Onset of Filament Eruption observed by
SDO/AIA, RHESSI, and Nobeyama
Radiohelioraph
Sujin Kim1, Bhuwan Joshi2, and Kyung-Suk Cho1
1
Korea Astronomy and Space Science Institute, Rep. of Korea
2
Udaipur observatory, India
sjkim@kasi.re.kr
We have investigated an onset of an active region filament which developed into a
Halo CME. The main eruption accompanied an M-class flare which occurred in 2011
August 4. For this study, we used the Nobryama Radioheliograph (NoRH) 17 and 34
GHz, RHESSI Hard X-ray satellite, and Atmospheric Imaging Assembly (AIA) and the
Heliospheric Magentic Imager(HMI) onboard the Solar Dynamic Observatory (SDO).
During the pre-eruption phase, clear nonthermal emission was detected in microwaves
of NoRH and hard-X-ray of RHESSI. At the moment that the nonthermal emission
start, the nonthermal sources appeared at the one edge of the filament structure on a
polarity inversion line and the filament structure in AIA 94 A underwent a sudden
acceleration on its ascendance. Sequential magnetograms revealed that the positive
magnetic field began to cancel out at the position where the nonthermal source appeared
at around 4 hours before the nonthermal emission started. These results demonstrate
that the magnetic reconnection at the lower layer, such as tether-cutting process, is a
trigger which leads the explosive filament eruption eventually.