Revealing a Highly Dynamic Cluster Core in Abell 1664 with Chandra
Revealing a Highly Dynamic Cluster Core in Abell 1664 with Chandra
复制标题
DOI：
10.3847/1538-4357/ab09f6
复制
发表时间：
2018-10
期刊：
影响因子：
--
通讯作者：
M. Calzadilla;H. Russell;Michael McDonald;A. Fabian;S. Baum;F. Combes;M. Donahue;A. Edge;B. McNamara;P. Nulsen;C. O’Dea;J. B. R. Oonk;G. Tremblay;A. Vantyghem
中科院分区：
文献类型：
--
作者：
M. Calzadilla;H. Russell;Michael McDonald;A. Fabian;S. Baum;F. Combes;M. Donahue;A. Edge;B. McNamara;P. Nulsen;C. O’Dea;J. B. R. Oonk;G. Tremblay;A. Vantyghem
我们提出了新的，深（245 ks）钱德拉观测星系团阿贝尔1664（z = 0.1283）。这些图像揭示了丰富的结构，包括在NE-SW方向上的X射线等照度线的伸长和伴随的压缩，这表明热气体在引力势中晃动。这种晃动导致了冷锋，距离星团中心分别为50、110和325千秒差距。我们的研究结果表明，A1664的核心是高度扰动的，因为全球金属丰度和冷却时间在小半径处变平，这意味着在一系列尺度上的混合。活动星系核（AGN）最近似乎经历了一次机械爆发，我们对空洞的探测证明了这一点。这些空洞是由活动星系核膨胀的射电泡的X射线表现，可以解释以前用阿塔卡马大型毫米波阵列（阿尔马）观测到的冷分子CO云的运动。以空洞膨胀所需的最小能量作为替代，活动星系核的机械能估计为erg s−1，这可能足以驱动分子气体流，并抵消团内介质的冷却光度erg s−1。这个机械能比活动星系核中心X射线光度的测量上限高出几个数量级，这表明它的黑洞可能非常大和/或辐射效率低下。我们映射的温度变化在相同的空间尺度上的分子气体，并发现，最迅速冷却的气体大多是一致的分子气体水库集中在最明亮的星系团星系的系统速度观察与阿尔马，并可能是燃料冷吸积到中央黑洞。
We present new, deep (245 ks) Chandra observations of the galaxy cluster Abell 1664 (z = 0.1283). These images reveal rich structure, including elongation and accompanying compressions of the X-ray isophotes in the NE–SW direction, suggesting that the hot gas is sloshing in the gravitational potential. This sloshing has resulted in cold fronts, at distances of 50, 110, and 325 kpc from the cluster center. Our results indicate that the core of A1664 is highly disturbed, as the global metallicity and cooling time flatten at small radii, implying mixing on a range of scales. The central active galactic nucleus (AGN) appears to have recently undergone a mechanical outburst, as evidenced by our detection of cavities. These cavities are the X-ray manifestations of radio bubbles inflated by the AGN and may explain the motion of cold molecular CO clouds previously observed with the Atacama Large Millimeter Array (ALMA). The estimated mechanical power of the AGN, using the minimum energy required to inflate the cavities as a proxy, is erg s−1, which may be enough to drive the molecular gas flows, and offset the cooling luminosity of the intracluster medium, at erg s−1. This mechanical power is orders of magnitude higher than the measured upper limit on the X-ray luminosity of the central AGN, suggesting that its black hole may be extremely massive and/or radiatively inefficient. We map temperature variations on the same spatial scale as the molecular gas and find that the most rapidly cooling gas is mostly coincident with the molecular gas reservoir centered on the brightest cluster galaxy’s systemic velocity observed with ALMA and may be fueling cold accretion onto the central black hole.