Mechanisms for Central Abundance Enhancements in Clusters of Galaxies

We use spatially resolved ASCA spectral data for the cooling flow cluster Abell 496 to show that its central metal abundance enhancement is due to Type I supernovae, whereas the bulk of the cluster metals are from SN II. We describe evidence which distinguishes whether the central SN I component is due to either metal-rich gas ram-pressure stripped from other cluster galaxies or the accumulation of normal stellar mass loss in the central dominant galaxy. We also present evidence for large scale abundance gradients in clusters at intermediate red shifts, in particular for Abell 1413, the farthest cluster presenting indications of central abundance enhancements.