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arXiv 1411.5477astro-ph.HE
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磁星自旋下降能量注入的短伽马射线暴的宽带模拟及其对无线电可探测性的影响

Broadband modelling of short gamma-ray bursts with energy injection from magnetar spin-down and its implications for radio detectability

B. P. Gompertz, A. J. van der Horst, P. T. O'Brien, G. A. Wynn, K. Wiersema

摘要:

磁星模型已被提出来解释短伽马射线暴(SGRB)的X射线光变曲线中的视能量注入,但其在整个宽带光谱中的意义还没有得到很好的探索。我们研究了四个SGRB的宽带建模,并在其X射线光变曲线中提供了能量注入的证据,应用了一个物理激励模型,在该模型中,新形成的磁星将能量注入到正向激波中,因为它沿着开放场线失去了角动量。通过对冲击波中的基本物理参数进行数量级搜索,我们限制了同步加速器光谱的特征断裂频率,以对抗其在每个突发的多波长观测中的表现。磁星能量注入配置文件的应用限制了成功的匹配到一个有限的家庭的模型,是自洽的磁偶极子自旋下降framework.We生产的合成光变曲线,描述了如何无线电签名的这些SGRB应该看的限制所施加的现有数据,并讨论了这些签名的可探测性与现今和不久的将来的射电望远镜。我们的研究结果表明,阿塔卡马大型毫米阵列和升级后的超大阵列现在都足够灵敏,可以在大多数SGRB触发后两周内检测到无线电特征,假设我们的样本代表整个人群。我们还发现,即将到来的平方公里阵列将敏感的深度大于我们的下限预测。

英文摘要:

The magnetar model has been proposed to explain the apparent energy injection in the X-ray light curves of short gamma-ray bursts (SGRBs), but its implications across the full broadband spectrum are not well explored. We investigate the broadband modelling of four SGRBs with evidence for energy injection in their X-ray light curves, applying a physically motivated model in which a newly formed magnetar injects energy into a forward shock as it loses angular momentum along open field lines. By performing an order of magnitude search for the underlying physical parameters in the blast wave, we constrain the characteristic break frequencies of the synchrotron spectrum against their manifestations in the available multi-wavelength observations for each burst. The application of the magnetar energy injection profile restricts the successful matches to a limited family of models that are self-consistent within the magnetic dipole spin-down framework.We produce synthetic light curves that describe how the radio signatures of these SGRBs ought to have looked given the restrictions imposed by the available data, and discuss the detectability of these signatures with present-day and near-future radio telescopes. Our results show that both the Atacama Large Millimetre Array and the upgraded Very Large Array are now sensitive enough to detect the radio signature within two weeks of trigger in most SGRBs, assuming our sample is representative of the population as a whole. We also find that the upcoming Square Kilometre Array will be sensitive to depths greater than those of our lower limit predictions.

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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