Flare-associated oscillations in coronal multiple loops observed with
the Norikura Green-Line Imaging System
Hori, K; Ichimoto, K; Sakurai, T
We report a standing Kink oscillation in coronal loops
that was observed in the coronal green line emission (Fe XIV 5303A,
2MK) by the Norikura Green-Line Imaging System (NOGIS), a 2D Doppler
coronagraph at the Norikura Solar Observatory, NAOJ.
Similarly to the TRACE observations in EUV lines, our event was
induced by flare-associated disturbances, i.e., an MHD wave and
a mass expansion. The oscillation started in Doppler shifts among an
aggregate of face-on coronal loops near the solar limb.
Thanks to the favorable loop configuration, we could investigate
the difference in oscillation profiles (e.g., period, amplitude,
decay time) among the inner loops and outer loops, which can
give a hint to understand trigger and damping mechanisms of
coronal loop oscillations. We compare the parameters with those
obtained from recent numerical simulations and other observations
of coronal loop oscillations and examine our flare-oscillation
scenario.
Because the NOGIS observation is sensitive to the plasma
temperature, we need imaging spectroscopic observations
with a wide temperature range. In this point, Solar-B/EIS
will be a good partner for a further investigation of
coronal disturbances.
Correspondence
Kuniko Hori (hori@solar.mtk.nao.ac.jp), Solar Observatory, NAOJ
presentation
oral