A Sunyaev-Zeldovich Map of the Massive Core in the Luminous X-Ray Cluster RX J1347−1145

Abstract

We have mapped the Sunyaev-Zel'dovich decrement (hereafter SZ) in the direction of the most luminous X-ray cluster known to date, RXJ1347-1145, at z = 0.451.This has been achieved with an angular resolution of about 23" using the Diabolo photometer running on the IRAM 30 meter radio telescope.We present here a map of the cluster central region at 2.1mm.The Comptonization parameter towards the cluster center, y c = (12.7 +2.9 -3.1 ) × 10 -4 , corresponds to the deepest SZ decrement ever observed.Using the gas density distribution derived from X-ray data, this measurement implies a gas temperature T e = 16.2 ± 3.8 keV.The resulting total mass of the cluster is, under hydrostatic equilibrium, M(r < 1Mpc) = (1.0 ± 0.3) × 10 15 M ⊙ for a corresponding gas fraction f gas (r < 1Mpc) = (19.5 ± 5.8)%.