From cosmic ray source to the Galactic pool
From cosmic ray source to the Galactic pool
复制标题
从宇宙射线源到银河池
DOI：
10.1093/mnras/stt2089
复制
发表时间：
2013
影响因子：
4.8
通讯作者：
Anthony R. Bell
中科院分区：
文献类型：
--
作者：
K. Schure;Anthony R. Bell
银河宇宙射线谱是一个非常直的幂律。我们目前的理解是，将宇宙射线加速到膝盖（3 × 10^{15}$ eV）甚至脚踝（3 × 10^{18}$ eV）的主要来源是年轻的银河系超新星遗迹。然而，从理论上讲，不同来源的频谱可能不同，原因有多种，如果在最有效的加速阶段应用非线性冲击加速度，则频谱甚至可能不是幂律。我们展示了加速器的光谱如何转化为组成逃逸宇宙射线的光谱，这些逃逸宇宙射线补充了银河系的宇宙射线池。我们假设宇宙射线的约束和逃逸与磁场放大的水平有关，并且磁场根据非共振混合或共振不稳定性被流动的宇宙射线放大。当能量的固定部分转移到宇宙射线时，结果是比E^{-2}$平坦的源光谱将导致E^{-2}$逃逸光谱，而更陡的源光谱将导致具有相同陡度的逃逸光谱。这说明了一些可能引起的关注，从预期的平坦或凹宇宙射线谱与非线性冲击修改。
The Galactic cosmic ray spectrum is a remarkably straight power law. Our current understanding is that the dominant sources that accelerate cosmic rays up to the knee ($3 \times 10^{15}$ eV) or perhaps even the ankle ($3 \times 10^{18}$ eV), are young Galactic supernova remnants. In theory, however, there are various reasons why the spectrum may be different for different sources, and may not even be a power law if nonlinear shock acceleration applies during the most efficient stages of acceleration. We show how the spectrum at the accelerator translates to the spectrum that make up the escaping cosmic rays that replenish the Galactic pool of cosmic rays. We assume that cosmic ray confinement, and thus escape, is linked to the level of magnetic field amplification, and that the magnetic field is amplified by streaming cosmic rays according to the non-resonant hybrid or resonant instability. When a fixed fraction of the energy is transferred to cosmic rays, it turns out that a source spectrum that is flatter than $E^{-2}$ will result in a $E^{-2}$ escape spectrum, whereas a steeper source spectrum will result in an escape spectrum with equal steepening. This alleviates some of the concern that may arise from expected flat or concave cosmic ray spectra associated with nonlinear shock modification.
年轻超新星遗迹中的宇宙射线加速
影响因子：
4.8
作者：
Schure K
通讯作者：
Schure K