A Semianalytic Afterglow with Thermal Electrons and Synchrotron Self-Compton Emission
A Semianalytic Afterglow with Thermal Electrons and Synchrotron Self-Compton Emission
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DOI：
10.3847/1538-4357/ac2f43
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
D. Warren;M. Dainotti;M. Barkov;B. Ahlgren;Hirotaka Ito;S. Nagataki
中科院分区：
文献类型：
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作者：
D. Warren;M. Dainotti;M. Barkov;B. Ahlgren;Hirotaka Ito;S. Nagataki
我们扩展了之前关于伽马射线爆发余辉的工作，这些余辉涉及激波加速的尾巴底部的热热电子。利用基于第一性原理模拟的物理激励电子分布，计算了从无线电到TeV伽马射线的宽带辐射。首次研究了电子热分布对同步加速器自康普顿发射的影响。热电子的存在导致了整个可观测余辉的时间和光谱结构，这与假设电子的纯指数分布的模型有本质上的不同。我们发现，对于我们的基准参数，早期的TeV发射增加了一个数量级以上，并且具有一个时变的光谱指数，这在纯电子幂定律中是不存在的。我们进一步表明，当热电子存在时，X射线闭合关系具有非常不同的、也与时间相关的形式；X射线余辉描绘的形状与传统衰变阶段的观测结果定性匹配。
We extend previous work on gamma-ray burst afterglows involving hot thermal electrons at the base of a shock-accelerated tail. Using a physically motivated electron distribution based on first-principles simulations, we compute the broadband emission from radio to TeV gamma rays. For the first time, we present the effects of a thermal distribution of electrons on synchrotron self-Compton emission. The presence of thermal electrons causes temporal and spectral structure across the entire observable afterglow, which is substantively different from models that assume a pure power-law distribution for the electrons. We show that early-time TeV emission is enhanced by more than an order of magnitude for our fiducial parameters, with a time-varying spectral index that does not occur for a pure power law of electrons. We further show that the X-ray closure relations take a very different, also time-dependent, form when thermal electrons are present; the shape traced out by the X-ray afterglows is a qualitative match to observations of the traditional decay phase.