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arXiv 1605.04022astro-ph.SR
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太阳耀斑和伴随的CME激波中的粒子加速

Particle Acceleration in Solar Flares and Associated CME Shocks

Vahe' Petrosian

摘要:

对近地电子(SEP)和产生耀斑辐射的电子特征的观测表明,在某些(瞬发)事件中,这两个群体的起源似乎都是耀斑的位置,这表明SEP和硬X射线辐射电子的数量和光谱指数之间有很强的相关性,但在其他(延迟)与快速CME有关的事件中,这种关系很复杂,SEP往往更难。瞬发事件谱关系与厚靶或薄靶模型的预期结果不一致。我们表明,使用一个更准确的处理的加速电子的运输到的足迹和地球可以解释这种差异。我们的结果与Chen和Petrosian(2013)使用非参数反演方法对两个耀斑的结果一致,根据这些结果,我们具有弱扩散条件和由磁场会聚介导的捕获。延迟事件的弱关联和硬谱可以通过CME冲击环境中电子的再加速来实现。我们描述了在什么条件下可以实现这种硬化。使用这个(加速耀斑和再加速的CME)的情况下,我们表明,我们可以描述类似的二分法之间存在的所谓的脉冲,高度富集($^3$他和重离子)和软SEP事件,更强的更渐进的SEP事件与接近正常的离子丰度和更硬的光谱。这些方法可以用来区分加速机制和约束其特性。

英文摘要:

Observations relating the characteristics of electrons seen near Earth (SEPs) and those producing flare radiation show that in certain (prompt) events the origin of both population appears to be the flare site, which show strong correlation between the number and spectral index of SEP and hard X-ray radiating electrons, but in others(delayed), which are associated with fast CMEs, this relation is complex and SEPs tend to be harder. Prompt event spectral relation disagrees with that expected in thick or thin target models. We show that using a a more accurate treatment of the transport of the accelerated electrons to the footpoints and to the Earth can account for this discrepancy. Our results are consistent with those found by Chen and Petrosian (2013) for two flares using non-parametric inversion methods, according to which we have weak diffusion conditions, and trapping mediated by magnetic field convergence. The weaker correlations and harder spectra of delayed events can come about by re-acceleration of electrons in the CME shock environment. We describe under what conditions such a hardening can be achieved. Using this (acceleration at the flare and re-acceleration in the CME) scenario we show that we can describe the similar dichotomy that exists between the so called impulsive, highly enriched ($^3$He and heavy ions) and softer SEP events, and stronger more gradual SEP events with near normal ionic abundances and harder spectra. These methods can be used to distinguish the acceleration mechanisms and to constrain their characteristics.

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。

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