Cosmological constraints from X-ray AGN clustering and type Ia supernova data

We put constraints on the main cosmological parameters of different spatially flat cosmological models by combining the recent clustering results of XMM-Newton soft (0.5-2 keV) X-ray sources, which have a redshift distribution with median redshift z similar to 1.2, and Type Ia supernova data. Using a likelihood procedure we find that the model that best reproduces the observational data and which is consistent with stellar ages is the concordance cold dark matter model with omega m similar or equal to 0.28, w similar or equal to-1, H-0 72 km s(-1) Mpc(-1) and t(0)similar or equal to 13.5 Gyr, and has an X-ray active galactic nucleus clustering evolution which is constant in physical coordinates. For a different clustering evolution model (constant in comoving coordinates) we find another viable model, although less probable because of the smaller age of the universe, with omega(m)similar or equal to 0.38, w similar or equal to-1.25, H-0 70 km s(-1) Mpc(-1) and t(0)similar or equal to 12.9 Gyr.