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

We have mapped the Sunyaev-Zeldovich (SZ) decrement in the direction of the most luminous X-ray cluster known to date, RX J1347-1145, at z = 0.451. This has been achieved with an angular resolution of about 23'' using the Diabolo photometer running on the IRAM 30 m radio telescope. We present here a map of the cluster central region at 2.1 mm. The Comptonization parameter toward the cluster center, yc = (12.7) × 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 of Te = 16.2 ± 3.8 keV. The resulting total mass of the cluster is, under hydrostatic equilibrium, M(r < 1 Mpc) = (1.0 ± 0.3) × 1015 M☉ for a corresponding gas fraction fgas(r < 1 Mpc) = 19.5% ± 5.8%.