The XMM-Newton survey in the H-ATLAS field

Wide-area X-ray and far-infrared surveys are a fundamental tool to investigate the link between AGN growth and star formation, especially in the low-redshift universe (z less than or similar to 1). The Herschel Terahertz Large Area survey (H-ATLAS) has covered 550 deg(2) in five far-infrared and sub-mm bands, 16 deg(2) of which have been presented in the Science Demonstration Phase (SDP) catalogue. Here we introduce the XMM-Newton observations in the H-ATLAS SDP area, covering 7.1 deg(2) with flux limits of 2 x 10(-15), 6 x 10(-15), and 9x10(-15) erg s(-1) cm(-2) in the 0.5-2, 0.5-8, and 2-8 keV bands, respectively. We present the source detection and the catalogue, which includes 1700, 1582, and 814 sources detected by EMLDetect in the 0.5-8, 0.5-2, and 2-8 keV bands, respectively; the number of unique sources is 1816. We extract spectra and derive fluxes from power-law fits for 398 sources with more than 40 counts in the 0.5-8 keV band. We compare the best-fit fluxes with those in the catalogue, which are obtained assuming a common photon index of Gamma = 1.7; we find no bulk difference between the fluxes and a moderate dispersion of s = 0.33 dex. Using the fluxes from the spectral fits wherever possible, we derive the 2-10 keV Log N-Log S, which is consistent with a Euclidean distribution. Finally, we release the computer code for the tools developed for this project.