FREQUENCY-SPECTRUM OF SOLAR MICROWAVE-BURSTS ASSOCIATED WITH CORONAL MASS EJECTIONS

It is shown that in events accompanied by coronal mass ejections (CME) , a soft radio spectrum (with spectral maximum f(m) less-than-or-equal -to 5-7 GHz) is found mainly in the longest (effective duration d grea ter-than-or-equal-to 5 min) microwave flares of moderate and high inte nsity, i.e., for parameters typical of flares with intense CME eruptio n. It is proposed that in such events, both the significant duration a nd the soft spectrum of the microwave flares are determined by lengtht y energy release high in the corona, where the magnetic field above th e active region, having been severely disturbed by the CME, relaxes to its original state by means of magnetic reconnection in a vertical cu rrent sheet and formation of a post-flare loop system.