2002A&A...387...56P

We have performed a combined analysis of X-ray and Sunyaev-Zel'dovich data in the direction of the distant galaxy cluster, RX J2228+2037. Fitting a β-model to the high-resolution HRI data gives r_c=103±12h₇₀^–1kpc and β=0.54±0.03. The dependency of the Sunyaev-Zel'dovich effect with respect to the gas temperature allows us, through the additional use of the 21 GHz data of the cluster, to determine k_BT_e=10.4±1.8h₇₀^1/2keV. Extrapolating the gas density profile out to the virial radius (R_v=r₁₇₈=2.9Mpc), we derived a gas mass of M_g(r<R_v)=(4.0±0.2)x10¹⁴h₇₀^–5/2M_☉. Within the hypothesis of hydrostatic equilibrium, the corresponding extrapolated total mass for this source is: M_tot(r<R_v)=(1.8 ±0.4)x10¹⁵h^–1M_☉, which corresponds to a gas fraction of f_gas=0.22±0.06h₇₀^–3/2. Our results on the temperature and on the cluster mass classify RX J2228+2037 among the distant, hot and very massive galaxy clusters. Our work highlights the power of the association of galaxy cluster mapping observations in X-ray and the SZ effect to derive the cluster's physical properties, even without X-ray spectroscopy.