Gamma-ray bursts: afterglows from cylindrical jets
文献类型：期刊论文
| 作者 | Cheng, KS; Huang, YF; Lu, T |
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2001 |
| 卷号 | 325期号:2页码:599-606 |
| 关键词 | radiation mechanisms : non-thermal stars : neutron ISM : jets and outflows gamma-rays : bursts |
| 通讯作者 | Univ Hong Kong, Dept Phys, Hong Kong, Hong Kong, Peoples R China ; Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China ; Nanjing Univ, Astron & Astrophys Ctr E China, Nanjing 210093, Peoples R China ; Chinese Acad Sci, Inst High Energy Phys, LCRHEA, Beijing 100039, Peoples R China |
| 英文摘要 | Nearly all previous discussions on beaming effects in gamma-ray bursts (GRBs) have assumed a conical geometry. However, more and more observations on relativistic jets in radio galaxies, active galactic nuclei, and 'microquasars' in the Galaxy have shown that many of these outflows are not conical, but cylindrical, i.e. they maintain constant cross-sections at large scales. Thus it is necessary to discuss the possibility of gamma-ray bursts being due to highly collimated cylindrical jets, not conical ones. Here we study the dynamical evolution of cylindrical jets and discuss their afterglows. Both analytical and numerical results are presented. It is shown that when the lateral expansion is not taken into account, a cylindrical jet typically remains highly relativistic for similar to 10(8)-10(9) s. During this relativistic phase, the optical afterglow at first decays as S-nu proportional to t(-p/2), where p is the index characterizing the power-law energy distribution of electrons. Then the light curve steepens to S-nu proportional to t(-(p+1)/2) due to cooling of electrons. After entering the non-relativistic phase (i.e. t greater than or equal to 10(11) s), the afterglow is S-nu proportional to t(-(5p-4)/6). However, if the cylindrical jet expands laterally at the comoving sound speed, then the decay becomes S-nu proportional to t(-p) and S-nu proportional to t(-(15p-21)/10) - t(-(15p-20)/10) in the ultrarelativistic and in the non-relativistic phase respectively. Note that in both cases the light curve turns flatter after the relativistic-Newtonian transition point, which differs markedly from the behaviour of a conical jet. It is suggested that some GRBs with afterglows decaying as t(-1.1)-t(-1.3) may be due to cylindrical jets, not necessarily isotropic fireballs. |
| 学科主题 | Astronomy & Astrophysics |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 原文出处 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000170568100017 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/238072]  |
| 专题 | 高能物理研究所_粒子天体物理中心 |
| 作者单位 | 中国科学院高能物理研究所 |
| 推荐引用方式 GB/T 7714 | Cheng, KS,Huang, YF,Lu, T. Gamma-ray bursts: afterglows from cylindrical jets[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2001,325(2):599-606. |
| APA | Cheng, KS,Huang, YF,&Lu, T.(2001).Gamma-ray bursts: afterglows from cylindrical jets.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,325(2),599-606. |
| MLA | Cheng, KS,et al."Gamma-ray bursts: afterglows from cylindrical jets".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 325.2(2001):599-606. |
入库方式： OAI收割
来源：高能物理研究所
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