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arXiv 2103.15355astro-ph.HE
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短伽马射线暴中超幂律谱分量的普遍性

Prevalence of Extra Power-Law Spectral Components in Short Gamma-Ray Bursts

Qing-Wen Tang, Kai Wang, Liang Li, Ruo-Yu Liu

摘要:

在某些明亮的伽马射线暴(GRB)中发现了瞬发额外幂律(PL)谱分量,它通常在数十keV以下或约10 MeV以上的谱能量分布中占据主导地位。然而,其起源仍不清楚。本文系统分析了截至2020年8月的13个费米短伽玛暴,同时在瞬发阶段探测到keV-MeV和GeV。我们发现,额外的PL组件是一个普遍存在的光谱特征短伽玛暴,出现在所有13个分析的伽玛暴。PL指数大多比-2.0硬,这可以通过考虑由在瞬发发射阶段加速的超相对论质子或电子引起的电磁级联来很好地再现。这些额外的PL分量的平均通量与主要光谱分量的平均通量正相关,这意味着它们可能具有相同的物理起源。

英文摘要:

Prompt extra power-law (PL) spectral component is discovered in some bright gamma-ray bursts (GRBs), which usually dominates the spectral energy distribution below tens of keV or above about 10 MeV. However, its origin is still unclear. In this paper, we present a systematic analysis 13 Fermi short GRBs as of August 2020, with the contemporaneous keV-MeV and GeV detections at the prompt emission phase. We find that the extra PL component is a ubiquitous spectral feature for short GRBs, showing up in all 13 analyzed GRBs. The PL indices are mostly harder than -2.0, which may be well reproduced by considering the electromagnetic cascade induced by ultra-relativistic protons or electrons accelerated in the prompt emission phase. The average flux of these extra PL components positively correlates with that of the main spectral components, which implies they may share the same physical origin.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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