ESTIMATION OF THE VISCOSITY PARAMETER IN ACCRETION DISKS OF BLAZARS

doi:10.1088/0004-637X/707/2/866

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	ESTIMATION OF THE VISCOSITY PARAMETER IN ACCRETION DISKS OF BLAZARS
	Xie, ZH 1; Ma, L 1; Zhang, X 1; Du, LM 1; Hao, JM 1; Yi, TF 1; Qiao EL(乔二林)2 ; Xie, ZH (reprint author), Yunnan Normal Univ, Dept Phys, Kunming 650092, Peoples R China.
发表期刊	ASTROPHYSICAL JOURNAL
	2009-12-20
卷号	707 期号:2 页码:866-869
DOI	10.1088/0004-637X/707/2/866
产权排序	第2完成单位
收录类别	SCI
关键词	Galaxies: Active Accretion Galaxies: General Accretion Disks Galaxies: Nuclei Galaxy: Disk
摘要	For an optical monitoring blazar sample set whose typical minimum variability timescale is about 1 hr, we estimate a mean value of the viscosity parameter in their accretion disk. We assume that optical variability on timescales of hours is caused by local instabilities in the inner accretion disk. Comparing the observed variability timescales to the thermal timescales of alpha-disk models, we could obtain constraints on the viscosity parameter (alpha) and the intrinsic Eddington ratio (L(in)/L(Edd) = (m) over dot), 0.104 <= alpha <= 0.337, and 0.0201 <= L(in)/L(Edd) <= 0.1646. These narrow ranges suggest that all these blazars are observed in a single state, and thus provide a new evidence for the unification of flat-spectrum radio quasars and BL Lacs into a single blazar population. The values of alpha we derive are consistent with the theoretical expectation alpha similar to 0.1-0.3 of Narayan & Mcclintock for advection-dominated accretion flow and are also compatible with Pessah et al.'s predictions (alpha >= 0.1) by numerical simulations in which magnetohydrodynamic turbulence is driven by the saturated magnetorotational instability.
项目资助者	National Natural Science Foundation of China [10978019, 10778726] ; Natural Science Foundation of Yunnan Province of China [20082c045M]
语种	英语
学科领域	Astronomy & Astrophysics
文章类型	Article
ISSN	0004-637X
URL	查看原文
WOS记录号	WOS:000272465400002
WOS研究方向	Astronomy & Astrophysics
WOS类目	Astronomy & Astrophysics
关键词[WOS]	BL-LACERTAE OBJECTS ; INTRANIGHT OPTICAL VARIABILITY ; ACTIVE GALACTIC NUCLEI ; RAY-LOUD BLAZARS ; CCD PHOTOMETRY ; RAPID VARIABILITY ; BLACK-HOLE ; SIMULATIONS ; CONSTRAINTS ; TURBULENCE
引用统计	被引频次：10[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ynao.ac.cn/handle/114a53/4969
专题	高能天体物理研究组
通讯作者	Xie, ZH (reprint author), Yunnan Normal Univ, Dept Phys, Kunming 650092, Peoples R China.
作者单位	1.Physics Department, Yunnan Normal University, Kunming 650092, China 2.Yunnan Observatory, Kunming, China
推荐引用方式 GB/T 7714	Xie, ZH,Ma, L,Zhang, X,et al. ESTIMATION OF THE VISCOSITY PARAMETER IN ACCRETION DISKS OF BLAZARS[J]. ASTROPHYSICAL JOURNAL,2009,707(2):866-869.
APA	Xie, ZH.,Ma, L.,Zhang, X.,Du, LM.,Hao, JM.,...&Xie, ZH .(2009).ESTIMATION OF THE VISCOSITY PARAMETER IN ACCRETION DISKS OF BLAZARS.ASTROPHYSICAL JOURNAL,707(2),866-869.
MLA	Xie, ZH,et al."ESTIMATION OF THE VISCOSITY PARAMETER IN ACCRETION DISKS OF BLAZARS".ASTROPHYSICAL JOURNAL 707.2(2009):866-869.

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