A Chandra study of Abell 795 -- a sloshing cluster with a FR0 radio galaxy at its center

TL;DR

This study uses Chandra X-ray data to analyze the dynamical state, cooling properties, and radio features of galaxy cluster Abell 795, revealing cold fronts, cavities, and a potential mini-halo, with implications for cluster cooling and radio galaxy growth.

Contribution

First detailed X-ray analysis of Abell 795 highlighting cold fronts, cavities, and a candidate mini-halo, linking sloshing to cluster cooling regulation.

Findings

A795 is a weak cool core cluster with low mass deposition rate.

Identification of two X-ray cavities and cold fronts along a spiral feature.

Extended radio emission suggests a candidate mini-halo.

Abstract

We present the first X-ray dedicated study of the galaxy cluster A795 and of the Fanaroff-Riley Type 0 hosted in its brightest cluster galaxy. Using an archival 30 ks \textit{Chandra} observation we study the dynamical state and cooling properties of the intracluster medium, and we investigate whether the growth of the radio galaxy is prevented by the surrounding environment. We discover that A795 is a weakly cool core cluster, with an observed mass deposition rate $\lessapprox 14\,$ M$_{\odot}$yr$^{-1}$ in the cooling region (central $\sim$66 kpc). In the inner $\sim$ 30 kpc we identify two putative X-ray cavities, and we unveil the presence of two prominent cold fronts at $\sim$60 kpc and $\sim$178 kpc from the center, located along a cold ICM spiral feature. The central galaxy, which is offset by 17.7 kpc from the X-ray peak, is surrounded by a multi-temperature gas with an average density of $n_{\text{e}} = 2.14 \times 10^{-2}$ cm$^{-3}$. We find extended radio emission at 74-227 MHz centered on the cluster, exceeding the expected flux from the radio galaxy extrapolated at low frequency. We propose that sloshing is responsible for the spiral morphology of the gas and the formation of the cold fronts, and that the environment alone cannot explain the compactness of the radio galaxy. We argue that the power of the two cavities and the sloshing kinetic energy can reduce and offset cooling. Considering the spectral and morphological properties of the extended radio emission, we classify it as a candidate radio mini-halo.