XMM- Newton Observation of the Coma Galaxy Cluster: The temperature structure in the central region

TL;DR

This study uses XMM-Newton data to map the temperature distribution of the Coma cluster's core, revealing a relaxed central region and signs of recent accretion and compression at larger radii.

Contribution

It provides the first detailed temperature map of the Coma cluster's central region using XMM-Newton, challenging previous ASCA results and highlighting complex thermal structures.

Findings

Homogeneous temperature distribution near the center

Evidence of gas stripping from an infalling group

Indications of a hot front due to compression

Abstract

We present a temperature map and a temperature profile of the central part (r < 20' or 1/4 virial radius) of the Coma cluster. We combined 5 overlapping pointings made with XMM/EPIC/MOS and extracted spectra in boxes of 3.5' X 3.5'. The temperature distribution around the two central galaxies is remarkably homogeneous (r<10'), contrary to previous ASCA results, suggesting that the core is actually in a relaxed state. At larger distance from the cluster center we do see evidence for recent matter accretion. We confirm the cool area in the direction of NGC 4921, probably due to gas stripped from an infalling group. We find indications of a hot front in the South West, in the direction of NGC4839, probably due to an adiabatic compression.