A REDSHIFT SURVEY OF HERSCHEL FAR-INFRARED SELECTED STARBURSTS AND IMPLICATIONS FOR OBSCURED STAR FORMATION

Journal Article · Thu Dec 20 00:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/761/2/140· OSTI ID:22139972

Casey, C. M.; Budynkiewicz, J. ^[1]; Berta, S.; Lutz, D.; Magnelli, B. ^[2]; Bethermin, M.; Le Floc'h, E.; Magdis, G. ^[3]; Bock, J.; Bridge, C. ^[4]; Burgarella, D. ^[5]; Chapin, E. ^[6]; Chapman, S. C. ^[7]; Clements, D. L. ^[8]; Conley, A. ^[9]; Conselice, C. J. ^[10]; Cooray, A. ^[11]; Farrah, D. ^[12]; Hatziminaoglou, E. ^[13]; Ivison, R. J. ^[14] ; others, and

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1. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
2. Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, 85748 Garching (Germany)
3. Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu - CNRS - Universite Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France)
4. California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States)
5. Laboratoire d'Astrophysique de Marseille - LAM, Universite d'Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, 13388 Marseille Cedex 13 (France)
6. Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)
7. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
8. Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)
9. Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States)
10. School of Physics and Astronomy, University of Nottingham, NG7 2RD (United Kingdom)
11. Dept. of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)
12. Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States)
13. ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei Muenchen (Germany)
14. UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

We present Keck spectroscopic observations and redshifts for a sample of 767 Herschel-SPIRE selected galaxies (HSGs) at 250, 350, and 500 {mu}m, taken with the Keck I Low Resolution Imaging Spectrometer and the Keck II DEep Imaging Multi-Object Spectrograph. The redshift distribution of these SPIRE sources from the Herschel Multitiered Extragalactic Survey peaks at z = 0.85, with 731 sources at z < 2 and a tail of sources out to z {approx} 5. We measure more significant disagreement between photometric and spectroscopic redshifts (({Delta}z/(1 + z{sub spec})) = 0.29) than is seen in non-infrared selected samples, likely due to enhanced star formation rates and dust obscuration in infrared-selected galaxies. The infrared data are used to directly measure integrated infrared luminosities and dust temperatures independent of radio or 24 {mu}m flux densities. By probing the dust spectral energy distribution (SED) at its peak, we estimate that the vast majority (72%-83%) of z < 2 Herschel-selected galaxies would drop out of traditional submillimeter surveys at 0.85-1 mm. We find that dust temperature traces infrared luminosity, due in part to the SPIRE wavelength selection biases, and partially from physical effects. As a result, we measure no significant trend in SPIRE color with redshift; if dust temperature were independent of luminosity or redshift, a trend in SPIRE color would be expected. Composite infrared SEDs are constructed as a function of infrared luminosity, showing the increase in dust temperature with luminosity, and subtle change in near-infrared and mid-infrared spectral properties. Moderate evolution in the far-infrared (FIR)/radio correlation is measured for this partially radio-selected sample, with q{sub IR}{proportional_to}(1 + z){sup -0.30{+-}0.02} at z < 2. We estimate the luminosity function and implied star formation rate density contribution of HSGs at z < 1.6 and find overall agreement with work based on 24 {mu}m extrapolations of the LIRG, ULIRG, and total infrared contributions. This work significantly increased the number of spectroscopically confirmed infrared-luminous galaxies at z >> 0 and demonstrates the growing importance of dusty starbursts for galaxy evolution studies and the build-up of stellar mass throughout cosmic time.

• OSTI ID: 22139972
• Journal Information: Astrophysical Journal, Vol. 761, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTRONOMY
ASTROPHYSICS
COLOR
CORRELATIONS
COSMIC DUST
EMISSION SPECTROSCOPY
ENERGY SPECTRA
FLUX DENSITY
GALAXIES
LUMINOSITY
MASS
PHOTOMETRY
RED SHIFT
RESOLUTION
STAR EVOLUTION
STARS
WAVELENGTHS