Simultaneous Transverse Oscillations of a Prominence and a Filament and Longitudinal Oscillation of another Filament Induced by a Single Shock Wave

TL;DR

This study reports the first combined stereoscopic and Doppler observations of multiple solar filament oscillations triggered by a single shock wave, revealing insights into their dynamics and underlying restoring forces.

Contribution

It provides new three-dimensional velocity measurements and analysis of filament oscillations, highlighting the influence of orientation and magnetic forces on their behavior.

Findings

Prominence oscillates as a linear vertical rigid body with consistent periods at different heights.

Weak transverse oscillation observed in a low-altitude filament possibly due to shock weakening.

Large amplitude longitudinal oscillation characterized by specific velocity and period.

Abstract

We present the first stereoscopic and Doppler observations of simultaneous transverse oscillations of a prominence and a filament and longitudinal oscillation of another filament launched by a single shock wave. Using H-alpha Doppler observations, we derive the three-dimensional oscillation velocities at different heights along the prominence axis. The results indicate that the prominence has a larger oscillation amplitude and damping time at higher altitude, but the periods at different heights are the same (i.e., 13.5 minutes). This suggests that the prominence oscillates like a linear vertical rigid body with one end anchored on the Sun. One of the filaments shows weak transverse oscillation after the passing of the shock, which is possibly due to the low altitude of the filament and the weakening (due to reflection) of the shock wave before the interaction. Large amplitude longitudinal oscillation is observed in the other filament after the passing of the shock wave. The velocity amplitude and period are about 26.8 km/s and 80.3 minutes, respectively. We propose that the orientation of a filament or prominence relative to the normal vector of the incoming shock should be an important factor for launching transverse or longitudinal filament oscillations. In addition, the restoring forces of the transverse prominence are most likely due to the coupling of gravity and magnetic tension of the supporting magnetic field, while that for the longitudinal filament oscillation is probably the resultant force of gravity and magnetic pressure.