Using numerical simulations we show that low-amplitude Alfvén waves from a magnetar quake propagate to the outer magnetosphere and convert to “plasmoids” (closed magnetic loops) that accelerate from the star, driving blast waves into the magnetar wind. Quickly after its formation, the plasmoid becomes a thin relativistic pancake. It pushes out the magnetospheric field lines, and they gradually reconnect behind the pancake, generating a variable wind far stronger than the normal spindown wind of the magnetar. Repeating ejections drive blast waves in the amplified wind. We suggest that these ejections generate the simultaneous X-ray and radio bursts detected from SGR 1935+2154. A modest energy budget of the magnetospheric perturbation ∼10 40 erg is sufficient to produce the observed bursts. Our simulation predicts a narrow (a few milliseconds) X-ray spike from the magnetosphere, arriving almost simultaneously with the radio burst emitted far outside the magnetosphere. Th...

中文翻译：

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SGR 1935 + 2154的Alfvén波等离子喷射和快速射电爆发

使用数值模拟，我们显示了来自磁地震的低振幅Alfvén波传播到外磁层，并转换为从恒星加速的“等离子体”（闭合磁环），将爆炸波驱动到磁风中。等离子体在形成后很快就变成了薄的相对论薄煎饼。它推出了磁层磁力线，它们逐渐在薄饼后面重新连接，产生的变风远强于磁层的正常下降风。重复喷射会在放大的风中驱动爆炸波。我们建议这些喷射会同时产生从SGR 1935 + 2154检测到的X射线和无线电脉冲。磁层扰动的适度能量收支约为10 40 erg，足以产生观测到的爆发。我们的模拟预测了来自磁层的一个狭窄的（几毫秒）X射线尖峰，几乎与远在磁层之外发射的无线电脉冲串同时到达。那个...