Two large-scale sloshing cold fronts in the outskirts of the galaxy cluster Abell 3558

TL;DR

This study reports the discovery of two large-scale sloshing cold fronts in the galaxy cluster Abell 3558, extending far beyond the core, indicating that sloshing affects the entire cluster and can influence its global properties.

Contribution

First detection of two large-scale cold fronts far outside the cooling radius in Abell 3558, demonstrating that sloshing is a cluster-wide phenomenon.

Findings

Cold fronts located 600 kpc and 1.2 Mpc from the core

Cold fronts are among the most distant observed in galaxy clusters

Sloshing extends beyond the cooling radius, affecting global cluster properties

Abstract

Previous studies of the massive nearby galaxy cluster Abell 3558 reported a cold front around the cluster core, which is attributed to the sloshing of the core as it responds to the gravitational disturbance created by a past minor merger. Here, using XMM-Newton mosaic, we report the detection of two rare large-scale sloshing cold fronts far outside the cooling radius of Abell 3558. One of the detected cold fronts is located 600 kpc from the cluster core to the south-east, while the other is located 1.2 Mpc from the cluster core to the north-west. The latter cold front is one of the most distant cold fronts ever observed in a galaxy cluster. Our findings are in agreement with previous studies that sloshing can extend well beyond the cooling radius, on scales exceeding half the virial radius, suggesting that sloshing is a cluster-wide phenomenon and may affect the cluster's global properties.