OPTICAL AND X-RAY IDENTIFICATION OF FAINT RADIO SOURCES IN THE GOODS CDF-S ADVANCED CAMERA FOR SURVEYS FIELD

We present optical and X-ray identifications for the 64 radio sources in the Great Observatories Origins Deep Survey Chandra Deep Field–South Advanced Camera for Surveys (ACS) field revealed in the Australia Telescope Compact Array 1.4 GHz survey of the Chandra Deep Field–South. Optical identifications are made using the ACS images and catalogs, while the X-ray view is provided by the Chandra X-Ray Observatory 1 Ms observations. Redshifts for the identified sources are drawn from publicly available catalogs of spectroscopic observations and multiband photometric-based estimates. Using this multiwavelength information we provide a first characterization of the faint radio source population in this region. The sample contains a mixture of star-forming galaxies and active galactic nuclei, as identified by their X-ray properties and optical spectroscopy. A large number of morphologically disturbed galaxies are found, possibly related to star formation. In spite of the very deep optical data available in this field, seven of the 64 radio sources have no optical identification to z850 ~28 mag. Only one of these is identified in the X-ray.