Simultaneous determination of ${\Omega }_{M0}$ and $H_0$ from joint Sunyaev-Zeldovich effect and X-ray observations with median statistics

Abstract

Clusters of galaxies contain a fair sample of the universal baryonic mass fraction. A combined analysis of the intracluster medium (ICM) within their hydrostatic regions, as derived from both Sunyaev-Zeldovich effect (SZE) measurements and X-ray images, makes it possible to constrain the cosmological parameters. We consider both gas fraction estimates and angular diameter distance measurements. Adopting median statistics, we find, at the 2-$\sigma$ level, the pressureless matter density, ${\Omega }_{M0}$, to be between 0.30 and 0.40 and the Hubble constant, $H_0$, between 44 and 66 Km s${}^{-1}$ Mpc${}^{-1}$.

8 pages, 2 figures, to appear in A&A