086267

We propose a deep XMM observation of the 1e14 Msun cluster XLSSC 105 at z=0.43 comma which exhibits clear merging signatures in existing multi-wavelength data. The two peaks revealed by high-resolution SZ data do not have obvious counterparts in the existing shallow XMM data comma which implies that this system is a high-velocity head-on merger along the plane of the sky. The two SZ peaks likely coincide with high-temperature openPar>virgul20 keVclosePar shock-heated regions. We propose a deep openPar175 ksclosePar XMM observation of this system to measure the temperature of the gas in the shocked regions and constrain the geometry of the merger comma together with a joint 70ks Chandra high-resolution observation to detect the density jumps.