arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0909.0016astro-ph.HE
收藏

GRB 090510的GeV余辉的开始

The onset of the GeV afterglow of GRB 090510

G. Ghirlanda, G. Ghisellini, L. Nava

摘要:

我们研究了费米卫星上的大面积望远镜(LAT)观测到的能量> 0.1 GeV的短/硬GRB 090510的发射。GeV的通量随时间以t^2的形式上升,以t^-1.5的形式衰减,直到200 s。相对于费米γ爆发监测器(GBM)探测到的~MeV主脉冲,高能通量的峰值延迟了0.2s。它的能谱符合F(E)=E^-1。高能量LAT通量的时间行为和光谱是余辉起源的有力证据。然后,我们将其解释为同步辐射产生的向前冲击的火球具有大量的洛伦兹因子伽玛~ 2000。余辉峰值时间与0.1-30 GeV范围内的能量无关,并且与最高能量光子(~ 30 GeV)的到达时间一致。由于GBM和LAT检测到的通量具有不同的起源,因此这两个分量之间的延迟并不完全是由于可能违反洛伦兹不变性。LAT分量本身允许对量子引力质量设定严格的下限,即4.7倍普朗克质量。

英文摘要:

We study the emission of the short/hard GRB 090510 at energies > 0.1 GeV as observed by the Large Area Telescope (LAT) onboard the Fermi satellite. The GeV flux rises in time as t^2 and decays as t^-1.5 up to 200 s. The peak of the high energy flux is delayed by 0.2 s with respect to the main ~MeV pulse detected by the Fermi Gamma Burst Monitor (GBM). Its energy spectrum is consistent with F(E)=E^-1. The time behavior and the spectrum of the high energy LAT flux are strong evidences of an afterglow origin. We then interpret it as synchrotron radiation produced by the forward shock of a fireball having a bulk Lorentz factor Gamma ~ 2000. The afterglow peak time is independent of energy in the 0.1-30 GeV range and coincides with the arrival time of the highest energy photon (~ 30 GeV). Since the flux detected by the GBM and the LAT have different origins, the delay between these two components is not entirely due to possible violation of the Lorentz invariance. It is the LAT component by itself that allows to set a stringent lower limit on the quantum-gravity mass of 4.7 times the Planck mass.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑