Thermal Trigger for Solar Flares II: Effect of the Guide Magnetic Field

Abstract

We investigate the effect of the thermal imbalance on the structural stability of the magnetohydrodynamic model of the preflare current layer (Ledentsov, Sol. Phys. 296, 74, 2021). The piecewise homogeneous model of the current layer is supplemented by a magnetic field longitudinal with respect to the direction of the current. It is shown that the presence of a weak longitudinal field does not change the previously calculated spatial period of the thermal instability in the most expected range of the parameters of the preflare current layer and, moreover, contributes to the formation of the instability. On the other hand, a strong longitudinal magnetic field contributes to the spatial stabilization of the current layer.