伽玛射线暴的高能辐射

High energy emission from gamma-ray bursts

伽玛暴是宇宙中最剧烈的恒星级高能爆发现象,一般被认为产生于大质量恒星死亡(一些爆发时标长于2 s的伽玛暴在观测上被证实与一类特殊的超新星成协)或者双致密星(比如双中子星系统)并合(这类并合时标很短,可产生时标短于2 s的伽玛暴).工作在8 ke V–300 Ge V能段的Fermi伽玛射线空间望远镜自2008年升空工作之后,伽玛暴瞬时辐射和高能辐射研究取得了重要进展.本综述将介绍Fermi卫星在过去几年内关于伽玛暴领域的一些重要观测结果,并着重介绍这些观测对探索伽玛暴物理(伽玛暴外流体的光球辐射、磁化、Ge V高能辐射起源),特别是Fermi卫星大面积望远镜(LAT)的高能(>100 Me V)辐射观测对限制伽玛暴初始速度/洛伦兹因子,限制宇宙河外背景光模型以及检验光速不变原理等方面的主要研究进展.

Gamma-ray bursts are the most violent stellar explosions in the universe. They are believed to be originated from deaths of massive stars （It has been confirmed that some gamma-ray bursts with durations longer than 2 s are confirmed to be associated with a special type of supernovae.） or mergers of two compact stars （e.g. mergers of double neutron stars, which have rather short time scales, and are responsible for short bursts with durations shorter than 2 s）. Since the launch and commission of Fermi Gamma-Ray Space Telescope, working at 8 keV-300 GeV band, in 2008, significant achievements of gamma-ray bursts prompt emission and high-energy radiation have been made. This review will show some of the important observations of gamma-ray bursts provided by Fermi in recent years, highlighting the implications of these observations to the physics of gamma-ray bursts （including photosphere emission and magnetization of gamma-ray burst ejecta, as well as origins of GeV high-energy emission）, especially the major advancements in constraining gamma-ray bursts initial velocity/Lorentz factor, constraining models of extragalactic background light, and testing Lorentz invariance violation provided by high-energy （〉 100 MeV） observations made by Fermi＇s LAT instrument.