论文标题
宇宙射线修饰冲击的动力学模拟I：流体动力学
Kinetic Simulations of Cosmic-Ray-Modified Shocks I: Hydrodynamics
论文作者
论文摘要
无碰撞血浆冲击是空间和天体物理系统中非热颗粒加速度的有效来源。我们使用杂交（动力学 - 流体电子）模拟来检查休克流体动力学上自苯二甲的能量颗粒（宇宙射线，CRS）的非线性反馈。当CR加速度有效时，我们发现上游前体的证据，即压缩和加热的流化血浆，以及下游的邮政库，其中CRS中的能量和放大的磁场起着动态作用。我们第一次评估后者中的非线性磁波动如何优先以大约在局部AlfVén速度相对于下游等离子体的冲击。相对于热等离子体的磁性和Cr能的漂移显着增加了相对于标准预测的冲击压缩比，特别是超过4。这种修饰也对通过扩散性休克加速加速的颗粒的光谱有影响，这是伴侣纸Caprioli，Haggerty＆Blasi 2020，Arxiv：2009.00007 [astro-ph.he]中详细介绍的重要结果。
Collisionless plasma shocks are efficient sources of non-thermal particle acceleration in space and astrophysical systems. We use hybrid (kinetic ions -- fluid electrons) simulations to examine the non-linear feedback of the self-generated energetic particles (cosmic rays, CRs) on the shock hydrodynamics. When CR acceleration is efficient, we find evidence of both an upstream precursor, where the inflowing plasma is compressed and heated, and a downstream postcursor, where the energy flux in CRs and amplified magnetic fields play a dynamical role. For the first time, we assess how non-linear magnetic fluctuations in the postcursor preferentially travel away from the shock at roughly the local Alfvén speed with respect to the downstream plasma. The drift of both magnetic and CR energy with respect to the thermal plasma substantially increases the shock compression ratio with respect to the standard prediction, in particular exceeding 4 for strong shocks. Such modifications also have implications for the spectrum of the particles accelerated via diffusive shock acceleration, a significant result detailed in a companion paper, Caprioli, Haggerty & Blasi 2020, arXiv:2009.00007 [astro-ph.HE].
