The XMM-LSS cluster sample and its cosmological applications: Prospects for the XMM next decade

Abstract

The well defined selection function of the XMM-LSS surveys enables a simultaneous modelling of the observed cluster number counts and of the evolution of the L_X-T_X relation. We present results pertaining to the first 5 deg² for a well controlled sample comprising 30 objects: they are compatible with the WMAP3 parameter set along with cluster self-similar evolution. Extending such a survey to 200 deg² would (1) allow discriminating between the major scenarios of the cluster L_X-T_X evolution and (2) provide a unique self-sufficient determination of σ₈ and Γ with an accuracy of ∼ 5% and 10% respectively, when adding mass information from weak lensing and S-Z observations.