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arXiv 1706.04802astro-ph.HE
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新生磁星的回退吸积:具有扩展发射的短伽玛暴

Fallback Accretion onto a Newborn Magnetar: short GRBs with Extended Emission

Sarah Gibson, Graham Wynn, Benjamin Gompertz, Paul O'Brien

摘要:

短伽马射线暴(SGRB)的一个子集在其高能光变曲线中表现出重新变亮,称为扩展发射。这些爆发有可能区分提出来描述SGRB的各种模型,因为任何模型都需要考虑扩展发射。在本文中,我们结合回退吸积到磁星螺旋桨模型和调查的形态变化回退吸积模型的光变曲线,并适合15个SGRB的余辉表现出扩展的发射从雨燕档案。我们已经在螺旋桨模型内的现有参数化的回退,并解决了磁盘质量和角频率的磁星随着时间的推移。然后,我们应用马尔可夫链蒙特卡罗程序来产生适合的数据。我们目前适合我们的扩展发射SGRB样本,形态和能量与Swift BAT和XRT望远镜提供的数据一致。从这些拟合得出的参数与磁星性质和回退吸积模型的预测是一致的。与以前的工作相比,回退吸积提供了一个显着的改善与延长发射SGRB的光变曲线的拟合,并可能在解释功能,如可变性,耀斑和长偶极高原发挥重要作用。

英文摘要:

There are a subset of short gamma-ray bursts (SGRBs) which exhibit a rebrightening in their high-energy light curves known as extended emission. These bursts have the potential to discern between various models proposed to describe SGRBs as any model needs to account for extended emission. In this paper, we combine fallback accretion into the magnetar propeller model and investigate the morphological changes fallback accretion has on model light curves and fit to the afterglows of 15 SGRBs exhibiting extended emission from the Swift archive. We have parameterised the fallback in terms of existing parameters within the propeller model and solved for the disc mass and angular frequency of the magnetar over time. We then apply a Markov chain Monte Carlo routine to produce fits to the data. We present fits to our extended emission SGRB sample that are morphologically and energetically consistent with the data provided by Swift BAT and XRT telescopes. The parameters derived from these fits are consistent with predictions for magnetar properties and fallback accretion models. Fallback accretion provides a noticeable improvement to the fits of the light curves of SGRBs with extended emission when compared to previous work and could play an important role in explaining features such as variability, flares and long dipole plateaux.

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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