Non-linear diffusive acceleration of heavy nuclei in supernova remnant shocks
Non-linear diffusive acceleration of heavy nuclei in supernova remnant shocks
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DOI：
10.1016/j.astropartphys.2010.10.011
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发表时间：
2011-01-01
影响因子：
3.5
通讯作者：
Amato, E.
中科院分区：
文献类型：
--
作者：
Caprioli, D.;Blasi, P.;Amato, E.
我们描述了一种在质子以外的原子核也被加速的情况下非线性扩散冲击加速的半解析方法。激波的结构是由所有原子核的复杂相互作用决定的，而这种激波结构又决定了所有成分的光谱。上游磁场放大被描述为由于所有核素的流动不稳定性。然后考虑放大的磁场对冲击结构的动态反馈以及进入粒子输运方程的散射中心速度的感应修改。仅当磁场被充分放大并且散射中心在背景等离子体框架中具有高速时，加速粒子的光谱才足够陡峭，可以与观测到的宇宙射线光谱进行比较。我们讨论了这种广义方法对全粒子宇宙射线光谱中膝盖结构的影响，我们将其解释为由于超过 10(15) eV 的化学成分越来越重。当伽马射线是强子起源时，源处的重要化学成分对超新星遗迹的伽马射线发射的影响也进行了讨论。 (C) 2010 Elsevier B.V. 保留所有权利。
We describe a semi-analytical approach to non-linear diffusive shock acceleration in the case in which nuclei other than protons are also accelerated. The structure of the shock is determined by the complex interplay of all nuclei, and in turn this shock structure determines the spectra of all components. The magnetic field amplification upstream is described as due to streaming instability of all nuclear species. The amplified magnetic field is then taken into account for its dynamical feedback on the shock structure as well as in terms of the induced modification of the velocity of the scattering centers that enters the particle transport equation. The spectra of accelerated particles are steep enough to be compared with observed cosmic ray spectra only if the magnetic field is sufficiently amplified and the scattering centers have high speed in the frame of the background plasma. We discuss the implications of this generalized approach on the structure of the knee in the all-particle cosmic ray spectrum, which we interpret as due to an increasingly heavier chemical composition above 10(15) eV. The effects of a non trivial chemical composition at the sources on the gamma ray emission from a supernova remnant when gamma rays are of hadronic origin are also discussed. (C) 2010 Elsevier B.V. All rights reserved.