Implications for Additional Plasma Heating Driving the Extreme-ultraviolet Late Phase of a Solar Flare with Microwave Imaging Spectroscopy

Extreme-ultraviolet late phase (ELP) refers to the second extreme-ultraviolet (EUV) radiation enhancement observed in certain solar flares, which usually occurs tens of minutes several hours after peak soft X-ray emission. The coronal loop system that hosts ELP emission is often different from main flaring arcade, and enhanced EUV therein may imply an additional heating process. However, origin remains rather unclear. Here we present analysis a C1.4 flare features such ELP, also microwave wavelengths by Expanded Owens Valley Solar Array (EOVSA). Similar case find gradual about three impulsive peaks. Radio sources coincide with both footpoints loops spectral fits on time-varying spectra demonstrate clear deviation electron distribution Maxwellian case, could result injected nonthermal electrons or nonuniform footpoint plasma. We further point out delayed suggests presence process, be responsible for evaporation heated plasma fills loops, producing prolonged