Spatial and Spectral Evolution of Microwave and X-Ray Sources During the Solar Limb Flare on February 5, 2023

We present an empirical scenario of the energy release process during a solar limb flare on February 5, 2023. This event was observed by the Siberian Radioheliograph (SRH) within the 3 – 12 GHz range and the Advanced Space-based Solar Observatory / Hard X-ray Imager (ASO-S/HXI) within 10 – 300 keV range. The combination of these data allowed us to use information not only about the spectral features but also about the spatial evolution of the flare. The main source of the energy released was a small compact loop which was revealed in both the X-ray and microwave ranges. During the early phases of the flare evolution, a spectral analysis of microwave emission showed that thermal gyrosynchrotron emission turned to gyrosynchrotron emission of nonthermal electrons. This indicated the transition from the heating process to the acceleration processes. Spectral indices derived from hard X-ray and microwave data closely agree with each other and show the classical soft–hard–soft scenario of acceleration. The hardening of the average microwave spectrum at the end of the impulsive phase was caused by the contribution of jet emission to microwaves rather than by peculiarities of the acceleration processes.