Studies of the atmospheric structure of the solar white-light flare of August 9, 2011

Resumo

Semi-empirical models for three kernels emitting in the continuum during the pre-impulsive and impulsive phases of the white-light flare of August 9, 2011 have been calculated, based on observations of the continuum brightness near 6579 Å, Hα profiles, and photospheric iron lines. These computations show that, in order to achieve agreement between the computed and observed profiles and the contrast of the continuum emission of the impulsive kernels of the white-light flare, the temperature must be increased in both the lower chromosphere and the upper photosphere. The most efficient heating is located deeper in the photosphere in the pre-impulsive than in the impulsive phase, and chromospheric heating is negligible in the pre-impulsive phase. Spectral data and the results of model computations indicate that it is difficult to explain the emission of the white-light flare kernels as the effect of heating by energy transported from the corona into lower-lying, deep layers of the atmosphere by canonical transport mechanisms.