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~ 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 concordanceΛ cold dark matter model with Ω_m~= 0.28, w ~=-1, H₀~= 72kms^-1Mpc^-1 and t₀~= 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 Ω_m~= 0.38, w ~=-1.25, H₀~= 70kms^-1Mpc^-1 and t₀~= 12.9 Gyr.