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Title: Multi-wavelength seds of Herschel-selected galaxies in the cosmos field

We combine Herschel Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging Receiver maps of the full 2 deg{sup 2} Cosmic Evolution Survey (COSMOS) field with existing multi-wavelength data to obtain template and model-independent optical-to-far-infrared spectral energy distributions (SEDs) for 4218 Herschel-selected sources with log(L {sub IR}/L {sub ☉}) = 9.4-13.6 and z = 0.02-3.54. Median SEDs are created by binning the optical to far-infrared (FIR) bands available in COSMOS as a function of infrared luminosity. Herschel probes rest-frame wavelengths where the bulk of the infrared radiation is emitted, allowing us to more accurately determine fundamental dust properties of our sample of infrared luminous galaxies. We find that the SED peak wavelength (λ{sub peak}) decreases and the dust mass (M {sub dust}) increases with increasing total infrared luminosity (L {sub IR}). In the lowest infrared luminosity galaxies (log(L {sub IR}/L {sub ☉}) = 10.0-11.5), we see evidence of polycyclic aromatic hydrocarbon (PAH) features (λ ∼ 7-9 μm), while in the highest infrared luminosity galaxies (L {sub IR} > 10{sup 12} L {sub ☉}) we see an increasing contribution of hot dust and/or power-law emission, consistent with the presence of heating from an active galactic nucleus (AGN). We study themore » relationship between stellar mass and star formation rate of our sample of infrared luminous galaxies and find no evidence that Herschel-selected galaxies follow the SFR/M {sub *} 'main sequence' as previously determined from studies of optically selected, star-forming galaxies. Finally, we compare the mid-infrared to FIR properties of our infrared luminous galaxies using the previously defined diagnostic, IR8 ≡ L {sub IR}/L {sub 8}, and find that galaxies with L {sub IR} ≳ 10{sup 11.3} L {sub ☉} tend to systematically lie above (× 3-5) the IR8 'infrared main sequence', suggesting either suppressed PAH emission or an increasing contribution from AGN heating.« less
Authors:
; ; ;  [1] ; ; ;  [2] ; ;  [3] ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11]
  1. Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  2. California Institute of Technology, MS 105-24, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
  3. UMR AIM (CEA-UP7-CNRS), CEA-Saclay, Orme des Merisiers, Bât. 709, F-91191 Gif-sur-Yvette Cedex (France)
  4. Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France)
  5. National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)
  6. Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
  7. Max-Planck for Extraterrestrial Physics, Giessenbachstrasse 1, D-85748 Garching (Germany)
  8. European Southern Observatory, Alonso de Córdova 3107, Vitacura Santiago (Chile)
  9. Max-Planck-Institut für Extraterrestrische Physik (MPE), Postfach 1312, D-85741 Garching (Germany)
  10. NASA Ames Research Center, Moffett Field, CA (United States)
  11. Department of Physics and Astronomy, University of Sussex, Pevensey 2 Building, Falmer, Brighton BN1 9QH, Sussex (United Kingdom)
Publication Date:
OSTI Identifier:
22341923
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; DUSTS; EMISSION; ENERGY SPECTRA; EVOLUTION; GALAXIES; INFRARED RADIATION; LUMINOSITY; MASS; POLYCYCLIC AROMATIC HYDROCARBONS; RED SHIFT; SPECTROMETERS; STARS; UNIVERSE; WAVELENGTHS