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. Th is has been achieved with an angular resolution of about 23 " using the Dia bolo 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, y(c) = (12.7(-3.1)(+2.9)) x 10(-4), corresponds to the deepest SZ decrement ever observed. Using the gas density distributi on derived from X-ray data, this measurement implies a gas temperature of T -e = 16.2 +/- 3.8 keV The resulting total mass of the cluster is, under hyd rostatic equilibrium, M(r<1 Mpc)= (1.0 +/- 0.3) x 10(15) M. for a correspon ding gas fraction f(gas)(r<1 Mpc)= 19.5% +/- 5.8%.