Spatial positions of fast-time structures of a solar burst observed at 48 GHz

The impulsive solar burst of October 28, 1992 showed temporal and spatial fine structures that were observed at 48 GHz with the multi-beam antenna of the Itapetinga Radio Observatory. The relative positions of burst centroids were determined with a spatial accuracy of 2, with a temporal resolution of 1 millisecond. The burst intensity time profile shows fast pulses of about one second duration, superimposed by subsecond time structures. The spatial analysis of the fast pulses suggests that the emission originated from distinct locations, separated by about 5. Our results favour the idea that impulsive solar bursts are a superposition of small elementary events spread both in time and space, probably resulting from discontinuous energy release processes.