A deep ATCA 20 cm radio survey of the AKARI Deep Field South near the South Ecliptic Pole


E-mail: G.J.White@open.ac.uk


The results of a deep radio survey at 20 cm wavelength are reported for a region containing the AKARI Deep Field South (ADF-S) near the South Ecliptic Pole (SEP), using the Australia Telescope Compact Array (ATCA). The survey (hereafter referred to as the ATCA-ADFS survey) has 1σ detection limits ranging from 18.7 to 50 μJy beam−1 over an area of ∼1.1 deg2, and ∼2.5 deg2 to lower sensitivity. The observations, data reduction and source count analysis are presented along with a description of the overall scientific objectives, and a catalogue containing 530 radio sources detected with a resolution of 6.2 × 4.9 arcsec. The derived differential source counts show a pronounced excess of sources fainter than ∼1 mJy, consistent with an emerging population of star-forming galaxies. Cross-correlating the radio with AKARI sources and archival data we find 95 cross-matches, with most galaxies having optical R-magnitudes in the range 18–24 mag, similar to that found in other optical deep field identifications, and 52 components lying within 1 arcsec of a radio position in at least one further catalogue (either IR or optical). We have reported redshifts for a sub-sample of our catalogue finding that they vary between galaxies in the local Universe and those having redshifts of up to 0.825. Associating the radio sources with the Spitzer catalogue at 24 μm, we find 173 matches within one Spitzer pixel, of which a small sample of the identifications are clearly radio loud compared to the bulk of the galaxies. The radio luminosity plot and a colour–colour analysis suggest that the majority of the radio sources are in fact luminous star-forming galaxies rather than radio-loud active galactic nuclei (AGN). There are additionally five cross-matches between the Atacama Submillimetre Telescope Experiment (ASTE) or the Balloon-borne Large Aperture Submillimetre Telescope (BLAST) galaxies and radio sources from this survey, two of which are also detected at 90 μm, and 41 cross-matches with submillimetre sources detected in the Herschel Multi-tiered Extragalactic Survey (HerMES) Public Data release.