A Chandra Observation of Abell 13: Investigating the Origin of the Radio Relic

TL;DR

This study uses Chandra X-ray observations to analyze the properties of the hot gas in galaxy cluster Abell 13 and its association with a noncentral radio relic, revealing insights into cluster merger dynamics.

Contribution

First X-ray focused study of Abell 13 revealing gas substructure and its relation to the radio relic, suggesting gas uplift or displacement during a merger.

Findings

X-ray emission shows substructure indicating a recent merger

Radio relic associated with cooler gas in the cluster

No evidence of a cooling flow in Abell 13

Abstract

We present results from the Chandra X-ray observation of Abell 13, a galaxy cluster that contains an unusual noncentral radio source, also known as a radio relic. This is the first pointed X-ray observation of Abell 13, providing a more sensitive study of the properties of the X-ray gas. The X-ray emission from Abell 13 is extended to the northwest of the X-ray peak and shows substructure indicative of a recent merger event. The cluster X-ray emission is centered on the bright galaxy H of Slee et al. 2001. We find no evidence for a cooling flow in the cluster. A knot of excess X-ray emission is coincident with the other bright elliptical galaxy F. This knot of emission has properties similar to the enhanced emission associated with the large galaxies in the Coma cluster. With these Chandra data we are able to compare the properties of the hot X-ray gas with those of the radio relic from VLA data, to study the interaction of the X-ray gas with the radio emitting electrons. Our results suggest that the radio relic is associated with cooler gas in the cluster. We suggest two explanations for the coincidence of the cooler gas and radio source. First, the gas may have been uplifted by the radio relic from the cluster core. Alternatively, the relic and cool gas may have been displaced from the central galaxy during the cluster merger event.