Nonthermal Radio Emission from Solar Soft X-Ray Transient Brightenings

摘要: We compare microwave total power spectral data from the Owens Valley Radio Observatory Solar Array with soft X-ray transient brightenings observed Yohkoh telescope. find that are clearly detected in microwaves 12 of 34 events (35%), possibly another 17 (50%), and only five (15%) had no apparent counterpart. Comparing radio characteristics, we (1) peak is delayed relative to 16 20 events, (2) flux correlated seen X-rays, (3) when fluence used instead (24 events) correlation increases substantially, (4) spectra range 1-18 GHz vary greatly event event, (5) often 5-10 (13 events), (6) some show narrowband a steep low-frequency slope. conclude emission at least result nonthermal population electrons, as whole can therefore be identified microflares, low-energy extension general flare energy distribution. Soft brightenings, cannot heat corona.