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arXiv · 1112.5955

X-Ray View of the Shock Front in the Merging Cluster Abell 3376 with Suzaku

Hiroki Akamatsu·Motokazu Takizawa·Kazuhiro Nakazawa·Yasushi Fukazawa·Yoshitaka Ishisaki·Takaya Ohashi
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Abstract

We report on a Suzaku measurement of the shock feature associated with the western radio relic in the merging cluster A3376. The temperature profile is characterized by an almost flat radial shape with kT ~ 4 keV within 0.5 r200 and a rise by about 1 keV inside the radio relic. Across the relic region (0.6-0.8 r200), the temperature shows a remarkable drop from about 4.7 keV to 1.3 keV. This is a clear evidence that the radio relic really corresponds to a shock front possibly caused by a past major merger. The observed sharp changes of the temperature and electron density indicate the Mach number M~3. The radial entropy profile is flatter than the prediction (r^1.1) of numerical simulations within 0.5 r200}, and becomes steeper around the relic region. These observed features and time-scale estimation consistently imply that the ICM around the radio relic has experienced a merger shock and is in the middle of the process of dynamical and thermal relaxation.

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Hiroki Akamatsu, Motokazu Takizawa, Kazuhiro Nakazawa, Yasushi Fukazawa, Yoshitaka Ishisaki, Takaya Ohashi. 2011-12-27. X-Ray View of the Shock Front in the Merging Cluster Abell 3376 with Suzaku. https://doi.org/10.1093/pasj%2F64.4.67

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