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arXiv 2008.05635astro-ph.HE
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在同步脉泽激波模型中理解FRB 200428:一致性和可能的挑战

Understanding FRB 200428 in the synchrotron maser shock model: consistency and possible challenge

Q. Wu, G. Q. Zhang, F. Y. Wang, Z. G. Dai

摘要:

最近,与SGR 1935+2154的X射线爆发(XRB)相关的银河系FRB 200428的发现在FRB和磁星活动之间建立了一座桥梁。在本文中,我们假设XRB发生在磁星磁层。我们发现,FRB 200428和相关的XRB的观测特性是一致的同步脉泽发射在超相对论磁化冲击的预测,包括辐射效率,类似的能量发生频率分布,同时到达时间。它要求上游介质是由先前的耀斑喷射出的温和的相对论性重子壳层。射电爆发的耀斑能量注入将产生磁星风星云,它已被用来解释与FRB 121102相关的持久射电源。我们发现,SGR 1935+2154周围的无线电连续可以很好地理解磁星风星云模型,通过假设相同的能量注入率$\dot{E} \propto t^{-1.37}$ FRB 121102。根据GBT和FAST对FRB 121102的观测结果,估算了所需的重子质量。假设相同的辐射效率$η\sim 10^{-5}$,从中心磁星喷射出的重子总质量约为0.005太阳质量。这个值比磁星外壳的典型质量大得多,但与磁星外壳的总质量相当。

英文摘要:

Recently, the discovery of Galactic FRB 200428 associated with a X-ray burst (XRB) of SGR 1935+2154 has built a bridge between FRBs and magnetar activities. In this paper, we assume that the XRB occurs in the magnetar magnetosphere. We show that the observational properties of FRB 200428 and the associated XRB are consistent with the predictions of synchrotron maser emission at ultrarelativistic magnetized shocks, including radiation efficiency, similar energy occurrence frequency distributions, and simultaneous arrive times. It requires that the upstream medium is a mildly relativistic baryonic shell ejected by a previous flare. The energy injection by flares responsible for the radio bursts will produce a magnetar wind nebula, which has been used to explain the persistent radio source associated FRB 121102. We find that the radio continuum around SGR 1935+2154 can be well understood in the magnetar wind nebula model, by assuming the same energy injection rate $\dot{E} \propto t^{-1.37}$ as FRB 121102. The required baryonic mass is also estimated form the observations of FRB 121102 by GBT and FAST. By assuming the same radiation efficiency $η\sim 10^{-5}$, the total baryonic mass ejected from the central magnetar is about 0.005 solar mass. This value is much larger than the typical mass of a magnetar outer crust, but is comparable to the total mass of a magnetar crust.

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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