HELIOS 1 energetic particle observations of the solar gamma-ray/neutron flare events of 1982 June 3 and 1980 June 21

Abstract

view Abstract Citations (52) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS HELIOS 1 energetic particle observations of the solar gamma-ray/neutron flare events of 1982 June 3 and 1980 June 21 McDonald, F. B. ; Van Hollebeke, M. A. I. Abstract The characteristics of the energetic particles associated with the solar gamma-ray/neutron flare events of June 3, 1982 and June 21, 1980 observed by the Goddard cosmic-ray experiment on Helios 1 (at heliocentric distances of 0.57 and 0.54 AU, respectively) differ in several important respects from typical sonar particle increases. In particular, the June 3, 1982 event has a proton energy spectrum which fits a remarkable flat power law in kinetic energy with a spectral index of 1.2, an electron/proton ratio of 1 at 4 MeV, and a small but well-defined precursor event that began some 3 hr before the impulsive flare increase. Similar energetic particle precursors were observed for the gamma-ray associated 1980 June 21 and June 7 flare events. At energies less than about 40 MeV, the particle onset time measured for the June 3, 1982 event is anomalous, suggesting that these lower energy particles may have been released at the sun about 1-2 minutes before the higher energy particles. Publication: The Astrophysical Journal Pub Date: March 1985 DOI: 10.1086/184445 Bibcode: 1985ApJ...290L..67M Keywords: Energetic Particles; Gamma Ray Bursts; Helios 1; Particle Acceleration; Solar Corpuscular Radiation; Solar Flares; Solar Neutrons; Energy Spectra; Interplanetary Medium; Neutron Emission; Shock Waves; Solar Physics full text sources ADS |