Spatial Offsets of Interplanetary Ion and Electron Source Regions

Abstract

Observations of impulsive solar energetic particles provide unique insight into the process of particle acceleration in the solar atmosphere. X-ray and γ-ray observations of precipitating particles from solar flares have shown offsets between the ion and the electron emission. We present Advanced Composition Explorer (ACE) observations of interplanetary energetic ion and suprathermal electron events with intensity variations related to connection or lack thereof to the particle source. These results indicate an offset between the acceleration regions of ions and electrons of the same order of magnitude as that observed in the γ-ray events. However, if the particle event originates at the magnetic footpoints of an interplanetary coronal mass ejection, the ACE observations do not exhibit this offset, suggesting that different magnetic geometry or acceleration processes may be present in those regions.