Jet deflection by very weak guide fields during magnetic reconnection

TL;DR

This study uses PIC simulations to show that even very weak guide magnetic fields can significantly deflect electron jets during magnetic reconnection, affecting the structure of the diffusion region.

Contribution

It demonstrates that small out-of-plane guide fields influence jet trajectories and diffusion region morphology during magnetic reconnection, with implications for space plasma observations.

Findings

Jets are deflected towards the separatrix by weak guide fields.

Outer electron diffusion region is distorted but diffusion rate remains unchanged.

Simulation results align with magnetosheath measurements.

Abstract

Simulations of antiparallel reconnection have shown collimated electron jets outflowing from the x-point, and associated highly elongated "outer electron diffusion regions." New PIC simulations with ion/electron mass ratios as large as 1836 show that jets are deflected towards the magnetic separatrix by out-of-plane guide fields, Bg, as small as 0.05 times the asymptotic reconnecting field, B0. The outer electron diffusion region is distorted and broken up, but the diffusion rate is unchanged. These results are interpreted in terms of electron dynamics and are compared to recent measurements of reconnection jets in the magnetosheath.