MHD Modeling of an Observed Solar Filament

Abstract:

The physical mechanisms by which solar prominences (or filaments) form are still not well understood. The presently most favored scenario invokes the evaporation of chromospheric plasma via localized heating at the footprints of a magnetic flux rope (MFR) or sheared arcade, and the subsequent condensation of this plasma in the corona due to thermal non-equilibrium (TNE). This scenario has been modeled extensively in one-dimensional (1D) hydrodynamic simulations along static magnetic field lines and, very recently, also in fully 3D magnetohydrodynamic (MHD) simulations, using idealized MFR configurations. However, such configurations lack the complexity of real prominence magnetic fields, which poses additional challenges. Here we report on our recent attempts to employ data-constrained MHD simulations to model the formation of observed filaments. To this end, we selected the filament that erupted in a spectacular manner on June 7, 2011 in NOAA AR 11226. To model its formation, we first develop a semi-realistic ("thermodynamic MHD") model of the solar corona, using SDO/HMI data as boundary condition for the magnetic field. Next, we insert an MFR constructed with the RBSL method (Titov et al., 2018) into the source region of the filament. Finally, after a short relaxation of the system, we impose localized heating in the footprint regions of the MFR. In our study, we vary the geometry and footprint locations of the MFR, as well as the amount of heating in the respective MFR footprints, and investigate how these parameters affect the formation of persistent plasma condensations. We compare our results with simulations of prominence formation in idealized MFR configurations, and we discuss the difficulties that arise once realistic cases are considered.