Shocking Features in the Merging Galaxy Cluster RXJ0334.2-0111

TL;DR

This study presents detailed Chandra X-ray observations of the galaxy cluster RXJ0334.2-0111, revealing a bow shock, cold front, and complex substructures that shed light on the ongoing merger dynamics.

Contribution

First detailed X-ray analysis of RXJ0334.2-0111 uncovering shock fronts, cold fronts, and substructures, advancing understanding of cluster merger processes.

Findings

Detected a bow shock with Mach number ~1.6.

Identified a cold front separating infalling subcluster from main cluster.

Discovered overpressurized regions possibly indicating ongoing merger activity.

Abstract

We present a 66 ksec $\textit{Chandra}$ X-ray observation of the galaxy cluster RXJ0334.2-0111. This deep observation revealed a unique bow shock system associated with a wide angle tail (WAT) radio galaxy and several intriguing substructures. The temperature across the bow shock jumps by a factor of $\sim$ 1.5 (from 4.1 keV to 6.2 keV), and is consistent with the Mach number $M = 1.6_{-0.3}^{+0.5}$. A second inner surface brightness edge is a cold front that marks the border between infalling subcluster cool core and the ICM of the main cluster. The temperature across the cold front increases from $1.3_{-0.8}^{+0.3}$ keV to $6.2_{-0.6}^{+0.6}$ keV. We find an overpressurized region $\sim$ 250 kpc east of the cold front that is named "the eastern extension (EE)". The EE may be a part of the third subcluster in the ongoing merger. We also find a tail shaped feature that originates near the bow shock and may extend up to a distance of $\sim$ 1 Mpc. This feature is also likely overpressurized. The luminous FR-I radio galaxy, 3C89, appears to be the cD galaxy of the infalling subcluster. We estimated 3C89's jet power from jet bending and the possible interaction between the X-ray gas and the radio lobes. A comparison between the shock stand-off distance and the Mach number for all known shock front/cold front combinations suggests that the core is continuously shrinking in size by stripping.