This work expands the current understanding of the 15 November 1991 Solar Flare. The flare was a well observed event in radio to gamma-rays and is the first flare to be extensively studied with the benefit of detailed soft and hard X-ray images. In this work, we add data from all four instruments on the Compton Gamma Ray Observatory. Using these data we determined that the accelerated electron spectrum above 170 keV is best fit with a power law with a spectral index of −4.6, while the accelerated proton spectrum above 0.6 MeV is fit with a power law of spectral index −4.5. From this we computed lower limits for the energy content of these particles of∼1023 ergs (electrons) and ∼1027 ergs (ions above 0.6 MeV). These particles do not have enough energy to produce the white-light emission observed from this event. We computed a time constant of 26+20−15 s for the 2.223 MeV neutron capture line, which is consistent at the 2σ level with the lowest values of ∼70 s found for other flares. The mechanism for this short capture time may be better understood after analyses of high energy EGRET data that show potential evidence for pion emission near ∼100 MeV.
Space Science Center, Physics
AIP Conference Proceedings
Digital Object Identifier (DOI)
X- and gamma-ray observations of the 15 November 1991 Solar Flare Arndt, M. B. and Connors, A. and Lockwood, J. and McConnell, M. and Suleiman, R. and Ryan, J. and Young, C. A. and Rank, G. and Schönfelder, V. and Debrunner, H. and Bennett, K. and Williams, O. and Winkler, C., AIP Conference Proceedings, 587, 618-622 (2001), DOI:http://dx.doi.org/10.1063/1.1419473
© 2001 American Institute of Physics