Complex Type III bursts SAComplex Type IIIlikeType IIIl
Complex Type III bursts: (SA/Complex Type III-like/Type III-l bursts) R. Mac. Dowall M. Kaiser Goddard Space Flight Center
Cane et al. , 1982
SA/Complex Type III-like/III-l bursts Paper Cane et al. (1981) Kundu and Stone (1984) Mac. Dowall et al. (1987) Shock Source? Yes No “Associated” with shocks” Bougeret et al. (1998) Discusses problems Reiner and Kaiser (1999) “Not supported” Reiner et al. (2000) No Dulk et al. (2000) Yes Gopalswamy et al. (2000) “Presence of shock essential” Cane et al. (2002) No See Cane et al. (2002) for additional references.
Bougeret et al. , 1998
Reiner et al. , 2000
What’s new (Cane et al. , 2002)? • Type III-l bursts are long duration, extend to low frequencies, and include components that begin late relative to the flare • Type III-l bursts only occur in association with proton acceleration at the Sun • CMEs without type III-l bursts do not produce >20 Me. V protons v Type III-ls imply open field lines exist, and consequently, some flare particles will be detected for all major solar particle events
ftp: //www. ips. gov. au/data/Solar/Culgoora Observatory/ in Historical Data/SEP Related Events/
Mac. Dowall et al. , 2003 • Examined Type III-l bursts as part of LWS CDAW • Examined 4 groups of events – SEP-related group and 3 control groups • Given 3 criteria (based on hectometric data only) Group CDAW SEP Xrays/no SEP CMEs/no SEP 3 He rich 3 criteria Less than 3 No radio Total # satisfied events 37 0 0 2 10 12 15 35 0 13 4 1 47 25 19 38
What else can be done? • Spectra with low energy electrons suggest acceleration high in the corona -> modeling • Imaging of the type III-l burst components will help to locate the acceleration region • Comprehensive analysis and understanding of the “complex” components may be significant in the overall understanding of III-ls
Lin (1985)
What else can be done? • Spectra with low energy electrons suggest acceleration high in the corona -> modeling • Imaging of the type III-l burst components will help to locate the acceleration region • Comprehensive analysis and understanding of the “complex” components may be significant in the overall understanding of III-ls
Imaging – limb event
What else can be done? • Spectra with low energy electrons suggest acceleration high in the corona -> modeling • Imaging of the type III-l burst components will help to locate the acceleration region • Comprehensive analysis and understanding of the “complex” components may be significant in the overall understanding of III-ls
Summary • Complex type III bursts have attracted attention because of uncertainty about the acceleration source • Imaging may permit association of the complex features with structures in the corona • Analysis of the electron spectra may also be helpful • Because of the association of these events with SEPs and their connections to particle acceleration, they deserve further study
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