The Solar Continuum from 900 to 130000 Å and the Photospheric Temperature Model

Abstract

In order to obtain a better agreement between observed and computed values of the solar intensity, an improved temperature distribution is deduced for the range 0.02 < τ₀ < 10. The intensity observations here considered refer to the wavelength region between λ 1980 and λ 129 500, and the center-limb variations generally go down to cosθ = 0.11a1. The improved model, given in Figure 4 and Table II, differs rather little from the Utrecht 1964 model, used here as a reference.

It appears necessary to introduce an empirical correction function to be applied to the continuous absorption coefficient. This function was derived for the spectral region between 2000 and 130000 Å; it is shown in Figure 5.

Furthermore, an extension of the model (1.10⁻⁷ < τ₀ < 2.10⁻²) is deduced (see Table III and Figure 8), which reasonably well represents the observations of the ultraviolet solar flux (λλ 900–1700 Å).