Letter to the Editor

Implications of the central metal abundance peak in cooling core clusters of galaxies

¹ Max-Planck-Institut für extraterr. Physik, 85740 Garching, Germany
² Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjyuku, Tokyo 162-8601, Japan
³ Max-Planck-Institut für Astrophysik, 85740 Garching, Germany
⁴ Joint Center for Astrophysics, Physics Department, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA

Corresponding author: H. Böhringer, hxb@mpe.mpg.de

Received: 24 December 2003
Accepted: 7 February 2004

Abstract

Recent XMM-Newton observations of clusters of galaxies have provided detailed information on the distribution of heavy elements in the central regions of clusters with cooling cores providing strong evidence that most of these metals come from recent SN type Ia. In this paper we compile information on the cumulative mass profiles of iron, the most important metallicity tracer. We find that long enrichment times (≥5 Gyr) are necessary to produce the central abundance peaks. Classical cooling flows, a strongly convective intracluster medium, and a complete metal mixing by cluster mergers would destroy the observed abundance peaks too rapidly. Thus the observations set strong constraints on cluster evolution models requiring that the cooling cores in clusters are preserved over very long times. We further conclude from the observations that the innermost part of the intracluster medium is most probably dominated by gas originating predominantly from stellar mass loss of the cD galaxy.