Non-adiabatic magnetohydrodynamic waves in a cylindrical prominence thread with mass flow

TL;DR

This study analyzes how non-adiabatic effects and steady mass flows influence the damping of magnetohydrodynamic waves in cylindrical prominence threads, revealing that certain modes are efficiently attenuated while others are less affected, with flow direction impacting damping.

Contribution

It provides a detailed theoretical investigation of wave damping in prominence threads considering non-adiabatic effects and steady flows, highlighting differences among wave modes and the limited role of flow in matching observed damping times.

Findings

Slow and thermal modes are efficiently attenuated by non-adiabatic mechanisms.

Fast kink modes are less affected and have longer damping times than observed.

Steady mass flows influence the damping of kink oscillations depending on flow direction.

Abstract

High-resolution observations show that oscillations and waves in prominence threads are common and that they are attenuated in a few periods. In addition, observers have also reported the presence of material flows in such prominence fine-structures. Here we investigate the time damping of non-leaky oscillations supported by a homogeneous cylindrical prominence thread embedded in an unbounded corona and with a steady mass flow. Thermal conduction and radiative losses are taken into account as damping mechanisms, and the effect of these non-ideal effects and the steady flow on the attenuation of oscillations is assessed. We solve the general dispersion relation for linear, non-adiabatic magnetoacoustic and thermal waves supported by the model, and find that slow and thermal modes are efficiently attenuated by non-adiabatic mechanisms. On the contrary, fast kink modes are much less affected and their damping times are much larger than those observed. The presence of flow has no effect on the damping of slow and thermal waves, whereas fast kink waves are more (less) attenuated when they propagate parallel (anti-parallel) to the flow direction. Although the presence of steady mass flows improves the efficiency of non-adiabatic mechanisms on the attenuation of transverse, kink oscillations for parallel propagation to the flow, its effect is still not enough to obtain damping times compatible with observations.