The spectrum of gamma-ray burst: a clue
文献类型：期刊论文
| 作者 | Fan, Yi-Zhong1,2,3
|
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2010-03-21 |
| 卷号 | 403期号:1页码:483-490 |
| 关键词 | hydrodynamics radiation mechanisms: non-thermal gamma rays: bursts |
| ISSN号 | 0035-8711 |
| 英文摘要 | In this work, we numerically calculate the thermal radiation efficiency of the baryonic outflow. The possible outflow acceleration in the transparent stage, which lowers thermal radiation efficiency, has been taken into account. In the standard internal shock model for the prompt emission, the fast shells should move with a typical Lorentz factor similar to 5 Gamma(i) otherwise the gamma-ray burst (GRB) efficiency will be in disagreement with the observations, where Gamma(i) is the bulk Lorentz factor of the shocked/emitting region. The photosphere radius of these fast shells is small and the thermal radiation is too strong to be effectively outshone by the internal shock emission. This is particularly the case for some extremely bright events having Gamma(i) similar to 103, like GRBs 080319B and 080916C. The absence of a distinct thermal component in the spectrum of most GRBs challenges the standard internal shock model and may suggest a non-baryonic (magnetic) outflow component. Though the magnetic outflow model seems favoured by more and more data, it can hardly reproduce the typical GRB spectrum. In the photosphere-gradual magnetic dissipation scenario, the spectrum cuts off at similar to 1 GeV, too low to account for the observations of GRBs 080916C. In the sudden magnetic energy dissipation model, the low-energy spectrum is expected to be F(nu) proportional to nu-1/2, too soft to be consistent with the data F(nu) proportional to nu 0. We speculate that the low-energy spectrum puzzle could be unveiled by the mechanism that particles, in the magnetic dissipation process, are repeatedly accelerated. |
| 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] | SELF-COMPTON EMISSION ; HIGH-ENERGY EMISSION ; GRB 080916C ; PROMPT EMISSION ; PHYSICAL PARAMETERS ; RELATIVISTIC SHOCKS ; DOMINATED OUTFLOW ; ACCRETION MODELS ; LORENTZ FACTORS ; EARLY AFTERGLOW |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000276351600058 |
| 公开日期 | 2011-11-23 |
| 源URL | [http://159.226.72.40/handle/332002/1155]  |
| 专题 | 紫金山天文台_宇宙伽马暴、中子星及相关物理研究团组 |
| 作者单位 | 1.Univ Copenhagen, Niels Bohr Inst, Niels Bohr Int Acad, DK-2100 Copenhagen, Denmark 2.Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark 3.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China |
| 推荐引用方式 GB/T 7714 | Fan, Yi-Zhong. The spectrum of gamma-ray burst: a clue[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2010,403(1):483-490. |
| APA | Fan, Yi-Zhong.(2010).The spectrum of gamma-ray burst: a clue.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,403(1),483-490. |
| MLA | Fan, Yi-Zhong."The spectrum of gamma-ray burst: a clue".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 403.1(2010):483-490. |
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来源：紫金山天文台
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