论文标题
低亮度伽玛射线爆发的外部逆孔子发射：GRB 190829a的应用
External Inverse-Compton Emission from Low-Luminosity Gamma-Ray Bursts: Application to GRB 190829A
论文作者
论文摘要
TEV伽马射线爆发（GRB）的检测为研究相对论冲击时粒子加速的物理学带来了新的机会。 \ hess望远镜最近观察到附近低亮度GRB的高能发射（VHE），GRB 190829a。例如，Swift-XRT的后续观察结果显示，在$ \ sim 10^3 \ rm〜s $中，这可能是由持久的中央发动机引起的。我们证明了H.E.S.S.期间的VHE发射观察时间自然产生在外部逆孔子（EIC）方案中，其中耀斑或其他延迟耗散所提供的种子光子通过在外部正向休克上加速的非热电子将其降低至VHE能量。我们的计算表明，EIC耀斑几乎与后期的耀斑相吻合，但延长了$ \ sim3-4 $ $倍的时间，比后期推出的耀斑持续时间长。我们模型中使用的首选动能和初始Lorentz因子分别为$ \ sim 10^{52} \ rm〜Erg $和$ \ sim 20 $。了解低亮度GRB的VHE发射机制将有助于我们限制流出和中央发动机活动的特性以及粒子加速机制。
The detection of TeV gamma-ray bursts (GRBs) brought new opportunities for studying the physics of particle acceleration at relativistic shocks. The \hess telescopes recently observed very-high-energy (VHE) emission from a nearby low-luminosity GRB, GRB 190829A. Follow-up observations with, e.g., Swift-XRT, revealed unusual flare activities at $\sim 10^3\rm~s$, which can be caused by a long-lasting central engine. We show that the VHE emission during the H.E.S.S. observation time is naturally produced in the external inverse-Compton (EIC) scenario, where seed photons supplied by the flares or other late-time dissipation are upscattered to VHE energies by the non-thermal electrons accelerated at the external forward shock. Our calculations show that the EIC flare nearly coincides with the late-prompt flare, but extends $\sim3-4$ times longer than the duration of the late-prompt flare. The preferred kinetic energy and initial Lorentz factor used in our model are $\sim 10^{52}\rm~erg$ and $\sim 20$, respectively. Understanding the mechanisms of the VHE emission from low-luminosity GRBs will help us constrain the properties of the outflow and the central engine activities, as well as the particle acceleration mechanism.
