The first OPEA model for solar X-ray flares

Abstract

ABSTRACT In this study, the flares detected in the solar hard X-ray (λ0.5–4.0 Å) data accumulated by the Geostationary Operational Environmental Satellite (GOES) from 2001 March–May were analysed. For the first time in the literature, the One Phase Exponential Association (OPEA) model was derived for the Sun and, for the first time, over X-ray data. 1014 flares were detected in the analysis. Contrary to expectations, it was seen that the flares can be modelled with three different OPEA models, not one model. The Plateau value was found to be 5.053 ± 0.110 s with the half-time of 2316.12 s for the flares during 2001 March, while it was 5.676 ± 0.138 s with the half-time of 3967.59 s for 2001 April and 5.338 ± 0.080 s with the half-time of 2755.66 s for 2001 May. The results indicate that the models exhibit a fluctuation in their form time by time. This means that there is a phenomenon that changes the energy of flares obtained in three consecutive months. We also demonstrate that the linear parts of the flare cumulative frequency distributions obtained in these data interestingly show a separation.