The Astrophysical Journal · 1992 · 86 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsSolar AstronomyX-ray AstronomySolar Energetic ParticlesSolar FlaresFlare ClassificationSolar Energetic Particle EventsSolar Flare Gamma-ray EmissionSolar Flare X-ray EmissionSolar X-ray Flares
A list of 77 flare-associated solar energetic particle (SEP) parent flares are classified as impulsive (25 cases) or gradual (52 cases) on the basis of their soft X-ray durations. The intensities of the prompt component of about 0.5 MeV electrons, about 10 MeV protons, and about 10 MeV per nucleon helium for the two classes of SEP flares are compared. SEPs from gradual flares have higher intensities than SEPs from impulsive flares. These differences are most pronounced for protons (about two orders of magnitude), and less for electrons (about one order of magnitude), and helium (about a factor of 5). The SEPs from impulsive flares have a 'cone of emission' of +/- 50 deg vs +/- 120 deg for gradual flares.