Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter alpha

	Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter alpha
	Qiao EL(乔二林)1,2 ; Liu BF(刘碧芳)1
刊名	PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
	2009
卷号	61 期号:2 页码:403-410
关键词	accretion, accretion disks X-rays: individual (GX 339-4, GS 2000+251) X-rays: stars
ISSN号	0004-6264
通讯作者	Qiao, EL (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, POB 110, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	A wealth of Galactic accreting X-ray binaries has been observed in both the low/hard and high/soft states. The transition between these two states has often been detected. Observations show that the transition huminosity between these two states is different for different sources, ranging from 1% to 4% of the Eddington luminosity L(Edd). Even for the same source, the transition luminosity at different outbursts call be different. The transition call occur at luminosities from 0.0069 to 0.15 L(Edd). In order to investigate the underlying physics, we study the influence of viscosity parameter alpha on the transition luminosity on the basis of the disk-corona model for black holes. We calculate the mass-evaporation rate for a wide range of viscosity parameters such as 0.1 <= alpha <= 0.9. Fitting the numerical results, we obtain fitting formulae for both the transition accretion rate and the corresponding radius as a function of alpha. We find that the transition luminosity is very sensitive to the value of ce, L/L(Edd) proportional to alpha(2,34). For 0.1 <= alpha <= 0.6, the transition luminosity varies by two orders of magnitude, from 0.001 to 0.2 L(Edd). Comparing with observations, we find that transition luminosity can be fitted by adjusting the value of alpha, and the model-determined values of a are mostly in the range of observationally inferred values. We also investigate the truncation of the disk in the low/hard state for some luminous sources. Our results agree roughly with the observations.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	ADVECTION-DOMINATED ACCRETION ; X-RAY BINARIES ; 3-DIMENSIONAL MAGNETOHYDRODYNAMIC SIMULATIONS ; BLACK-HOLE ; THIN DISK ; CORONAL FLOW ; CATACLYSMIC VARIABLES ; VERTICAL STRUCTURE ; GALACTIC NUCLEI ; DWARF NOVAE
收录类别	SCI
原文出处	http://pasj.oxfordjournals.org/content/61/2/403
语种	英语
WOS记录号	WOS:000266228300025
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/4990]
专题	云南天文台_高能天体物理研究组
作者单位	1.National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, PO Box 110, Kunming 650011, P. R. China 2.Graduate School of Chinese Academy of Sciences, Beijing 100049, P. R. China
推荐引用方式 GB/T 7714	Qiao EL,Liu BF. Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter alpha[J]. PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN,2009,61(2):403-410.
APA	Qiao EL,&Liu BF.(2009).Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter alpha.PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN,61(2),403-410.
MLA	Qiao EL,et al."Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter alpha".PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN 61.2(2009):403-410.