Captures of red giant stars by black holes in elliptical galaxies: Feedback to the hot gas

	Captures of red giant stars by black holes in elliptical galaxies: Feedback to the hot gas
	Wang, JM ; Hu, C
刊名	ASTROPHYSICAL JOURNAL
	2005-09-10
卷号	630 期号:2 页码:L125-L128
关键词	galaxies : active X-rays : galaxies
英文摘要	The highly disturbed hot gas in elliptical galaxies, as revealed in many Chandra X-ray images, implies a source of energy in the galactic nucleus. In some elliptical galaxies, faint X-ray "ghost" cavities appear without corresponding radio lobes. It has been suggested that ghost cavities are caused by short-lived activity with a timescale of similar to 10(3) - 10(4) yr, but this is difficult to understand within the popular paradigm of active galactic nuclei. We suggest an episode model for ghost cavities, invoking captures of red giant stars by the black hole located at the center of elliptical galaxies at a typical rate of 10(-5) yr(-1) per galaxy. The accretion of tidally disrupted red giant stars onto the black hole powers activity in a timescale of a few years. The total energy channeled into the jet/outflow during the cooling time of the hot gas is similar to 10(56) ergs, which is the typical work required to form the observed cavities. In this scenario, the faint cavities are produced by the feedback following accretion of the debris of the captured red giant stars onto the black holes. We apply the present model to several elliptical galaxies and find that it can explain the formation of the ghost cavities. This model can be tested in the future by comparisons between radio and X-ray observations.
收录类别	SCI
语种	英语
WOS记录号	WOS:000231664600006
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/7021]
专题	国家天文台_空间科学研究部
作者单位	1.Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Wang, JM,Hu, C. Captures of red giant stars by black holes in elliptical galaxies: Feedback to the hot gas[J]. ASTROPHYSICAL JOURNAL,2005,630(2):L125-L128.
APA	Wang, JM,&Hu, C.(2005).Captures of red giant stars by black holes in elliptical galaxies: Feedback to the hot gas.ASTROPHYSICAL JOURNAL,630(2),L125-L128.
MLA	Wang, JM,et al."Captures of red giant stars by black holes in elliptical galaxies: Feedback to the hot gas".ASTROPHYSICAL JOURNAL 630.2(2005):L125-L128.