1307.0527 (O. Melnyk et al.)

Classification and environmental properties of X-ray selected point-like sources in the XMM-LSS field    [PDF]

O. Melnyk, M. Plionis, A. Elyiv, M. Salvato, L. Chiappetti, N. Clerc, P. Gandhi, M. Pierre, T. Sadibekova, A. Pospieszalska-Surdej, J. Surdej

The XMM-Large Scale Structure survey, covering an area of 11.1 sq. deg., contains more than 6000 X-ray point-like sources detected with XMM-Newton down to a flux of 3x10^-15 erg s^-1 cm^-2 in the [0.5-2] keV band, the vast majority of which have optical (CFHTLS), infrared (SWIRE), near-infrared (UKIDSS) and/or ultraviolet (GALEX) counterparts. We wish to investigate the environmental properties of the different types of the XMM-LSS X-ray sources, defining their environment using the i-band CFHTLS W1 catalog of optical galaxies down to a magnitude limit of 23.5 mag. We have classified 4435 X-ray selected sources on the basis of their spectra, SEDs and X-ray luminosity and estimated their photometric redshifts, having 4-11 band photometry, with an accuracy sigma=0.076 and 22.6% outliers for i<26 mag. We estimated the local overdensities of 777 X-ray sources which have spectro-z or photo-z calculated using more than 7 bands (accuracy sigma=0.061 with 13.8% outliers) within the volume-limited region defined by 0.1=-0.2) are located in more overdense regions with respect to the Soft AGN (HR<-0.2), a fact clearly seen in both redshift ranges, although it appears to be stronger in the higher redshift range (0.551.5) within which Soft AGN are embedded appear to evolve more rapidly with respect to the corresponding overdensities around Hard AGN.

View original: http://arxiv.org/abs/1307.0527