Spatial characterization of a flare using radio observations and magnetic field topology

CRISTIANI, G.; MARTÍNEZ, G.; MANDRINI, C.H.; GIMÉNEZ DE CASTRO, C.G.; DA SILVA, C.W.; ROVIRA, M.G.; KAUFMANN, P.

SOLAR PHYSICS

SPRINGER

Año: 2007 vol. 240 p. 271 - 281

0038-0938

Using magnetograms, EUV and H’¦Á images, Owens Valley Solar Array microwave observations, and 212-GHz flux density derived from the Solar Submillimeter Telescope data, we determine the spatial characteristics of the 1B/M6.9 flare that occurred on November 28, 2001, starting at 16:26 UT in active region (AR) NOAA 9715. This flare is associated with a chromospheric mass ejection or surge observed at 16:42 UT in the H’¦Á images. We compute the coronal magnetic field under the linear force-free field assumption, constrained by the photospheric data of the Michelson Doppler Imager and loops observed by the Extreme Ultraviolet Imaging Telescope. The analysis of the magnetic field connectivity allows us to conclude that magnetic field reconnection between two different coronal/chromospheric sets of arches was at the origin of the flare and surge, respectively. The optically thick microwave spectrum at peak time shows a shape compatible with the emission from two different sites. Fitting gyrosynchrotron emission to the observed spectrum, we derive parameters for each source.