[en] Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample with wide multiwavelength coverage. We selected a sample of 136 X-ray sources detected at a significance of >=3{sigma} in the 2-10keV band (F[SUB]2-10[/SUB]>~10[SUP]-14[/SUP]erg/cm[SUP]2[/SUP]/s) in a ~1deg[SUP]2[/SUP] area in the XMM Medium Deep Survey (XMDS, Cat. ). The XMDS area is covered with optical photometry from the VVDS and CFHTLS surveys and infrared Spitzer data from the SWIRE survey. Based on the X-ray luminosity and X-ray to optical ratio, 132 sources are likely AGN, of which 122 have unambiguous optical - IR identification. The observed optical and IR spectral energy distributions of all identified sources are fitted with AGN/galaxy templates in order to classify them and compute photometric redshifts. X-ray spectral analysis is performed individually for sources with a sufficient number of counts and using a stacking technique for subsamples of sources at different flux levels. Hardness ratios are used to estimate X-ray absorption in individual weak sources. (1 data file).
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Tajer, M.
Polletta, M.
Chiappetti, L.
Maraschi, L.
Trinchieri, G.
Maccagni, D.
Andreon, S.
Garcet, O.
Surdej, Jean ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astroph. extragalactique et observations spatiales (AEOS)