主要内容:
这个暴从关系到GeV的观测数据都有。
文章说LAT的暴普遍比较亮，余辉也更亮。
精彩摘抄:
光变曲线
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上面是GBM的，下面是LAT的
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| 上面是光学的，下面是X射线的 |
文章信息:
- · arXiv e-print (arXiv:1004.5099)
- · References in the Article
- · Also-Read Articles (Reads History)
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| Title: |
| GRB 090926A and Bright Late-time Fermi LAT GRB Afterglows |
| Authors: |
| Swenson, C. A.; Maxham, A.; Roming, P. W. A.; Schady, P.; Vetere, L.; Zhang, B.; Zhang, B. B.; Holland, S. T.; Kennea, J. A.; Kuin, N. P. M.; Oates, S. R.; Page, K. L.; De Pasquale, M. |
| Publication: |
| eprint arXiv:1004.5099 |
| Publication Date: |
| 04/2010 |
| Origin: |
| ARXIV |
| Keywords: |
| Astrophysics - High Energy Astrophysical Phenomena |
| Comment: |
| 8 pages, 4 figures, submitted to ApJ Letters; doi:10.1088/2041-8205/718/1/L14 |
| Bibliographic Code: |
| 2010arXiv1004.5099S |
Abstract
GRB 090926A was detected by both the GBM and LAT instruments on-board the Fermi Gamma-Ray Space Telescope. Swift follow-up observations began ~13 hours after the initial trigger. The optical afterglow was detected for nearly 23 days post trigger, placing it in the long lived category. The afterglow is of particular interest due to its brightness at late times, as well as the presence of optical flares at T0+10^5 s and later, which may indicate late-time central engine activity. The LAT has detected a total of 16 GRBs; 9 of these bursts, including GRB 090926A, also have been observed by Swift. Of the 9 Swift observed LAT bursts, 6 were detected by UVOT, with 5 of the bursts having bright, long-lived optical afterglows. In comparison, Swift has been operating for 5 years and has detected nearly 500 bursts, but has only seen ~30% of bursts with optical afterglows that live longer than 10^5 s. We have calculated the predicted gamma-ray fluence, as would have been seen by the BAT on-board Swift, of the LAT bursts to determine whether this high percentage of long-lived optical afterglows is unique, when compared to BAT-triggered bursts. We find that, with the exception of the short burst GRB 090510A, the predicted BAT fluences indicate the LAT bursts are more energetic than 88% of all Swift bursts, and also have brighter than average X-ray and optical afterglows.
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