A Sunyaev-Zel'dovich map of the massive core in the luminous X-ray cluster RXJ1347-1145

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, $\yc=(12.7^{+2.9}_{-3.1})\times 10^{-4}$, corresponds to the deepest SZ decrement ever observed. Using the gas density distribution derived from X-ray data, this measurement implies a gas temperature $\te=16.2 \pm 3.8$ keV. The resulting total mass of the cluster is, under hydrostatic equilibrium, $M(r<1Mpc)=(1.0\pm 0.3)\times 10^{15}{M}_{\odot }$ for a corresponding gas fraction $f_{gas}(r<1Mpc)=(19.5\pm 5.8)$.

16 pages, 2 figures, accepted for publication in ApJ Letters