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Large Solar Energetic Particle Events Associated With Filament Eruptions Outside Active RegionsWe report on four large filament eruptions (FEs) from solar cycles 23 and 24 that were associated with large solar energetic particle (SEP) events and interplanetary type II radio bursts. The post-eruption arcades corresponded mostly to C-class soft X-ray enhancements, but an M1.0 flare was associated with one event. However, the associated coronal mass ejections (CMEs) were fast (speeds approx. 1000 km/s) and appeared as halo CMEs in the coronagraph field of view. The interplanetary type II radio bursts occurred over a wide wavelength range, indicating the existence of strong shocks throughout the inner heliosphere. No metric type II bursts were present in three events, indicating that the shocks formed beyond 2-3 Rs. In one case, there was a metric type II burst with low starting frequency, indicating a shock formation height of approx.2 Rs. The FE-associated SEP events did have softer spectra (spectral index >4) in the 10-100 MeV range, but there were other low-intensity SEP events with spectral indices ⩾4. Some of these events are likely FE-SEP events, but were not classified as such in the literature because they occurred close to active regions. Some were definitely associated with large active region flares, but the shock formation height was large. We definitely find a diminished role for flares and complex type III burst durations in these large SEP events. Fast CMEs and shock formation at larger distances from the Sun seem to be the primary characteristics of the FE-associated SEP events.
Document ID
20160005853
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Gopalswamy, N.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Makela, P.
(Catholic Univ. of America Washington, DC, United States)
Akiyama, S.
(Catholic Univ. of America Washington, DC, United States)
Yashiro, S.
(Catholic Univ. of America Washington, DC, United States)
Xie, H.
(Catholic Univ. of America Washington, DC, United States)
Thakur, N.
(Catholic Univ. of America Washington, DC, United States)
Kahler, S. W.
(Air Force Research Lab. Albuquerque, NM, United States)
Date Acquired
May 5, 2016
Publication Date
June 3, 2015
Publication Information
Publication: The Astrophysical Journal
Publisher: IOP Science
Volume: 806
Issue: 1
e-ISSN: 2041-8213
Subject Category
Solar Physics
Report/Patent Number
GSFC-E-DAA-TN31880
Funding Number(s)
CONTRACT_GRANT: NNX15AB77G
CONTRACT_GRANT: NNX15AB70G
CONTRACT_GRANT: NNG11PL10A
Distribution Limits
Public
Copyright
Other
Keywords
filaments
flares
coronal mass ejections

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