Association between solar soft X-ray flares and microwave bursts: AAnS 34/2 (1993)263–269

Abstract

The statistical analysis of the appropriate physical parameters of solar soft X-ray (SXR) flares and microwave bursts originating in four larger active regions (Boulder Nos. 5395, 5629, 5669 and 5680) in 1989 shows that their correlation coefficient R reach 0.9≤R1. This fact indicates that there is a close association between SXR flares and microwave bursts.Such result can be interpreted by the physical process that a strong enough nonthermal electron beam injected downward from the microwave source (at the top of a flare loop) into the chromosphere is able to cause the chromospheric evaporation due to collision heating, the evaporated chromospheric plasma with superhot temperature Te(≈107K) moves upwards along the flare loop and emits SXR radiation. As the flare loop is filled with superhot plasma, the SXR emission reaches the peak flux. Thus the peak flux of SXR emission appears often later than that of microwave burst.