Plasma Dynamics and Particle Acceleration in Relativistic Turbulent Magnetic Reconnection
Abstract
In strongly magnetized astrophysical plasma systems such as pulsar wind nebulae, magnetic reconnection is believed to be the primary process during which explosive energy release and particle acceleration occur, leading to significant high-energy emission. Past years have seen an active development on kinetic modeling of relativistic magnetic reconnection, supporting the magnetically dominated scenario. A much less explored issue in studies of relativistic reconnection is the consequence of three-dimensional physics, where turbulent structures are naturally generated as various types of instabilities develop. This paper presents a series of large-scale three-dimensional fully kinetic simulations of relativistic turbulent magnetic reconnection (RTMR) in positron-electron plasmas. Our simulations start from a force-free current sheet with several different modes of long wavelength magnetic field perturbations, which drives additional turbulence in the reconnection region. Because of this, the current layer breaks up and the reconnection region quickly evolves into a turbulent layer filled with coherent structures such as flux ropes and current sheets. We find that plasma dynamics in RTMR is quite different from their 2D counterparts in many aspects. The flux ropes evolve rapidly after their generation, and can completely disrupt due to the secondary kink instability. However, nonthermal particle acceleration and energy release time scale can be very fast and robust. The main acceleration mechanism is a Fermi-like acceleration process supported by the motional electric field, whereas the non-ideal electric field acceleration plays a subdominant role. We also discuss possible observation implications of three-dimensional turbulent relativistic magnetic reconnection.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23534805G