OBSERVATIONS OF EUV WAVES IN {sup 3}He-RICH SOLAR ENERGETIC PARTICLE EVENTS
- Max-Planck-Institut für Sonnensystemforschung, D-37077 Göttingen (Germany)
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States)
Small {sup 3}He-rich solar energetic particle (SEP) events with their anomalous abundances, markedly different from the solar system, provide evidence for a unique acceleration mechanism that operates routinely near solar active regions. Although the events are sometimes accompanied by coronal mass ejections (CMEs), it is believed that mass and isotopic fractionation is produced directly in the flare sites on the Sun. We report on a large-scale extreme-ultraviolet (EUV) coronal wave observed in association with {sup 3}He-rich SEP events. In the two examples discussed, the observed waves were triggered by minor flares and appeared concurrently with EUV jets and type III radio bursts, but without CMEs. The energy spectra from one event are consistent with so-called class-1 (characterized by power laws) {sup 3}He-rich SEP events, while the other with class-2 (characterized by rounded {sup 3}He and Fe spectra), suggesting different acceleration mechanisms in the two. The observation of EUV waves suggests that large-scale disturbances, in addition to more commonly associated jets, may be responsible for the production of {sup 3}He-rich SEP events.
- OSTI ID:
- 22518843
- Journal Information:
- Astrophysical Journal, Vol. 812, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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