X6.9-class Flare Induced Vertical Kink Oscillations in a Large-Scale Plasma Curtain as Observed by SDO/AIA

TL;DR

This study reports the observation of vertical kink oscillations in a large-scale plasma curtain triggered by an X6.9 solar flare, revealing how large-scale disturbances induce oscillations with properties dependent on local plasma conditions.

Contribution

First observational evidence of flare-induced vertical kink oscillations in a large-scale plasma curtain with detailed analysis of their periods and triggering mechanisms.

Findings

Vertical kink oscillations with periods of 530-896 seconds observed.

Large-scale disturbance from the flare triggers asymmetric oscillations.

Oscillation properties depend on local plasma and magnetic field conditions.

Abstract

We present rare observational evidence of vertical kink oscillations in a laminar and diffused large-scale plasma curtain as observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). The X6.9 class flare in the Active Region 11263 on 09 August 2011, induces a global large-scale disturbance that propagates in a narrow lane above the plasma curtain and creates a low density region that appears as a dimming in the observational image data. This large-scale propagating disturbance acts as a non-periodic driver that interacts asymmetrically and obliquely with the top of the plasma curtain, and triggers the observed oscillations. In the deeper layers of the curtain, we find evidence of vertical kink oscillations with two periods (795 s and 530 s). On the magnetic surface of the curtain where the density is inhomogeneous due to the coronal dimming, non-decaying vertical oscillations are also observed (period $\approx$ 763-896 s). We infer that the global large-scale disturbance triggers vertical kink oscillations in the deeper layers as well as on the surface of the large-scale plasma curtain. The properties of the excited waves strongly depend on the local plasma and magnetic field conditions.