Filament Mass Losses Forced by Magnetic Reconnection in the Solar Corona

TL;DR

This paper models how magnetic reconnection causes mass loss in solar coronal filaments, explaining observed coronal rain phenomena through a detailed MHD simulation incorporating thermal conduction and radiation.

Contribution

It introduces a physical model demonstrating magnetic reconnection as a mechanism for filament mass loss, linking evaporation-condensation processes with coronal rain formation.

Findings

Magnetic reconnection drives filament mass loss and coronal rain.

Simulation shows three phases of current sheet evolution during reconnection.

Rebound shocks and retractive upflows contribute to dynamic thermal runaway.

Abstract

Recent observations of the solar atmosphere in cool extreme ultraviolet (EUV) lines have reported the prevalence of coronal rain falling from coronal cloud filaments that are associated with the magnetic dips of coronal X-point structures. These filaments mysteriously appear as clouds of mass in the corona that subsequently shrink and disappear due to mass losses that drain as coronal rain along arced field lines. Using a two and a half dimensional, magnetohydrodynamic model, we investigated evaporation-condensation as the formation mechanism of the subset of coronal cloud filaments that form above coronal X-points. Our simulation included the effects of field-aligned thermal conduction and optically thin radiation and used the state-of-the-art Transition Region Adaptive Conduction (TRAC) method to model the formation, maintenance, and mass loss of a filament above a coronal X-point. This paper presents a physical model that demonstrates magnetic reconnection as a filament loss mechanism, producing hybrid filament/coronal rain via mass losses through the X-point. A detailed analysis of how the mass of the filament forces the field to reconnect is also presented, revealing three phases that characterize the evolution of the reconnecting current sheet and associated mass losses. We conclude that the formation of certain coronal cloud filaments and subsequent mass losses via coronal rain can be explained by the evaporation-condensation model combined with filament mass losses forced by magnetic reconnection. We also report that rebound shocks generated by the impact of coronal rain condensations on the chromosphere together with retractive upflows can cause upward propagating condensations to form through a dynamic thermal runaway process.