A CHANDRA STUDY OF THE LARGE-SCALE SHOCK AND COOL FILAMENTS IN HYDRA A: EVIDENCE FOR SUBSTANTIAL GAS DREDGE-UP BY THE CENTRAL OUTBURST
A CHANDRA STUDY OF THE LARGE-SCALE SHOCK AND COOL FILAMENTS IN HYDRA A: EVIDENCE FOR SUBSTANTIAL GAS DREDGE-UP BY THE CENTRAL OUTBURST
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钱德拉对九头蛇 A 中大规模激波和冷细丝的研究：中央爆发大量天然气疏浚的证据
DOI：
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
M. Wise
中科院分区：
文献类型：
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作者：
M. Gitti;P. Nulsen;L. David;B. McNamara;M. Wise
我们展示了钱德拉对九头蛇a星系团的研究结果，在那里一个强大的活动星系核（AGN）爆发产生了大规模的茧状激波。我们研究了激波强度和形状可能的方位角变化，发现马赫数在1.2-1.3范围内的弱激波迹象。我们测量了整个激波锋面的温度变化。然而，探测到紧接在锋面内部的区域的温度上升，由于星团大气的底层温度分布而变得复杂。我们测量了该星系团的全球温度分布，最高可达700kpc，这是钱德拉对该星系团进行的最远测量。温度剖面在~ 70 - 150kpc范围内的“平台”表明存在冷气体，这可能是AGN突出隆起物质的结果。在掩盖硬度比图中可见的冷丝后，平台消失，温度曲线恢复到典型形状，峰值约为190 kpc，就在激波前沿内。然而，这样的温度特征不太可能是由激波产生的，因为它与观测到的松弛星系团的温度分布的一般形状是一致的。我们研究了冷丝的光谱特性，发现证据表明低熵物质的~ 1011M☉已经被从中心30kpc上升到观测到的当前位置75 - 150kpc的上升叶所吸收。抬升冷气体所需的能量为约2.2 × 1060 erg，相当于膨胀空腔所需的功，约占大尺度激波总能量的25%。我们的研究结果表明，九头蛇A中的AGN反馈不仅直接加热气体，而且还为超大质量黑洞消除了大量潜在的燃料。
We present the results of a Chandra study of the Hydra A galaxy cluster, where a powerful active galactic nucleus (AGN) outburst created a large-scale cocoon shock. We investigated possible azimuthal variations in shock strength and shape, finding indications for a weak shock with a Mach number in the range ∼1.2–1.3. We measured the temperature change across the shock front. However, the detection of a temperature rise in the regions immediately inside of the front is complicated by the underlying temperature profile of the cluster atmosphere. We measured the global temperature profile of the cluster up to 700 kpc, which represents the farthest measurement obtained with Chandra for this cluster. A “plateau” in the temperature profile in the range ∼70–150 kpc indicates the presence of cool gas, which is likely the result of uplift of material by the AGN outburst. After masking the cool filaments visible in the hardness ratio map, the plateau disappears and the temperature profile recovers a typical shape with a peak around 190 kpc, just inside the shock front. However, it is unlikely that such a temperature feature is produced by the shock as it is consistent with the general shape of the temperature profiles observed for relaxed galaxy clusters. We studied the spectral properties of the cool filaments finding evidence that ∼1011M☉ of low-entropy material has been dredged up by the rising lobes from the central 30 kpc to the observed current position of 75–150 kpc. The energy required to lift the cool gas is ≳ 2.2 × 1060 erg, which is comparable to the work required to inflate the cavities and is ∼25% of the total energy of the large-scale shock. Our results show that the AGN feedback in Hydra A is acting not only by directly heating the gas, but also by removing a substantial amount of potential fuel for the supermassive black hole.
长蛇座 A 星系团的大规模激波
影响因子：
6.5
作者：
Simionescu;Roediger;Nulsen;P. E. J;Brüggen;Forman;Böhringer;H.Werner;Finoguenov
通讯作者：
Finoguenov
影响因子：
6.5
作者：
A. Simionescu;N. Werner;H. Böhringer;J. Kaastra;A. Finoguenov;M. Brüggen;P. Nulsen
通讯作者：
A. Simionescu;N. Werner;H. Böhringer;J. Kaastra;A. Finoguenov;M. Brüggen;P. Nulsen