The XMM-Newton serendipitous survey *

We present the first results on the identifications of a medium sensitivity survey (X-ray flux limit $2\times 10^{-14}\, {\rm erg}\, {\rm cm}^{-2}\, {\rm s}^{-1}$in the 0.5–4.5 keV band) at high galactic latitude (${{\mid}b{\mid}}>20^{\circ}$) carried out with the XMM-Newton X-ray observatory within the AXIS observing programme. This study is being conducted as part of the XMM-Newton Survey Science Centre activities towards the identification of the sources in the X-ray serendipitous sky survey. The sample contains 29 X-ray sources in a solid angle of $0.26\deg^2$(source density $113\pm 21$sources $\deg^{-2}$), out of which 27 (93%) have been identified. The majority of the sources are broad-line AGN (19), followed by narrow emission line X-ray emitting galaxies (6, all of which turn out to be AGN), 1 nearby non-emission line galaxy (NGC 4291) and 1 active coronal star. Among the identified sources we find 2 broad-absorption line QSOs ($z\sim 1.8$and $z\sim 1.9$), which constitute ~10% of the AGN population at this flux level, similar to optically selected samples. Identifications of a further 10 X-ray sources fainter than our survey limit are also presented.