Enrichment of the ICM of galaxy clusters due to ram-pressure stripping

¹ Institut für Astro- und Teilchenphysik, Leopold-Franzens Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria e-mail: wilfried.domainko@uibk.ac.at
² Institut für Astrophysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
³ School of Mathematics, University of Edinburgh, Edinburgh EH9 3JZ, Scotland, UK

Received: 26 July 2005
Accepted: 22 February 2006

Abstract

We investigate the impact of galactic mass loss triggered by ram-pressure stripping of cluster galaxies on the evolution of the intra-cluster medium (ICM). We use combined N-body and hydrodynamic simulations together with a phenomenological galaxy formation model and a prescription of the effect of ram-pressure stripping on the galaxies. We analyze the effect of galaxy – ICM interaction for different model clusters with different masses and different merger histories. Our simulations show that ram-pressure stripping can account for ~10% of the overall observed level of enrichment in the ICM within a radius of 1.3 Mpc. The efficiency of metal ejection of cluster galaxies depends in the first few Gyr of the simulation mainly on the cluster mass and is significantly increased during major merger events. Additionally we show that ram-pressure stripping is most efficient in the center of the galaxy cluster and the level of enrichment drops quite fast at larger radii. We present emission-weighted metallicity maps of the ICM which can be compared with X-ray observations. The resulting distribution of metals in the ICM shows a complex pattern with stripes and plumes of metal-rich material. The metallicity maps can be used to trace the present and past interactions between the ICM and cluster galaxies.