论文标题
相对论磁爆炸
Relativistic magnetic explosions
论文作者
论文摘要
许多爆炸性的天体物理事件，例如磁铁的爆发和耀斑，都是磁性驱动的。我们考虑了这种磁性爆炸的动力学 - 高度磁化和高度磁过压的云的相对论扩展。由于磁通量的拓扑约束，相应的动力学与流体爆炸的质量爆炸质量不同。使用分析，相对论的MHD以及无力量计算，我们发现相对扩展的，因果关系脱节的流量遵守阈值条件：它需要足够高的初始过度压力，并且需要足够高的外部培养基中的压力（预示例风）。在亚临界情况下，磁性云只是“膨胀”，并随着前风风而悄悄地扩展。我们还发现了针对Prendergast问题的紧凑分析解决方案 - 无力等离子体扩展到真空中。
Many explosive astrophysical events, like magnetars' bursts and flares, are magnetically driven. We consider dynamics of such magnetic explosions - relativistic expansion of highly magnetized and highly magnetically over-pressurized clouds. The corresponding dynamics is qualitatively different from fluid explosions due to the topological constraint of the conservation of the magnetic flux. Using analytical, relativistic MHD as well as force-free calculations, we find that the creation of a relativistically expanding, causally disconnected flow obeys a threshold condition: it requires sufficiently high initial over-pressure and sufficiently quick decrease of the pressure in the external medium (the pre-explosion wind). In the subcritical case the magnetic cloud just "puffs-up" and quietly expands with the pre-flare wind. We also find a compact analytical solution to the Prendergast's problem - expansion of force-free plasma into vacuum.
