Response of the solar atmosphere to flux emergence: With emergence-driven prominence formation

TL;DR

This study uses magnetohydrodynamic simulations to explore how flux emergence influences solar eruptions, revealing mechanisms like magnetic reconnection, jet formation, and prominence creation driven by flux interactions.

Contribution

It introduces a new prominence formation mechanism driven by flux emergence and systematically analyzes the effects of magnetic field strength and angle on eruptions.

Findings

Stronger magnetic fields lead to earlier, more energetic eruptions.

Magnetic islands influence jet structure and dynamics.

Flux emergence can generate prominences via plasma injection.

Abstract

Flux emergence is crucial for the formation of solar active regions and triggering of various eruptions. However, the detailed mechanisms by which flux emergence drives these eruptions remain unclear and require numerical investigation. Using 2.5-dimensional magnetohydrodynamic simulations, we investigate the interaction between emerging flux and background magnetic fields and dynamics of the induced eruptions. By systematically varying the strength and angle of the emerging magnetic field relative to the background field, we investigate its impact on the initiation and evolution of solar eruptions. The simulations show that magnetic reconnection between the emerging flux and background field drives the formation of current sheets, magnetic islands and multithermal jets. Stronger magnetic fields result in earlier eruptions, more energetic jets, and enhanced heating. The formation and ejection of magnetic islands affect the structure and dynamics of the jet. When the hot and cool components of jets reach the other footpoint of magnetic loops, they will generate spicules near the transition region. Varying the angle between the emerging flux and the background field, we find that larger angles delay filament ascent and eruption timing but facilitate filament formation. Filaments form a hot shell and oscillate with a period of 10 minutes driven by periodic plasma ejections. Repetitive reconnection events inject cold plasma into the self-consistently formed filament channel, introducing a new prominence formation mechanism by flux-emergence-fed injection. Our analysis highlights the dynamic interplay between magnetic reconnection, plasma cooling and heating, and filament dynamics. These findings provide insights into solar eruptions and their observational signatures, emphasizing the role of multi-thermal structures in the corona.