Chandra and XMM-Newton Observations of the Abell 3391/Abell 3395 Intercluster Filament

TL;DR

This study uses Chandra and XMM-Newton X-ray data to analyze the properties of the intercluster filament between Abell 3391 and Abell 3395, revealing its alignment, thermodynamics, and evidence of early-stage merger activity.

Contribution

First detailed X-ray analysis of the Abell 3391/Abell 3395 filament, showing its properties and dynamical state, including evidence of tidal disruption and ram pressure stripping.

Findings

Filament aligned close to the plane of the sky.

Filament temperature ~4.45 keV, electron density ~1.08e-4 cm^-3.

Evidence of tidal disruption and ram pressure stripping.

Abstract

We present Chandra and XMM-Newton X-ray observations of the Abell 3391/Abell 3395 intercluster filament. It has been suggested that the galaxy clusters Abell 3395, Abell 3391, and the galaxy group ESO-161 located between the two clusters, are in alignment along a large-scale intercluster filament. We find that the filament is aligned close to the plane of the sky, in contrast to previous results. We find a global projected filament temperature kT = $4.45_{-0.55}^{+0.89}$~keV, electron density $n_e=1.08^{+0.06}_{-0.05} \times 10^{-4}$~cm$^{-3}$, and $M_{\rm gas} = 2.7^{+0.2}_{-0.1} \times 10^{13}$~M$_\odot$. The thermodynamic properties of the filament are consistent with that of intracluster medium (ICM) of Abell 3395 and Abell 3391, suggesting that the filament emission is dominated by ICM gas that has been tidally disrupted during an early stage merger between these two clusters. We present temperature, density, entropy, and abundance profiles across the filament. We find that the galaxy group ESO-161 may be undergoing ram pressure stripping in the low density environment at or near the virial radius of both clusters due to its rapid motion through the filament.