Submillimeter and Far Infrared Emission from Solar Flares

Abstract

The mechanisms for emission in the submillimeter and far-infrared (1011 and 1013 Hz) regions by solar flares and expected fluxes at these frequencies are described and evaluated. These inferences are based on observations of flare emission at other frequencies and on models for these emissions. In the impulsive phase, non-thermal synchrotron emission by electrons responsible for > 10 MeV gamma-ray emission can give rise to significant radiation in the 1011 to 1013 Hz region from large flares. Free-free or thermal gyrosynchrotron from the hot plasma responsible for the gradual soft X-ray emission can produce significant radiation in the 1011 to 1013 Hz range. However, only radiation in the lower end of this range would have a brightness temperature exceeding the quiet sun brightness.