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تسجيل مستخدم جديدChandra Observations of the Spectacular A3411-12 Merger Event
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We present deep Chandra observations of A3411-12, a remarkable merging cluster that hosts the most compelling evidence for electron re-acceleration at cluster shocks to date. Using the $Y_X-M$ scaling relation, we find $r_{500} sim 1.3$ Mpc, $M_{500} = (7.1 pm 0.7) times 10^{14} M_{rm{odot}}$, $kT=6.5pm 0.1$ keV, and a gas mass of $M_{rm g,500} = (9.7 pm 0.1) times 10^{13} M_odot$. The gas mass fraction within $r_{500}$ is $f_{rm g} = 0.14 pm 0.01$. We compute the shock strength using density jumps to conclude that the Mach number of the merging subcluster is small ($M leq 1.15_{-0.09}^{+0.14}$). We also present pseudo-density, projected temperature, pseudo-pressure, and pseudo-entropy maps. Based on the pseudo-entropy map we conclude that the cluster is undergoing a mild merger, consistent with the small Mach number. On the other hand, radio relics extend over Mpc scale in the A3411-12 system, which strongly suggests that a population of energetic electrons already existed over extended regions of the cluster.
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