Attenuation of non-adiabatic oscillations in a cartesian prominence fibril

Abstract

AbstractOne of the typical features shown by observations of solar prominence oscillations is that they are quickly damped in time by one or several not well-known mechanisms. In addition, recent high resolution observations have revealed that the prominence fine structures, called fibrils, can oscillate with their own periods, independently from the rest of the prominence. The main aim of the present work is to study the attenuation of oscillations supported by a single prominence fibril. We consider an equilibrium made of a prominence plasma Cartesian slab of finite width embedded in a coronal medium, and assume non-adiabatic effects (thermal conduction, radiation losses and heating) as damping mechanisms. The magnetic field is taken uniform and parallel to the slab axis. We find that the efficiency of the non-adiabatic effects as damping mechanisms is different for each magnetoacoustic mode. The obtained values of the damping time are compatible with those observed in the case of the slow modes, but the fast modes are much less attenuated.