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 on board the Solar Dynamics Observatory. The X6.9-
class flare in active region 11263 on 2011 August 9 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 coronal dimming, non-decaying vertical oscillations are also
observed (period ≈ 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.
