CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-mass Black Holes?

doi:10.3847/2041-8213/ab481b

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	CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-mass Black Holes?
	Peng,Zong-Kai 1,2; Yang,Yi-Si 1,2; Shen,Rong-Feng 3; Wang,Ling-Jun 4; Zou,Jin-Hang 5; Zhang,Bin-Bin 1,2,6
刊名	The Astrophysical Journal Letters
	2019-10-14
卷号	884 期号:2
关键词	Intermediate-mass black holes Tidal disruption White dwarf stars X-ray transient sources
ISSN号	2041-8205
DOI	10.3847/2041-8213/ab481b
英文摘要	Abstract Recently, two fast X-ray transients (XT1 and XT2) have been reported from the search in the Chandra Deep Field (CDF) data. Each transient shows an initial plateau lasting around hundreds to thousands of seconds followed by a rapid decay in the light curve. In particular, CDF-S XT2 is found to be associated with a galaxy at redshift z?=?0.738 and was explained as a counterpart of a binary neutron-star merger event. In this Letter, motivated by the short duration and decay slopes of the two transients, we consider an alternative interpretation in which both events are accretion-driven flares from tidal disruption of white dwarfs by intermediate-mass black holes. We derive a theoretical model of the accretion rate history and find that it fits the observed X-ray light curves well. The extremely super-Eddington peak luminosity of XT2 can be explained by the beaming effect of the system, likely in the form of a jet.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:2041-8205-884-2-AB481B
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/28472]
专题	中国科学院国家天文台
作者单位	1.School of Astronomy and Space Science, Nanjing University, Nanjing 210093, People’s Republic of China; bbzhang@nju.edu.cn 2.Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing, People’s Republic of China 3.School of Physics & Astronomy, Sun Yat-Sen University, Zhuhai 519082, People’s Republic of China; shenrf3@mail.sysu.edu.cn 4.National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China 5.Department of Space Sciences and Astronomy, Hebei Normal University, Shijiazhuang 050024, People’s Republic of China 6.Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154, USA
推荐引用方式 GB/T 7714	Peng,Zong-Kai,Yang,Yi-Si,Shen,Rong-Feng,et al. CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-mass Black Holes?[J]. The Astrophysical Journal Letters,2019,884(2).
APA	Peng,Zong-Kai,Yang,Yi-Si,Shen,Rong-Feng,Wang,Ling-Jun,Zou,Jin-Hang,&Zhang,Bin-Bin.(2019).CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-mass Black Holes?.The Astrophysical Journal Letters,884(2).
MLA	Peng,Zong-Kai,et al."CDF-S XT1 and XT2: White Dwarf Tidal Disruption Events by Intermediate-mass Black Holes?".The Astrophysical Journal Letters 884.2(2019).