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| Titel |
The injection of ten electron/3He-rich SEP events |
| VerfasserIn |
Linghua Wang, Säm Krucker, Glenn Mason, Gang Li |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250139019
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| Publikation (Nr.) |
 EGU/EGU2017-2180.pdf |
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| Zusammenfassung |
| We have derived the particle injections at the Sun for ten good electron/3He-rich solar
energetic particle (SEP) events, using a 1.2 AU particle path length (suggested by analysis of
the velocity dispersion). The inferred solar injections of high-energy (∼10 to 300 keV)
electrons and of ∼MeV/nucleon ions (carbon and heavier) start with a delay of 17±3 minutes
and 75±14 minutes, respectively, after the injection of low-energy (∼0.4 to 9 keV)
electrons. The injection duration (averaged over energy) ranges from ∼200 to 550
minutes for ions, from ∼90 to 160 minutes for low-energy electrons, and from
∼10 to 30 minutes for high-energy electrons. Most of the selected events have
no reported Hα flares or GOES SXR bursts, but all have type III radio bursts that
typically start after the onset of a low-energy electron injection. All nine events
with SOHO/LASCO coverage have a relatively fast (>570km/s), mostly narrow
(≲30∘), west-limb coronal mass ejection (CME) that launches near the start of
the low-energy electron injection, and reaches an average altitude of ∼1.0 and 4.7
RS, respectively, at the start of the high-energy electron injection and of the ion
injection. The electron energy spectra show a continuous power law extending
across the transition from low to high energies, suggesting that the low-energy
electron injection may provide seed electrons for the delayed high-energy electron
acceleration. The delayed ion injections and high ionization states may suggest an ion
acceleration along the lower altitude flanks, rather than at the nose of the CMEs. |
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