The Infrared Properties of Sources Matched in the WISE All-sky and Herschel ATLAS Surveys
Abstract
We describe the infrared properties of sources detected over ~36 deg^2 of sky in the GAMA 15 hr equatorial field, using data from both the Herschel Astrophysical Terahertz Large-Area Survey (H-ATLAS) and Wide-field Infrared Survey (WISE). With 5σ point-source depths of 34 and 0.048 mJy at 250 μm and 3.4 μm, respectively, we are able to identify 50.6% of the H-ATLAS sources in the WISE survey, corresponding to a surface density of ~630 deg^(–2). Approximately two-thirds of these sources have measured spectroscopic or optical/near-IR photometric redshifts of z < 1. For sources with spectroscopic redshifts at z < 0.3, we find a linear correlation between the infrared luminosity at 3.4 μm and that at 250 μm, with ±50% scatter over ~1.5 orders of magnitude in luminosity, ~10^9-10^(10.5) L_☉. By contrast, the matched sources without previously measured redshifts (r ≳ 20.5) have 250-350 μm flux density ratios which suggest either high-redshift galaxies (z ≳ 1.5) or optically faint low-redshift galaxies with unusually low temperatures (T ≾ 20). Their small 3.4-250 μm flux ratios favor a high-redshift galaxy population, as only the most actively star-forming galaxies at low redshift (e.g., Arp 220) exhibit comparable flux density ratios. Furthermore, we find a relatively large active galactic nucleus fraction (~30%) in a 12 μm flux-limited subsample of H-ATLAS sources, also consistent with there being a significant population of high-redshift sources in the no-redshift sample.
Additional Information
© 2012 American Astronomical Society. Received 2011 November 28; accepted 2012 March 21; published 2012 April 12. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia with significant participation from NASA. U.S. participants in Herschel ATLAS acknowledge support provided by NASA through a contract issued from JPL. In addition, we thank Dan Stern and Roberto Assef for helpful discussions about the quasar selection.Attached Files
Published - Bond2012p18128Astrophys_J_Lett.pdf
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Additional details
- Eprint ID
- 31443
- Resolver ID
- CaltechAUTHORS:20120514-075213078
- NASA/JPL/Caltech
- Created
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2012-05-14Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)