arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1103.2188astro-ph.SRphysics.plasm-ph
收藏

太阳耀斑日冕电子分布的漂移动力学模型

Coronal Electron Distribution in Solar Flares: Drift-Kinetic Model

Takashi Minoshima, Satoshi Masuda, Yoshizumi Miyoshi, Kanya Kusano

摘要:

利用一个太阳耀斑中粒子加速和输运的模型,通过研究与能量有关的俯仰角散射,研究了日冕电子的高度分布。当不包括俯仰角散射时,环顶电子的峰值高度是恒定的,而不管它们的能量如何,这是由于电子通过磁环收缩而连续加速和压缩。另一方面,在俯仰角散射下,电子高度是能量依赖的;中等能量的电子在较高的高度,而较低和较高能量的电子在较低的高度。这意味着中能电子被抑制跟随收缩的场线到较低的高度,因为俯仰角散射导致这些电子有效地沉淀到足点中,并随后从环中损失。这一结果与环顶硬X射线(HXR)源的位置定性一致,HXR源位于低能电子发射的日冕HXR环和高能电子发射的微波上方。与观测的定量协议可能会实现通过考虑主加速开始之前的环路收缩和额外的俯仰角散射通过波粒相互作用。

英文摘要:

Using a model of particle acceleration and transport in solar flares, we investigate the height distribution of coronal electrons by focusing on the energy-dependent pitch-angle scattering. When pitch-angle scattering is not included, the peak heights of loop-top electrons are constant, regardless of their energy, owing to the continuous acceleration and compression of the electrons via shrinkage of magnetic loops. On the other hand, under pitch-angle scattering, the electron heights are energy dependent; intermediate energy electrons are at a higher altitude, whereas lower and higher energy electrons are at lower altitudes. This implies that the intermediate energy electrons are inhibited to follow the shrinking field lines to lower altitudes because pitch-angle scattering causes efficient precipitation of these electrons into the footpoint and their subsequent loss from the loop. This result is qualitatively consistent with the position of the above-the-loop-top hard X-ray (HXR) source that is located above coronal HXR loops emitted by lower energy electrons and microwaves emitted by higher energy electrons. Quantitative agreement with observations might be achieved by considering primary acceleration before the onset of loop shrinkage and additional pitch-angle scattering via wave-particle interactions.

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。

↑