Stable Heating of Cluster Cooling Flows by Cosmic-Ray Streaming
Stable Heating of Cluster Cooling Flows by Cosmic-Ray Streaming
复制标题
宇宙射线流对团簇冷却流的稳定加热
DOI：
10.1088/0004-637x/738/2/182
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
& Y. Ohira
中科院分区：
文献类型：
--
作者：
Y. Fujita;& Y. Ohira
本文利用数值模拟研究了宇宙射线流对星系团冷核的加热作用。在这个模型中，CRs被中央活动星系核（AGN）注入，并随着阿尔文波向外移动。波被流本身激发并变得非线性。如果磁场足够大，由于阿尔文速度很大，CRs可以在整个核心中占主导地位并加热整个核心。我们发现，CR流可以稳定地加热高，低温集群在很长一段时间内没有热传导的帮助下，它可以防止大规模的冷却流的发展。如果热传导的贡献很小，加热可以进一步稳定。我们讨论的稳定性的原因，并指出，CR压力是不敏感的簇内介质（ICM）的变化和加热项的密度依赖性是类似的辐射冷却。
We study heating of cool cores in galaxy clusters by cosmic-ray (CR) streaming using numerical simulations. In this model, CRs are injected by the central active galactic nucleus (AGN) and move outward with Alfvén waves. The waves are excited by the streaming itself and become nonlinear. If magnetic fields are large enough, CRs can prevail in and heat the entire core because of a large Alfvén velocity. We find that the CR streaming can stably heat both high-and low-temperature clusters for a long time without the assistance of thermal conduction, and it can prevent the development of massive cooling flows. If there is even a minor contribution from thermal conduction, the heating can be stabilized further. We discuss the reason for the stability and indicate that the CR pressure is insensitive to changes in the intracluster medium (ICM) and that the density dependence of the heating term is similar to that of radiative cooling.