| タイトル | Global Properties of X-Ray Flashes and X-Ray-Rich GRBs Observed by Swift |
| 著者（英） | Gehrels, N.; Palmer, D.; Krimm, H.; Hullinger, D.; Fenimore, E.; Yamazaki, R.; Sato, G.; Cummings, J.; Barbier, L.; Parsons, A.; Markwardt, C.; Sakamoto, T.; Barthelmy, S.; Tueller, J. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2007-05-27 |
| 言語 | eng |
| 内容記述 | We describe and discuss the spectral and temporal characteristics of the prompt emission and X-ray afterglow emission of X-ray flashes (XRFs) detected and observed by Swift between December 2005 and September 2006. We compare these characteristics to a sample of X-ray rich gamma-ray bursts (XRRs) and conventional classical gamma-ray bursts (C-GRBs)observed during the same period. We confirm the correlation between Epeak and fluence noted by others and find further evidence that XRFs and C-GRBs form a continuum. We also confirmed that our known redshift samples are consistent with the correlation between the peak energy (Epeak) and the isotropic radiated energy (Eiso), so called the Epeak-Eiso relation. The spectral properties of X-ray afterglows are similar to those of gamma-ray burst afterglows, but the temporal properties of the two classes are quite different. We found that the light curves of C-GRBs afterglow show a break to steeper indices (shallow-to-steep break) at much earlier times than do XRF afterglows. Moreover, the overall luminosity of X-ray afterglows of XRFs are systematically smaller by a factor of two or more compared with that of C-GRBs. These distinct differences in the X-ray afterglow between XRFs and C-GRBs are key to understanding not only a mysterious shallow-to-steep phase in the X-ray afterglow but also the unique nature of XRFs. |
| NASA分類 | Astronomy |
| 権利 | Copyright |
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