KMS Institute Of Geographic Sciences And Natural Resources Research,CAS
| Physical processes shaping gamma-ray burst X-ray afterglow light curves: Theoretical implications from the Swift X-ray telescope observations | |
Zhang, B ; Fan, YZ; Dyks, J; Kobayashi, S; Meszaros, P; Burrows, DN; Nousek, JA; Gehrels, N
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| 2006-05-01 | |
| Source Publication | ASTROPHYSICAL JOURNAL
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| Volume | 642Issue:1Pages:354-370 |
| Abstract | With the successful launch of the Swift Gamma-Ray Burst Explorer, a rich trove of early X-ray afterglow data has been collected by its onboard X-Ray Telescope (XRT). Some interesting features are emerging, including a distinct rapidly decaying component preceding the conventional afterglow component in many sources, a shallow decay component before the more "normal'' decay component observed in a good fraction of GRBs, and X-ray flares in nearly half of the afterglows. In this paper we systematically analyze the possible physical processes that shape the properties of the early X-ray afterglow light curves and use the data to constrain various models. We suggest that the steep decay component is consistent with the tail emission of the prompt gamma-ray bursts and/or the X-ray flares. This provides strong evidence that the prompt emission and afterglow emission are likely two distinct components, supporting the internal origin of the GRB prompt emission. The shallow decay segment observed in a group of GRBs suggests that very likely the forward shock keeps being refreshed for some time. This might be caused by either a long-lived central engine, or a wide distribution of the shell Lorentz factors, or else possibly the deceleration of a Poynting flux-dominated flow. X-ray flares suggest that the GRB central engine is very likely still active after the prompt gamma-ray emission is over, but with a reduced activity at later times. In some cases, the central engine activity even extends to days after the burst triggers. Analyses of early X-ray afterglow data reveal that GRBs are indeed highly relativistic events and that early afterglow data of many bursts, starting from the beginning of the XRT observations, are consistent with the afterglow emission from an ISM environment. |
| Subtype | Review |
| Keyword | Gamma Rays : Bursts Radiation Mechanisms : Nonthermal Shock Waves |
| WOS Headings | Science & Technology ; Physical Sciences |
| WOS Subject Extended | Astronomy & Astrophysics |
| WOS Keyword | REVERSE SHOCK EMISSION ; CONTINUOUS ENERGY INJECTION ; EARLY OPTICAL AFTERGLOWS ; INTERNAL SHOCKS ; MILLISECOND PULSARS ; RELATIVISTIC JETS ; WIND ENVIRONMENTS ; FIREBALL MODEL ; COMMON ORIGIN ; PROMPT PHASE |
| Indexed By | SCI |
| Language | 英语 |
| WOS Subject | Astronomy & Astrophysics |
| WOS ID | WOS:000237206600028 |
| Publisher | UNIV CHICAGO PRESS |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.igsnrr.ac.cn/handle/311030/67906 |
| Collection | 中国科学院地理科学与资源研究所 |
| Corresponding Author | Zhang, B |
| Affiliation | 1.Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA 2.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 3.Chinese Acad Sci, Inst Geog, Natl Astron Observ, Beijing 100012, Peoples R China 4.Nicholas Copernicus Astron Ctr, Lab Astrophys 1, PL-87100 Torun, Poland 5.Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA 6.Penn State Univ, Dept Phys, University Pk, PA 16802 USA 7.Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England 8.NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA |
| Recommended Citation GB/T 7714 | Zhang, B,Fan, YZ,Dyks, J,et al. Physical processes shaping gamma-ray burst X-ray afterglow light curves: Theoretical implications from the Swift X-ray telescope observations[J]. ASTROPHYSICAL JOURNAL,2006,642(1):354-370. |
| APA | Zhang, B.,Fan, YZ.,Dyks, J.,Kobayashi, S.,Meszaros, P.,...&Gehrels, N.(2006).Physical processes shaping gamma-ray burst X-ray afterglow light curves: Theoretical implications from the Swift X-ray telescope observations.ASTROPHYSICAL JOURNAL,642(1),354-370. |
| MLA | Zhang, B,et al."Physical processes shaping gamma-ray burst X-ray afterglow light curves: Theoretical implications from the Swift X-ray telescope observations".ASTROPHYSICAL JOURNAL 642.1(2006):354-370. |
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