Large-scale Motions in the Perseus Galaxy Cluster

TL;DR

This study uses combined X-ray observations to reveal large-scale gas motions in the Perseus Cluster, showing that sloshing phenomena extend to near the virial radius, indicating complex intracluster dynamics.

Contribution

The paper provides the first evidence that gas sloshing occurs on scales approaching the virial radius in a galaxy cluster, expanding understanding of intracluster medium dynamics.

Findings

Detection of large-scale low-temperature, low-entropy arcs

Evidence of gas sloshing extending to the virial radius

Implication of minor mergers influencing cluster dynamics

Abstract

By combining large-scale mosaics of ROSAT PSPC, XMM-Newton, and Suzaku X-ray observations, we present evidence for large-scale motions in the intracluster medium of the nearby, X-ray bright Perseus Cluster. These motions are suggested by several alternating and interleaved X-ray bright, low-temperature, low-entropy arcs located along the east-west axis, at radii ranging from ~10 kpc to over a Mpc. Thermodynamic features qualitatively similar to these have previously been observed in the centers of cool core clusters, and were successfully modeled as a consequence of the gas sloshing/swirling motions induced by minor mergers. Our observations indicate that such sloshing/swirling can extend out to larger radii than previously thought, on scales approaching the virial radius.