Inhomogeneous Metal Distribution in the Intra-Cluster Medium

TL;DR

This study analyzes metal distribution in the intra-cluster medium of galaxy clusters using X-ray data, revealing inhomogeneities and potential underestimation of metal mass in previous measurements, with implications for understanding cluster evolution.

Contribution

It provides detailed metallicity maps of galaxy clusters, assesses the accuracy of metal mass estimates from X-ray observations, and compares observed abundances with theoretical supernova yields.

Findings

Metal distribution in clusters is highly inhomogeneous.

Metal mass estimates from spatially resolved maps are 10-30% higher.

Abundance ratios suggest combined SN Ia and SNCC enrichment.

Abstract

The hot gas that fills the space between galaxies in clusters is rich in metals. In their large potential wells, galaxy clusters accumulate metals over the whole cluster history and hence they retain important information on cluster formation and evolution. We use a sample of 5 cool core clusters to study the distribution of metals in the ICM. We investigate whether the X-ray observations yield good estimates for the metal mass and whether the heavy elements abundances are consistent with a certain relative fraction of SN Ia to SNCC. We derive detailed metallicity maps of the clusters from XMM - Newton observations and we use them as a measure for the metal mass in the ICM. We determine radial profiles for several elements and using population synthesis and chemical enrichment models, we study the agreement between the measured abundances and the theoretical yields. We show that even in relaxed clusters the distribution of metals show a lot of inhomogeneities. Using metal maps usually gives a metal mass 10-30% higher than the metal mass computed using a single extraction region, hence it is expected that most previous metal mass determination have underestimated metal mass. The abundance ratio of {\alpha}-elements to Fe, even in the central parts of clusters, are consistent with an enrichment due to the combination of SN Ia and SNCC.