主要内容:
用了正反激波、双成分喷流。对这个暴，说前者不行，后者可以。
精彩摘抄:
 |
| 对高能部分的拟合 |
文章信息:
- · arXiv e-print (arXiv:1009.1289)
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| Title: |
| Modeling the broadband emission of Fermi/LAT GRB 090902B |
| Authors: |
| Liu, Ruo-Yu; Wang, Xiang-Yu |
| Publication: |
| eprint arXiv:1009.1289 |
| Publication Date: |
| 09/2010 |
| Origin: |
| ARXIV |
| Keywords: |
| Astrophysics - High Energy Astrophysical Phenomena |
| Comment: |
| 27 pages, 4 figures, references added |
| Bibliographic Code: |
| 2010arXiv1009.1289L |
Abstract
GRB 090902B, detected by Fermi Large Array Telescope (Fermi/LAT), shows extend high-energy emission (>100 MeV) up to 10^3 s after the burst, which decays with time in a power-law as t^{-1.5}. It has been also observed by several follow-up low-energy instruments, including an early optical detection around 5000 s after the burst. The optical emission at early time decays faster than t^{-1.6}, which has been suspected to originate from the reverse shock. We here explore the models that can possibly explain the the broadband afterglow emission of GRB 090902B. We find that the reverse shock model for the early optical emission would overpredict the radio afterglow flux that is inconsistent with observations. A partially radiative blast wave model, which though is able to produce a sufficiently steep decay slope, can not explain the broadband data of GRB 090902B. The two-component jet model, which consists of a narrow and bright jet component in the core and a surrounding wider and less energetic jet component, is shown to be able to explain the broadband afterglow data, including the LAT high-energy data after ~50 s and low-energy (radio, optical and X-ray) afterglow data. The early-time high-energy emission detected by LAT before ~50 s is likely due to internal origin as that of the sub-MeV emission. The highest energy (33 GeV) photon of GRB090902B detected at 80 s can be marginally accommodated within the forward shock emission under the optimistic condition that electrons are accelerated by the Bohm diffusive shock.
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