Simultaneous Horizontal and Vertical Oscillation of a Quiescent Filament Observed by CHASE and SDO

In this paper, we present the imaging and spectroscopic observations of the simultaneous horizontal and vertical large-amplitude oscillation of a quiescent filament triggered by an extreme-ultraviolet (EUV) wave on 2022 October 2. Particularly, the filament oscillation involved winking phenomenon in H alpha images and horizontal motions in EUV images. Originally, a filament and its overlying loops across AR 13110 and 13113 erupted with a highly inclined direction, resulting in an X1.0 flare and a non-radial coronal mass ejection. The fast lateral expansion of loops excited an EUV wave and the corresponding Moreton wave propagating northward. Once the EUV wave front arrived at the quiescent filament, the filament began to oscillate coherently along the horizontal direction, and the winking filament appeared concurrently in H alpha images. The horizontal oscillation involved an initial amplitude of similar to 10.2 Mm and a velocity amplitude of similar to 46.5 km s-1, lasting for similar to 3 cycles with a period of similar to 18.2 minutes and a damping time of similar to 31.1 minutes. The maximum Doppler velocities of the oscillating filament are 18 km s-1 (redshift) and -24 km s-1 (blueshift), which were derived from the spectroscopic data provided by the Chinese H alpha Solar Explorer/H alpha Imaging Spectrograph. The three-dimensional velocity of the oscillation is determined to be similar to 50 km s-1 at an angle of similar to 50 degrees to the local photosphere plane. Based on the wave-filament interaction, the minimum energy of the EUV wave is estimated to be 2.7 x 1020 J. Furthermore, this event provides evidence that Moreton waves should be excited by the highly inclined eruptions.

Automated summary

In this paper, the imaging and spectroscopic observations of a quiescent filament undergoing simultaneous horizontal and vertical large-amplitude oscillation triggered by an extreme-ultraviolet wave are presented. The oscillation involved winking phenomenon in H alpha images and horizontal motions in EUV images. The study provides evidence that Moreton waves can be excited by highly inclined eruptions.