The deformation of an erupting magnetic flux rope in a confined solar flare

TL;DR

This study investigates the deformation of a magnetic flux rope during a confined solar flare, revealing a two-step magnetic reconnection process that influences the MFR's evolution and energy release.

Contribution

It provides new insights into the deformation of erupting magnetic flux ropes during confined solar flares and highlights the role of two-step magnetic reconnection in their evolution.

Findings

Confined MFR eruption involved two distinct energy release episodes.

Deformation of MFR caused by magnetic reconnection with underlying sheared arcade.

Two-step reconnection process linked to the flare's double-peaked profile.

Abstract

Magnetic flux ropes (MFRs), sets of coherently twisted magnetic field lines, are believed as core structures of various solar eruptions. Their evolution plays an important role to understand the physical mechanisms of solar eruptions, and can shed light on adverse space weather near the Earth. However, the erupting MFRs are occasionally prevented by strong overlying magnetic fields, and the MFR evolution during the descending phase in the confined cases is lack of attention. Here, we present the deformation of an erupting MFR accompanied by a confined double-peaked solar flare. The first peak corresponded to the MFR eruption in a standard flare model, and the second peak was closely associated with the flashings of an underlying sheared arcade (SA), the reversal slipping motion of the L-shaped flare ribbon, the falling of the MFR, and the shifting of top of filament threads. All results suggest that the confined MFR eruption involved in two-step magnetic reconnection presenting two distinct episodes of energy release in the flare impulsive phase, and the latter magnetic reconnection between the confined MFR and the underlying SA caused the deformation of MFR.