CONSTRAINING THE BULK LORENTZ FACTOR OF GAMMA-RAY BURST OUTFLOW IN THE MAGNETIC-DOMINATED JET MODEL
文献类型：期刊论文
| 作者 | Chang Z(常哲) ; Lin HN(林海南); 姜玉国;Chang, Z; Lin, HN; Jiang, YG
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| 刊名 | ASTROPHYSICAL JOURNAL
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| 出版日期 | 2012 |
| 卷号 | 759期号:2页码:129 |
| 关键词 | gamma-ray burst: general ISM: jets and outflows |
| 英文摘要 | Recent observations by the Fermi-LAT showed that there are delayed arrivals of GeV photons relative to the onset of MeV photons in some gamma-ray bursts (GRBs). In order to avoid a large optical depth, the minimal value of the Lorentz factor has been estimated to be higher than 1000 in some of the brightest bursts. In this paper, we present a detailed calculation of the time delay between the MeV and GeV photons in the framework of the magnetic-dominated jet model. We find that the time delay strongly depends on the saturated bulk Lorentz factor of the jet. Inspired by this fact, we use this model to calculate the Lorentz factors of the four brightest Fermi bursts. The results indicate that the Lorentz factors are much smaller than those obtained from the "single-zone" scenario. The short burst GRB 090510 has a minimal Lorentz factor of 385, while the three long bursts, GRB 080916c, GRB 090902b, and GRB 090926, have almost the same Lorentz factors with an average value near 260. Another interesting result is that, for long bursts, GeV photons are emitted after the bulk Lorentz factor saturates. For the short GRB, however, MeV and GeV photons are emitted at the same phase, i.e., either in the expansion phase or in the coasting phase. |
| 学科主题 | Astronomy & Astrophysics |
| 收录类别 | SCI |
| WOS记录号 | WOS:000310911300052 |
| 公开日期 | 2016-05-03 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/224427]  |
| 专题 | 高能物理研究所_理论物理室 |
| 推荐引用方式 GB/T 7714 | Chang Z,Lin HN,姜玉国；Chang, Z,et al. CONSTRAINING THE BULK LORENTZ FACTOR OF GAMMA-RAY BURST OUTFLOW IN THE MAGNETIC-DOMINATED JET MODEL[J]. ASTROPHYSICAL JOURNAL,2012,759(2):129. |
| APA | 常哲,林海南,姜玉国；Chang, Z,Lin, HN,&Jiang, YG.(2012).CONSTRAINING THE BULK LORENTZ FACTOR OF GAMMA-RAY BURST OUTFLOW IN THE MAGNETIC-DOMINATED JET MODEL.ASTROPHYSICAL JOURNAL,759(2),129. |
| MLA | 常哲,et al."CONSTRAINING THE BULK LORENTZ FACTOR OF GAMMA-RAY BURST OUTFLOW IN THE MAGNETIC-DOMINATED JET MODEL".ASTROPHYSICAL JOURNAL 759.2(2012):129. |
入库方式： OAI收割
来源：高能物理研究所
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