X-ray analysis of filaments in galaxy clusters
X-ray analysis of filaments in galaxy clusters
复制标题
星系团中细丝的 X 射线分析
DOI：
10.1093/mnras/stv1829
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发表时间：
2015
影响因子：
4.8
通讯作者：
J. S. Sanders
中科院分区：
文献类型：
--
作者：
S. Walker;P. Kosec;A. Fabian;J. S. Sanders
我们执行一个详细的X射线研究的细丝周围的最明亮的星系团的样本附近的星系团使用深钱德拉观测，即英仙座，半人马座和室女座星系团，和阿贝尔1795。我们比较了所有这些系统中灯丝的X射线性质和光谱，发现它们的Chandra X射线光谱都与吸收的两个温度热模型大致一致，温度分量为0.75和1.7 keV。我们发现，它也是可能的钱德拉ACIS灯丝光谱与电荷交换模型提供的热成分也存在，和丰度的氧被抑制相对于丰度的Fe。在这个模型中，电荷交换提供了占主导地位的贡献，在0.5-1.0 keV频带的频谱。然而，当我们研究半人马座X射线中所见的对流羽流的高光谱分辨率RGS光谱时，情况似乎相反。我们的星系团样本中的灯丝的属性也比较后发座星系团和阿贝尔3627星系的X射线尾巴。在英仙座星系团中，我们寻找吸收的迹象，在NGC 1275周围的行星结构的分子气体的突出区域。我们确实发现在低于2千电子伏的X射线谱中有一个衰减，这表明吸收。然而，光谱形状与简单地添加额外的吸收分量所引起的这种衰减不一致。我们发现，光谱可以很好地拟合（物理上敏感的参数）与一个模型，包括分子气体的吸收和X射线发射的灯丝，这部分抵消了吸收。
We perform a detailed X-ray study of the filaments surrounding the brightest cluster galaxies in a sample of nearby galaxy clusters using deep Chandra observations, namely the Perseus, Centaurus and Virgo clusters, and Abell 1795. We compare the X-ray properties and spectra of the filaments in all of these systems, and find that their Chandra X-ray spectra are all broadly consistent with an absorbed two temperature thermal model, with temperature components at 0.75 and 1.7 keV. We find that it is also possible to model the Chandra ACIS filament spectra with a charge exchange model provided a thermal component is also present, and the abundance of oxygen is suppressed relative to the abundance of Fe. In this model, charge exchange provides the dominant contribution to the spectrum in the 0.5-1.0 keV band. However, when we study the high spectral resolution RGS spectrum of the filamentary plume seen in X-rays in Centaurus, the opposite appears to be the case. The properties of the filaments in our sample of clusters are also compared to the X-ray tails of galaxies in the Coma cluster and Abell 3627. In the Perseus cluster, we search for signs of absorption by a prominent region of molecular gas in the filamentary structure around NGC 1275. We do find a decrement in the X-ray spectrum below 2 keV, indicative of absorption. However the spectral shape is inconsistent with this decrement being caused by simply adding an additional absorbing component. We find that the spectrum can be well fit (with physically sensible parameters) with a model that includes both absorption by molecular gas and X-ray emission from the filament, which partially counteracts the absorption.