Observation of inverse Compton emission from a long γ-ray burst
Observation of inverse Compton emission from a long γ-ray burst
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DOI：
10.1038/s41586-019-1754-6
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发表时间：
2019-11-21
期刊：
影响因子：
64.8
通讯作者：
Young, D. R.
中科院分区：
文献类型：
--
作者：
Acciari, V. A.;Ansoldi, S.;Young, D. R.
长持续时间的伽马射线暴(GRB)起源于从濒临死亡的大质量恒星的塌缩核心发射的极端相对论喷流。它们的特点是在千电子伏特到兆兆电子伏带内有一个明亮和高度可变的初始阶段的辐射，这种辐射很可能是在喷流中产生的，持续时间从毫秒到几分钟，被称为瞬时发射(1，2)。随后，喷流与周围介质的相互作用产生的冲击波是余辉发射的原因，余辉发射持续几天到几个月，发生在从无线电到千兆电子伏频带(1-6)的广泛能量范围内。余辉发射通常被很好地解释为由外部冲击加速的电子发出的同步辐射(7-9)。最近，从伽玛暴190114C(10，11)观测到了0.2到1太电子伏之间的强烈的长时间发射。在这里，我们报道了伽玛暴190114C的多频观测，并研究了从5×10(-6)电子伏特到10(12)电子伏特17个数量级能量范围内伽玛暴发射的时间演化。我们发现，宽带光谱能量分布是双峰的，太电子伏特发射构成了一个明显的光谱分量，其功率与同步加速器分量相当。这一成分与余辉有关，并用高能电子对同步光子的逆康普顿上散射进行了令人满意的解释。我们发现，解释观测到的太电子伏特分量所需的条件对于伽玛暴来说是典型的，这支持了在伽玛暴中通常产生逆康普顿发射的可能性。
Long-duration gamma-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectron volt-to-mega electronvoltband, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission(1,2). Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands(1-6). The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock(7-9). Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C(10,11). Here we report multifrequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 x 10(-6) to 10(12) electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.