Hyperaccreting Black Hole as Gamma-Ray Burst Central Engine. II. Temporal Evolution of the Central Engine Parameters during the Prompt and Afterglow Phases

doi:10.3847/1538-4357/aa9074

	Hyperaccreting Black Hole as Gamma-Ray Burst Central Engine. II. Temporal Evolution of the Central Engine Parameters during the Prompt and Afterglow Phases
	Lei,Wei-Hua 1,2; Zhang,Bing 2; Wu,Xue-Feng 3; Liang,En-Wei 4
刊名	The Astrophysical Journal
	2017-10-30
卷号	849 期号:1
关键词	accretion, accretion disks gamma-ray burst: general magnetic fields neutrinos
ISSN号	0004-637X
DOI	10.3847/1538-4357/aa9074
英文摘要	Abstract A hyperaccreting stellar-mass black hole (BH) has been proposed as the candidate central engine of gamma-ray bursts (GRBs). The rich observations of GRBs by Fermi and Swift make it possible to constrain the central engine model by comparing the model predictions against data. This paper is dedicated to studying the temporal evolution of the central engine parameters for both the prompt emission and afterglow phases. We consider two jet-launching mechanisms, i.e., ν ν ˉ annihilations and the Blandford–Znajek (BZ) process, and obtain analytical solutions to these two models. We then investigate the BH central engine parameters, such as the jet power, the dimensionless entropy η, and the central engine parameter μ0?=?η (1?+?σ0) (where σ0 is the initial magnetization of the engine) at the base of the jet. The BH may be spun up by accretion or spun down by the BZ process, leaving imprints in the GRB light curves. Usually, a BZ jet is more powerful and is likely responsible for the late-time central engine activities. However, an initially non-spinning BH central engine may first launch a thermal “fireball” via neutrino annihilations, and then launch a Poynting-flux-dominated jet via the BZ process. Multiple flares, giant bumps, and plateaus in GRB afterglows can be produced as the result of late-time accretion onto the BH.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:0004-637X-849-1-AA9074
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/22598]
专题	中国科学院紫金山天文台
作者单位	1.School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China; leiwh@hust.edu.cn 2.Department of Physics and Astronomy, University of Nevada Las Vegas, NV 89154, USA; zhang@physics.unlv.edu 3.Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China 4.Guangxi Key Laboratory for Relativistic Astrophysics, Department of Physics, Guangxi University, Nanning 530004, China
推荐引用方式 GB/T 7714	Lei,Wei-Hua,Zhang,Bing,Wu,Xue-Feng,et al. Hyperaccreting Black Hole as Gamma-Ray Burst Central Engine. II. Temporal Evolution of the Central Engine Parameters during the Prompt and Afterglow Phases[J]. The Astrophysical Journal,2017,849(1).
APA	Lei,Wei-Hua,Zhang,Bing,Wu,Xue-Feng,&Liang,En-Wei.(2017).Hyperaccreting Black Hole as Gamma-Ray Burst Central Engine. II. Temporal Evolution of the Central Engine Parameters during the Prompt and Afterglow Phases.The Astrophysical Journal,849(1).
MLA	Lei,Wei-Hua,et al."Hyperaccreting Black Hole as Gamma-Ray Burst Central Engine. II. Temporal Evolution of the Central Engine Parameters during the Prompt and Afterglow Phases".The Astrophysical Journal 849.1(2017).