Deep ATLAS Radio Observations of the Chandra Deep Field?South/SpitzerWide?Area Infrared Extragalactic Field

Abstract

We present the first results from the Australia Telescope Large Area Survey, which consists of deep radio observations of a 3.7 deg2 field surrounding the Chandra Deep Field-South, largely coincident with the infrared Spitzer Wide-Area Infrared Extragalactic (SWIRE) Survey. We also list cross-identifications to infrared and optical photometry data from SWIRE, and ground-based optical spectroscopy. A total of 784 radio components are identified, corresponding to 726 distinct radio sources, nearly all of which are identified with SWIRE sources. Of the radio sources with measured redshifts, most lie in the redshift range 0.5-2 and include both star-forming galaxies and active galactic nuclei. We identify a rare population of infrared-faint radio sources that are bright at radio wavelengths but are not seen in the available optical, infrared, or X-ray data. Such rare classes of sources can only be discovered in wide, deep surveys such as this.