A systematic Chandra study of Sgr A*: II. X-ray flare statistics
文献类型：期刊论文
| 作者 | Yuan, Qiang; Wang, Q. Daniel; Liu, Siming; Wu, Kinwah |
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2018 |
| 卷号 | 473期号:1页码:306-316 |
| 英文摘要 | The routinely flaring events from Sgr A* trace dynamic, high-energy processes in the immediate vicinity of the supermassive black hole. We statistically study temporal and spectral properties, as well as fluence and duration distributions, of the flares detected by the Chandra X-ray Observatory from 1999 to 2012. The detection incompleteness and bias are carefully accounted for in determining these distributions. We find that the fluence distribution can be well characterized by a power law with a slope of 1.73(-0.19)(+ 0.20), while the durations (tau in seconds) by a lognormal function with a mean log(tau) = 3.39(-0.24)(+0.27) and an intrinsic dispersion sigma = 0.28(-0.06)(+0.08). No significant correlation between the fluence and duration is detected. The apparent positive correlation, as reported previously, is mainly due to the detection bias (i.e. weak flares can be detected only when their durations are short). These results indicate that the simple self-organized criticality model has difficulties in explaining these flares. We further find that bright flares usually have asymmetric light curves with no statistically evident difference/preference between the rising and decaying phases in terms of their spectral/timing properties. Our spectral analysis shows that although a power-law model with a photon index of 2.0 +/- 0.4 gives a satisfactory fit to the joint spectra of strong and weak flares, there is weak evidence for a softer spectrum of weaker flares. This work demonstrates the potential to use statistical properties of X-ray flares to probe their trigger and emission mechanisms, as well as the radiation propagation around the black hole. |
| 语种 | 英语 |
| WOS记录号 | WOS:000415653600025 |
| 源URL | [http://libir.pmo.ac.cn/handle/332002/17989]  |
| 专题 | 中国科学院紫金山天文台 |
| 推荐引用方式 GB/T 7714 | Yuan, Qiang,Wang, Q. Daniel,Liu, Siming,et al. A systematic Chandra study of Sgr A*: II. X-ray flare statistics[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2018,473(1):306-316. |
| APA | Yuan, Qiang,Wang, Q. Daniel,Liu, Siming,&Wu, Kinwah.(2018).A systematic Chandra study of Sgr A*: II. X-ray flare statistics.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,473(1),306-316. |
| MLA | Yuan, Qiang,et al."A systematic Chandra study of Sgr A*: II. X-ray flare statistics".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473.1(2018):306-316. |
入库方式： OAI收割
来源：紫金山天文台
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