Abstract
The observed good temporal correlation between white-light flares and hard X-ray bursts suggests that energetic electrons could be the cause of white-light flare emission. However, even if sufficient energy can be deposited in the chromosphere by electron bombardment, direct collisional heating of the photosphere requires too high a flux of electrons of a few hundred keV and does not appear plausible. We show that nonthermal effects increase the opacity of the upper photosphere and temperature minimum region. Then these regions are consequently radiatively heated both by the beam-produced flare chromospheric emission and by the quiet photospheric emission. As a consequence, a temporary decrease of the continuum intensity ( negative flare ) is expected. After less than 20 seconds, the radiative heating of the upper photosphere and temperature minimum region produces a white-light flare.
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© 1992 Springer-Verlag
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Hénoux, J.C., Aboudarham, J. (1992). White-light flares. In: Švestka, Z., Jackson, B.V., Machado, M.E. (eds) Eruptive Solar Flares. Lecture Notes in Physics, vol 399. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-55246-4_86
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DOI: https://doi.org/10.1007/3-540-55246-4_86
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