T he ultra - deep 20 cm Australia telescope survey of the Chandra Deep Field South

The advent of ultra-deep X-ray surveys with telescopes such as Chandra and XMM, together with deep multi-waveband ground-based and HST imaging covering radio and optical /near-IR wavelengths, allows us to directly probe the detailed properties of the environments, host galaxies and central accretion disks of both radio-loud and radio-quiet active galaxies up to cosmological redshifts. Here we present results from our ultra-deep 20 cm radio survey with the Australia Telescope of the Chandra Deep Field South, as part of the multi-waveband GOODS project. We present results on a sample of AGN selected on the basis of exhibiting both X-ray and radio emission. The relationship between X-ray, radio and optical properties are discussed in the context of the physical processes responsible for this emission, and how these in turn govern the observed differences between the various classes of sources in our sample.  2003 Elsevier B.V. All rights reserved.