Microjansky Sources at 1.4 GH[CLC]z[/CLC]

Abstract

We present a deep 1.4 GHz survey made with the Australia Telescope Compact Array, having a background rms of 9 μJy near the image phase center, up to 25 μJy at the edge of a 50′ field of view. Over 770 radio sources brighter than 45 μJy have been cataloged in the field. The differential source counts in the deep field provide tentative support for the growing evidence that the microjansky radio population exhibits significantly higher clustering than found at higher flux density cutoffs. The optical identification rate on CCD images is approximately 50% to R = 22.5, and the optical counterparts of the faintest radio sources appear to be mainly single galaxies close to this optical magnitude limit.