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