Affiliation: | a NUCATE / UNICAMP and CRAAE, R.Roxo Moreira, 1752, Cidade Universitaria, 13083-592, Campinas, SP, Brasil b CRAAE-Centro de Radio Astronomia e Aplicacoes Espaciais, EPUSP, CP-61548, 05427-970, S.Paulo, Brasil c Institute of Applied Physics, Division of Solar Observations, University of Bern, Sidlestrasse 5, CH-3012, Switzerland d P.N.Lebedev Physical Institute RAS, Leninsky Prospect 53, 117924, Moscow, Russia e Geophysics Directorate, Phillips Laboratory, 29 Randolph Road, Hanscom AFB, Bedford, MA 0173, U.S.A. |
Abstract: | ![]() Itapetinga measurements at 48 GHz with the multibeam technique are used to determine the relative position of solar burst centroid of emission with high spatial accuracy and time resolution. For the Great Bursts of October 19,22, 1989, with a large production of relativistic particles, and October 23, it is suggested that, at 48 GHz, the bursts might have originated in more then one source in space and time. Additionally the October 19 and 22 Ground Level Events exhibited very unusual intensity-time profiles including double component structures for the onset phase. The Bern observatory spectral radio emission data show a strong spectral flattening typical for large source inhomogeneties. The interpretation for this is that large solar flares are a superposition of a few strong bursts (separated both in space and time) in the same flaring region. |