Solar prominence models
The existence of solar prominences is mainly due to coronal magnetic fields. By coupling together magnetohydrodynamic (MHD) simulations and radiative transfer (RT) modelling, the COMBINED MHD AND RT (Magnetohydrodynamics and radiative transfer: Development of a combined solar prominence modeling technique) project has established a new modelling technique. This allows, for the first time, the detailed study of the complex relationships between the prominence magnetic field, prominence fine structure plasma and the radiation it produces. To achieve this, 3D Non-Linear Force-free Field (NLFF) simulations were extended with a randomisation method for the selection of individual dipped magnetic field lines from high-resolution MHD simulations. The NLFF magnetic dips were then filled with realistic prominence plasma. This method produces numerous prominence plasma fine structures to form complex prominences. To effectively model the emerging radiation in such complex 3D plasma structures an innovative fast approximate RT method was developed for the H-alpha line. This novel visualisation method allows the consistent study of the structure of prominences at the solar limb and filaments on the solar disk using a single model. It also enables the first direct comparison of synthetic images of modelled prominences/filaments with high-resolution observations. COMBINED MHD AND RT employed 3D MHD simulations with an evolving parasitic polarity and studied the evolution of the modelled prominences. This produced 3D prominence magnetic field configurations from several prominence evolutionary steps, allowing the study of the variations in the prominence magnetic field configuration caused by changes in the underlying photospheric magnetic flux distribution. Detailed representations of the prominence plasma were produced for each evolution step, providing a sequence of synthetic H-alpha images of the modelled prominence, both when viewed as a prominence on the solar limb and as a filament against the solar disk. Distributions of the magnetic field strength, its orientation and the distribution of plasma-beta values were calculated within modelled prominences. The results have implications for prominence magnetic field observations, the origin of prominence mass and the stability of prominences. The mass of the prominence plasma within the modelled prominences was calculated and its evolution due to the changes of the underlying photospheric magnetic field were as followed.
Keywords
Solar prominence, magnetic fields, magnetohydrodynamic, radiative transfer, COMBINED MHD AND RT
