Electron distribution functions in the electron diffusion region of magnetic reconnection: Physics behind the fine structures

被引：60

作者：

Bessho, N. ^{[1
,2
]}

Chen, L-J ^{[1
,2
]}

Shuster, J. R. ^{[3
]}

Wang, S. ^{[3
]}

机构：

[1] Univ Maryland, Dept Astron, College Pk, MD 20742 USA

[2] NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA

[3] Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA

来源：

GEOPHYSICAL RESEARCH LETTERS | 2014年 / 41卷 / 24期

基金：

美国国家科学基金会;

关键词：

magnetic reconnection; electron distribution function; electron diffusion region; particle-in-cell simulation;

D O I：

10.1002/2014GL062034

中图分类号：

P [天文学、地球科学];

学科分类号：

07 ;

摘要：

Highly structured electron distribution functions in the electron diffusion region (EDR) during magnetic reconnection are studied by means of fully kinetic simulations. Four types of structures (striations, arcs, swirls, and rings) in momentum space are analyzed to understand their formation mechanisms. Discrete striations are formed by particles undergoing different numbers of meandering bounces in the EDR and are a result of oscillations in the out-of-plane force on meandering electrons. Predictions for the separation between striations and the triangular shape of the distribution are obtained analytically. Arcs and swirls are due to partial remagnetization of accelerated electrons. Near the end of the outflow jet, electron remagnetization gives rise to the ring structure. Understanding the distribution structures is critical to unraveling the kinetic processes occurring in the EDR and will guide the identification of EDRs based on satellite measurements.

引用

页码：8688 / 8695

页数：8

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