Magnetic Sources of flares and CMEs from multiwavelength studies

SCHMIEDER, B.; MANDRINI, C.H.; BERLICKI, A.; LIU, Y.

Giardini Naxos

Workshop; SOHO-17. 10 Years of SOHO and Beyond; 2006

ESA

We present the data analysis of an observing campaign on October 2003 with the objective of understanding the onset of Coronal Mass Ejections (CME) and solar flares. The magnetic field was observed with THEMIS and MDI, the chromosphere with the MSDP operating on THEMIS, the EUV images with SOHO/EIT and TRACE, the X-rays with RHESSI. Two examples of flares will be presented: the 28 Oct 2003 X17 flare and the 20 October 2003 M1.9 flare. The magnetic field analysis of the active regions is done using a linear-force-free field code. The X17 flare is at the origin of a halo CME while the M1.9 flare has no corresponding CME. Before the X17 flare there was a pre-flare event which allowed to change the connectivities in a first phase and to destabilize the stressed field in a second phase producing the X17 flare. A compact twisted emerging flux was responsible of the M1.9 flare, which remains a compact flare due to very tied overlaying loops. These two examples illustrate the major role of the magnetic configuration involved on the flare physical characteristics.