BORNANCINI, C.; GARCIA LAMBAS, D.

Malargüe

Workshop; 50º Reunión Anual de la Asociación Argentina de Astronomía; 2007

IAFE

We study the Distant Red Galaxy (DRG, J-Ks > 2.3) neighbourpopulation of Quasi Stellar Objects (QSOs) selected from the SloanDigital Sky Survey (SDSS) in the redshift range 1 < z < 2. Weperform a similar analysis for optically obscured AGNs (i.e. with alimiting magnitude I > 24) detected in the mid-infrared (24 microns)with the Spitzer Space Telescope and a mean redshift z~2.2 in theFlamingos Extragalactic Survey (FLAMEX). We present results on thecross-correlation function of DRGs around QSOs and optically faintmid-infrared sources. The corresponding correlation length obtained forthe QSO sample targets is r_0=5.4+/-1.6Mpc. For the optically obscured galaxy sample we find r_0=8.9+/-1.4 Mpc.These results indicate that optically faint obscured sources are locatedin denser environment of evolved red galaxies compare to QSOs.