Observation of solar energetic particle (SEP) events associated with narrow CMEs

A. Al-Sawad, H. Allawi, W. Al-Ramdhan, E. Valtonen
2012 Astrophysics and Space Sciences Transactions (ASTRA)  
We report here on two proton energetic particle events observed by the Energetic and Relativistic Nuclei and Electron (ERNE) instrument on the Solar and Heliospherical Observatory (SOHO). Both events were impulsive (SEP) events with intensities of > 10 −3 cm −2 sr −1 s −1 MeV −1 at an energy range of tens of MeVs and were associated with CMEs of angular widths < 60 • and linear speed of > 800 kms −1 . In one of the events there was no associated solar flare, which indicates that the first
more » ... hat the first injected protons were completely due to the associated CME and in the second event the associated solar flare was an impulsive M1.1 class flare and the calculated first injection time for protons of energies ∼ 36 MeV and propagating along 1.2 AU path length, was close to the liftoff time of the CME. These observations are inconsistent with the view presented in some studies that narrow fast CME are not associated with SEP events. Published by Copernicus Publications on behalf of the Arbeitsgemeinschaft Extraterrestrische Forschung e.V.
doi:10.5194/astra-8-1-2012 fatcat:cih6dfno5rg5dl2og2sk72k6t4