A Model for Spectral States and Their Transition in Cyg X-1

doi:10.3847/1538-4357/aac50d

CORC > 国家天文台 > 中国科学院国家天文台

	A Model for Spectral States and Their Transition in Cyg X-1
	Taam,Ronald E.1,2; Qiao,Erlin 3,4; Liu,B. F.3,4; Meyer-Hofmeister,E.5
刊名	The Astrophysical Journal
	2018-06-25
卷号	860 期号:2
关键词	accretion, accretion disks black hole physics stars: individual (Cyg X-1) X-rays: binaries X-rays: stars
ISSN号	0004-637X
DOI	10.3847/1538-4357/aac50d
英文摘要	Abstract A new accretion picture based on a small disk surrounding a black hole is developed for the wind-fed source Cyg X-1. The hard and soft spectral states of Cyg X-1 are interpreted in terms of co-spatial two-component flows for the innermost region of an accretion disk. The state transitions result from the outward expansion and inward recession of this inner disk for the hard-to-soft and soft-to-hard transition, respectively. The theoretical framework for state transitions in black hole X-ray binaries with high-mass companions involving a change in the inner disk size, thus it differs from systems with low-mass companions involving the change in the outer disk size. This fundamental difference stems from the fact that matter captured and supplied to the black hole in wind-fed systems has low specific angular momentum and is hot essentially heated in the bow and spiral shocks, whereas it has high specific angular momentum and is cool in Roche lobe overflow systems. The existence of a weak cool disk around the ISCO region in the hard state allows for the presence of a relativistically broadened Fe K line. The small disk fed by gas condensation forms without an extensive outer disk, precluding thermal instabilities and large outbursts, resulting in the lack of large amplitude outbursts and hysteresis effects in the light curve of high-mass black hole X-ray binaries. Their relatively persistent X-ray emission is attributed to their wind-fed nature.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:0004-637X-860-2-AAC50D
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/35535]
专题	中国科学院国家天文台
作者单位	1.Institute of Astronomy and Astrophysics—TIARA, Academia Sinica, P.O. Box 23-141, Taipei, 10617, Taiwan 2.Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA 3.Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China; bfliu@nao.cas.cn 4.School of Astronomy and Space Science, University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, People’s Republic of China 5.Max-Planck-Institut für Astrophysik, Karl Schwarzschildstr. 1, D-85740, Garching, Germany
推荐引用方式 GB/T 7714	Taam,Ronald E.,Qiao,Erlin,Liu,B. F.,et al. A Model for Spectral States and Their Transition in Cyg X-1[J]. The Astrophysical Journal,2018,860(2).
APA	Taam,Ronald E.,Qiao,Erlin,Liu,B. F.,&Meyer-Hofmeister,E..(2018).A Model for Spectral States and Their Transition in Cyg X-1.The Astrophysical Journal,860(2).
MLA	Taam,Ronald E.,et al."A Model for Spectral States and Their Transition in Cyg X-1".The Astrophysical Journal 860.2(2018).