COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. III. EFFICIENT COSMIC RAY ACCELERATION
COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. III. EFFICIENT COSMIC RAY ACCELERATION
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部分电离介质中的无碰撞冲击。
DOI：
10.1088/0004-637x/768/2/148
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
D. Caprioli
中科院分区：
文献类型：
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作者：
G. Morlino;P. Blasi;R. Bandiera;E. Amato;D. Caprioli
在本文中，我们提出的非线性粒子加速理论的第一个公式，在无碰撞冲击中的中性氢的存在下，在加速区。还包括加速粒子的动力学反应、磁场放大和磁动力学对激波的影响。然而，这项研究的主要新方面包括电荷交换和中性氢的电离，这深刻地改变了冲击波的结构，正如我们以前的工作所讨论的那样。中性粒子的这种重要动力学效应主要与所谓的中性返回通量有关，即热中性粒子从下游区域返回上游，在那里它们通过电荷交换和电离沉积存款能量和动量。我们还提出了自洽计算的冲击区的巴耳末线发射，并讨论如何使用测量的异常宽度的不同组成部分的巴耳末线推断宇宙射线加速效率的超新星遗迹显示巴耳末发射：宽的巴耳末线，这是由于氢原子与冲击下游的热离子的电荷交换，的能量流失到宇宙射线的结果，而狭窄的巴耳末线，由于宇宙射线诱导的前体中的电荷交换，被证明是变得更宽。除了这两个众所周知的组件，中性返回通量导致形成的第三个组件与中间宽度：这也包含在冲击正在进行的过程的信息。
In this paper, we present the first formulation of the theory of nonlinear particle acceleration in collisionless shocks in the presence of neutral hydrogen in the acceleration region. The dynamical reaction of the accelerated particles, the magnetic field amplification, and the magnetic dynamical effects on the shock are also included. The main new aspect of this study, however, consists of accounting for charge exchange and the ionization of a neutral hydrogen, which profoundly change the structure of the shock, as discussed in our previous work. This important dynamical effect of neutrals is mainly associated with the so-called neutral return flux, namely the return of hot neutrals from the downstream region to upstream, where they deposit energy and momentum through charge exchange and ionization. We also present the self-consistent calculation of Balmer line emission from the shock region and discuss how to use measurements of the anomalous width of the different components of the Balmer line to infer cosmic ray acceleration efficiency in supernova remnants showing Balmer emission: the broad Balmer line, which is due to charge exchange of hydrogen atoms with hot ions downstream of the shock, is shown to become narrower as a result of the energy drainage into cosmic rays, while the narrow Balmer line, due to charge exchange in the cosmic-ray-induced precursor, is shown to become broader. In addition to these two well-known components, the neutral return flux leads to the formation of a third component with an intermediate width: this too contains information on ongoing processes at the shock.