Three-dimensional magnetic reconnection in astrophysical plasmas

TL;DR

This paper reviews the complex nature of three-dimensional magnetic reconnection in astrophysical plasmas, especially solar flares, highlighting theoretical, simulation, and observational insights and proposing a new paradigm for solar flare mechanisms.

Contribution

It provides a comprehensive overview of 3D magnetic reconnection in astrophysical plasmas, including theory, simulations, observations, and introduces a new paradigm for solar flares.

Findings

Different types of 3D reconnection are described and distinguished.

Numerical simulations and observations support the theoretical framework.

A new paradigm for understanding solar flares involving 3D reconnection is proposed.

Abstract

Magnetic reconnection is a fundamental process in a laboratory, magnetospheric, solar and astrophysical plasma, whereby magnetic energy is converted into heat, bulk kinetic energy and fast particle energy. Its nature in two dimensions is much better understood than in three dimensions (3D), where its character is completely different and has many diverse aspects that are currently being explored. Here we focus on the magnetohydrodynamics of 3D reconnection in the plasma environment of the solar system, especially solar flares. The theory of reconnection at null points, separators and quasi-separators is described, together with accounts of numerical simulations and observations of these three types of reconnection. The distinction between separator and quasi-separator reconnection is a theoretical one that is unimportant for the observations of energy release. A new paradigm for solar flares, in which 3D reconnection plays a central role, is proposed.