arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0912.2964astro-ph.HE
收藏

超新星遗迹对银河系cosmic ray光谱的贡献

The contribution of supernova remnants to the galactic cosmic ray spectrum

D. Caprioli, E. Amato, P. Blasi

摘要:

星系宇宙射线起源的超新星范式深受冲击波粒子加速非线性理论发展的影响。在这里,我们讨论的影响,应用这种理论的计算光谱的宇宙射线在地球上加速超新星遗迹和传播的银河系。考虑到加速粒子对冲击波的动力学反应、增强冲击波附近散射的磁湍流的产生以及放大场对等离子体的动力学反应,计算了该谱。最重要的是,计算地球上宇宙射线的光谱时考虑到了在Sedov-Taylor阶段从上游逃逸的粒子通量,以及被限制在膨胀壳层中并在以后逃逸的膨胀减压粒子。我们展示了如何以这种方式获得的频谱是很好地描述了幂律的动量与频谱指数接近-4,尽管凹形状的瞬时加速粒子的频谱。另一方面,我们还展示了如何的频谱形状是敏感的加速过程和环境的细节,这是,并可能会保持非常不为人知。

英文摘要:

The supernova paradigm for the origin of galactic cosmic rays has been deeply affected by the development of the non-linear theory of particle acceleration at shock waves. Here we discuss the implications of applying such theory to the calculation of the spectrum of cosmic rays at Earth as accelerated in supernova remnants and propagating in the Galaxy. The spectrum is calculated taking into account the dynamical reaction of the accelerated particles on the shock, the generation of magnetic turbulence which enhances the scattering near the shock, and the dynamical reaction of the amplified field on the plasma. Most important, the spectrum of cosmic rays at Earth is calculated taking into account the flux of particles escaping from upstream during the Sedov-Taylor phase and the adiabatically decompressed particles confined in the expanding shell and escaping at later times. We show how the spectrum obtained in this way is well described by a power law in momentum with spectral index close to -4, despite the concave shape of the instantaneous spectra of accelerated particles. On the other hand we also show how the shape of the spectrum is sensible to details of the acceleration process and environment which are and will probably remain very poorly known.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑