On the dynamics, thermodynamics and fine structure of virtual erupting filaments

TL;DR

This paper uses advanced MHD simulations to explore the dynamics, heating, and fine structures of erupting solar filaments, revealing the roles of magnetic reconnection and internal heating in CME evolution.

Contribution

It provides a detailed simulation-based analysis of filament eruption mechanisms, including thermal instability, reconnection, and fine structure formation, linking these to observations.

Findings

Erupting flux ropes show nested circular fine structures in EUV images.

Magnetic reconnection modulates the slow-rise and impulsive phases of eruptions.

Internal heating processes contribute to prominence evaporation during eruptions.

Abstract

It is not fully understood why some solar filaments erupt while others do not. Those that do typically undergo a slow rise followed by an acceleration phase, though this transition requires further investigation. Erupting prominences have been observed to heat up during the acceleration phase, but the origin of this heating remains unclear. Moreover, some coronal mass ejections possess additional fine structure in white-light observations beyond the classical three-part morphology. We aim to elaborate on the dynamics of erupting prominences, investigate the heating during the acceleration phase, and correlate our findings with observations. We employ the open-source MPI-AMRVAC code to solve the 2.5D MHD equations on a coronal domain extending to 300 Mm, using adaptive mesh refinement to attain high resolution. Controlled combinations of footpoint shearing and converging motions applied to an initial magnetic arcade produce erupting flux ropes with self-consistent prominence and coronal rain formation due to thermal instability. We find both non-erupting and erupting cases related to the system energization. Comparison with observations from the AIA Filament Eruption Catalog shows that the slow-rise and impulsive phases are modulated by magnetic reconnection. The transition to acceleration corresponds to an increase in the inflow Alfv\'en Mach number. Thermal conduction and compressional heating can lead to prominence evaporation. We obtain nested circular fine structure in EUV images of the ejected flux ropes, partly resulting from plasmoid interactions. We conclude that internal heating processes and magnetic reconnection play key roles in the early evolution of CMEs.