2007A&A...471.1105T

The low-frequency radio survey of the XMM-Large Scale Structure (XMM-LSS) field aims to study the connection between the extragalactic radio source populations and their environment as traced by X-ray and optical emission. In this paper we present new radio observations of the XMM-LSS field carried out using the Giant Meterwave Radio Telescope at 240 and 610MHz. These observations complement the observations presented by Cohen at al. (2003ApJ...591..640C) and Tasse et al. (2006A&A...456..791T) at 74 and 325MHz with the Very Large Array. At 240 and 610MHz, we reach noise levels of ∼2.5 and ∼0.3mJy/beam, leading to the detection of 466 and 769 sources over 18.0 and 12.7degree² with resolutions of 14.7'' and 6.5'' respectively. Combining these data with the available source lists at 74, 325 (Tasse et al., 2006A&A...456..791T) and 1400MHz (NVSS), we build a multifrequency catalogue containing 1611 radio sources. We check for consistency of the astrometry and flux density estimates. We fit a simple synchrotron radiation model to the flux density measurements of the 318 radio sources being detected in at least 4 bands. While ∼26% of them show signature of spectral ageing, ∼6% show self absorption.