Shock heating by Fanaroff–Riley type I radio sources in galaxy clusters
Shock heating by Fanaroff–Riley type I radio sources in galaxy clusters
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DOI：
10.1111/j.1745-3933.2007.00351.x
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发表时间：
2007-06
影响因子：
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通讯作者：
M. Brueggen;S. Heinz;E. Roediger;M. Ruszkowski;A. Simionescu
中科院分区：
文献类型：
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作者：
M. Brueggen;S. Heinz;E. Roediger;M. Ruszkowski;A. Simionescu
活动星系核（AGN）的反馈经常被用来解释星系光度函数在亮端的截止和星系团中冷却流的缺乏。与此同时，最近在射电大活动星系核周围观测到了冲击波阵面。利用真实的三维模拟星系团中的喷流，我们解决了这样一个问题，即活动星系核能量的一小部分是在冲击中耗散的。我们发现，弱的冲击，包括AGN的马赫数为1.1-1.2和耗散至少2%的机械光度的AGN。在现实的星系团介质中，即使是连续的喷流也可能导致多重激波结构，这可能导致根据波的空间分布推断的活动星系核占空比的高估。
Feedback by active galactic nuclei (AGN) is frequently invoked to explain the cut-off of the galaxy luminosity function at the bright end and the absence of cooling flows in galaxy clusters. Meanwhile, there are recent observations of shock fronts around radio-loud AGN. Using realistic 3D simulations of jets in a galaxy cluster, we address the question what of fraction of AGN energy is dissipated in shocks. We find that weak shocks that encompass the AGN have Mach numbers of 1.1–1.2 and dissipate at least 2 per cent of the mechanical luminosity of the AGN. In a realistic cluster medium, even a continuous jet can lead to multiple shock structures, which may lead to an overestimate of the AGN duty cycles inferred from the spatial distribution of waves.