Paper detail

A coronal wave and an asymmetric eruptive filament in SUMER, CDS, EIT, and TRACE co-observations

The objectives of the present study is to provide a better physical understanding of the complex inter-relation and evolution of several solar coronal features comprising a double-peak flare, a coronal dimming caused by a CME, a CME-driven compression, and a fast-mode wave. For the first time, the evolution of an asymmetric eruptive filament is analysed in simultaneous SUMER spectroscopic and TRACE and EIT imaging data. We use imaging observations from EIT and TRACE in the 195A channel and spectroscopic observations from the CDS in a rastering and SUMER in a sit-and-stare observing mode. The SUMER spectra cover spectral lines with formation temperatures from logT(K) ~ 4.0 to 6.1. Although the event was already analysed in two previous studies, our analysis brings a wealth of new information on the dynamics and physical properties of the observed phenomena. We found that the dynamic event is related to a complex flare with two distinct impulsive peaks, one according to the GOES classification as C1.1 and the second - C1.9. The first energy release triggers a fast-mode wave and a CME with a clear CME driven compression ahead of it. This activity is related to, or possibly caused, by an asymmetric filament eruption. The filament is observed to rise with its leading edge moving at a speed of ~300 km/s detected both in the SUMER and CDS data. The rest of the filament body moves at only ~150 km/s while untwisting. No signature is found of the fast-mode wave in the SUMER data, suggesting that the plasma disturbed by the wave had temperatures above 600 000 K. The erupting filament material is found to emit only in spectral lines at transition region temperatures. Earlier identification of a coronal response detected in the Mg X 609.79 A line is found to be caused by a blend from the O IV 609.83 A line.