Magnetic sources of flares and CMEs from multi-wavelength flare studies

SCHMIEDER, B.; MANDRINI, C.H.; BERLICKI, A.; DÉMOULIN, P.; LI, H.

Giardini Naxos, Sicilia, Italia

Congreso; SOHO 17 - 10 Years of SOHO and Beyond; 2006

We will 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. We will show how important is the magnetic configuration of the active region to produce CMEs. 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 gave 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 relax 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. RHESSI showed that even during the M1.9 flare both components thermal and non thermal component are present.