Association of magnetic topology and radiative emissions in solar flares
Abstract
We relate the energetic process in flares to the detailed topology, dynamics and evolution of magnetic field for NOAA active region 10720, which proved to be the most flare productive region of Cycle 23. We obtain the locations of quasi-separatrix layers (QSLs) from photospheric vector magnetic field observations based on the squashing degree, Q of Titov et al. (2002)and compare these to the distribution of vertical current, magnetic field evolution, and the chromospheric sites of UV and hard X-ray flare emissions. We find a close relationship between the distribution of the QSLs and the flare emission sources. Moreover, opposite vertical current is found to concentrate near the QSLs and that several large flares occur in the vicinity of the current concentrations and QSLs. We argue that the magnetic emergence and fast evolution of the sunspot magnetic fields alter the topology of the field in the corona resulting in the production of large solar flares and the release of the free energy associated with the currents.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2008
- Bibcode:
- 2008AGUSMSP51C..14A
- Keywords:
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- 7519 Flares;
- 7524 Magnetic fields;
- 7554 X-rays;
- gamma rays;
- and neutrinos