| A comprehensive analysis of Swift XRT data. I. Apparent spectral evolution of gamma-ray burst X-ray tails | |
Zhang BB(张彬彬)1,2 ; Liang, EW1,3; Zhang, B1; Zhang, BB (reprint author), Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA.
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| 发表期刊 | ASTROPHYSICAL JOURNAL
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| 2007-09-10 | |
| 卷号 | 666期号:2页码:1002-1011 |
| DOI | 10.1086/519548 |
| 产权排序 | 第2完成单位 |
| 收录类别 | SCI |
| 关键词 | Gamma Rays : Bursts |
| 摘要 | An early steep decay component following the prompt GRBs is commonly observed in Swift XRT light curves, which is regarded as the tail emission of the prompt gamma rays. Prompted by the observed strong spectral evolution in the tails of GRBs 060218 and 060614, we present a systematic time-resolved spectral analysis for the Swift GRB tails detected between 2005 February and 2007 January. We select a sample of 44 tails that are bright enough to perform time-resolved spectral analyses. Among them 11 tails are smooth and without superimposing significant flares, and their spectra have no significant temporal evolution. We suggest that these tails are dominated by the curvature effect of the prompt gamma rays due to delay of propagation of photons from large angles with respect to the line of sight. More interestingly, 33 tails show clear hard-to-soft spectral evolution, with 16 of them being smooth tails directly following the prompt GRBs, and the others being superimposed with large flares. We focus on the 16 clean, smooth tails and consider three toy models to interpret the spectral evolution. The curvature effect of a structured jet and a model invoking superposition of the curvature effect tail and a putative underlying soft emission component cannot explain all the data. The third model, which invokes an evolving exponential spectrum, seems to reproduce both the light curve and the spectral evolution of all the bursts, including GRBs 060218 and 060614. More detailed physical models are called for to understand the apparent evolution effect. |
| 语种 | 英语 |
| 学科领域 | Astronomy & Astrophysics |
| 文章类型 | Article |
| ISSN | 0004-637X |
| URL | 查看原文 |
| WOS记录号 | WOS:000249305700031 |
| WOS研究方向 | Astronomy & Astrophysics |
| WOS类目 | Astronomy & Astrophysics |
| 关键词[WOS] | AFTERGLOW LIGHT CURVES ; VIEWING ANGLE ; BLACK-HOLES ; LONG ; EMISSION ; GRB-060218 ; FLARES ; ENERGY ; PROFILES ; BEHAVIOR |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.ynao.ac.cn/handle/114a53/7020 |
| 专题 | 星系研究组 |
| 通讯作者 | Zhang, BB (reprint author), Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA. |
| 作者单位 | 1.Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154 2.National Astronomical Observatories/Yunnan Observatory, CAS, Kunming 650011, China 3.Department of Physics, Guangxi University, Nanning 530004, China |
| 第一作者单位 | 中国科学院云南天文台 |
| 推荐引用方式 GB/T 7714 | Zhang BB,Liang, EW,Zhang, B,et al. A comprehensive analysis of Swift XRT data. I. Apparent spectral evolution of gamma-ray burst X-ray tails[J]. ASTROPHYSICAL JOURNAL,2007,666(2):1002-1011. |
| APA | Zhang BB,Liang, EW,Zhang, B,&Zhang, BB .(2007).A comprehensive analysis of Swift XRT data. I. Apparent spectral evolution of gamma-ray burst X-ray tails.ASTROPHYSICAL JOURNAL,666(2),1002-1011. |
| MLA | Zhang BB,et al."A comprehensive analysis of Swift XRT data. I. Apparent spectral evolution of gamma-ray burst X-ray tails".ASTROPHYSICAL JOURNAL 666.2(2007):1002-1011. |
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| A Comprehensive Anal（1750KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | 浏览 请求全文 | |
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