AI 中文总结
该研究推导了不同场景下反向激波的SSC闭合关系，发现其辐射可解释GRB余辉的初始阶段，且光变曲线拟合结果支持能量注入及恒密度环境的场景。
AI 中文摘要
伽马射线暴（GRBs）是宇宙中最具能量的河外暂现源，为研究高能光变曲线和光谱中观测到的多样形态的物理起源提供了独特实验室。这些形态通过同步辐射和同步自康普顿（SSC）闭合关系（CRs）来解释，可能取决于暴周环境密度分布、能量注入以及绝热或辐射 regime 下反向激波的动力学演化。我们针对厚壳和薄壳两种情况，推导了反向激波区域产生的SSC闭合关系，考虑了恒密度和分层的暴周介质。分析假设电子谱指数服从两种幂律（PL）分布，并包含前身星有和无能量注入的场景。我们表明，根据物理参数的不同，反向激波的SSC辐射可重现GRB余辉中常见的初始陡降和平台阶段。随后，我们将预测的谱指数和时标指数与第二费米-LAT伽马射线暴星表（2FLGC）中报告的PL和折断幂律（BPL）拟合结果进行比较。我们的结果表明，PL（BPL）光变曲线拟合更倾向于有（无）能量注入的场景；在有能量注入的场景中，数据更支持恒密度环境而非星风轮廓。
英文摘要
Gamma-ray bursts (GRBs) are among the most energetic extragalactic transients, providing a unique laboratory to investigate the physical origin of the diverse morphologies observed in high-energy light curves and spectra. These morphologies, interpreted through synchrotron and synchrotron self-Compton (SSC) closure relations (CRs), may depend on the circumburst density profile, energy injection, and the dynamical evolution of the reverse shock in the adiabatic or radiative regime. We derive the SSC closure relations produced in the reverse-shock region for both thick- and thin-shell cases, considering constant-density and stratified circumburst media. The analysis assumes two power-law (PL) distributions for the electron spectral index and includes scenarios with and without energy injection from the progenitor. We show that, depending on the physical parameters, SSC emission from the reverse shock can reproduce the initial steep-decay and plateau phases commonly observed in GRB afterglows. We then compare the predicted spectral and temporal indices with those derived from PL and broken power-law (BPL) fits reported in the Second Fermi-LAT Gamma-ray Burst Catalog (2FLGC). Our results indicate that PL (BPL) light-curve fits preferentially favor scenarios with (without) energy injection. In scenarios with energy injection, the data preferentially support a constant-density environment over a stellar-wind profile.
Comments43 pages, 7 tables, 13 figures. The Astrophysical Journal, Volume 1006, Issue 2, id.227
Journal refThe Astrophysical Journal 2026
