Coronal heating in multiple magnetic threads

TL;DR

This study uses 3D MHD simulations to explore how magnetic instability in one coronal loop thread can trigger energy release in neighboring threads, shedding light on coronal heating mechanisms.

Contribution

It demonstrates that energy release in one magnetic thread can destabilize nearby threads, potentially causing an avalanche of energy release in coronal loops.

Findings

Unstable magnetic threads can trigger neighboring threads under certain conditions.

Magnetic reconnection occurs during kink instability, releasing energy.

Nearby structures close to marginal stability can be destabilized.

Abstract

Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can destabilise a neighbouring magnetic thread. Aims. By running a series of simulations, we aim to understand under what conditions the destabilisation of a single magnetic thread can also trigger a release of energy in a nearby thread. Methods. The 3D magnetohydrodynamics code, Lare3d, is used to simulate the temporal evolution of coronal magnetic fields during a kink instability and the subsequent relaxation process. We assume that a coronal magnetic loop consists of non-potential magnetic threads that are initially in an equilibrium state. Results. The non-linear kink instability in one magnetic thread forms a helical current sheet and initiates magnetic reconnection. The current sheet fragments, and magnetic energy is released throughout that thread. We find that, under certain conditions, this event can destabilise a nearby thread, which is a necessary requirement for starting an avalanche of energy release in magnetic threads. Conclusions. It is possible to initiate an energy release in a nearby, non-potential magnetic thread, because the energy released from one unstable magnetic thread can trigger energy release in nearby threads, provided that the nearby structures are close to marginal stability.