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Theoretical implications of the derivativity' effect in solar flares

Conference · · American Astronomical Society, Bulletin; (United States)
OSTI ID:6645904
;  [1]
  1. Univ. of California, Berkeley (United States)
We discuss recent observational results which substantiate the derivativity' effect in solar flares, namely the face that the time profiles of impulsive emissions such as hard X-rays and microwaves reflect not so much the time profile of the soft X-ray emission, but rather its time derivative. We have performed numerical simulations of the atmospheric response to flare heating both by nonthermal electrons and by thermal conduction from a superhot coronal region. We find that the predictions of the electron heated model are in excellent agreement with the derivativity' observations and that both temperature and density enhancements play a significant role in determining the relationship between the hard X-ray and soft X-ray emissions. On the other hand, the conductively-heated model predicts no clear correlations between the hard and soft X-ray emissions, and certainly not a derivativity' relationship. We conclude that these observations point strongly toward a prominent role for nonthermal electron heating in solar flares.
OSTI ID:
6645904
Report Number(s):
CONF-930189--
Conference Information:
Journal Name: American Astronomical Society, Bulletin; (United States) Journal Volume: 24:4
Country of Publication:
United States
Language:
English