Lockman Hole/XMM VLBI observations

However, identifying them is difficult, since radio observations typically have a resolution between 1arcsec and 10arcsec, which is equally sensitive to radio emission from star-forming activity and from AGN. Very Long Baseline Interferometry (VLBI) observations allow only the most compact non-thermal emission to be to be filtered from radio survey data.

The observational and computational demands to do this in large surveys have, until recently, been too high to make this practical. Only the recent advent of wide-field observing techniques have enabled such observations, and we here present the results of a survey of 217 radio sources in the Lockman Hole/XMM field. We detected 65 out of the 217 radio sources and were able to construct, for the first time, the source counts of VLBI-detected AGN.