On the evolution of the Fe abundance and of the Type Ia supernova rate in clusters of galaxies

Abstract

The study of the Fe abundance in the intracluster medium (ICM) provides strong constraints on the integrated star formation history and supernova rate of the cluster galaxies, as well as on the ICM enrichment mechanisms. In this Letter, using chemical evolution models for galaxies of different morphological types, we study the evolution of the Fe content of clusters of galaxies. We assume that the ICM Fe enrichment occurs by means of galactic winds arising from elliptical galaxies and from gas stripped from the progenitors of SO galaxies via external mechanisms, due to the interaction of the interstellar medium with the ICM. The Fe-rich gas ejected by ellipticals accounts for the XFe,ICM values observed at z > 0.5, whereas the gas stripped from the progenitors of the SO galaxies accounts for the increase of XFe,ICM observed at z < 0.5. We test two different scenarios for Type la supernova (SN) progenitors and we model the Type la SN rate observed in clusters, finding a good agreement between our predictions and the available observations. © 2007 The Authors. Journal compilation © 2007 RAS.