A magnetic reconnection event in the solar atmosphere driven by relaxation of a twisted arch filament system

TL;DR

This study presents high-resolution observations of a solar magnetic reconnection event driven by the relaxation of a twisted arch filament system, revealing detailed dynamics and energy release processes in the solar atmosphere.

Contribution

It provides the first detailed observational evidence linking the relaxation of a twisted arch filament system to magnetic reconnection and plasma heating in the solar atmosphere.

Findings

Reconnection driven by twisted AFS relaxation causes inflows and X-shaped features.

Post-reconnection loops remain bright, indicating heating and plasma filling.

Magnetic cancellation and flows support the reconnection process.

Abstract

We present high-resolution observations of a magnetic reconnection event in the solar atmosphere taken with the New Vacuum Solar Telescope, AIA and HMI. The reconnection event occurred between the threads of a twisted arch filament system (AFS) and coronal loops. Our observations reveal that the relaxation of the twisted AFS drives some of its threads to encounter the coronal loops, providing inflows of the reconnection. The reconnection is evidenced by flared X-shape features in the AIA images, a current-sheet-like feature apparently connecting post-reconnection loops in the \halpha$+$1 \AA\ images, small-scale magnetic cancellation in the HMI magnetograms and flows with speeds of 40--80 km/s along the coronal loops. The post-reconnection coronal loops seen in AIA 94 \AA\ passband appear to remain bright for a relatively long time, suggesting that they have been heated and/or filled up by dense plasmas previously stored in the AFS threads. Our observations suggest that the twisted magnetic system could release its free magnetic energy into the upper solar atmosphere through reconnection processes. While the plasma pressure in the reconnecting flux tubes are significantly different, the reconfiguration of field lines could result in transferring of mass among them and induce heating therein.