Suzaku Observations of the Outskirts of the Galaxy Cluster Abell 3395 including a Filament toward Abell 3391

TL;DR

Suzaku observations of Abell 3395's outskirts reveal temperature and abundance profiles, hinting at early cluster merger interactions and consistent early enrichment, with discrepancies in Compton y parameters compared to SZ results.

Contribution

First detailed Suzaku X-ray analysis of Abell 3395's outskirts including a filament toward Abell 3391, exploring temperature, abundance, and ICM properties in the filament region.

Findings

Temperature profile consistent with universal profile except in filament.

Detected ICM heating possibly due to early cluster merger.

Metallicity measurements align with early enrichment scenarios.

Abstract

The results of Suzaku observations of the outskirts of Abell 3395 including a large-scale structure filament toward Abell 3391 are presented. We measured temperature and abundance distributions from the southern outskirt of Abell 3395 to the north at the virial radius, where a filament structure has been found in the former X-ray and Sunyaev-Zel'dovich effect observations between Abell 3391 and 3395. The overall temperature structure is consistent with the universal profile proposed by Okabe et al.(2014) for relaxed clusters except for the filament region. A hint of the ICM heating is found between the two clusters, which might be due to the interaction of them in the early phase of a cluster merger. Although we obtained relatively low metal abundance of $Z=0.169^{+0.164+0.009+0.018 }_{-0.150-0.004-0.015 }$ solar, where the first, second, and third errors are statistical, cosmic X-ray background systematic, and non X-ray background systematic, respectively, at the virial radius in the filament, our results are still consistent with the former results of other clusters ($Z \sim 0.3$ solar) within errors. Therefore, our results are also consistent with the early enrichment scenario. We estimated Compton $y$ parameters only from X-ray results in the region between Abell 3391 and 3395 assuming a simple geometry. They are smaller than the previous SZ results with Planck satellite. The difference could be attributed to a more elaborate geometry such as a filament inclined to the line-of-sight direction, or underestimation of the X-ray temperature because of the unresolved multi-temperature structures or undetected hot X-ray emission of the shock heated gas.