Analysis of active region loops dynamics associated with a small C-class flare

P. Gömöry1, J. Rybák1, A. Kucera1, H. Wöhl2

1Astronomical Institute of the Slovak Academy of Sciences, SK-05960 Tatranská Lomnica, Slovakia
2Kiepenheuer-Institut für Sonnenphysik, D-79104 Freiburg, Germany

Abstract:

Analysis of the magnetic loops dynamics before and during a C-class flare activity in NOAA AR 10646 is presented using data of the SOHO/CDS spectrometer. The sit-and-stare observational mode of the SOHO/CDS was used to measure the temporal evolution of the spectral line profiles of He I 584.33 A chromosphere), O V 629.73 A (transition region) and Si xii 520.67 A(corona). Several precursor events and main impulsive phase of the flare were detected at different position along the CDS slit 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 chromospheric/transition region and coronal occurrence of events, significant upflows during precursor events and peaks of downflow and upflow velocities during main impulsive phase. This findings lead to a conclusion that the chromospheric evaporation was probably the driving mechanism responsible for the observed flare emission. Further investigation of remaining precursors and also analysis of the co-observations obtained by TRACE instrument and the DOT/LaPalma telescope is necessary for confirmation of this conclusion.


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