Cosmological Parameters from the Clustering of AGN

Abstract

We attempt to put constraints on different cosmological and biasing models by combining the recent clustering results of X-ray sources in the local (z ≤ 0.1) and distant universe (z ∼ 1). To do this we compare the measured angular correlation function for bright [1] and faint [23] ROSATX-ray sources respectively with those expected in three spatially flat cosmological models. Taking into account the different functional forms of the bias evolution, we find that a low-Ω_o cosmological model (Ω_A = 0.7) which contains high usas τ ^mass₈ = 1.13 with different bias behaviour, best reproduce the AGN clustering results. While τCDM models with different bias behaviour are ruled out at a high significance level.