Baryon cycles in the biggest galaxies
Baryon cycles in the biggest galaxies
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DOI：
10.1016/j.physrep.2022.04.005
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发表时间：
2022-04
期刊：
影响因子：
--
通讯作者：
M. Donahue;G. Voit
中科院分区：
文献类型：
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作者：
M. Donahue;G. Voit
宇宙中最大的星系既有巨大的大气层，又有超大质量的中心黑洞。本文综述了一个大星系的这两个组成部分是如何耦合并调节星系的恒星形成速率的。超大质量黑洞和大尺度大气之间相互作用的模型表明，冷气体云吸积到黑洞上时释放的能量将大气悬浮在一种对冷云形成略微稳定的状态。越来越多的观测证据表明，从星系团的巨大中心星系到我们的银河系，许多大质量星系都接近这个边缘状态。在这样一个边缘状态的星系中，恒星形成的气体供应与恒星的中心速度色散（σ v）密切相关。因此，我们探索了一个模型的结果，在这个模型中，当σ v超过由星系超新星加热速率决定的临界值时，黑洞吸积过程中释放的能量会关闭恒星形成。
The universe’s biggest galaxies have both vast atmospheres and supermassive central black holes. This article reviews how those two components of a large galaxy couple and regulate the galaxy’s star formation rate. Models of interactions between a supermassive black hole and the large-scale atmosphere suggest that the energy released as cold gas clouds accrete onto the black hole suspends the atmosphere in a state that is marginally stable to formation of cold clouds. A growing body of observational evidence indicates that many massive galaxies, ranging from the huge central galaxies of galaxy clusters down to our own Milky Way, are close to that marginal state. The gas supply for star formation within a galaxy in such a marginal state is closely tied to the central velocity dispersion (σ v) of its stars. We therefore explore the consequences of a model in which energy released during black-hole accretion shuts down star formation when σ v exceeds a critical value determined by the galaxy’s supernova heating rate.