A STUDY OF THE EVOLUTION OF ELECTRON AND ION-ACCELERATION DURING THE 09 09 UT SOLAR-FLARE ON 1989 SEPTEMBER 9/

Citation
El. Chupp et al., A STUDY OF THE EVOLUTION OF ELECTRON AND ION-ACCELERATION DURING THE 09 09 UT SOLAR-FLARE ON 1989 SEPTEMBER 9/, Astronomy and astrophysics, 275(2), 1993, pp. 602-612
Citations number
37
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046361
Volume
275
Issue
2
Year of publication
1993
Pages
602 - 612
Database
ISI
SICI code
0004-6361(1993)275:2<602:ASOTEO>2.0.ZU;2-1
Abstract
By use of radio, optical, X-ray and gamma-ray observations we have stu died the evolution of electron and ion acceleration during the 09:09 U T solar flare on 1989 September 9. The event is characterized by chang es in the energetic photon spectrum as new radio sources appear. As th e flare develops in energetic photon emissions the hard X-ray emission increases sporadically and low level nuclear line emission appears. A t the time of initiation of the major increase in intensity of energet ic photons, the power law bremsstrahlung spectrum hardens significantl y and photons > 10 MeV are produced. During this increase the electron and proton interaction rates are enhanced, respectively, by factors o f 8 and (11-16). This may indicate that proton acceleration became sli ghtly more efficient than the acceleration of electrons. The increased efficiency in producing the energetic electrons and ions is clearly a ssociated with the appearance of a new radio source. It is of particul ar interest that a new eruptive Halpha feature appears outside the mai n flare ribbons in association with the major phase of the flare.