Analysis of dynamics of loops in an active region associated with a small C-class flare
Gömöry P.1, Rybák J.1, Kucera A.1, Wöhl H.2
1 Astronomical Institute of the Slovak Academy of Sciences,
SK-05960 Tatranská Lomnica, Slovakia
2 Kiepenheuer-Institut für Sonnenphysik, D-79104 Freiburg, Germany
Abstract:
A study of the dynamics of magnetic loops before and during
an X-ray C1.4 class flare in NOAA AR 10646 is presented using data taken by the SOHO/CDS spectrometer in
He I 584.33 A (chromosphere), O V 629.73 A (transition region) and Si XII 520.67 A (corona) lines. Several precursors
and the main impulsive phase of the flare were detected in all spectral lines. Analysis of two selected chromospheric
precursors with clear relation to the main impulsive phase and the main impulsive phase of the flare itself has
shown time delays between the chromospheric/transition region and coronal occurrence of events, upflows during
precursor events and peaks of downflow and upflow velocities during the main impulsive phase. These results indicate
that the chromospheric evaporation could be the driving mechanism of the observed flare. Further investigation
of remaining precursors and analysis of the co-observations obtained by the TRACE and the DOT telescope are necessary
for confirmation of this conclusion.