| タイトル | Swift and Fermi Observations of X-Ray Flares: The Case of Late Internal Shock |
| 著者（英） | McEnery, J. E.; Burgess, J. M.; Piro, L.; Cutini, S.; Troja, E.; Connaughton, V.; Vasileiou, V.; Omodei, N. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2015-04-07 |
| 言語 | eng |
| 内容記述 | Simultaneous Swift and Fermi observations of gamma-ray bursts (GRBs) offer a unique broadband view of their afterglow emission, spanning more than 10 decades in energy. We present the sample of X-ray flares observed by both Swift and Fermi during the first three years of Fermi operations. While bright in the X-ray band, X-ray flares are often undetected at lower (optical), and higher (MeV to GeV) energies. We show that this disfavors synchrotron self-Compton processes as the origin of the observed X-ray emission. We compare the broadband properties of X-ray flares with the standard late internal shock model, and find that in this scenario, X-ray flares can be produced by a late-time relativistic (gamma greater than 50) outflow at radii R approximately 10(exp 13) - 10(exp 14) cm. This conclusion holds only if the variability timescale is significantly shorter than the observed flare duration, and implies that X-ray flares can directly probe the activity of the GRB central engine. |
| NASA分類 | Astrophysics |
| レポートNO | GSFC-E-DAA-TN34910 |
| 権利 | Copyright |
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