Ni Abundance in the Core of the Perseus Cluster: An Answer to the Significance of Resonant Scattering

Abstract

Using an XMM-Newton observation of the Perseus cluster we show that the excess in the flux of the 7-8 keV line complex previously detected by ASCA and BeppoSAX is due to an overabundance of nickel rather than to an anomalously high Fe Heβ/Fe Heα ratio. This observational fact leads to the main result that resonant scattering, which was assumed to be responsible for the supposed anomalous Fe Heβ/Fe Heα ratio, is no longer required. The absence of resonant scattering points toward the presence of significant gas motions (either turbulent or laminar) in the core of the Perseus Cluster.