the Spitzer Infrared Spectrograph ("IRS"; Houck,1.R. et .11. [20041. Astrophys, 1. SuppL 154, 18-24) together with new ground-based lightcurve data and near-IR spectra. From the visible lightcurve photometry, we determine a rotation period of 16.494 +/- 0.001 h, identify the rotational phase of the Spitzer observations, and estimate the visible absolute magnitude (Hv) at that rotational phase to be 12.58 +/- 0.04. From radiometric analysis of the thermal flux spectrum, we find that at the time of observation 956 Elisa had a projected radius of 5.3 +/- 0.4 km with a visible albedo pv = 0.142+/- 0.022, significantly lower than that of the prototype V-type asteroid, 4 Vesta. (This corresponds to a radius of 5.2 +/- 0.4 km at lightcurve mean.) Analysis with the standard thermal model (STM) results in a sub-solar temperature of 292.3 +/- 2.8 K and beaming parameter eta = 1.16 +/- 0.05. Thermophysical modeling places a lower limit of 20 J m(exp -2)K(exp -1)s(exp -1/2) on the thermal inertia of the asteroid's surface layer (if the surface is very smooth) but more likely values fall between 30 and 150 J m(exp -2)K(exp -1)s(exp -1/2) depending on the sense of rotation. The emissivity spectrum, calculated by dividing the measured thermal flux spectrum by the modeled thermal continuum, exhibits mineralogically interpretable spectral features within the 9-12 micrometer reststrahlen band, the 15-16.5 micrometer Si-O-Si stretching region, and the 16-25 micrometer reststrahlen region that are consistent with pyroxene of diogenitic composition: extant diogenitic pyroxenes fall within the narrow compositional range W0(sub 2+/-1)En(sub 74+/-2)Fs(sub 24+/-1). Spectral deconvolution of the 9-12 micrometer reststrahlen features indicates that up to approximately 20% olivine may also be present, suggesting an olivine-diogenite-like mineralogy. The mid-IR spectrum is inconsistent with non

Recent advances in mid- and near-infrared spectroscopy with applications for research and teaching, focusing on petrochemistry and biotechnology relevant products

Science.gov (United States)

Heise, H. M.; Fritzsche, J.; Tkatsch, H.; Waag, F.; Karch, K.; Henze, K.; Delbeck, S.; Budde, J.

2013-11-01

Mid- and near-infrared spectroscopy is introduced as a versatile analytical method for characterizing liquid and solid chemicals as obtained from petrochemistry and biotechnology processes. Besides normal transmission measurements, special equipment with silver halide fiber-optic probes allowing efficient analysis based on mid-infrared attenuated total reflection, and an accessory for near-infrared diffuse reflection measurements, are presented. The latter technique can be used advantageously for powdered samples such as microalgae biomass and polysaccharides, as well as for different tissues such as meat samples. The advantages and disadvantages of both methods, which can be used for industrial process monitoring and chemical quality control applications, are discussed, and have been used in several research projects of BSc students within their degree course of bio- and nano-technologies of our University of Applied Sciences.

Recent advances in mid- and near-infrared spectroscopy with applications for research and teaching, focusing on petrochemistry and biotechnology relevant products

International Nuclear Information System (INIS)

Heise, H M; Fritzsche, J; Tkatsch, H; Waag, F; Karch, K; Henze, K; Delbeck, S; Budde, J

2013-01-01

Mid- and near-infrared spectroscopy is introduced as a versatile analytical method for characterizing liquid and solid chemicals as obtained from petrochemistry and biotechnology processes. Besides normal transmission measurements, special equipment with silver halide fiber-optic probes allowing efficient analysis based on mid-infrared attenuated total reflection, and an accessory for near-infrared diffuse reflection measurements, are presented. The latter technique can be used advantageously for powdered samples such as microalgae biomass and polysaccharides, as well as for different tissues such as meat samples. The advantages and disadvantages of both methods, which can be used for industrial process monitoring and chemical quality control applications, are discussed, and have been used in several research projects of BSc students within their degree course of bio- and nano-technologies of our University of Applied Sciences. (paper)

Galactic Bulge Giants: Probing Stellar and Galactic Evolution. 1. Catalogue of Spitzer IRAC and MIPS Sources (PREPRINT)

Science.gov (United States)

Uttenthaler, Stefan; Stute, Matthias; Sahai, Raghvendra; Blommaert, Joris A.; Schultheis, Mathias; Kraemer, Kathleen E.; Groenewegen, Martin A.; Price, Stephan D.

2010-01-01

Aims. We aim at measuring mass-loss rates and the luminosities of a statistically large sample of Galactic bulge stars at several galactocentric radii. The sensitivity of previous infrared surveys of the bulge has been rather limited, thus fundamental questions for late stellar evolution, such as the stage at which substantial mass-loss begins on the red giant branch and its dependence on fundamental stellar properties, remain unanswered. We aim at providing evidence and answers to these questions. Methods. To this end, we observed seven 15 15 arcmin2 fields in the nuclear bulge and its vicinity with unprecedented sensitivity using the IRAC and MIPS imaging instruments on-board the Spitzer Space Telescope. In each of the fields, tens of thousands of point sources were detected. Results. In the first paper based on this data set, we present the observations, data reduction, the final catalogue of sources, and a detailed comparison to previous mid-IR surveys of the Galactic bulge, as well as to theoretical isochrones. We find in general good agreement with other surveys and the isochrones, supporting the high quality of our catalogue.

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

Science.gov (United States)

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

2018-04-01

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

Recent advances of mid-infrared compact, field deployable sensors: principles and applications

Science.gov (United States)

Tittel, Frank; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Dong, Lei; Li, Chunguang; Patimisco, Pietro; Sampaolo, Angelo; Spagnolo, Vincenzo; Wojtas, Jacek

2016-04-01

The recent development of compact interband cascade lasers(ICLs) and quantum cascade lasers (QCLs) based trace gas sensors will permit the targeting of strong fundamental rotational-vibrational transitions in the mid-infrared which are one to two orders of magnitude more intense than transitions in the overtone and combination bands in the near-infrared. This has led to the design and fabrication of mid-infrared compact, field deployable sensors for use in the petrochemical industry, environmental monitoring and atmospheric chemistry. Specifically, the spectroscopic detection and monitoring of four molecular species, methane (CH4) [1], ethane (C2H6), formaldehyde (H2CO) [2] and hydrogen sulphide (H2S) [3] will be described. CH4, C2H6 and H2CO can be detected using two detection techniques: mid-infrared tunable laser absorption spectroscopy (TDLAS) using a compact multi-pass gas cell and quartz enhanced photoacoustic spectroscopy (QEPAS). Both techniques utilize state-of-the-art mid-IR, continuous wave (CW), distributed feedback (DFB) ICLs and QCLs. TDLAS was performed with an ultra-compact 54.6m effective optical path length innovative spherical multipass gas cell capable of 435 passes between two concave mirrors separated by 12.5 cm. QEPAS used a small robust absorption detection module (ADM) which consists of a quartz tuning fork (QTF), two optical windows, gas inlet/outlet ports and a low noise frequency pre-amplifier. Wavelength modulation and second harmonic detection were employed for spectral data processing. TDLAS and QEPAS can achieve minimum detectable absorption losses in the range from 10-8 to 10-11cm-1/Hz1/2. Several recent examples of real world applications of field deployable gas sensors will be described. For example, an ICL based TDLAS sensor system is capable of detecting CH4 and C2H6 concentration levels of 1 ppb in a 1 sec. sampling time, using an ultra-compact, robust sensor architecture. H2S detection was realized with a THz QEPAS sensor

THE SPITZER c2d SURVEY OF WEAK-LINE T TAURI STARS. III. THE TRANSITION FROM PRIMORDIAL DISKS TO DEBRIS DISKS

International Nuclear Information System (INIS)

Wahhaj, Zahed; Cieza, Lucas; Koerner, David W.; Case, April; Stapelfeldt, Karl R.; Chapman, Nicholas; Padgett, Deborah L.; Brooke, Tim; Keller, James R.; MerIn, Bruno; Evans, Neal J.; Harvey, Paul; Sargent, Anneila; Van Dishoeck, Ewine F.; Allen, Lori; Blake, Geoff; Mundy, Lee; Myers, Philip C.

2010-01-01

We present 3.6 to 70 μm Spitzer photometry of 154 weak-line T Tauri stars (WTTSs) in the Chamaeleon, Lupus, Ophiuchus, and Taurus star formation regions, all of which are within 200 pc of the Sun. For a comparative study, we also include 33 classical T Tauri stars which are located in the same star-forming regions. Spitzer sensitivities allow us to robustly detect the photosphere in the IRAC bands (3.6 to 8 μm) and the 24 μm MIPS band. In the 70 μm MIPS band, we are able to detect dust emission brighter than roughly 40 times the photosphere. These observations represent the most sensitive WTTSs survey in the mid- to far-infrared to date and reveal the frequency of outer disks (r = 3-50 AU) around WTTSs. The 70 μm photometry for half the c2d WTTSs sample (the on-cloud objects), which were not included in the earlier papers in this series, those of Padgett et al. and Cieza et al., are presented here for the first time. We find a disk frequency of 19% for on-cloud WTTSs, but just 5% for off-cloud WTTSs, similar to the value reported in the earlier works. WTTSs exhibit spectral energy distributions that are quite diverse, spanning the range from optically thick to optically thin disks. Most disks become more tenuous than L disk /L * = 2 x 10 -3 in 2 Myr and more tenuous than L disk /L * = 5 x 10 -4 in 4 Myr.

MID- AND FAR-INFRARED PROPERTIES OF A COMPLETE SAMPLE OF LOCAL ACTIVE GALACTIC NUCLEI

International Nuclear Information System (INIS)

Ichikawa, Kohei; Ueda, Yoshihiro; Terashima, Yuichi; Oyabu, Shinki; Gandhi, Poshak; Nakagawa, Takao; Matsuta, Keiko

2012-01-01

We investigate the mid- (MIR) to far-infrared (FIR) properties of a nearly complete sample of local active galactic nuclei (AGNs) detected in the Swift/Burst Alert Telescope (BAT) all-sky hard X-ray (14-195 keV) survey, based on the cross correlation with the AKARI infrared survey catalogs complemented by those with Infrared Astronomical Satellite and Wide-field Infrared Survey Explorer. Out of 135 non-blazer AGNs in the Swift/BAT nine-month catalog, we obtain the MIR photometric data for 128 sources either in the 9, 12, 18, 22, and/or 25 μm band. We find good correlation between their hard X-ray and MIR luminosities over three orders of magnitude (42 λ (9, 18 μm) < 45), which is tighter than that with the FIR luminosities at 90 μm. This suggests that thermal emission from hot dusts irradiated by the AGN emission dominate the MIR fluxes. Both X-ray unabsorbed and absorbed AGNs follow the same correlation, implying isotropic infrared emission, as expected in clumpy dust tori rather than homogeneous ones. We find excess signals around 9 μm in the averaged infrared spectral energy distribution from heavy obscured 'new type' AGNs with small scattering fractions in the X-ray spectra. This could be attributed to the polycyclic aromatic hydrocarbon emission feature, suggesting that their host galaxies have strong starburst activities.

Broadly tunable mid-infrared VECSEL for multiple components hydrocarbon gas sensing

Science.gov (United States)

Rey, J. M.; Fill, M.; Felder, F.; Sigrist, M. W.

2014-12-01

A new sensing platform to simultaneously identify and quantify volatile C1 to C4 alkanes in multi-component gas mixtures is presented. This setup is based on an optically pumped, broadly tunable mid-infrared vertical-external-cavity surface-emitting laser (VECSEL) developed for gas detection. The lead-chalcogenide VECSEL is the key component of the presented optical sensor. The potential of the proposed sensing setup is illustrated by experimental absorption spectra obtained from various mixtures of volatile hydrocarbons and water vapor. The sensor has a sub-ppm limit of detection for each targeted alkane in a hydrocarbon gas mixture even in the presence of a high water vapor content.

Probing the mid-infrared spectrum of YBa2Cu3O6.0 with high magnetic fields and Zink doping

NARCIS (Netherlands)

Gruninger, M; vanderMarel, D; vanBentum, PJM; Erb, A; Wolf, T; Kopp, T

1996-01-01

The mid-infrared phonon and spin-wave spectrum of antiferromagnetic YBa2Cu3O6.0 was investigated by infrared transmission measurements (k(-->) parallel to c-axis) at T=4K. Peaks at 178 meV, 346 meV and 470 meV were previously interpreted as excitations of single magnons of the optical branch and of

DO WE REALLY KNOW THE DUST? SYSTEMATICS AND UNCERTAINTIES OF THE MID-INFRARED SPECTRAL ANALYSIS METHODS

International Nuclear Information System (INIS)

Juhasz, A.; Henning, Th.; Bouwman, J.; Dullemond, C. P.; Pascucci, I.; Apai, D.

2009-01-01

disk. The effect of different noise levels on the results has also been tested. We find that for a signal-to-noise ratio (S/N) of 100 one can expect an absolute uncertainty in the value of the crystallinity of about 11% using ground-based observations (8-13 μm). For space-based observations (7-17 μm) the expected uncertainty is about 5% for the same S/N value. Moreover, the average value of the estimated crystallinity increases toward lower S/N in general. On the basis of our results, we propose a recipe for the analysis and interpretation of dust spectroscopy data in the mid-infrared which should be especially valuable for analyzing Spitzer spectroscopy data and ground-based infrared spectroscopy data in the 10 μm window.

Low-luminosity Blazars in Wise: A Mid-infrared View of Unification

Science.gov (United States)

Plotkin, Richard M.; Anderson, S. F.; Brandt, W. N.; Markoff, S.; Shemmer, O.; Wu, J.

2012-01-01

We use the preliminary data release from the Wide-Field Infrared Survey Explorer (WISE) to perform the first statistical study on the mid-infrared (IR) properties of a large number ( 102) of BL Lac objects -- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions (SEDs), and the shape of their SEDs in the IR correlates well with SED peak frequency. In other BL Lac objects, the jet is not strong enough to completely dilute the rest of the AGN, and we do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. While at odds with simple unification, the missing torus is consistent with recent suggestions that BL Lac objects are fed by radiatively inefficient accretion flows. We discuss implications on the ``nature vs. nurture" debate for FR I and FR II galaxies, and also on the standard orientation-based AGN unification model.

MN48: a new Galactic bona fide luminous blue variable revealed by Spitzer and SALT

Science.gov (United States)

Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.

2016-07-01

In this paper, we report the results of spectroscopic and photometric observations of the candidate evolved massive star MN48 disclosed via detection of a mid-infrared circular shell around it with the Spitzer Space Telescope. Follow-up optical spectroscopy of MN48 with the Southern African Large Telescope (SALT) carried out in 2011-2015 revealed significant changes in the spectrum of this star, which are typical of luminous blue variables (LBVs). The LBV status of MN48 was further supported by photometric monitoring which shows that in 2009-2011 this star has brightened by ≈0.9 and 1 mag in the V and Ic bands, respectively, then faded by ≈1.1 and 1.6 mag during the next four years, and apparently started to brighten again recently. The detected changes in the spectrum and brightness of MN48 make this star the 18th known Galactic bona fide LBV and increase the percentage of LBVs associated with circumstellar nebulae to more than 70 per cent. We discuss the possible birth place of MN48 and suggest that this star might have been ejected either from a putative star cluster embedded in the H II region IRAS 16455-4531 or the young massive star cluster Westerlund 1.

Optical–Mid-infrared Period–Luminosity Relations for W UMa-type Contact Binaries Based on Gaia DR 1: 8% Distance Accuracy

Science.gov (United States)

Chen, Xiaodian; Deng, Licai; de Grijs, Richard; Wang, Shu; Feng, Yuting

2018-06-01

W Ursa Majoris (W UMa)-type contact binary systems (CBs) are useful statistical distance indicators because of their large numbers. Here, we establish (orbital) period–luminosity relations (PLRs) in 12 optical to mid-infrared bands (GBVRIJHK s W1W2W3W4) based on 183 nearby W UMa-type CBs with accurate Tycho–Gaia parallaxes. The 1σ dispersion of the PLRs decreases from optical to near- and mid-infrared wavelengths. The minimum scatter, 0.16 mag, implies that W UMa-type CBs can be used to recover distances to 7% precision. Applying our newly determined PLRs to 19 open clusters containing W UMa-type CBs demonstrates that the PLR and open cluster CB distance scales are mutually consistent to within 1%. Adopting our PLRs as secondary distance indicators, we compiled a catalog of 55,603 CB candidates, of which 80% have distance estimates based on a combination of optical, near-infrared, and mid-infrared photometry. Using Fourier decomposition, 27,318 high-probability W UMa-type CBs were selected. The resulting 8% distance accuracy implies that our sample encompasses the largest number of objects with accurate distances within a local volume with a radius of 3 kpc available to date. The distribution of W UMa-type CBs in the Galaxy suggests that in different environments, the CB luminosity function may be different: larger numbers of brighter (longer-period) W UMa-type CBs are found in younger environments.

VizieR Online Data Catalog: Spitzer observations of Taurus members (Luhman+, 2010)

Science.gov (United States)

Luhman, K. L.; Allen, P. R.; Espaillat, C.; Hartmann, L.; Calvet, N.

2016-03-01

For our census of the disk population in Taurus, we use images at 3.6, 4.5, 5.8, and 8.0um obtained with Spitzer's Infrared Array Camera (IRAC) and images at 24um obtained with the Multiband Imaging Photometer for Spitzer (MIPS). The cameras produced images with FWHM=1.6"-1.9" from 3.6 to 8.0um and FWHM=5.9" at 24um. The available data were obtained through Guaranteed Time Observations for PID = 6, 36, 37 (G. Fazio), 53 (G. Rieke), 94 (C. Lawrence), 30540 (G. Fazio, J. Houck), and 40302 (J. Houck), Director's Discretionary Time for PID = 462 (L. Rebull), Legacy programs for PID = 139, 173 (N. Evans), and 30816 (D. Padgett), and General Observer programs for PID = 3584 (D. Padgett), 20302 (P. Andre), 20386 (P. Myers), 20762 (J. Swift), 30384 (T. Bourke), 40844 (C. McCabe), and 50584 (D. Padgett). The IRAC and MIPS observations were performed through 180 and 137 Astronomical Observation Requests (AORs), respectively. The characteristics of the resulting images are summarized in Tables 1 and 2. (6 data files).

A mid- to far-infrared variability study of the intermediate Seyfert galaxy, Mk 6

International Nuclear Information System (INIS)

Clement, R.; Sembay, S.; Coe, M.J.; Hanson, C.G.

1988-01-01

A mid- to far-infrared (MFIR) variability study of the intermediate Seyfert galaxy, Mk 6, is presented using data from the Infrared Astronomical Satellite (IRAS). We have analysed 25 observations of this source covering a period of about 1 month. Within the expected errors, the source shows no evidence for variability and this may be an indication that there is a strong contribution to the MFIR emission from thermal re-radiation by dust. This interpretation is consistent with previous studies which suggest that the bulk of the far-infrared (30 -100 μm) emission in Seyfert galaxies originates from cool (35 - 75 K) dust associated with star formation regions in the surrounding envelope of the active nucleus. The lack of variability at 12 and 25 μm can also be readily explained by dust emission. However, in this case, the dust temperatures required to produce emission at these wavelengths makes the narrow-line region a more feasible location for the dust grains. (author)

Eating to save wild-life: is a truly conservation-minded zoo/aquarium a vegan zoo/aquarium?

DEFF Research Database (Denmark)

Gjerris, Mickey; Birkved, Morten; Gamborg, Christian

2016-01-01

are to work for sustainability and species conservation – should food served in zoos be part of considerations – and to what extent? To answer this question the paper presents the goals of EAZA along with environmental impact profiles, relying on previously published life cycle assessments of the entirety (i......According to the European Association of Zoos and Aquaria their mission is ‘to facilitate cooperation … towards the goals of education, research and conservation’. Livestock production is one of the leading causes of often-irreversible land use changes, greenhouse gas emissions, loss...... of biodiversity and different types of environmental degradation – all affecting wildlife negatively, and hence undermining conservation policies that aim to protect individuals, populations and species. But what is the link between livestock production and zoos and aquariums? One link, putting it a bit boldly...

Eating to save wild-life: is a truly conservation-minded zoo/aquarium a vegan zoo/aquarium?

DEFF Research Database (Denmark)

Gjerris, Mickey; Birkved, Morten; Gamborg, Christian

are to work for sustainability and species conservation – should food served in zoos be part of considerations – and to what extent? To answer this question the paper presents the goals of EAZA along with environmental impact profiles, relying on previously published life cycle assessments of the entirety (i......According to the European Association of Zoos and Aquaria their mission is ‘to facilitate cooperation … towards the goals of education, research and conservation’. Livestock production is one of the leading causes of often-irreversible land use changes, greenhouse gas emissions, loss...... of biodiversity and different types of environmental degradation – all affecting wildlife negatively, and hence undermining conservation policies that aim to protect individuals, populations and species. But what is the link between livestock production and zoos and aquariums? One link, putting it a bit boldly...

MID-INFRARED SPECTRA OF TRANSITIONAL DISKS IN THE CHAMAELEON I CLOUD

International Nuclear Information System (INIS)

Kim, K. H.; Watson, Dan M.; Manoj, P.; Forrest, W. J.; Sargent, B.; McClure, M. K.; Green, J. D.; Harrold, Samuel T.; Furlan, E.; Najita, J.; Espaillat, C.; Calvet, N.; Luhman, K. L.

2009-01-01

We present 5-40 μm Spitzer Infrared Spectrograph spectra of a collection of transitional disks, objects for which the spectral energy distribution (SED) indicates central clearings (holes) or gaps in the dust distribution, in the Chamaeleon I star-forming region. Like their counterparts in the Taurus-Auriga star-forming region that we have previously observed, the spectra of these young objects (1-3 Myr old) reveal that the central clearings or gaps are very sharp-edged, and are surrounded by optically thick dusty disks similar to those around other classical T Tauri stars in the Chamaeleon I association. Also like the Taurus transitional disks, the Chamaeleon I transitional disks have extremely large depletion factors for small dust grains in their gaps, compared to the full accretion disks whose SEDs are represented by the median SED of Class II objects in the region. We find that the fraction of transitional disks in the Chamaeleon I cloud is somewhat higher than that in the Taurus-Auriga cloud, possibly indicating that the frequency of transitional disks, on average, increases with cluster age. We also find a significant correlation between the stellar mass and the radius of the outer edge of the gap. We discuss the disk structures implied by the spectra and the constraints they place on gap-formation mechanisms in protoplanetary disks.

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-01

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

Study of starburst galaxies and active galactic nuclei in the mid-infrared with the ISOCAM instrument

International Nuclear Information System (INIS)

Laurent, Olivier

1999-01-01

This thesis is dedicated to the study of starburst galaxies and active galactic nuclei (AGNs) in the mid-infrared between 3 and 16 μm with the ISOCAM instrument. The study of nearby prototypical galaxies such as NGC 1068 and M 82 lead me to decompose the emission into three components. The star forming regions are characterized by (1) the infrared bands at 6.2, 7.7, 8.6, 11.3 and 12.7 μm originating from the photo-dissociation regions and also by (2) a continuum at 15 μm produced by the very small grains in HII regions. I show that AGNs have (3) strong continuum with an important contribution between 3 and 10 μm arising from hot dust heated to high temperatures of the order of 1000 K. I present two diagnostic diagrams based on the spectral properties of the three components allowing me to distinguish AGNs from starburst regions. In interacting galaxies, I show that some extra-nuclear regions harboring starburst activity can dominate the emission at 15 μm as in the Cartwheel and the Antennae galaxies. Using mid-infrared spectral features, I also define two prototypes of ultra-luminous galaxies dominated either by starburst activity in the case of Arp 220 or by the AGN in the Super-Antennae galaxy (IRAS 19254-7245). I explain how this diagram and the selection criteria evolve according to redshift. Finally, I show how we can develop new diagnostics using filters of the IRAC instrument on board the next infrared space observatory SIRTF. (author) [fr

A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite - A mid-infrared and near-infrared study

Energy Technology Data Exchange (ETDEWEB)

Cheng, H.F.; Yang, J.; Liu, Q.F.; Zhang, J.S.; Frost, R.L. [Queensland University of Technology, Brisbane, Qld. (Australia). Faculty of Science & Technology

2010-11-15

Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been compared and evaluated for differentiating kaolinite, coal bearing kaolinite and halloysite. Kaolinite, coal bearing kaolinite and halloysite are the three relative abundant minerals of the kaolin group, especially in China. In the MIR spectra, the differences are shown in the 3000-3600 cm{sup -1} between kaolinite and halloysite. It cannot obviously differentiate the kaolinite and halloysite, leaving alone kaolinite and coal bearing kaolinite. However, NIR, together with MIR, gives us the sufficient evidence to differentiate the kaolinite and halloysite, especially kaolinite and coal bearing kaolinite. There are obvious differences between kaolinite and halloysite in all range of their spectra, and they also show some difference between kaolinite and coal bearing kaolinite. Therefore, the reproducibility of measurement, signal to noise ratio and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for mineral analysis.

Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs

KAUST Repository

Yue, Weisheng

2016-01-11

We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.

Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs

KAUST Repository

Yue, Weisheng; Wang, Zhihong; Whittaker, John; Schedin, Fredrik; Wu, Zhipeng; Han, Jiaguang

2016-01-01

We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.

Comparative study of wine tannin classification using Fourier transform mid-infrared spectrometry and sensory analysis.

Science.gov (United States)

Fernández, Katherina; Labarca, Ximena; Bordeu, Edmundo; Guesalaga, Andrés; Agosin, Eduardo

2007-11-01

Wine tannins are fundamental to the determination of wine quality. However, the chemical and sensorial analysis of these compounds is not straightforward and a simple and rapid technique is necessary. We analyzed the mid-infrared spectra of white, red, and model wines spiked with known amounts of skin or seed tannins, collected using Fourier transform mid-infrared (FT-MIR) transmission spectroscopy (400-4000 cm(-1)). The spectral data were classified according to their tannin source, skin or seed, and tannin concentration by means of discriminant analysis (DA) and soft independent modeling of class analogy (SIMCA) to obtain a probabilistic classification. Wines were also classified sensorially by a trained panel and compared with FT-MIR. SIMCA models gave the most accurate classification (over 97%) and prediction (over 60%) among the wine samples. The prediction was increased (over 73%) using the leave-one-out cross-validation technique. Sensory classification of the wines was less accurate than that obtained with FT-MIR and SIMCA. Overall, these results show the potential of FT-MIR spectroscopy, in combination with adequate statistical tools, to discriminate wines with different tannin levels.

SUBMILLIMETER ARRAY AND SPITZER OBSERVATIONS OF BOK GLOBULE CB 17: A CANDIDATE FIRST HYDROSTATIC CORE?

Energy Technology Data Exchange (ETDEWEB)

Chen Xuepeng; Arce, Hector G.; Dunham, Michael M. [Department of Astronomy, Yale University, Box 208101, New Haven, CT 06520-8101 (United States); Zhang Qizhou; Bourke, Tyler L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Launhardt, Ralf; Schmalzl, Markus; Henning, Thomas, E-mail: xuepeng.chen@yale.edu [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)

2012-06-01

We present high angular resolution Submillimeter Array (SMA) and Spitzer observations toward the Bok globule CB 17. SMA 1.3 mm dust continuum images reveal within CB 17 two sources with an angular separation of {approx}21'' ({approx}5250 AU at a distance of {approx}250 pc). The northwestern continuum source, referred to as CB 17 IRS, dominates the infrared emission in the Spitzer images, drives a bipolar outflow extending in the northwest-southeast direction, and is classified as a low-luminosity Class 0/I transition object (L{sub bol} {approx} 0.5 L{sub Sun }). The southeastern continuum source, referred to as CB 17 MMS, has faint dust continuum emission in the SMA 1.3 mm observations ({approx}6{sigma} detection; {approx}3.8 mJy), but is not detected in the deep Spitzer infrared images at wavelengths from 3.6 to 70 {mu}m. Its bolometric luminosity and temperature, estimated from its spectral energy distribution, are {<=}0.04 L{sub Sun} and {<=}16 K, respectively. The SMA CO (2-1) observations suggest that CB 17 MMS may drive a low-velocity molecular outflow ({approx}2.5 km s{sup -1}), extending in the east-west direction. Comparisons with prestellar cores and Class 0 protostars suggest that CB 17 MMS is more evolved than prestellar cores but less evolved than Class 0 protostars. The observed characteristics of CB 17 MMS are consistent with the theoretical predictions from radiative/magnetohydrodynamical simulations of a first hydrostatic core, but there is also the possibility that CB 17 MMS is an extremely low luminosity protostar deeply embedded in an edge-on circumstellar disk. Further observations are needed to study the properties of CB 17 MMS and to address more precisely its evolutionary stage.

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

Science.gov (United States)

Hill, Michael D.; Shanks, Tom

2011-07-01

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

Generation and application of ultrashort coherent mid-infrared electromagnetic radiation

Science.gov (United States)

Wandel, Scott

Particle accelerators are useful instruments that help address critical issues for the future development of nuclear energy. Current state-of-the-art accelerators based on conventional radio-frequency (rf) cavities are too large and expensive for widespread commercial use, and alternative designs must be considered for supplying relativistic beams to small-scale applications, including medical imaging, secu- rity screening, and scientific research in a university-scale laboratory. Laser-driven acceleration using micro-fabricated dielectric photonic structures is an attractive approach because such photonic microstructures can support accelerating fields that are 10 to 100 times higher than that of rf cavity-based accelerators. Dielectric laser accelerators (DLAs) use commercial lasers as a driving source, which are smaller and less expensive than the klystrons used to drive current rf-based accelerators. Despite the apparent need for compact and economical laser sources for laser-driven acceleration, the availability of suitable high-peak-power lasers that cover a broad spectral range is currently limited. To address the needs of several innovative acceleration mechanisms like DLA, it is proposed to develop a coherent source of mid-infrared (IR) electromagnetic radiation that can be implemented as a driving source of laser accelerators. The use of ultrashort mid-IR high peak power laser systems in various laser-driven acceleration schemes has shown the potential to greatly reduce the optical pump intensities needed to realize high acceleration gradients. The optical intensity needed to achieve a given ponderomotive potential is 25 times less when using a 5-mum mid-IR laser as compared to using a 1-mum near-IR solid-state laser. In addition, dielectric structure breakdown caused by multiphoton ionization can be avoided by using longer-wavelength driving lasers. Current mid-IR laser sources do not produce sufficiently short pulse durations, broad spectral bandwidths

Mid-infrared emissions of Pr{sup 3+}-doped GeS{sub 2}–Ga{sub 2}S{sub 3}–CdI{sub 2} chalcohalide glasses

Energy Technology Data Exchange (ETDEWEB)

Lu, Chunfeng [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Guo, Haitao, E-mail: guoht_001@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Xu, Yantao; Hou, Chaoqi; Lu, Min [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); He, Xin [School of Applied Physics and Materials, Wuyi University, Jiangmen, Guangdong 529020 (China); Wang, Pengfei; Li, Weinan [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China); Peng, Bo, E-mail: bpeng@opt.ac.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and precision Mechanics, Chinese Academy of Science (CAS), Xi’an, Shaanxi 710119 (China)

2014-12-15

Graphical abstract: ∼4.6 μm mid-infrared fluorescence emission from Pr{sup 3+} in the sulfide glass is successfully observed at room temperature excited by a 2.01 μm Tm{sup 3+}:YAG ceramic laser system. - Highlights: • Serial Pr{sup 3+}-doped GeS{sub 2}–Ga{sub 2}S{sub 3}–CdI{sub 2} chalcohalide glasses were synthesized. • ∼4.6 μm mid-infrared fluorescence from Pr{sup 3+} was observed at room temperature. • The compositional dependence of luminescence properties was studied. • Radiative properties have been determined using the Judd–Ofelt theory. - Abstract: For elucidation of the glass composition’s influence on the spectroscopic properties in the chalcohalide system and the discovery of a new material for applications in mid-infrared fiber-lasers, a serial Pr{sup 3+}-doped (100 − x)(0.8GeS{sub 2}·0.2Ga{sub 2}S{sub 3})xCdI{sub 2} (x = 5, 10, 15 and 20) chalcohalide glasses were prepared. ∼4.6 μm mid-infrared fluorescence emission from Pr{sup 3+} in the sulfide glass is successfully observed at room temperature excited by a 2.01 μm Tm{sup 3+}:YAG ceramic laser system, and the effective line-width of fluorescence band is 106–227 nm. Intense compositional dependence of mid-infrared emissions is found. The radiative rates of Pr{sup 3+} ions in these glasses were calculated by using the Judd–Ofelt theory.

Source brightness fluctuation correction of solar absorption fourier transform mid infrared spectra

Directory of Open Access Journals (Sweden)

T. Ridder

2011-06-01

Full Text Available The precision and accuracy of trace gas observations using solar absorption Fourier Transform infrared spectrometry depend on the stability of the light source. Fluctuations in the source brightness, however, cannot always be avoided. Current correction schemes, which calculate a corrected interferogram as the ratio of the raw DC interferogram and a smoothed DC interferogram, are applicable only to near infrared measurements. Spectra in the mid infrared spectral region below 2000 cm⁻¹ are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents the established source brightness fluctuation correction. This problem can be overcome by a determination of the offset using the modulation efficiency of the instrument. With known modulation efficiency the offset can be calculated, and the source brightness correction can be performed on the basis of offset-corrected interferograms. We present a source brightness fluctuation correction method which performs the smoothing of the raw DC interferogram in the interferogram domain by an application of a running mean instead of high-pass filtering the corresponding spectrum after Fourier transformation of the raw DC interferogram. This smoothing can be performed with the onboard software of commercial instruments. The improvement of MCT spectra and subsequent ozone profile and total column retrievals is demonstrated. Application to InSb interferograms in the near infrared spectral region proves the equivalence with the established correction scheme.

Mid-infrared nonlinear upconversion imaging and sensing

DEFF Research Database (Denmark)

Pedersen, Christian; Tidemand-Lichtenberg, Peter

2016-01-01

The mid-IR wavelength range is highly relevant for a number of applications related to gas spectroscopy and spectral analysis of complex molecules such as those including CH bounds. The main obstacles for exploitation of mid-IR applications include suitable and affordable mid-IR light sources...

Zoo and Wildlife Libraries: An International Survey

Science.gov (United States)

Coates, Linda L.; Tierney, Kaitlyn Rose

2010-01-01

The conservation and well-being of exotic animals is core to the mission of zoos, aquariums and many small nonprofit wildlife groups. Increasingly, these organizations are committed to scientific research, both basic and applied. To ascertain the current state of the libraries that support their efforts, librarians at the San Diego Zoo conducted…

Room-temperature mid-infrared single-photon imaging using upconversion

DEFF Research Database (Denmark)

Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

2014-01-01

The mid-wave infrared (MWIR) region is a fast developing research area due to many possible applications. Indeed a lot of research has been put into the development of novel light sources in the MWIR. This has led to very powerful sources such as quantum cascade lasers (QCL) and optical parametric...... detectors, when compared to silicon based detectors available for the visible and near visible spectral range. In fact, camera sensitivities down to the single photon level have been developed for sub-μm wavelengths. This discrepancy in sensitivity makes it attractive to perform wavelength upconversion...... upconversion efficiencies of 20 % for polarized collinear MWIR light. To make the module truly portable the laser cavity is assembled in a closed mechanical unit which ensures that visible light cannot enter from the outside, and provides a very stable mount for the optical components. Figure 1 depicts...

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-04-01

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

Comparison of laser-based mitigation of fused silica surface damage using mid- versus far-infrared lasers

Energy Technology Data Exchange (ETDEWEB)

Yang, S T; Matthews, M J; Elhadj, S; Cooke, D; Guss, G M; Draggoo, V G; Wegner, P J

2009-12-16

Laser induced growth of optical damage can limit component lifetime and therefore operating costs of large-aperture fusion-class laser systems. While far-infrared (IR) lasers have been used previously to treat laser damage on fused silica optics and render it benign, little is known about the effectiveness of less-absorbing mid-IR lasers for this purpose. In this study, they quantitatively compare the effectiveness and efficiency of mid-IR (4.6 {micro}m) versus far-IR (10.6 {micro}m) lasers in mitigating damage growth on fused silica surfaces. The non-linear volumetric heating due to mid-IR laser absorption is analyzed by solving the heat equation numerically, taking into account the temperature-dependent absorption coefficient {alpha}(T) at {lambda} = 4.6 {micro}m, while far-IR laser heating is well-described by a linear analytic approximation to the laser-driven temperature rise. In both cases, the predicted results agree well with surface temperature measurements based on infrared radiometry, as well as sub-surface fictive temperature measurements based on confocal Raman microscopy. Damage mitigation efficiency is assessed using a figure of merit (FOM) relating the crack healing depth to laser power required, under minimally-ablative conditions. Based on their FOM, they show that for cracks up to at least 500 {micro}m in depth, mitigation with a 4.6 {micro}m mid-IR laser is more efficient than mitigation with a 10.6 {micro}m far-IR laser. This conclusion is corroborated by direct application of each laser system to the mitigation of pulsed laser-induced damage possessing fractures up to 225 {micro}m in depth.

"Slow-scanning" in Ground-based Mid-infrared Observations

Science.gov (United States)

Ohsawa, Ryou; Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Okada, Kazushi; Mori, Kiyoshi; Uchiyama, Masahito S.; Yamaguchi, Junpei; Fujiyoshi, Takuya; Morii, Mikio; Ikeda, Shiro

2018-04-01

Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at a frequency larger than a few hertz. We propose an alternative observing method, a "slow-scanning" observation. Images are continuously captured as movie data, while the field of view is slowly moved. The signal from an astronomical object is extracted from the movie data by a low-rank and sparse matrix decomposition. The performance of the "slow-scanning" observation was tested in an experimental observation with Subaru/COMICS. The quality of a resultant image in the "slow-scanning" observation was as good as in a conventional chopping observation with COMICS, at least for a bright point-source object. The observational efficiency in the "slow-scanning" observation was better than that in the chopping observation. The results suggest that the "slow-scanning" observation can be a competitive method for the Subaru telescope and be of potential interest to other ground-based facilities to avoid chopping.

Mid-wavelength infrared unipolar nBp superlattice photodetector

Science.gov (United States)

Kazemi, Alireza; Myers, Stephen; Taghipour, Zahra; Mathews, Sen; Schuler-Sandy, Ted; Lee, Seunghyun; Cowan, Vincent M.; Garduno, Eli; Steenbergen, Elizabeth; Morath, Christian; Ariyawansa, Gamini; Scheihing, John; Krishna, Sanjay

2018-01-01

We report a Mid-Wavelength Infrared (MWIR) barrier photodetector based on the InAs/GaSb/AlSb type-II superlattice (T2SL) material system. The nBp design consists of a single unipolar barrier (InAs/AlSb SL) placed between a 4 μm thick p-doped absorber (InAs/GaSb SL) and an n-type contact layer (InAs/GaSb SL). At 80 K, the device exhibited a 50% cut-off wavelength of 5 μm, was fully turned-ON at zero bias and the measured QE was 50% (front side illumination with no AR coating) at 4.5 μm with a dark current density of 4.7 × 10-6 A/cm2 at Vb = 50 mV. At 150 K and Vb = 50 mV, the 50% cut-off wavelength increased to 5.3 μm, and the QE was 54% at 4.5 μm with a dark current of 5.0 × 10-4 A/cm2.

AN INTERFEROMETRIC STUDY OF THE FOMALHAUT INNER DEBRIS DISK. II. KECK NULLER MID-INFRARED OBSERVATIONS

Energy Technology Data Exchange (ETDEWEB)

Mennesson, B.; Serabyn, E.; Colavita, M. M. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena CA 91109-8099 (United States); Absil, O. [Departement d' Astrophysique, Geophysique et Oceanographie, Universite de Liege, 17 Allee du Six Aout, B-4000 Sart Tilman (Belgium); Lebreton, J.; Augereau, J.-C. [IPAG, UMR 5274, CNRS and Universite Joseph Fourier, BP 53, F-38041 Grenoble (France); Millan-Gabet, R. [Michelson Science Center, California Institute of Technology, 770 South Wilson Avenue, Pasadena CA 91125 (United States); Liu, W. [Infrared Processing and Analysis Center, California Institute of Technology, Mail Code 100-22, Pasadena, CA 91125 (United States); Hinz, P. [Steward Observatory, University of Arizona, 933 N Cherry Avenue, Tucson, AZ 85721 (United States); Thebault, P. [Observatoire de Paris, Section de Meudon, F-92195 Meudon Principal Cedex (France)

2013-02-15

We report on high-contrast mid-infrared observations of Fomalhaut obtained with the Keck Interferometer Nuller (KIN) showing a small resolved excess over the level expected from the stellar photosphere. The measured null excess has a mean value of 0.35% {+-} 0.10% between 8 and 11 {mu}m and increases from 8 to 13 {mu}m. Given the small field of view of the instrument, the source of this marginal excess must be contained within 2 AU of Fomalhaut. This result is reminiscent of previous VLTI K-band ({approx_equal}2{mu}m) observations, which implied the presence of a {approx}0.88% excess, and argued that thermal emission from hot dusty grains located within 6 AU from Fomalhaut was the most plausible explanation. Using a parametric two-dimensional radiative transfer code and a Bayesian analysis, we examine different dust disk structures to reproduce both the near- and mid-infrared data simultaneously. While not a definitive explanation of the hot excess of Fomalhaut, our model suggests that the most likely inner few AU disk geometry consists of a two-component structure, with two different and spatially distinct grain populations. The 2-11 {mu}m data are consistent with an inner hot ring of very small ({approx_equal}10-300 nm) carbon-rich grains concentrating around 0.1 AU. The second dust population-inferred from the KIN data at longer mid-infrared wavelengths-consists of larger grains (size of a few microns to a few tens of microns) located further out in a colder region where regular astronomical silicates could survive, with an inner edge around 0.4 AU-1 AU. From a dynamical point of view, the presence of the inner concentration of submicron-sized grains is surprising, as such grains should be expelled from the inner planetary system by radiation pressure within only a few years. This could either point to some inordinate replenishment rates (e.g., many grazing comets coming from an outer reservoir) or to the existence of some braking mechanism preventing the grains

Infrared Astronomy Professional Development for K-12 Educators: WISE Telescope

Science.gov (United States)

Borders, Kareen; Mendez, B. M.

2010-01-01

K-12 educators need effective and relevant astronomy professional development. WISE Telescope (Wide-Field Infrared Survey Explorer) and Spitzer Space Telescope Education programs provided an immersive teacher professional development workshop at Arecibo Observatory in Puerto Rico during the summer of 2009. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance 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 Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of WISE lenticulars and diagramming of infrared data, listening to light by using speakers hooked up to photoreceptor cells, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars. We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development. Funding was provided by WISE Telescope, Spitzer Space Telescope, Starbucks, Arecibo Observatory, the American Institute of Aeronautics and Astronautics, and the Washington Space Grant Consortium.

Upconversion enhanced degenerate four-wave mixing in the mid-infrared for sensitive detection of acetylene in gas flows

DEFF Research Database (Denmark)

Høgstedt, Lasse; Dam, Jeppe Seidelin; Sahlberg, Anna-Lena

2014-01-01

We present a new background free method for in situ gas detection that combines degenerate four-wave mixing with an infra-red light detector based on parametric frequency upconversion of infra-red light. The system is demonstrated at mid infrared wavelengths for low concentration measurements...... of acetylene diluted in a N2 gas flow at ambient conditions. It is demonstrated that the system is able to cover more than 100 nm in scanning range and detect concentrations as low as 3 ppm based on the R9e line. A major issue in small signal measurements is scattered light and it is showed how a spatial...

Quantitative determination of additive Chlorantraniliprole in Abamectin preparation: Investigation of bootstrapping soft shrinkage approach by mid-infrared spectroscopy

Science.gov (United States)

Yan, Hong; Song, Xiangzhong; Tian, Kuangda; Chen, Yilin; Xiong, Yanmei; Min, Shungeng

2018-02-01

A novel method, mid-infrared (MIR) spectroscopy, which enables the determination of Chlorantraniliprole in Abamectin within minutes, is proposed. We further evaluate the prediction ability of four wavelength selection methods, including bootstrapping soft shrinkage approach (BOSS), Monte Carlo uninformative variable elimination (MCUVE), genetic algorithm partial least squares (GA-PLS) and competitive adaptive reweighted sampling (CARS) respectively. The results showed that BOSS method obtained the lowest root mean squared error of cross validation (RMSECV) (0.0245) and root mean squared error of prediction (RMSEP) (0.0271), as well as the highest coefficient of determination of cross-validation (Qcv2) (0.9998) and the coefficient of determination of test set (Q2test) (0.9989), which demonstrated that the mid infrared spectroscopy can be used to detect Chlorantraniliprole in Abamectin conveniently. Meanwhile, a suitable wavelength selection method (BOSS) is essential to conducting a component spectral analysis.

Adding a dimension to the infrared spectra of interfaces: 2D SFG spectroscopy via mid-IR pulse shaping

Science.gov (United States)

Zanni, Martin

2012-02-01

Sum-frequency generation spectroscopy provides an infrared spectrum of interfaces and thus has widespread use in the materials and chemical sciences. In this presentation, I will present our recent work in developing a 2D pulse sequence to generate 2D SFG spectra of interfaces, in analogy to 2D infrared spectra used to measure bulk species. To develop this spectroscopy, we have utilized many of the tricks-of-the-trade developed in the 2D IR and 2D Vis communities in the last decade, including mid-IR pulse shaping. With mid-IR pulse shaping, the 2D pulse sequence is manipulated by computer programming in the desired frequency resolution, rotating frame, and signal pathway. We believe that 2D SFG will become an important tool in the interfacial sciences in an analogous way that 2D IR is now being used in many disciplines.

A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study.

Science.gov (United States)

Cheng, Hongfei; Yang, Jing; Liu, Qinfu; Zhang, Jinshan; Frost, Ray L

2010-11-01

Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been compared and evaluated for differentiating kaolinite, coal bearing kaolinite and halloysite. Kaolinite, coal bearing kaolinite and halloysite are the three relative abundant minerals of the kaolin group, especially in China. In the MIR spectra, the differences are shown in the 3000-3600 cm⁻¹ between kaolinite and halloysite. It cannot obviously differentiate the kaolinite and halloysite, leaving alone kaolinite and coal bearing kaolinite. However, NIR, together with MIR, gives us the sufficient evidence to differentiate the kaolinite and halloysite, especially kaolinite and coal bearing kaolinite. There are obvious differences between kaolinite and halloysite in all range of their spectra, and they also show some difference between kaolinite and coal bearing kaolinite. Therefore, the reproducibility of measurement, signal to noise ratio and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for mineral analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

TOTAL INFRARED LUMINOSITY ESTIMATION OF RESOLVED AND UNRESOLVED GALAXIES

International Nuclear Information System (INIS)

Boquien, M.; Calzetti, D.; Bendo, G.; Dale, D.; Engelbracht, C.; Kennicutt, R.; Lee, J. C.; Van Zee, L.; Moustakas, J.

2010-01-01

The total infrared (TIR) luminosity from galaxies can be used to examine both star formation and dust physics. We provide here new relations to estimate the TIR luminosity from various Spitzer bands, in particular from the 8 μm and 24 μm bands. To do so, we use data for 45'' subregions within a subsample of nearby face-on spiral galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) that have known oxygen abundances as well as integrated galaxy data from the SINGS, the Local Volume Legacy survey (LVL), and Engelbracht et al. samples. Taking into account the oxygen abundances of the subregions, the star formation rate intensity, and the relative emission of the polycyclic aromatic hydrocarbons at 8 μm, the warm dust at 24 μm, and the cold dust at 70 μm and 160 μm, we derive new relations to estimate the TIR luminosity from just one or two of the Spitzer bands. We also show that the metallicity and the star formation intensity must be taken into account when estimating the TIR luminosity from two wave bands, especially when data longward of 24 μm are not available.

Ocular oxyspirurosis of primates in zoos: intermediate host, worm morphology, and probable origin of the infection in the Moscow zoo

Directory of Open Access Journals (Sweden)

Ivanova E.

2007-12-01

Full Text Available Over the last century, only two cases of ocular oxyspirurosis were recorded in primates, both in zoos, and two species were described: in Berlin, Germany, Oxyspirura (O. conjunctivalis from the lemurid Microcebus murinus, later also found in the lorisid Loris gracilis; in Jacksonville, Florida, O. (O. youngi from the cercopithecid monkey Erythrocebus patas. In the present case from the Moscow zoo, oxyspirurosis was recorded in several species of Old World lemuriforms and lorisiforms, and some South American monkeys. i The intermediate host was discovered to be a cockroach, as for O. (O. mansoni, a parasite of poultry. The complete sequence identity between ITS-1 rDNA from adult nematodes of the primate and that of the larval worms from the vector, Nauphoete cinerea, confirmed their conspecificity. ii Parasites from Moscow zoo recovered from Nycticebus c. coucang were compared morphologically to those from other zoos. The length and shape of the gubernaculum, used previously as a distinct character, were found to be variable. However, the vulvar bosses arrangement, the distal extremity of left spicule and the position of papillae of the first postcloacal pair showed that the worms in the different samples were not exactly identical and that each set seemed characteristic of a particular zoo. iii The presence of longitudinal cuticular crests in the infective stage as well as in adult worms was recorded. Together with several other morphological and biological characters (long tail and oesophagus, cockroach vector, this confirmed that Oxyspirura is not closely related to Thelazia, another ocular parasite genus. iv The disease in the Moscow zoo is thought to have started with Nycticebus pygmaeus imported fromVietnam, thus the suggestion was that Asiatic lorisids were at the origin of the Moscow set of cases. The natural host(s for the Berlin and Jacksonville cases remain unknown but they are unlikely to be the species found infected in zoos

Brown dwarf distances and atmospheres: Spitzer Parallaxes and the Keck/NIRSPEC upgrade

Science.gov (United States)

Martin, Emily C.

2018-01-01

Advances in infrared technology have been essential towards improving our understanding of the solar neighborhood, revealing a large population of brown dwarfs, which span the mass regime between planets and stars. My thesis combines near-infrared (NIR) spectroscopic and astrometric analysis of nearby low-mass stars and brown dwarfs with instrumentation work to upgrade the NIRSPEC instrument for the Keck II Telescope. I will present results from a program using Spitzer/IRAC data to measure precise locations and distances to 22 of the coldest and closest brown dwarfs. These distances allow us to constrain absolute physical properties, such as mass, radius, and age, of free-floating planetary-mass objects through comparison to atmospheric and evolutionary models. NIR spectroscopy combined with the Spitzer photometry reveals a detailed look into the atmospheres of brown dwarfs and gaseous extrasolar planets. Additionally, I will discuss the improvements we are making to the NIRSPEC instrument at Keck. NIRSPEC is a NIR echelle spectrograph, capable of R~2000 and R~25,000 observations in the 1-5 μm range. As part of the upgrade, I performed detector characterization, optical design of a new slit-viewing camera, mechanical testing, and electronics design. NIRSPEC’s increased efficiency will allow us to obtain moderate- and high-resolution NIR spectra of objects up to a magnitude fainter than the current NIRSPEC design. Finally, I will demonstrate the utility of a NIR laser frequency comb as a high-resolution calibrator. This new technology will revolutionize precision radial velocity measurements in the coming decade.

Preferential flow pathways revealed by field based stable isotope analysis of CO2 by mid-infrared laser spectroscopy

Science.gov (United States)

van Geldern, Robert; Nowak, Martin; Zimmer, Martin; Szizybalski, Alexandra; Myrttinen, Anssi; Barth, Johannes A. C.; Jost, Hj

2016-04-01

A newly developed and commercially available isotope ratio laser spectrometer for CO2 analyses has been tested during a 10-day field monitoring campaign at the Ketzin pilot site for CO2 storage in northern Germany. The laser instrument is based on tunable laser direct absorption in the mid-infrared. The instrument recorded a continuous 10-day carbon stable isotope data set with 30 minutes resolution directly on-site in a field-based laboratory container during a tracer experiment. To test the instruments performance and accuracy the monitoring campaign was accompanied by daily CO2 sampling for laboratory analyses with isotope ratio mass spectrometry (IRMS). The carbon stable isotope ratios measured by conventional IRMS technique and by the new mid-infrared laser spectrometer agree remarkably well within 2σ analytical precision (<0.3 ‰). This proves the capability of the new mid-infrared direct absorption technique to measure high precision and accurate real-time table isotope data directly in the field. The injected CO2 tracer had a distinct δ13C value that was largely different from the reservoir background value. The laser spectroscopy data revealed a prior to this study unknown, intensive dynamic with fast changing δ13C values. The arrival pattern of the tracer suggest that the observed fluctuations were probably caused by migration along separate and distinct preferential flow paths between injection well and observation well. The new technique might contribute to a better tracing of the migration of the underground CO2 plume and help to ensure the long-term integrity of the reservoir.

The influence of melt purification and structure defects on mid-infrared light emitting diodes

CERN Document Server

Krier, A

2003-01-01

Mid-infrared light emitting diodes which exhibit more than 7 mW (pulsed) and 0.35 mW dc output power at 3.3 mu m and at room temperature have been fabricated by liquid phase epitaxy using Pb as a neutral solvent. Using Pb solution an increase in pulsed output power of between two and three times was obtained compared with InAs light emitting diodes (LEDs) made using rare-earth gettering. The performance improvements were attributed to a reduction in residual carrier concentration arising from the removal of un-intentional donors and structure defects in the InAs active region material. These LEDs are well matched to the CH sub 4 absorption spectrum and potentially could form the basis of a practical infrared CH sub 4 gas sensor.

Human Milk Analysis Using Mid-Infrared Spectroscopy.

Science.gov (United States)

Groh-Wargo, Sharon; Valentic, Jennifer; Khaira, Sharmeel; Super, Dennis M; Collin, Marc

2016-04-01

The composition of human milk is known to vary with length of gestation, stage of lactation, and other factors. Human milk contains all nutrients required for infant health but requires fortification to meet the needs of low-birth-weight infants. Without a known nutrient profile of the mother's milk or donor milk fed to a baby, the composition of the fortified product is only an estimate. Human milk analysis has the potential to improve the nutrition care of high-risk newborns by increasing the information about human milk composition. Equipment to analyze human milk is available, and the technology is rapidly evolving. This pilot study compares mid-infrared (MIR) spectroscopy to reference laboratory milk analysis. After obtaining informed consent, we collected human milk samples from mothers of infants weighing milk obtained by MIR vs reference laboratory analysis. MIR analysis appears to provide an accurate assessment of macronutrient content in expressed human milk from mothers of preterm infants. The small sample size of this study limits confidence in the results. Measurement of lactose is confounded by the presence of oligosaccharides. Human milk analysis is a potentially useful tool for establishing an individualized fortification plan. © 2015 American Society for Parenteral and Enteral Nutrition.

Indirect absorption spectroscopy using quantum cascade lasers: mid-infrared refractometry and photothermal spectroscopy.

Science.gov (United States)

Pfeifer, Marcel; Ruf, Alexander; Fischer, Peer

2013-11-04

We record vibrational spectra with two indirect schemes that depend on the real part of the index of refraction: mid-infrared refractometry and photothermal spectroscopy. In the former, a quantum cascade laser (QCL) spot is imaged to determine the angles of total internal reflection, which yields the absorption line via a beam profile analysis. In the photothermal measurements, a tunable QCL excites vibrational resonances of a molecular monolayer, which heats the surrounding medium and changes its refractive index. This is observed with a probe laser in the visible. Sub-monolayer sensitivities are demonstrated.

Two fatal tiger attacks in zoos.

Science.gov (United States)

Tantius, Britta; Wittschieber, Daniel; Schmidt, Sven; Rothschild, Markus A; Banaschak, Sibylle

2016-01-01

Two captive tiger attacks are presented that took place in Cologne and Münster zoos. Both attacks occurred when the handlers, intent on cleaning the enclosures, entered whilst the tigers accidently retained access to the location, and thus defended their territory against the perceived intruders. Both victims suffered fatal neck injuries from the bites. At Münster, colleagues managed to lure the tiger away from its victim to enable treatment, whilst the Cologne zoo tiger had to be shot in order to allow access to be gained. Whilst it was judged that human error led to the deaths of the experienced zookeepers, the investigation in Münster was closed as no third party was found to be at fault, whereas the Cologne zoo director was initially charged with being negligent. These charges were subsequently dismissed as safety regulations were found to be up to date.

Development of an ultra-compact mid-infrared attenuated total reflectance spectrophotometer

Science.gov (United States)

Kim, Dong Soo; Lee, Tae-Ro; Yoon, Gilwon

2014-07-01

Mid-infrared spectroscopy has been an important tool widely used for qualitative analysis in various fields. However, portable or personal use is size and cost prohibitive for either Fourier transform infrared or attenuated total reflectance (ATR) spectrophotometers. In this study, we developed an ultra-compact ATR spectrophotometer whose frequency band was 5.5-11.0 μm. We used miniature components, such as a light source fabricated by semiconductor technology, a linear variable filter, and a pyro-electric array detector. There were no moving parts. Optimal design based on two light sources, a zippered configuration of the array detector and ATR optics could produce absorption spectra that might be used for qualitative analysis. A microprocessor synchronized the pulsed light sources and detector, and all the signals were processed digitally. The size was 13.5×8.5×3.5 cm3 and the weight was 300 grams. Due to its low cost, our spectrophotometer can replace many online monitoring devices. Another application could be for a u-healthcare system installed in the bathroom or attached to a smartphone for monitoring substances in body fluids.

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.

Cadmium zinc telluride as a mid-infrared variable retarder

Science.gov (United States)

FitzGerald, William; Taherion, Saeid; Kumar, F. Joseph; Giles, David; Hore, Dennis

2018-04-01

The electro-optic behavior of cadmium zinc telluride is examined in the mid-infrared region between 3 and 11 μm, for applied DC field strengths of up to 106 V/m. The measurements performed here include full characterization of the polarization state of the transmitted light by means of the Stokes vector. We demonstrate the suitability of this material for DC variable retarder applications such as those achieved by quarter- or half-wave retardation. A comparison of two different metallic coatings for electrodes, gold and indium, reveals important differences in performance that are attributed to the homogeneity of the field through the bulk of the crystal. We illustrate that, in the case of both metals, the same electro-optic coefficients are measured, but regions of higher and lower retardation result in significant depolarization in the case of gold. Such depolarization may adversely affect the contrast ratio in a light valve, or increase the voltage necessary for the operation of an arbitrary polarization state generator.

Two-color mid-infrared spectroscopy of optically doped semiconductors

International Nuclear Information System (INIS)

Forcales, M.; Klik, M.A.J.; Vinh, N.Q.; Phillips, J.; Wells, J-P.R.; Gregorkiewicz, T.

2003-01-01

Optical doping is an attractive method to tailor photonic properties of semiconductor matrices for development of solid-state electroluminescent structures. For practical applications, thermal stability of emission obtained from these materials is required. Thermal processes can be conveniently investigated by two-color spectroscopy in the visible and the mid-infrared. Free-electron laser is a versatile high-brilliance source of radiation in the latter spectral range. In this contribution, we briefly review some of the results obtained recently by the two-color spectroscopy with a free-electron laser in different semiconductors optically doped with rare earth and transition metal ions. Effects leading to both enhancement and quenching of emission from optical dopants will be presented. For InP:Yb, Si:Er, and Si:Cu activation of particular optically induced non-radiative recombination paths will be shown. For Si:Er and Si:Ag, observation of a low temperature optical memory effect will be reported

Multivariate curve resolution using a combination of mid-infrared and near-infrared spectra for the analysis of isothermal epoxy curing reaction

Science.gov (United States)

Yamasaki, Hideki; Morita, Shigeaki

2018-05-01

Multivariate curve resolution (MCR) was applied to a hetero-spectrally combined dataset consisting of mid-infrared (MIR) and near-infrared (NIR) spectra collected during the isothermal curing reaction of an epoxy resin. An epoxy monomer, bisphenol A diglycidyl ether (BADGE), and a hardening agent, 4,4‧-diaminodiphenyl methane (DDM), were used for the reaction. The fundamental modes of the Nsbnd H and Osbnd H stretches were highly overlapped in the MIR region, while their first overtones could be independently identified in the NIR region. The concentration profiles obtained by MCR using the hetero-spectral combination showed good agreement with the results of calculations based on the Beer-Lambert law and the mass balance. The band assignments and absorption sites estimated by the analysis also showed good agreement with the results using two-dimensional (2D) hetero-correlation spectroscopy.

WISE TF: A MID-INFRARED, 3.4 {mu}m EXTENSION OF THE TULLY-FISHER RELATION USING WISE PHOTOMETRY

Energy Technology Data Exchange (ETDEWEB)

Lagattuta, David J.; Mould, Jeremy R. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia); Staveley-Smith, Lister; Hong Tao; Springob, Christopher M. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Redfern, NSW (Australia); Masters, Karen L. [Institute for Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Koribalski, Baerbel S. [CSIRO Astronomy and Space Science, Australia Telescope National Facility (ATNF) P.O. Box 76, Epping, NSW 1710 (Australia); Jones, D. Heath, E-mail: dlagattu@astro.swin.edu.au [School of Physics, Monash University, Clayton, VIC 3800 (Australia)

2013-07-10

We present a mid-infrared Tully-Fisher (TF) relation using photometry from the 3.4 {mu}m W1 band of the Wide-field Infrared Survey Explorer (WISE) satellite. The WISE TF relation is formed from 568 galaxies taken from the all-sky 2MASS Tully-Fisher (2MTF) galaxy catalog, spanning a range of environments including field, group, and cluster galaxies. This constitutes the largest mid-infrared TF relation constructed to date. After applying a number of corrections to galaxy magnitudes and line widths, we measure a master TF relation given by M{sub corr} = -22.24 - 10.05[log (W{sub corr}) - 2.5], with an average dispersion of {sigma}{sub WISE} = 0.686 mag. There is some tension between WISE TF and a preliminary 3.6 {mu}m relation, which has a shallower slope and almost no intrinsic dispersion. However, our results agree well with a more recent relation constructed from a large sample of cluster galaxies. We additionally compare WISE TF to the near-infrared 2MTF template relations, finding a good agreement between the TF parameters and total dispersions of WISE TF and the 2MTF K-band template. This fact, coupled with typical galaxy colors of (K - W1) {approx} 0, suggests that these two bands are tracing similar stellar populations, including the older, centrally-located stars in the galactic bulge which can (for galaxies with a prominent bulge) dominate the light profile.

WISE TF: A MID-INFRARED, 3.4 μm EXTENSION OF THE TULLY-FISHER RELATION USING WISE PHOTOMETRY

International Nuclear Information System (INIS)

Lagattuta, David J.; Mould, Jeremy R.; Staveley-Smith, Lister; Hong Tao; Springob, Christopher M.; Masters, Karen L.; Koribalski, Bärbel S.; Jones, D. Heath

2013-01-01

We present a mid-infrared Tully-Fisher (TF) relation using photometry from the 3.4 μm W1 band of the Wide-field Infrared Survey Explorer (WISE) satellite. The WISE TF relation is formed from 568 galaxies taken from the all-sky 2MASS Tully-Fisher (2MTF) galaxy catalog, spanning a range of environments including field, group, and cluster galaxies. This constitutes the largest mid-infrared TF relation constructed to date. After applying a number of corrections to galaxy magnitudes and line widths, we measure a master TF relation given by M corr = –22.24 – 10.05[log (W corr ) – 2.5], with an average dispersion of σ WISE = 0.686 mag. There is some tension between WISE TF and a preliminary 3.6 μm relation, which has a shallower slope and almost no intrinsic dispersion. However, our results agree well with a more recent relation constructed from a large sample of cluster galaxies. We additionally compare WISE TF to the near-infrared 2MTF template relations, finding a good agreement between the TF parameters and total dispersions of WISE TF and the 2MTF K-band template. This fact, coupled with typical galaxy colors of (K – W1) ∼ 0, suggests that these two bands are tracing similar stellar populations, including the older, centrally-located stars in the galactic bulge which can (for galaxies with a prominent bulge) dominate the light profile.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-20

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Mid-Infrared Spectrum of the Zodiacal Emission: Detection of Crystalline Silicates in Interplanetary Dust

Science.gov (United States)

Ootsubo, T.; Onaka, T.; Yamamura, I.; Ishihara, D.; Tanabe, T.; Roellig, T. L.

2003-01-01

Within a few astronomical units of the Sun the solar system is filled with interplanetary dust, which is believed to be dust of cometary and asteroidal origin. Spectroscopic observations of the zodiacal emission with moderate resolution provide key information on the composition and size distribution of the dust in the interplanetary space. They can be compared directly to laboratory measurements of candidate materials, meteorites, and dust particles collected in the stratosphere. Recently mid-infrared spectroscopic observations of the zodiacal emission have been made by two instruments on board the Infrared Space Observatory; the camera (ISOCAM) and the spectrophotometer (ISOPHOT-S). A broad excess emission feature in the 9-11 micron range is reported in the ISOCAM spectrum, whereas the ISOPHOT-S spectra in 6-12 microns can be well fitted by a blackbody radiation without spectral features.

the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. II. Framework, strategy, and first result

International Nuclear Information System (INIS)

Wright, J. T.; Griffith, R. L.; Sigurdsson, S.; Povich, M. S.; Mullan, B.

2014-01-01

We describe the framework and strategy of the Ĝ infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations' waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although GAIA will significantly improve our capability to identify the latter. We present a zeroth order null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited 'free' energy generation.

the Ĝ infrared search for extraterrestrial civilizations with large energy supplies. II. Framework, strategy, and first result

Energy Technology Data Exchange (ETDEWEB)

Wright, J. T.; Griffith, R. L.; Sigurdsson, S. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA, 16802 (United States); Povich, M. S. [Department of Physics and Astronomy, California State Polytechnic University, Pomona, 3801 West Temple Avenue, Pomona, CA 91768 (United States); Mullan, B. [Blue Marble Space Institution of Science, P.O. Box 85561, Seattle, WA 98145-1561 (United States)

2014-09-01

We describe the framework and strategy of the Ĝ infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations' waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although GAIA will significantly improve our capability to identify the latter. We present a zeroth order null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited 'free' energy generation.

The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. II. Framework, Strategy, and First Result

Science.gov (United States)

Wright, J. T.; Griffith, R. L.; Sigurdsson, S.; Povich, M. S.; Mullan, B.

2014-09-01

We describe the framework and strategy of the Ĝ infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations' waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although GAIA will significantly improve our capability to identify the latter. We present a zeroth order null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited "free" energy generation.

Determination of carbohydrates present in Saccharomyces cerevisiae using mid-infrared spectroscopy and partial least squares regression.

Science.gov (United States)

Plata, Maria R; Koch, Cosima; Wechselberger, Patrick; Herwig, Christoph; Lendl, Bernhard

2013-10-01

A fast and simple method to control variations in carbohydrate composition of Saccharomyces cerevisiae, baker's yeast, during fermentation was developed using mid-infrared (mid-IR) spectroscopy. The method allows for precise and accurate determinations with minimal or no sample preparation and reagent consumption based on mid-IR spectra and partial least squares (PLS) regression. The PLS models were developed employing the results from reference analysis of the yeast cells. The reference analyses quantify the amount of trehalose, glucose, glycogen, and mannan in S. cerevisiae. The selection and optimization of pretreatment steps of samples such as the disruption of the yeast cells and the hydrolysis of mannan and glycogen to obtain monosaccharides were carried out. Trehalose, glucose, and mannose were determined using high-performance liquid chromatography coupled with a refractive index detector and total carbohydrates were measured using the phenol-sulfuric method. Linear concentration range, accuracy, precision, LOD and LOQ were examined to check the reliability of the chromatographic method for each analyte.

Mid - infrared transmission of polycrystalline (LaSr) (MnNi)O3

International Nuclear Information System (INIS)

Laksanawati, W. D.; Kurniawan, B.; Saptari, S. A.

2016-01-01

Polycrystalline (LaSr)(MnNi)O 3 was shintesized using sol gel methods with nitrat precursors La(NO 3 ) 3 , Sr(NO 3 ) 2 , Mn(NO 3 ) 2 .4H 2 O, and Ni(NO3)2.6H2O and the different heating process. Sample (LaSr)(MnNi)O 3 with chemical formulation La 0,67 Sr 0,33 Mn 1-x Ni x O 3 with × = 0,05 and 0,10. We report the crystallite structure of La 0,67 Sr 0,33 Mn 1-x Ni x O 3 with x= 0,00 and 0,10 are single phase with characterization by X-ray diffraction. Refinement has result that crystallite size of La 0,67 Sr 0,33 Mn 0,95 Ni 0,05 O 3 is 24,67 and La 0,67 Sr 0,33 Mn 0,9 Ni 0,1 O 3 is 21,84 with crystallite system rombohedral, it show us that increasing at Ni composition influence of decreased crystallite size. Sampel (LaSr)(MnNi)O3 has been characterization with Fourier Transform Infrared with range of wave number from 450 to 4000 cm -1 were chategories at mid infrared wave. The FTIR pattern show to us that the Mn-O-Mn bounded has absorp infrared at wave number 605 cm -1 and the dominant peak at wave number 3750 cm -1 caused the hidroxy compound in sampel La 0,67 Sr 0,33 Mn 0,95 Ni 0,05 O 3 . (paper)

36 CFR 520.4 - Protection of zoo animals.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Protection of zoo animals... Protection of zoo animals. Except for official purposes, no person shall: (a) Kill, injure, or disturb any exhibit or research animal by any means except to secure personal safety; (b) Pet, attempt to pet, handle...

Static and time-resolved mid-infrared spectroscopy of Hg0.95Cd0.05Cr2Se4 spinel.

Science.gov (United States)

Barsaume, S; Telegin, A V; Sukhorukov, Yu P; Stavrias, N; Fedorov, V A; Menshchikova, T K; Kimel, A V

2017-08-16

Static and time-resolved mid-infrared spectroscopy of ferromagnetic single crystal Hg 0.95 Cd 0.05 Cr 2 Se 4 was performed below the absorption edge, in order to reveal the origin of the electronic transitions contributing to the magneto-optical properties of this material. The mid-infrared spectroscopy reveals a strong absorption peak around 0.236 eV which formerly was assigned to a transition within the selenide-chromium complexes ([Formula: see text] Se -Cr 2+ ). To reveal the sensitivity of the transition to the magnetic order, we performed the studies in a temperature range across the Curie temperature and magnetic fields across the value at which the saturation of ferromagnetic magnetization occurs. Despite the fact that the Curie temperature of this ferromagnetic semiconductor is around 107 K, the intensity of the mid-infrared transition reduces substantially increasing the temperature, so that already at 70 K the absorption peak is hardly visible. Such a dramatic decrease of the oscillator strength is observed simultaneously with the strong red-shift of the absorption edge in the magnetic semiconductor. Employing a time-resolved pump-and-probe technique enabled us to determine the lifetime of the electrons in the excited state of this optical transition. In the temperature range from 7 K to 80 K, the lifetime changes from 3 ps to 6 ps. This behavior agrees with the phenomenon of giant oscillator strength described earlier for weakly bound excitons in nonmagnetic semiconductors.

Polarization effects in above-threshold ionization with a mid-infrared strong laser field

Science.gov (United States)

Kang, Hui-Peng; Xu, Song-Po; Wang, Yan-Lan; Yu, Shao-Gang; Zhao, Xiao-Yun; Hao, Xiao-Lei; Lai, Xuan-Yang; Pfeifer, Thomas; Liu, Xiao-Jun; Chen, Jing; Cheng, Ya; Xu, Zhi-Zhan

2018-05-01

Using a semiclassical approach, we theoretically study the above-threshold ionization of magnesium by intense, mid-infrared laser pulses. The formation of low-energy structures in the photoelectron spectrum is found to be enhanced by comparing with a calculation based on the single-active electron approximation. By performing electron trajectory and recollision-time distribution analysis, we demonstrate that this phenomenon is due to the laser-induced ionic core polarization effects on the recolliding electrons. We also show that the polarization effects should be experimentally detectable. Our finding provides new insight into ultrafast control of strong-field photoionization and imaging of polar molecules.

Complementary periodic diffracting metallic nanohole and nanodipole arrays in the mid-infrared range

Science.gov (United States)

Ye, Yong-Hong; Zhang, Jia-Yu; Feng Ma, Hui; Yao, Jie; Wang, Xudong

2012-10-01

Metallic nanohole arrays and metallic nanodipole arrays are fabricated and experimentally characterized. A complementary response is observed in both transmission and reflection. For the metallic nanohole arrays, a peak (dip) in transmission (reflection) is observed at resonance whereas the metallic nanodipole arrays display a dip (peak) in transmission (reflection). The resonant frequency of both the metallic nanohole arrays and the nanodipole arrays depends on the dipole arm length, the incident angle, and the period. The resonant position of the nanohole arrays matches that of its complement, which means that Babinet's principle nearly holds for these structures in the mid-infrared region.

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

Science.gov (United States)

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

2016-01-01

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

Knowledge, Interest, and Value of Youth Zoo Visitors

Science.gov (United States)

Burris, Alexandra M.

2017-01-01

In the face of massive global extinction, the mission of zoos for conservation education has increasing importance. Zoos are in a unique position to affect the development of youth in ways that are consistent with cultivating pro-environmental behaviors. The purpose of this study was to examine three intrinsic traits of youth important to the…

The educational claims of zoos: where do we go from here?

Science.gov (United States)

Moss, Andrew; Esson, Maggie

2013-01-01

Zoos exude a certain self-confidence regarding their roles as education providers. Indeed, the education outputs of zoos are, at face value, pretty impressive, with most investing in learning opportunities for leisure visitors, education groups and in some cases, as part of their in situ programs. However, these outputs are not necessarily reliable indicators of the educational achievements of zoos. Quantity does not necessarily equate to quality, just as outputs do not necessarily lead to outcomes. Zoo-accreditation organizations such as the AZA and EAZA offer us clear insight into the strategic vision underpinning the education goals for zoo visitors; a heightened appreciation of the value of biodiversity and a connectedness with the natural world. Unsurprisingly, most zoos have educational goals that ally neatly with the vision of their respective accreditation body. Consequently, we are left with fairly narrow, top-down educational goals. This does not necessarily sit well with what we know about the unpredictability of "free choice" learning in environments such as zoos and aquariums, or what is known about public science communication. Research that seeks to explore the impacts of zoo visits often focuses on evaluating performance based on educational goals and the findings are used as a means of providing evidence of institutional achievement. However, any visitor outcome that falls outside of this narrow range could well be missed by the research. In this article, we propose that research that takes unpredictable and unexpected outcomes into account is necessary and overdue. © 2012 Wiley Periodicals, Inc.

Molecular Sex Determination of Captive Komodo Dragons (Varanus komodoensis at Gembira Loka Zoo, Surabaya Zoo, and Ragunan Zoo, Indonesia

Directory of Open Access Journals (Sweden)

SRI SULANDARI

2014-06-01

Full Text Available Captive breeding of endangered species is often difficult, and may be hampered by many factors. Sexual monomorphism, in which males and females are not easily distinguishable, is one such factor and is a common problem in captive breeding of many avian and reptile species. Species-specific nuclear DNA markers, recently developed to identify portions of sex chromosomes, were employed in this study for sex determination of Komodo dragons (Varanus Komodoensis. Each animal was uniquely tagged using a passive integrated micro-transponder (TROVAN 100A type transponders of 13 mm in length and 2 mm in diameter. The sex of a total of 81 individual Komodo dragons (44 samples from Ragunan zoo, 26 samples from Surabaya zoo, and 11 samples from Gembira Loka zoo were determined using primers Ksex 1for and Ksex 3rev. A series of preliminary PCR amplifications were conducted using DNA from individuals of known sex. During these preliminary tests, researchers varied the annealing temperatures, number of cycles, and concentrations of reagents, in order to identify the best protocol for sex determination using our sample set. We thus developed our own PCR protocol for this study, which resulted in the amplification of band A in females and band C in males. Results from band B, however, turned out to be non-determinative in our study because, for females, band B was not always visible, and for males sometimes a similar, but lighter band was also amplified, making interpretation difficult. In this study, sex determination was based mainly on the difference in size between the female-specific 812 bp fragment and the homologous, longer fragment amplified for males.

Temperature-sensitive junction transformations for mid-wavelength HgCdTe photovoltaic infrared detector arrays by laser beam induced current microscope

Energy Technology Data Exchange (ETDEWEB)

Qiu, Weicheng [College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Hu, Weida, E-mail: wdhu@mail.sitp.ac.cn; Lin, Tie; Yin, Fei; Zhang, Bo; Chen, Xiaoshuang; Lu, Wei [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Cheng, Xiang' ai, E-mail: xiang-ai-cheng@126.com; Wang, Rui [College of Photoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)

2014-11-10

In this paper, we report on the disappearance of the photosensitive area extension effect and the unusual temperature dependence of junction transformation for mid-wavelength, n-on-p HgCdTe photovoltaic infrared detector arrays. The n-type region is formed by B{sup +} ion implantation on Hg-vacancy-doped p-type HgCdTe. Junction transformations under different temperatures are visually captured by a laser beam induced current microscope. A physical model of temperature dependence on junction transformation is proposed and demonstrated by using numerical simulations. It is shown that Hg-interstitial diffusion and temperature activated defects jointly lead to the p-n junction transformation dependence on temperature, and the weaker mixed conduction compared with long-wavelength HgCdTe photodiode contributes to the disappearance of the photosensitive area extension effect in mid-wavelength HgCdTe infrared detector arrays.

Development of infrared Echelle spectrograph and mid-infrared heterodyne spectrometer on a small telescope at Haleakala, Hawaii for planetary observation

Science.gov (United States)

Sakanoi, Takeshi; Kasaba, Yasumasa; Kagitani, Masato; Nakagawa, Hiromu; Kuhn, Jeff; Okano, Shoichi

2014-08-01

We report the development of infrared Echelle spectrograph covering 1 - 4 micron and mid-infrared heterodyne spectrometer around 10 micron installed on the 60-cm telescope at the summit of Haleakala, Hawaii (alt.=3000m). It is essential to carry out continuous measurement of planetary atmosphere, such as the Jovian infrared aurora and the volcanoes on Jovian satellite Io, to understand its time and spatial variations. A compact and easy-to-use high resolution infrared spectrometer provide the good opportunity to investigate these objects continuously. We are developing an Echelle spectrograph called ESPRIT: Echelle Spectrograph for Planetary Research In Tohoku university. The main target of ESPRIT is to measure the Jovian H3+ fundamental line at 3.9 micron, and H2 nu=1 at 2.1 micron. The 256x256 pixel CRC463 InSb array is used. An appropriate Echelle grating is selected to optimize at 3.9 micron and 2.1 micron for the Jovian infrared auroral observations. The pixel scale corresponds to the atmospheric seeing (0.3 arcsec/pixel). This spectrograph is characterized by a long slit field-of-view of ~ 50 arcsec with a spectral resolution is over 20,000. In addition, we recently developed a heterodyne spectrometer called MILAHI on the 60 cm telescope. MILAHI is characterized by super high-resolving power (more than 1,500,000) covering from 7 - 13 microns. Its sensitivity is 2400 K at 9.6 micron with a MCT photo diode detector of which bandwidth of 3000 MHz. ESPRIT and MILAHI is planned to be installed on 60 cm telescope is planned in 2014.

YSOVAR: THE FIRST SENSITIVE, WIDE-AREA, MID-INFRARED PHOTOMETRIC MONITORING OF THE ORION NEBULA CLUSTER

International Nuclear Information System (INIS)

Morales-Calderon, M.; Stauffer, J. R.; Rebull, L. M.; Hillenbrand, L. A.; Carpenter, J. M.; Gutermuth, R.; Song, I.; Plavchan, P.; Whitney, B. A.; Covey, K.; De Oliveira, C. Alves; Winston, E.; McCaughrean, M. J.; Bouvier, J.; Guieu, S.; Vrba, F. J.; Holtzman, J.; Marchis, F.; Hora, J. L.; Wasserman, L. H.

2011-01-01

We present initial results from time-series imaging at infrared wavelengths of 0.9 deg 2 in the Orion Nebula Cluster (ONC). During Fall 2009 we obtained 81 epochs of Spitzer 3.6 and 4.5 μm data over 40 consecutive days. We extracted light curves with ∼3% photometric accuracy for ∼2000 ONC members ranging from several solar masses down to well below the hydrogen-burning mass limit. For many of the stars, we also have time-series photometry obtained at optical (I c ) and/or near-infrared (JK s ) wavelengths. Our data set can be mined to determine stellar rotation periods, identify new pre-main-sequence eclipsing binaries, search for new substellar Orion members, and help better determine the frequency of circumstellar disks as a function of stellar mass in the ONC. Our primary focus is the unique ability of 3.6 and 4.5 μm variability information to improve our understanding of inner disk processes and structure in the Class I and II young stellar objects (YSOs). In this paper, we provide a brief overview of the YSOVAR Orion data obtained in Fall 2009 and highlight our light curves for AA-Tau analogs-YSOs with narrow dips in flux, most probably due to disk density structures passing through our line of sight. Detailed follow-up observations are needed in order to better quantify the nature of the obscuring bodies and what this implies for the structure of the inner disks of YSOs.

Physical Characterization of Warm Spitzer Observed Near-Earth Objects

NARCIS (Netherlands)

Thomas, C. A.; Emery, J. P.; Trilling, D. E.; Delbo, M.; Hora, J. L.; Mueller, M.

2012-01-01

We have undertaken a spectroscopic observing campaign to complement the ExploreNEOs Warm Spitzer program. The combination of Spitzer derived albedos and diameters with spectroscopic data will enhance our understanding of the NEO population.

A SPITZER IRS STUDY OF INFRARED VARIABILITY IN TRANSITIONAL AND PRE-TRANSITIONAL DISKS AROUND T TAURI STARS

International Nuclear Information System (INIS)

Espaillat, C.; Furlan, E.; D'Alessio, P.; Sargent, B.; Muzerolle, J.; Nagel, E.; Calvet, N.; Watson, Dan M.

2011-01-01

We present a Spitzer IRS study of variability in 14 T Tauri stars in the Taurus and Chamaeleon star-forming regions. The sample is composed of transitional and pre-transitional objects which contain holes and gaps in their disks. We detect variability between 5 and 38 μm in all but two of our objects on timescales of 2-3 years. Most of the variability observed can be classified as seesaw behavior, whereby the emission at shorter wavelengths varies inversely with the emission at longer wavelengths. For many of the objects we can reasonably reproduce the observed variability using irradiated disk models, particularly by changing the height of the inner disk wall by ∼20%. When the inner wall is taller, the emission at the shorter wavelengths is higher since the inner wall dominates the emission at 2-8 μm. The taller inner wall casts a larger shadow on the outer disk wall, leading to less emission at wavelengths beyond 20 μm where the outer wall dominates. We discuss how the possible presence of planets in these disks could lead to warps that cause changes in the height of the inner wall. We also find that crystalline silicates are common in the outer disks of our objects and that in the four disks in the sample with the most crystalline silicates, variability on timescales of 1 week is present. In addition to explaining the infrared variability described above, planets can create shocks and collisions which can crystallize the dust and lead to short timescale variability.

Synergy Effect of Combining Fluorescence and Mid Infrared Fiber Spectroscopy for Kidney Tumor Diagnostics

Directory of Open Access Journals (Sweden)

Andrey Bogomolov

2017-11-01

Full Text Available Matching pairs of tumor and non-tumor kidney tissue samples of four patients were investigated ex vivo using a combination of two methods, attenuated total reflection mid infrared spectroscopy and fluorescence spectroscopy, through respectively prepared and adjusted fiber probes. In order to increase the data information content, the measurements on tissue samples in both methods were performed in the same 31 preselected positions. Multivariate data analysis revealed a synergic effect of combining the two methods for the diagnostics of kidney tumor compared to individual techniques.

Rapid determination of carbohydrates, ash, and extractives contents of straw using attenuated total reflectance fourier transform mid-infrared spectroscopy.

Science.gov (United States)

Tamaki, Yukihiro; Mazza, Giuseppe

2011-06-22

Analysis of the chemical components of lignocellulosic biomass is essential to understanding its potential for utilization. Mid-infrared spectroscopy and partial least-squares regression were used for rapid measurement of the carbohydrate (total glycans; glucan; xylan; galactan; arabinan; mannan), ash, and extractives content of triticale and wheat straws. Calibration models for total glycans, glucan, and extractives showed good and excellent predictive performance on the basis of slope, r², RPD, and R/SEP criteria. The xylan model showed good and acceptable predictive performance. However, the ash model was evaluated as providing only approximate quantification and screening. The models for galactan, arabinan, and mannan indicated poor and insufficient prediction for application. Most models could predict both triticale and wheat straw samples with the same degree of accuracy. Mid-infrared spectroscopic techniques coupled with partial least-squares regression can be used for rapid prediction of total glycans, glucan, xylan, and extractives in triticale and wheat straw samples.

Evaluation of chemical parameters in soft mold-ripened cheese during ripening by mid-infrared spectroscopy.

Science.gov (United States)

Martín-del-Campo, S T; Picque, D; Cosío-Ramírez, R; Corrieu, G

2007-06-01

The suitability of mid-infrared spectroscopy (MIR) to follow the evolution throughout ripening of specific physicochemical parameters in Camembert-type cheeses was evaluated. The infrared spectra were obtained directly from raw cheese samples deposited on an attenuated total reflectance crystal. Significant correlations were observed between physicochemical data, pH, acid-soluble nitrogen, nonprotein nitrogen, ammonia (NH4+), lactose, and lactic acid. Dry matter showed significant correlation only with lactose and nonprotein nitrogen. Principal components analysis factorial maps of physicochemical data showed a ripening evolution in 2 steps, from d 1 to d 7 and from d 8 to d 27, similar to that observed previously from infrared spectral data. Partial least squares regressions made it possible to obtain good prediction models for dry matter, acid-soluble nitrogen, nonprotein nitrogen, lactose, lactic acid, and NH4+ values from spectral data of raw cheese. The values of 3 statistical parameters (coefficient of determination, root mean square error of cross validation, and ratio prediction deviation) are satisfactory. Less precise models were obtained for pH.

Mid-infrared photoacoustic spectroscopy for atmospheric NO2 measurements

Science.gov (United States)

Lassen, Mikael; Lamard, Laurent; Balslev-Harder, David; Peremans, Andre; Petersen, Jan C.

2018-02-01

A photoacoustic (PA) sensor for spectroscopic measurements of NO2-N2 at ambient pressure and temperature is demonstrated. The PA sensor is pumped resonantly by a nanosecond pulsed single-mode mid-infrared (MIR) optical parametric oscillator (OPO). Spectroscopic measurements of NO2-N2 in the 3.25 μm to 3.55 μm wavelength region with a resolution bandwidth of 5 cm-1 and with a single shot detection limit of 1.6 ppmV (μmol/mol) is demonstrated. The measurements were conducted with a constant flow rate of 300 ml/min, thus demonstrating the suitability of the gas sensor for real time trace gas measurements. The acquired spectra is compared with data from the Hitran database and good agreement is found. An Allan deviation analysis shows that the detection limit at optimum integration time for the PAS sensor is 14 ppbV (nmol/mol) at 170 seconds of integration time, corresponding to a normalized noise equivalent absorption (NNEA) coefficient of 3.3×10-7 W cm-1 Hz-1/2.

THE SPITZER SPECTROSCOPIC SURVEY OF THE SMALL MAGELLANIC CLOUD (S4MC): PROBING THE PHYSICAL STATE OF POLYCYCLIC AROMATIC HYDROCARBONS IN A LOW-METALLICITY ENVIRONMENT

International Nuclear Information System (INIS)

Sandstrom, Karin M.; Bolatto, Alberto D.; Bot, Caroline; Draine, B. T.; Ingalls, James G.; Israel, Frank P.; Tielens, A. G. G. M.; Jackson, James M.; Leroy, Adam K.; Li, Aigen; Rubio, Mónica; Simon, Joshua D.; Smith, J. D. T.; Stanimirović, Snežana; Van Loon, Jacco Th.

2012-01-01

We present results of mid-infrared spectroscopic mapping observations of six star-forming regions in the Small Magellanic Cloud (SMC) from the Spitzer Spectroscopic Survey of the SMC (S 4 MC). We detect the mid-IR emission from polycyclic aromatic hydrocarbons (PAHs) in all of the mapped regions, greatly increasing the range of environments where PAHs have been spectroscopically detected in the SMC. We investigate the variations of the mid-IR bands in each region and compare our results to studies of the PAH bands in the SINGS sample and in a sample of low-metallicity starburst galaxies. PAH emission in the SMC is characterized by low ratios of the 6-9 μm features relative to the 11.3 μm feature and weak 8.6 and 17.0 μm features. Interpreting these band ratios in the light of laboratory and theoretical studies, we find that PAHs in the SMC tend to be smaller and less ionized than those in higher metallicity galaxies. Based on studies of PAH destruction, we argue that a size distribution shifted toward smaller PAHs cannot be the result of processing in the interstellar medium, but instead reflects differences in the formation of PAHs at low metallicity. Finally, we discuss the implications of our observations for our understanding of the PAH life-cycle in low-metallicity galaxies—namely that the observed deficit of PAHs may be a consequence of PAHs forming with smaller average sizes and therefore being more susceptible to destruction under typical interstellar medium conditions.

Fourier Transform Infrared Spectroscopic Studies Of Wheat In The Mid Infrared

Science.gov (United States)

Olinger, Jill M.; Griffiths, Peter R.

1989-12-01

Official grain standards of the United States state that wheat may be divided into seven classes which are: Durum, Red Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, White, and Mixed.1 Most end uses of wheat involve converting the grain into flour through one of a variety of grinding methods. The quality of wheat-based products is often very dependent upon the type or class of wheat which was used to make the flour. Pasta products, for example, are made almost exclusively from the flour of durum wheats, which are the hardest of the wheats listed above. The highest quality breads are produced using flour from wheats classed as hard, whereas cakes, cookies and pastries are considered best when flour from wheats classed as soft are used. It is obvious then that the capability of determining the class of a particular wheat, especially with respect to hardness, is of economic importance to growers, processors, and merchants of wheat and wheat products. Hardness has been measured in many different ways 2-5 but, as of yet, no one method has become the method of choice. This paper reports on the use of principal components analysis (PCA) of mid infrared diffuse reflectance (DR) spectra of diluted ground wheats to aid in the classification of those wheats with respect to their hardness. The theory and mathematics involved in a principal component analysis have been described elsewhere.9

Long Term Preservation of Data Analysis Software at the NASA/IPAC Infrared Science Archive

NARCIS (Netherlands)

Teplitz, H.I.; Groom, S.; Brooke, T.; Desai, V.; Engler, D.; Fowler, J.; Good, J.; Khan, I.; Levine, D.; Alexov, A.

2012-01-01

The NASA/IPAC Infrared Science Archive (IRSA) curates both data and analysis tools from NASA's infrared missions. As part of our primary goal, we provide long term access to mission-specific software from projects such as IRAS and Spitzer. We will review the efforts by IRSA (and within the greater

Fugitive methane leak detection using mid-infrared hollow-core photonic crystal fiber containing ultrafast laser drilled side-holes

Science.gov (United States)

Karp, Jason; Challener, William; Kasten, Matthias; Choudhury, Niloy; Palit, Sabarni; Pickrell, Gary; Homa, Daniel; Floyd, Adam; Cheng, Yujie; Yu, Fei; Knight, Jonathan

2016-05-01

The increase in domestic natural gas production has brought attention to the environmental impacts of persistent gas leakages. The desire to identify fugitive gas emission, specifically for methane, presents new sensing challenges within the production and distribution supply chain. A spectroscopic gas sensing solution would ideally combine a long optical path length for high sensitivity and distributed detection over large areas. Specialty micro-structured fiber with a hollow core can exhibit a relatively low attenuation at mid-infrared wavelengths where methane has strong absorption lines. Methane diffusion into the hollow core is enabled by machining side-holes along the fiber length through ultrafast laser drilling methods. The complete system provides hundreds of meters of optical path for routing along well pads and pipelines while being interrogated by a single laser and detector. This work will present transmission and methane detection capabilities of mid-infrared photonic crystal fibers. Side-hole drilling techniques for methane diffusion will be highlighted as a means to convert hollow-core fibers into applicable gas sensors.

Restraint deformation and corrosion protection of gold deposited aluminum mirrors for cold optics of mid-infrared instruments

Science.gov (United States)

Uchiyama, Mizuho; Miyata, Takashi; Sako, Shigeyuki; Kamizuka, Takafumi; Nakamura, Tomohiko; Asano, Kentaro; Okada, Kazushi; Onaka, Takashi; Sakon, Itsuki; Kataza, Hirokazu; Sarugaku, Yuki; Kirino, Okiharu; Nakagawa, Hiroyuki; Okada, Norio; Mitsui, Kenji

2014-07-01

We report the restraint deformation and the corrosion protection of gold deposited aluminum mirrors for mid-infrared instruments. To evaluate the deformation of the aluminum mirrors by thermal shrinkage, monitoring measurement of the surface of a mirror has been carried out in the cooling cycles from the room temperature to 100 K. The result showed that the effect of the deformation was reduced to one fourth if the mirror was screwed with spring washers. We have explored an effective way to prevent the mirror from being galvanically corroded. A number of samples have been prepared by changing the coating conditions, such as inserting an insulation layer, making a multi-layer and overcoating water blocking layer, or carrying out precision cleaning before coating. Precision cleaning before the deposition and protecting coat with SiO over the gold layer seemed to be effective in blocking corrosion of the aluminum. The SiO over-coated mirror has survived the cooling test for the mid-infrared use and approximately 1 percent decrease in the reflectance has been detected at 6-25 microns compared to gold deposited mirror without coating.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-11-10

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

I Love Petting Zoos!

Centers for Disease Control (CDC) Podcasts

2010-03-23

This Kidtastics podcast helps children learn about how to stay safe and healthy when visiting petting zoos and other animal exhibits.  Created: 3/23/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/23/2010.

NATO Advanced Research Workshop on Terahertz and Mid Infrared Radiation

CERN Document Server

Pereira, Mauro F; Terahertz and Mid Infrared Radiation

2011-01-01

Terahertz (THz) and Mid-Infrared (MIR) radiation  (TERA-MIR) can be transmitted through nearly any material without causing biological harm. Novel and rapid methods of detection can be created with devices operation in these spectral ranges allowing scanning for weapons, detecting hidden explosives (including plastic landmines), controlling the quality of food and a host of other exciting applications.  This book focuses on mathematical and physical aspects of the field, on unifying these two spectral domains (THz and MIR) with regard to common sources, detectors, materials and applications, and on key interdisciplinary topics. The main THz and MIR source is the quantum cascade laser (QCL). Thus significant attention is paid to the challenge of turning this advanced technology into affordable commercial devices so as to exploit its enormous potential. However other alternatives to THz QCLs are also presented, e.g.  sub-terahertz imaging from avalanching GaAs bipolar transistors, Josephson junctions as THz ...

Mesoscopic modeling of the response of human dental enamel to mid-infrared radiation

Science.gov (United States)

Vila Verde, Ana; Ramos, Marta; Stoneham, A. M.

2006-03-01

Ablation of human dental enamel, a composite biomaterial with water pores, is of significant importance in minimally invasive laser dentistry but progress in the area is hampered by the lack of optimal laser parameters. We use mesoscopic finite element models of this material to study its response to mid-infrared radiation. Our results indicate that the cost-effective, off-the-shelf CO2 laser at λ = 10.6 μm may in fact ablate enamel precisely, reproducibly and with limited unwanted side effects such as cracking or heating, provided that a pulse duration of 10 μs is used. Furthermore, our results also indicate that the Er:YAG laser (λ = 2.94 μm), currently popular for laser dentistry, may in fact cause unwanted deep cracking in the enamel when regions with unusually high water content are irradiated, and also provide an explanation for the large range of ablation threshold values observed for this material. The model may be easily adapted to study the response of any composite material to infrared radiation and thus may be useful for the scientific community.

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

DEFF Research Database (Denmark)

Farrah, Duncan; Baloković, Mislav; Stern, Daniel

2016-01-01

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

Mid-infrared spectroscopy of starbursts : from Spitzer-IRS to JWST-MIRI

NARCIS (Netherlands)