Abstract
We simultaneously solve the equations of radiative transfer and statistical equilibrium for a model hydrogen atom including Lyman-α, Lyman-β, Balmer-α and the Lyman, Balmer and Paschen continua. The model atmospheres we use are the results of Nakagawa et al. (1973) for a kinematic model of the chromospheric solar flare.
We find that the models adequately predict the total intensity of Bα, its wing broadening, the presence of a red-shifted wing, the maximum electron density, the total line-of-sight second-level population and the narrowness in height of the Bα emitting region. The profile of Bα is strongly self-reversed, however, and agrees with observations only in the presence of 40–70 km s−1 macroturbulent motion.
We find that Nakagawa et al. (1973) seriously overestimate the radiative loss function, which will have a large effect on their models. Proper radiative loss calculations must be included in any physically realistic model.
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The National Center for Atmospheric Research is sponsored by the National Science Foundation.
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Canfield, R.C., Athay, R.G. Theoretical chromospheric flare spectra. Sol Phys 34, 193–206 (1974). https://doi.org/10.1007/BF00149612
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DOI: https://doi.org/10.1007/BF00149612