Characteristics of solar coronal source regions producing3He-rich particle events

✍ Scribed by S. W. Kahler; R. P. Lin; D. V. Reames; R. G. Stone; M. Liggett

• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 752 KB
• Volume: 107
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00152032

✦ Synopsis

We use Ha, X-ray, and kilometric radio data to examine the solar coronal activity associated with energetic (~ 1 MeV/nucl-1) 3He.rich particle events observed near Earth. The basis of the study is the 12 3He-rich events observed in association with impulsive 2 to 100 keV electron events reported by Reames et aL (1985). We find that when Ha and X-ray brightenings can be associated with 3He/electron events, they have onsets coinciding to within 1 min of that of the associated metric type III bursts. In three or four events we found no associated Hc~ or X-ray flares, and in two events even the metric type III bursts were weak or absent. The measured low-energy (2 keV) electron spectra for these events show no evidence of a flattening due to Coulomb collisional losses. These results and several other recent findings are consistent with the idea that the 3He/electron events are due to particle acceleration in the corona well above the associated Hcr and X-ray flares.