Metallicity map of the galaxy cluster A3667

TL;DR

This study maps the metallicity distribution of galaxy cluster A3667 using XMM-Newton data, revealing inhomogeneous metal patterns and insights into the cluster's merger history and supernova contributions.

Contribution

It provides the first detailed metallicity map of A3667 and constrains supernova types contributing to intra-cluster medium enrichment.

Findings

Metals are unevenly distributed, with peaks indicating merger activity.

Approximately 65-80% of enrichment is from SN II supernovae.

Evidence supports a recent merger between the main cluster and a group.

Abstract

We use XMM-Newton data of the merging cluster Abell 3667 to analyze its metallicity distribution. A detailed abundance map of the central 1.1x1.1 Mpc region indicates that metals are inhomogeneously distributed in the cluster showing a non-uniform and very complex metal pattern. The highest peak in the map corresponds to a cold region, slightly offset South of the X-ray center. This could be interpreted as stripped gas due to a merger between a group moving from NW towards the SE and the main cluster. We note several clumps of high metallicity also in the opposite direction with respect to the X-ray peak. Furthermore we determined abundances for 5 elements (O, Si, S, Ar, Fe) in four different regions of the cluster. Comparisons between these observed abundances and theoretical supernovae yields allow to get constraints on the relative number of SN Ia and II contributing to the enrichment of the intra-cluster medium. To reproduce the observed abundances of the best determined elements (Fe, O and Si) in a region of 7 arcmin around the X-ray center, 65-80% of SN II are needed. The comparison between the metal map, a galaxy density map obtained using 550 spectroscopically confirmed cluster members and our simulations suggest a recent merger between the main cluster and the group in the SE.