Radio Type IV Burst Fine Structures and the Dynamics of the Flare Process

Abstract

AbstractWe present signatures of quasi-periodic release of nonthermal particles in different flare phases. In the decimetric range a characteristic pattern is identified with a recurrence period of 1...3 min accompanied by a slow drift toward lower frequencies. We explain these spectral features as evidence for repeated coronal energy release in a slowly (0.1vA) uprising particle accelerator. The analysis allows quite a new prospect to identify the source of the metric type II burst and its timing in the type IV radio spectrogram.