ESTIMATION OF THE VISCOSITY PARAMETER IN ACCRETION DISKS OF BLAZARS
文献类型：期刊论文
| 作者 | Xie, ZH1; Ma, L1; Zhang, X1; Du, LM1; Hao, JM1; Yi, TF1; Qiao EL(乔二林)2
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| 刊名 | ASTROPHYSICAL JOURNAL
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| 出版日期 | 2009-12-20 |
| 卷号 | 707期号:2页码:866-869 |
| 关键词 | accretion, accretion disks galaxies: active galaxies: general galaxies: nuclei Galaxy: disk |
| ISSN号 | 0004-637X |
| 产权排序 | 第二完成单位 |
| 通讯作者 | Xie, ZH (reprint author), Yunnan Normal Univ, Dept Phys, Kunming 650092, Peoples R China. |
| 英文摘要 | 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. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 学科主题 | Astronomy & Astrophysics |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | 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 |
| 收录类别 | SCI |
| 原文出处 | http://iopscience.iop.org/0004-637X/707/2/866/ |
| 语种 | 英语 |
| WOS记录号 | WOS:000272465400002 |
| 源URL | [http://ir.ynao.ac.cn/handle/114a53/4969]  |
| 专题 | 云南天文台_高能天体物理研究组 |
| 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.,...&Qiao EL.(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. |
入库方式： OAI收割
来源：云南天文台
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