The XMM-Newton wide-field survey in the COSMOS field. IV: X-ray spectral   properties of Active Galactic Nuclei
  We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through optical spectroscopy. The majority of the sources are well described by a simple power-law model with either no absorption (76%) or a significant intrinsic, absorbing column (20%).As expected, the distribution of intrinsic absorbing column densities is markedly different between AGN with or without broad optical emission lines. We find within our sample four Type-2 QSOs candidates (L_X > 10^44 erg/s, N_H > 10^22 cm^-2), with a spectral energy distribution well reproduced by a composite Seyfert-2 spectrum, that demonstrates the strength of the wide field XMM/COSMOS survey to detect these rare and underrepresented sources. 
V. Mainieri (MPE & ESO), G. Hasinger (MPE), N. Cappelluti (MPE), M.   Brusa (MPE), H. Brunner (MPE), F. Civano (INAF-OABo), ...