Analysis of radio observations of two consecutive flares

CRISTIANI, GIMÉNEZ DE CASTRO,DE BENEDETTO E SILVA, MANDRINI, ROVIRA, KAUFMANN

Córdoba

Congreso; Asociación Argentina de Astronomía; 2006

Observatorio de Córdoba

We analyze two solar flares that ocurred on December 20, 2002. The flares took place in active region (AR) 10226 (S26 W32) at 13:16 UT and 13:18 UT. Radio spectral information was obtained  at 212 GHz and 405 GHz from the Solar Submillimeter Telescope (SST), together with microwave data from the Radio Solar Telescope Network (RSTN) in the range from 0.265 to 15.4 GHz, and flux density  from six patrol radiotelescopes of the Bern University. One of these working as a null interferometer in the 8.4-89.4 GHz frequency interval. The radio spectra of the two flares are very different. The optically thin spectral index of the first one is harder than that of the second one. A peculiar spectrum is observed during the peak of the second flare. It has a plane region of about one decade extension. Images from the Halpha Solar Telescope for Argentina (HASTA) were used to identify the possible emission sources and to obtain light curves that were compared with the evolution of radio emission.