Ja n 20 05 The merging cluster Abell 85 caught between meals by XMM - Newton Florence

Our XMM-Newton observations of Abell 85 confirm the extended 4 Mpc filament first detected with ROSAT, which has an X-ray temperature of about ∼ 2 keV and is probably made of groups falling on to the cluster. A comparison of the temperature map with numerical simulations show that Abell 85 had intense merging activity in the past and is not fully relaxed, even in the central region. Finally, a deprojected temperature profile has been calculated and used, together with the suface brightness, to estimate the entropy and pressure profiles. Abell 85 only presents a mild flattening of the entropy profile in the center, showing no evidence of an “entropy floor”.