DYNAMICS OF CORONAL MAGNETIC FIELDS INFERRED FROM MULTI-FREQUENCY RADIO OBSERVATIONS OF A SOLAR FLARE

摘要

We analysed multi-frequency radio and hard X-Ray observations of an M1.5 solar flare that occurred on November 5, 1998. The event was observed at various discrete radio frequencies from decimetric to microwave wavelengths, covering a wide range of coronal altitudes. Using combined imaging radio and hard X-Ray emissions it was possible to follow the dynamics of solar magnetic fields from the low corona up to about 0.5 solar radius above the photosphere. The radio spectra show different characteristics during event evolution, suggesting the appearance of new sources. The imaging analysis at hard X-Rays and decimetric/metric waves confirmed the presence of various and distinct emitting sources during the event, suggesting a dynamic and complex magnetic topology, probably associated with different injections of non-thermal electrons.