Radial metallicity profiles for a large sample of galaxy clusters observed with XMM-Newton

TL;DR

This study measures radial metallicity profiles in about 50 galaxy clusters using XMM-Newton data, revealing a central peak and a flat profile beyond 0.2 R_{180}, with no evidence of evolution between redshifts 0.1 and 0.3.

Contribution

First large sample analysis of galaxy cluster metallicity profiles using background modeling and Monte Carlo simulations with XMM-Newton data.

Findings

Metallicity peaks at the center and declines to ~0.2 solar beyond 0.2 R_{180}

Profiles are consistent with being flat beyond 0.2 R_{180}

No evolution of metallicity profiles from z=0.1 to z=0.3

Abstract

Aims. We measured radial metallicity profiles for a sample of ~50 hot, intermediate redshift galaxy clusters, selected from the XMM-Newton archive. Methods. As in our previous paper, we used background modeling rather than background subtraction, and the Cash statistic rather than the chi square. This method requires a careful characterization of all background components. We also performed montecarlo simulations to assess systematic effects. Results. The mean metallicity profile shows a peak in the center, and gently declines out to 0.2 R_{180}. Beyond 0.2 R_{180} the metallicity is roughly 0.2 solar and, at variance with recently published expectations based on simulations, consistent with being flat. We find no evidence of profile evolution from z=0.1 to z=0.3. When comparing our mean profile to those obtained by recent works with BeppoSAX and Chandra, we find remarkable agreement over the entire radial range.