Resonance-line transfer with partial redistribution. II - The solar MG II lines

Line profiles for the Mg II h and k lines have been calculated, accounting for the partial frequency redistribution of photons. These profiles are compared with the complete redistribution calculations under identical assumptions for the atomic and atmospheric models, and the inadequacy of the latter approximation is demonstrated. In particular, the temperature as deduced from the intensities at h1 and k1 under the assumption of complete redistribution appears to be a lower limit for the chromospheric temperature minimum. The partial redistribution profiles are in substantially better agreement with observation than complete redistribution results in describing the wavelength position of h1 and k1, and the relative behavior of the h and k profiles.