An MHD Study of Large-Amplitude Oscillations in Solar Filaments

KRAUSE, G., CÉCERE, M., ZURBRIGGEN, E., COSTA, A., FRANCILE, C., ELASKAR, S.

SOLAR PHYSICS

SPRINGER

Lugar: Berlin; Año: 2021 vol. 173 p. 296 - 321

0038-0938

Quiescent filaments are usually affected by internal and/or external perturbations triggeringoscillations of different kinds. In particular, external large-scale coronal waves can perturbremote quiescent filaments leading to large-amplitude oscillations. Observational reportshave indicated that the activation time of oscillations coincides with the passage of a large-scale coronal wavefront through the filament, although the disturbing wave is not alwayseasily detected. Aiming to contribute to understanding how ?and to what extent? coronalwaves are able to excite filament oscillations, here we modelled with 2.5D magnetohydro-dynamic simulations a filament floating in a gravitationally stratified corona disturbed by acoronal shock wave. This simplified scenario results in a two-coupled-oscillation pattern ofthe filament, which is damped in a few cycles, enabling a detailed analysis. A parametricstudy was carried out varying parameters of the scenario such as height, size, and mass ofthe filament. An oscillatory analysis reveals a general tendency for periods of oscillations,amplitudes, and damping times to increase with height, whereas filaments of larger radiusexhibit shorter periods and smaller amplitudes. The calculation of forces exerted on the fil-ament shows that the main restoring force is the magnetic tension.