XMM-Newton observations of the relaxed, high-redshift galaxy cluster ClJ0046.3+8530 at z= 0.62

Abstract

A detailed analysis of XMM-Newton observations of ClJ0046.3+8530 (z= 0.624) is presented. The cluster has a moderate temperature (kT= 4.1 +/- 0.3 keV) and appears to be relaxed. Emission is detected at >=3σ significance to a radius of 88 per cent of R₂₀₀ (the radius enclosing an overdensity of 200 times the critical density at z= 0.624) in a surface brightness profile. A temperature profile (extending to 0.7R₂₀₀) and hardness ratio map show no significant departures from the global temperature, within the statistical limits of the data. The cluster bolometric X-ray luminosity is L_X= (4.3 +/- 0.3) × 10⁴⁴ erg s^-1, and the total mass derived within R₂₀₀, assuming isothermality and hydrostatic equilibrium, is M₂₀₀= 3.0^+0.6_-0.5× 10¹⁴ M_solar. The gas entropy measured at 0.1R₂₀₀ is compared with a sample of local systems, and found to be consistent with self-similar evolution with redshift. The metallicity, gas density profile slope and gas mass fraction are all consistent with those found in low-z clusters.