First observation of magnetic flux rope inside electron diffusion region

TL;DR

This paper reports the first direct observation of a magnetic flux rope within the electron diffusion region during magnetic reconnection, revealing its structure, dynamics, and role in energy dissipation.

Contribution

It provides the first observational evidence of an MFR inside the EDR, enhancing understanding of magnetic flux rope formation and behavior at electron scales.

Findings

First observation of MFR inside EDR

MFR modulates electric fields in EDR

Strong energy dissipation detected inside MFR

Abstract

Magnrtic flux ropes (MFRs) play a crucial role during magnetic reconnection. They are believed to be primarily generated by tearing mode instabilities in the electron diffusion region (EDR). However, they have never been observed inside the EDR. Here, we present the first observation of an MFR inside an EDR. The bifurcated non-force-free MFR, with a width of 27.5de in the L direction and 4.8de in the N direction, was moving away from the X-line. Inside the MFR, strong energy dissipation was detected. The MFR can modulate the electric field in the EDR. We reconstructed magnetic topology of the electron-scale MFR. Our study promotes understanding of MRFs' initial state and its role in electron-scale processes during magnetic reconnection.