Abstract

The recently completed Australia Telescope 20 GHz (AT20G) survey is a blind survey of the southern sky down to a limiting flux density of 40 mJy. As such, it provides by far the largest and most complete sample of high-frequency radio sources yet obtained, offering new insights into the nature of the high-frequency active galaxy population. Observations were carried out using the Australia Telescope Compact Array from 2004-2008 with the final catalogue consisting of nearly 6000 sources. In this talk I will present a brief overview of the AT20G survey and focus on some of the multi-wavelength properties of these sources. In particular, we find a large number of AT20G sources are also detected in gamma-rays in the Fermi-LAT 1-year Point Source Catalogue (1FGL; Abdo et al. 2010). Results from this cross matching also reveal a correlation between high-frequency radio flux density and gamma-ray flux density.