Cosmological constrains from X-ray AGN clustering and SNIa data

Abstract

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 $z\sim 1.2$, and SNIa data. Using a likelihood procedure we find that the model which best reproduces the observational data and that is consistent with stellar ages is the concordance $\Lambda$CDM model with: ${\Omega }_{\mathrm{m}}\simeq 0.28$, $w\simeq -1$, $H_{\circ }\simeq 72$ km s${}^{-1}$ Mpc${}^{-1}$, $t_{\circ }\simeq 13.5$Gyr and has an X-ray AGN 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 due to the smaller age of the Universe, with ${\Omega }_{\mathrm{m}}\simeq 0.38$, $w\simeq -1.25$, $H_{\circ }\simeq 70$ km s${}^{-1}$ Mpc${}^{-1}$, $t_{\circ }\simeq 12.9$Gyr.

5 pages, 2 figures, to appear in MNRAS Letters