Spatial and temporal features of the behavior of microwave and ultraviolet emission in eruptive events

Abstract

Observational signatures that determine the ability of a solar active region to cause a mass ejection into the high layers of the solar corona (CME) are not entirely clear to date. This makes it difficult to understand the physical mechanism of the CME trigger. This paper presents a search for observational signatures that may indicate the emergence of an eruptive process. For this aim, we have carried out a comparative analysis of the conditions before and during a flare for flare events both accompanied and not accompanied by CMEs. We studied the features of the spatial and temporal dynamics of microwave and ultraviolet emission (data from the Nobeyama Radio Heliograph, SDO/AIA), as well as magnetic fields (SDO/HMI) for 16 active regions (ARs). Using this sample, it was found that the flares accompanied by CMEs most often occur in open magnetic configurations, in regions with twisted magnetic ropes and emerging magnetic fluxes. CMEs are also observed most often in flares of longer duration and in those ARs that have sources in microwave radiation that are more extended in area.