标题： 快速射电暴从磁星磁层中的逃逸 显示英文标题

标题： Escape of Fast Radio Bursts from magnetars' magnetospheres

摘要： 我们讨论在磁星磁层中快速射电暴（FRBs）的产生和逃逸过程中发生的耗散过程，这些磁层被认为是FRBs的潜在来源。 发射区域需要强磁场，以解释FRBs的整体能量，并抑制无线电发射粒子的“正常”（非相干）辐射损失；这将发射半径限制为$\leq {\rm few} \times 10 R_{NS}$。 在较长自转周期的情况下，强FRB脉冲中粒子的辐射损失可能发生在磁层的外部区域，$P\geq 1$秒。 这些损失受到多种效应的抑制：（i）沿波传播方向的背景等离子体的动量预加速（损失大约按$\gamma_\parallel^{3}$减少，频率较小，$ \propto \gamma_\parallel^2$功率，时间尺度拉长，$ \propto \gamma_\parallel$）；这种加速是非耗散的，并在脉冲下降部分反转；（ii）兰道-波梅兰丘克-米加尔效应（长辐射形成长度和随之而来的散射波的破坏性干涉）。 在某些情况下，FRB脉冲可能会因外部扰动（例如，入射的阿尔芬波脉冲）而耗散：这可能会产生一个紫外线/软X射线脉冲，作为FRB的临终之声，可能被钱德拉探测到。 显示英文摘要

摘要： We discuss dissipative processes occurring during production and escape of Fast Radio Bursts (FRBs) from magnetars' magnetospheres, the presumed loci of FRBs. High magnetic fields are required in the emission region, both to account for the overall energetics of FRBs, and in order to suppress ``normal'' (non-coherent) radiative losses of radio emitting particles; this limits the emission radii to $\leq {\rm few} \times 10 R_{NS}$. Radiative losses by particles in the strong FRB pulse may occur in the outer regions of the magnetosphere for longer rotation periods, $P\geq 1$ second. These losses are suppressed by several effects: (i) the ponderomotive pre-acceleration of background plasma along the direction of wave propagation (losses reduced approximately as $\gamma_\parallel^{3}$: smaller frequency, $ \propto \gamma_\parallel^2$ in power, and times scales stretched, $ \propto \gamma_\parallel$); this acceleration is non-dissipative and is reversed on the declining part of the pulse; (ii) Landau-Pomeranchuk-Migdal effects (long radiation formation length and ensuing destructive interference of scattered waves). In some cases an FRB pulse may be dissipated on external perturbations (e.g., an incoming pulse of Alfven waves): this may produce a pulse of UV/soft X-rays, a swan song of an FRB, possibly detectable by Chandra.