中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Photosphere-internal shock model of gamma-ray bursts: case studies of Fermi/LAT bursts

文献类型:期刊论文

作者Toma, K.1,2; Wu, X. -F.1,2,3; Meszaros, P.1,2,4
刊名MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
出版日期2011-08-01
卷号415期号:2页码:1663-1680
关键词radiation mechanisms: non-thermal gamma-ray burst: general
英文摘要Radially inhomogeneous gamma-ray burst (GRB) jets release variable photospheric emission and can have internal shocks occurring above the photosphere. We generically formulate a photospheric emission model of GRBs including Compton up-scattered photospheric (UP) emission off the electrons (and positrons) in the internal shocks, and find that the photospheric emission may correspond to the traditional (band) component at less than or similar to 1 MeV and the UP emission to the high-energy emission observed by Fermi/LAT for some GRBs at greater than or similar to 10 MeV. The two components can be separate from each other in the spectrum in some cases or can mimic a smooth broad-band spectrum in other cases. We apply our formulation to the well-studied long and short LAT GRBs, GRB 080916C, GRB 090902B and GRB 090510, and typically find reasonable parameters for fitting the time-binned spectra, although fine-tuning of several parameters is required. The observed delays of the high-energy emission with respect to the MeV emission which are large compared to the variability times are unlikely to be due to simple kinematic effects of a non-evolving jet. These delays may instead be attributed to the temporal evolution of the physical parameters of the jet, and thus the delay time-scales could provide a potential tool for investigating the structures of GRB jets themselves and their progenitors. The difference of the delay time-scales of long and short GRBs inferred from the Fermi data might be due to the differences in the progenitors of long and short GRBs. Some other properties and consequences of this model are discussed, including temporal correlations among the prompt optical, the soft X-ray and the distinct high-energy component as well as the band component.
WOS标题词Science & Technology ; Physical Sciences
类目[WOS]Astronomy & Astrophysics
研究领域[WOS]Astronomy & Astrophysics
关键词[WOS]HIGH-ENERGY EMISSION ; SHORT GRB 090510 ; SCALE MAGNETIC-FIELDS ; PROMPT EMISSION ; SPECTRAL COMPONENT ; SYNCHROTRON EMISSION ; AFTERGLOW EMISSION ; RELATIVISTIC JETS ; DELAYED EMISSION ; LORENTZ FACTORS
收录类别SCI
语种英语
WOS记录号WOS:000293756300056
源URL[http://libir.pmo.ac.cn/handle/332002/15961]  
专题紫金山天文台_南极天文中心
作者单位1.Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA
2.Penn State Univ, Ctr Particle Astrophys, University Pk, PA 16802 USA
3.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China
4.Penn State Univ, Dept Phys, University Pk, PA 16802 USA
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Toma, K.,Wu, X. -F.,Meszaros, P.. Photosphere-internal shock model of gamma-ray bursts: case studies of Fermi/LAT bursts[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2011,415(2):1663-1680.
APA Toma, K.,Wu, X. -F.,&Meszaros, P..(2011).Photosphere-internal shock model of gamma-ray bursts: case studies of Fermi/LAT bursts.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,415(2),1663-1680.
MLA Toma, K.,et al."Photosphere-internal shock model of gamma-ray bursts: case studies of Fermi/LAT bursts".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 415.2(2011):1663-1680.

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来源:紫金山天文台

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