Heating of Intergalactic Gas and Cluster Scaling Relations
Heating of Intergalactic Gas and Cluster Scaling Relations
复制标题
星系间气体的加热与星团尺度关系
DOI：
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发表时间：
1999
期刊：
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通讯作者：
M. Loewenstein
中科院分区：
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作者：
M. Loewenstein
星系群和星系团的X射线观测结果与最简单的分层聚类模型的预测不一致，其中非重子和重子成分在引力的唯一影响下聚集在一起。这些偏离是指星系际介质比预期的更热，更长，并且在质量较小的系统中变得越来越强。我通过构建标准化高温集群和数值模拟观测的流体静力学多方模型的基线序列来模拟这些效应，然后通过在集群中心添加禁止的每个粒子的热量来转换它们。我目前的序列与此加热参数的普遍价值，同时再现最近发表的观察（气体和总引力）的质量温度和熵温度的关系。所需的能量注入量是一致的超新星的数量上的限制，需要考虑到观察到的集群内硅丰度，只要能量注入集中。我认为，大部分的加热过程中或之后发生的集群的组装，而不是完全在崩溃前的原星团碎片。
X-ray observations of galaxy groups and clusters are inconsistent with the predictions of the simplest hierarchical clustering models, wherein nonbaryonic and baryonic components are assembled together under the sole influence of gravity. These departures are in the sense that the intergalactic medium is hotter and more extended than expected, and become increasingly strong for less massive systems. I model these effects by constructing baseline sequences of hydrostatic polytropic models normalized to observations of high-temperature clusters and numerical simulations, and then transforming them by adding proscribed amounts of heat per particle at the cluster center. I present sequences with a universal value of this heating parameter that simultaneously reproduce recently published observed (gas and total gravitational) mass-temperature and entropy-temperature relations. The required amount of energy injection is consistent with constraints on the number of supernovae needed to account for observed intracluster silicon abundances, provided that energy injection is centrally concentrated. I argue that most of the heating occurred during or after the assembly of the cluster, and not exclusively in precollapse protocluster fragments.