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arXiv 1003.2582astro-ph.HE
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伽马射线暴热辐射的观测、理论和意义

Observations, theory and implications of thermal emission from gamma-ray bursts

Asaf Pe'er, Felix Ryde

摘要:

最近的分析表明,在伽玛暴的瞬发阶段,伴随着非热发射的热发射分量的证据。首先,我们证明了这个组件的存在的证据;其次,我们表明,这个组件是自然的解释,考虑从光球发射,考虑到高纬度光学厚相对论膨胀等离子体发射。结果表明,热通量在后期衰减为F_BB ~ t^{-2},观测温度衰减为T ~ t^{-α},α~ 1/2 - 2/3。这些理论预测与观测结果非常吻合。最后,我们讨论了这一解释的三个含义:(a)热辐射与费米观测到的高能非热谱之间的关系。(b)我们展示了如何热发射可以用来直接测量的洛伦兹因子的流量和初始半径的射流。(c)我们展示了如何缺乏检测的热组件可以用来限制伽玛射线暴射流的组成。

英文摘要:

Recent analyses show evidence for a thermal emission component that accompanies the non-thermal emission during the prompt phase of GRBs. First, we show the evidence for the existence of this component; Second, we show that this component is naturally explained by considering emission from the photosphere, taking into account high latitude emission from optically thick relativistically expanding plasma. We show that the thermal flux is expected to decay at late times as F_BB ~ t^{-2}, and the observed temperature as T ~ t^{-α}, with α~ 1/2 - 2/3. These theoretical predictions are in very good agreement with the observations. Finally, we discuss three implications of this interpretation: (a) The relation between thermal emission and high energy, non-thermal spectra observed by Fermi. (b) We show how thermal emission can be used to directly measure the Lorentz factor of the flow and the initial radius of the jet. (c) We show how the lack of detection of the thermal component can be used to constrain the composition of GRB jets.

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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