The log(N)-log(S) and the Broadband Properties of the Sources in the   HELLAS2XMM Survey
  We present the first results from an XMM-Newton serendipitous medium-deep survey, which covers nearly three square degrees. We show the log(N)-log(S) distributions for the 0.5-2, 2-10 and 5-10 keV bands, which are found to be in good agreement with previous determinations and with the predictions of XRB models. In the soft band we detect a break at fluxes around 5x10^-15 cgs. In the harder bands, we fill in the gap at intermediate fluxes between deeper Chandra and XMM-Newton observations and shallower BeppoSAX and ASCA surveys. Moreover, we present an analysis of the broad-band properties of the sources. 
A. Baldi, S. Molendi, A. Comastri, F. Fiore, G. Matt, C. Vignali (for   the HELLAS2XMM collaboration)