ar X iv : a st ro - p h / 96 10 05 9 v 1 9 O ct 1 99 6 Galaxy evolution : the effect of dark matter on the chemical evolution of ellipticals and galaxy clusters

In this paper we discuss the chemical evolution of elliptical galaxies and its consequences on the evolution of the intracluster medium (ICM). We use chemical evolution models taking into account dark matter halos and compare the results with previous models where dark matter was not considered. In particular, we examine the evolution of the abundances of some relevant heavy elements such as oxygen, magnesium and iron and conclude that models including dark matter halos and an initial mass function (IMF) containing more massive stars than the Salpeter (1955) IMF, better reproduce the observed abundances of Mg and Fe both in the stellar populations and in the ICM (ASCA results). We also discuss the origin of gas in galaxy clusters and conclude that most of it should have a primordial origin.