A Successful Sheared-arcade Eruption Triggered by a Failed Erupted Small Filament

Abstract

Abstract In this work, we analyze a successful eruption, accompanied by an X5.4-class flare in active region 11429. The eruptive structure is an elongated hot structure, with two curved brightenings below it. Additionally, we find that snail-shell-shaped flare loops are formed at the end of the flare, with a filament channel beneath the loops that implies a magnetic flux rope structure. The flare ribbons indicate a highly complex eruption process. During the eruption, using Global Oscillation Network Group data, we find a small filament that exists before and after the eruption. We reproduce the eruption using a full thermodynamic magnetohydrodynamic simulation, with the purpose to illustrate the mechanisms of the eruption. The small magnetic flux rope continuously rises due to arcade–arcade to rope–flare loop reconnection below, compressing the sheared magnetic arcades above. Slipping reconnection between the upper sheared magnetic arcades leads to the formation of new sheared magnetic arcades, resulting in a successful eruption. Simultaneously, the newly formed snail-shell-shaped flare loops constrain the elevation of the original magnetic flux rope below, implying that the original magnetic flux rope is not the eruptive structure of this successful eruption. Instead, the sheared magnetic arcades produced by the upper slipping reconnection above the original flux rope is the eruptive structure involved.