X-Ray Thermal Coronae of Galaxies in Hot Clusters: Ubiquity of Embedded Mini-Cooling Cores
X-Ray Thermal Coronae of Galaxies in Hot Clusters: Ubiquity of Embedded Mini-Cooling Cores
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DOI：
10.1086/510895
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发表时间：
2006-06
期刊：
影响因子：
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通讯作者：
M. Sun;C. Jones;W. Forman;A. Vikhlinin;M. Donahue;M. Voit
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文献类型：
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作者：
M. Sun;C. Jones;W. Forman;A. Vikhlinin;M. Donahue;M. Voit
本文对157个早型星系和22个晚型星系的X射线热日冕进行了系统的研究，这些星系来自于25个热（kT > 3 keV）、近（z 60%，LKs > 2L*）星系。这些嵌入在热星团中的日冕通常比在恶劣环境中的日冕更小，亮度更低，质量也更小，这表明了热星团环境对星系日冕的负面影响。尽管如此，这些日冕仍然设法生存ICM剥离，蒸发，快速冷却，和强大的活动星系核流出，使它们成为一个丰富的信息来源，气体剥离，微观运输，并在集群环境中的反馈过程。穿过日冕边界的热传导必须被抑制100倍，这意味着早型星系中的X射线气体是磁化的，磁场在能量传递中起着重要作用。发光的嵌入式日冕，具有高中心密度（0.1-0.4 cm-3），是集团和集群冷却核心的缩小版。由于大质量星系的日冕普遍存在意味着很长的寿命（大约几个Gyr），日冕内部必须有一个热源来抵消冷却。虽然我们认为，活动星系核加热可能不是一般的热源，我们得出结论，SN加热可以是足够的，只要SNe的动能可以有效地消散。在我们的样本中，22个晚型星系中至少有8个也检测到了弥散热日冕。在我们的样品中，发光的X射线活动星系核（>1041 ergs-1）所占的比例并不小（~5%）。
We present a systematic investigation of X-ray thermal coronae in 157 early-type and 22 late-type galaxies from a survey of 25 hot (kT > 3 keV), nearby (z 60% in LKs > 2L* galaxies. These embedded coronae in hot clusters are generally smaller, less luminous, and less massive than coronae in poor environments, demonstrating the negative effects of hot cluster environments on galactic coronae. Nevertheless, these coronae still manage to survive ICM stripping, evaporation, rapid cooling, and powerful AGN outflows, making them a rich source of information about gas stripping, microscopic transport, and feedback processes in the cluster environment. Heat conduction across the boundary of the coronae has to be suppressed by a factor of ≳100, which implies that the X-ray gas in early-type galaxies is magnetized and the magnetic field plays an important role in energy transfer. The luminous, embedded coronae, with high central density (0.1-0.4 cm-3), are miniversions of group and cluster cooling cores. As the prevalence of coronae of massive galaxies implies a long lifetime (≳several Gyr), there must be a heat source inside coronae to offset cooling. While we argue that AGN heating may not generally be the heat source, we conclude that SN heating can be enough as long as the kinetic energy of SNe can be efficiently dissipated. Diffuse thermal coronae have also been detected in at least 8 of 22 late-type galaxies in our sample. The fraction of luminous X-ray AGNs (>1041 ergs s-1) is not small (~5%) in our sample.