FRB 200428: An Impact between an Asteroid and a Magnetar
FRB 200428: An Impact between an Asteroid and a Magnetar
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FRB 200428：小行星与磁星之间的撞击
DOI：
10.3847/2041-8213/aba83c
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发表时间：
2020-08-01
影响因子：
7.9
通讯作者：
Huang, Yong-Feng
中科院分区：
文献类型：
--
作者：
Geng, Jin-Jun;Li, Bing;Huang, Yong-Feng
最近发现一个快速射电暴（FRB）与银河系磁星SGR 1935+2154的硬X射线暴有关。因此，涉及FRB的磁星的方案非常受欢迎。在这项工作中，我们认为小行星和磁星之间的撞击可以解释这样的探测。根据我们的计算，一颗质量为1020 g的小行星在接近磁星时，将在7 × 109 cm的距离处被破坏。吸积的物质将沿着磁场线从阿尔文半径107厘米处流动。落在磁星表面后，会形成一个瞬间的吸积柱，在磁层中产生康普顿化X射线爆发和FRB。我们发现，FRB 200428的所有观测特征都可以在这种情况下自洽地解释。我们预测在这个特定的X射线爆发，这可以作为一个独立的观测测试的准周期振荡。
A fast radio burst (FRB) was recently detected to be associated with a hard X-ray burst from the Galactic magnetar SGR 1935+2154. Scenarios involving magnetars for FRBs are hence highly favored. In this work, we suggest that the impact between an asteroid and a magnetar could explain such a detection. According to our calculations, an asteroid of mass 1020 g will be disrupted at a distance of 7 × 109 cm when approaching the magnetar. The accreted material will flow along the magnetic field lines from the Alfvén radius ∼107 cm. After falling onto the magnetar’s surface, an instant accretion column will be formed, producing a Comptonized X-ray burst and an FRB in the magnetosphere. We show that all the observational features of FRB 200428 could be interpreted self-consistently in this scenario. We predict quasi-periodic oscillations in this specific X-ray burst, which can serve as an independent observational test.