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arXiv 1311.2183astro-ph.HE
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具有中心引擎活动非单时标变化的伽马射线暴的瞬发光辐射

Prompt Optical Emission from Gamma-ray Bursts with Non-single Timescale Variability of Central Engine Activities

Si-Yao Xu, Zhuo Li

摘要:

雨燕GRB 080319 B的完整的高分辨率光变曲线提供了一个机会,为详细的即时光发射的时间分析。采用初始洛伦兹因子的二分量分布,在内激波模型的框架下,模拟了中心发动机弹射出壳的动力学过程。将发射的辐射分解到不同的频率范围内,用于不同能带的光变曲线之间的时间相关性分析。由此产生的即时光学和伽马射线发射显示出类似的时间剖面,作为一个缓慢的变化性组件和快速的变化性组件的叠加,除了伽马射线光变曲线是比它的光学对应更可变。在模拟的光变曲线和强相关的光学和伽马射线发射之间的时间滞后的变化特征与GRB 080319 B的观测结果吻合得很好。我们的模拟表明,光变曲线的变化源于从伽马射线暴的中央引擎注入的壳层的时间结构。未来对伽玛暴瞬发光辐射的高时间分辨率观测,通过UFFO-Pathfinder和SVOM-GWAC的研究,提供了一个有用的工具来研究中央发动机的活动。

英文摘要:

The complete high-resolution lightcurves of Swift GRB 080319B present an opportunity for detailed temporal analysis of the prompt optical emission. With a two-component distribution of initial Lorentz factors, we simulate the dynamical process of the ejected shells from the central engine in the framework of the internal shock model. The emitted radiation are decomposed into different frequency ranges for a temporal correlation analysis between the lightcurves in different energy bands. The resulting prompt optical and gamma-ray emission show similar temporal profiles, both as a superposition of a slow variability component and a fast variability component, except that the gamma-ray lightcurve is much more variable than its optical counterpart. The variability features in the simulated lightcurves and the strong correlation with a time lag between the optical and gamma-ray emission are in good agreement with the observations of GRB 080319B. Our simulations suggest that the variations seen in the lightcurves stem from the temporal structure of the shells injected from the central engine of gamma-ray bursts. The future high temporal resolution observations of prompt optical emission from GRBs, e.g., by UFFO-Pathfinder and SVOM-GWAC, provide a useful tool to investigate the central engine activity.

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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