The Role of Peak Temperatures in Solar X-Ray Flare Associations with CME Speeds and Widths and in Flare Size Distributions

Abstract

Recently, we reported that solar X-ray flares with relatively low peak (0.05-0.3 nm)/(0.1-0.8 nm) ratios R, a proxy for peak flare temperature T, were preferentially associated not only with solar energetic (E > 10 MeV) particle (SEP) events, but also with fast (V_cme ≥ 1000 km s^-1) coronal mass ejections (CMEs) that produce the SEP events. Flares associated with a characteristic CME speed V_cme range from small and cool to large and hot, and cooler X-ray flares were preferentially associated with broader CME widths. Here we increase the list of analyzed Geostationary Operational Environmental Satellite flares from the previous 450 to 588 and validate the earlier results with flare peak X-ray temperatures T from the TEBBS (Temperature and Emission measure-based Background Subtraction) method catalog. Power-law size distributions of flare peak fluxes F_p are increasingly steeper for X-ray flares with (1) fast (V_cme ≥ 1000 km s^-1); (2) slow (V_cme < 1000 km s^-1); and (3) no CMEs; in each case flares of larger F_p are characteristically hotter. The power-law size distribution of SEP event peak intensities I_p is flatter than any of the X-ray F_p distributions or a distribution formed from the product of the steep SEP I_p dependence on V_cme and the V_cme number distributions.