The Low Frequency Radio Counterpart of the XMM Large Scale Structure Survey

Abstract

The XMM Large Scale Structure Survey (XMM-LSS) is a major project to map the large scale structure of the universe out to cosmological distances. An 8 degree by 8 degree region will be surveyed by XMM with planned optical follow-up to produce a three-dimensional map of many hundreds of clusters out to a redshift of z = 1. To explore the relation of the large scale structure to the location and properties of extragalactic radio sources, the XMM-LSS project also includes a low frequency radio survey of this region. This combination will provide unprecedented insight into how the radio source formation and evolution are affected by the local environment. Here, we present preliminary results from our 325 MHz and 74 MHz surveys in this region. At 325 MHz, we have a flux limit of 4 mJy/beam, a resolution of 6.3", and a total of 256 source detections over 5.6 square degrees. At 74 MHz, we have a flux limit of 275 mJy/beam, a resolution of 30", and a total of 211 source detections over 110 square degrees. We describe these results and explore what they tell us about the population of extra-galactic low frequency radio sources. The 74 MHz survey represents the first presentation of a deep, sub-arcminute resolution survey at such a low frequency. This was made possible by recent advances in both hardware and data reduction algorithms which we describe in detail.