Measuring cluster temperature profiles with XMM/EPIC

Using the PV observation of A1795, we illustrate the capability of XMM-EPIC to measure cluster temperature profiles, a key ingredient for the determin ation of cluster mass profiles through the equation of hydrostatic equilibr ium: We develop a methodology for spatially resolved spectroscopy of extend ed sources, adapted to XMM background and vignetting characteristics. The e ffect of the particle induced background is discussed. A simple unbiased me thod is proposed to correct for vignetting effects, in which every photon i s weighted according to its energy and location on the detector. We were ab le to derive the temperature profile of A1795 up to 0.4 times the virial ra dius. A significant and spatially resolved drop in temperature towards the center (r < 200 kpc) is observed, which corresponds to the cooling flow reg ion of the cluster. Beyond that region, the temperature is constant with no indication of a fall-off at large radii out to 1.2 Mpc.