Suzaku Observations of Abell 1795: Cluster Emission to r 200
Suzaku Observations of Abell 1795: Cluster Emission to r 200
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阿贝尔 1795 年朱雀观测：星团发射至 r 200
DOI：
10.1093/pasj/61.5.1117
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发表时间：
2009
影响因子：
2.3
通讯作者：
Bautz M
中科院分区：
文献类型：
--
作者：
Bautz M
我们报告朱雀观测星系团阿贝尔1795延伸到2兆秒差距，半径内的平均质量密度是宇宙临界密度的200倍。这些观测是第一次探测该天体在1.3 Mpc时的团内介质状态。我们在星团外围（1.3 Mpc-1.9 Mpc）的两个不相交的扇区进行采样，并仅在其中一个扇区中检测到极限（3）软X射线表面亮度为1.810 erg scmdeg，低于宇宙X射线背景亮度的20%。我们跟踪半径为0.4 Mpc的温度变化，发现它福尔斯得相对较快（），在我们能测量到的最大半径处，它达到峰值的三分之一左右。假设团内介质处于流体静力平衡，并且是多方的，我们发现多方指数为1.3，我们估计质量为（4.1）10个在1.3Mpc范围内，略低于（2.7）以前观察员报告的值。然而，我们的观察提供了证据，偏离流体静力平衡的半径小至1.3百万分之一，这显然是规则和对称的集群。
We report Suzaku observations of the galaxy cluster Abell 1795 that extend to2 Mpc, the radius within which the mean cluster mass density is 200 times the cosmic critical density. These observations are the first to probe the state of the intracluster medium in this object at1.3 Mpc. We sample two disjoint sectors in the cluster outskirts (1.3 Mpc1.9 Mpc) and detect X-ray emission in only one of them to a limiting (3) soft X-ray surface brightness of1.810erg scmdeg, a level less than 20% of the cosmic X-ray background brightness. We trace the run of temperature with radius at0.4 Mpc and find that it falls relatively rapidly (), reaching a value about one third of its peak at the largest radius we can measure it. Assuming the intracluster medium is in hydrostatic equilibrium and is polytropic, we find a polytropic index of1.3and we estimate a mass of (4.1)10within 1.3 Mpc, somewhat (2.7) lower than that reported by previous observers. However, our observations provide evidence for departure from hydrostatic equilibrium at radii as small as1.3 Mpcin this apparently regular and symmetrical cluster.