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 } ) \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 { T _ { e } } = 16.2 \pm 3.8 keV .
The resulting total mass of the cluster is , under hydrostatic equilibrium , M ( r < 1 Mpc ) = ( 1.0 \pm 0.3 ) \times 10 ^ { 15 } M _ { \odot } for a corresponding gas fraction f _ { gas } ( r < 1 Mpc ) = ( 19.5 \pm 5.8 ) \% .