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arXiv 2005.06736astro-ph.HE
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银河系和宇宙学快速射电暴的统一图象

A unified picture of Galactic and cosmological fast radio bursts

Wenbin Lu, Pawan Kumar, Bing Zhang

摘要:

在我们的银河系中发现了一个与磁星(具有强磁场的中子星)相关的快速射电暴(FRB),它提供了一个关键的信息,帮助我们最终理解这些神秘的瞬态。我们表明,体积率的银河系FRB的事件是一致的宇宙学FRB率的微弱的结束,因此,他们最有可能属于同一类的瞬态。银河系FRB有一个伴随的X射线爆发,但来自同一物体的许多X射线爆发没有无线电对应物。它们的相对速率表明,对于每个FRB,大约有10^2到10^3个X射线爆发。银河系FRB的射电光变曲线在400-800 MHz频段有两个相隔30 ms的尖峰。这是一个重要的线索,也是对射电辐射产生于磁星光柱之外的一类模型的高度限制。我们认为,磁星表面附近的磁扰动传播到几十个中子星半径的距离,在那里它们阻尼并产生无线电发射。在这种情况下,可以理解与在该爆发中看到的两个FRB脉冲相关的重合硬X射线尖峰以及两个频带之间的通量比。这个模型提供了一个统一的图片微弱的爆发,如银河系FRB以及明亮的事件,在宇宙学的距离。

英文摘要:

The discovery of a fast radio burst (FRB) in our galaxy associated with a magnetar (neutron star with strong magnetic field) has provided a critical piece of information to help us finally understand these enigmatic transients. We show that the volumetric rate of Galactic-FRB like events is consistent with the faint end of the cosmological FRB rate, and hence they most likely belong to the same class of transients. The Galactic FRB had an accompanying X-ray burst but many X-ray bursts from the same object had no radio counterpart. Their relative rates suggest that for every FRB there are roughly 10^2 to 10^3 X-ray bursts. The radio lightcurve of the galactic FRB had two spikes separated by 30 ms in the 400-800 MHz frequency band. This is an important clue and highly constraining of the class of models where the radio emission is produced outside the light-cylinder of the magnetar. We suggest that magnetic disturbances close to the magnetar surface propagate to a distance of a few tens of neutron star radii where they damp and produce radio emission. The coincident hard X-ray spikes associated with the two FRB pulses seen in this burst and the flux ratio between the two frequency bands can be understood in this scenario. This model provides a unified picture for faint bursts like the Galactic FRB as well as the bright events seen at cosmological distances.

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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