High Speed Plasma Acceleration and Loop Oscillations at Flare Onset
Abstract
We analyse the postflare loop dynamics of events observed at the limb during the SUMER Flare Watch campaigns in 2000 and 2002. Observations of high blue and red Doppler shifts (up to 700 km/s in the line-of-sight) and large Doppler broadening have been made with the SUMER spectrometer in the emission lines Si III 1113.22 Å (0.1 MK), Ca X 557.8 Å (1 MK), and mainly in the flare lines Fe XIX 1118.1 Å (10 MK) and Fe XXI 1354 Å (12 MK). Some of the events have been simultaneously observed with the Transition Region and Coronal Explorer (TRACE) in the 195 Å passband and with the Nancay radioheliograph at 327 MHz. We propose that the recorded high Doppler shifts spreading over the large portion of the spectrometer slit sometimes followed by the emission at 327 MHz high up in the corona, are a signature of high speed plasma acceleration and loop oscillation in the wake of a propagating large scale wave.
- Publication:
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European Solar Physics Meeting
- Pub Date:
- September 2008
- Bibcode:
- 2008ESPM...122.101T