Abstract:
The Second Solar Spectrum formed by coherent scattering processes in
the Sun, is highly structured. It is characterized by numerous blend lines, both intrinsically polarizing and depolarizing, superposed on the background continuum. These
blend lines play an important role in the interpretation of the Second Solar Spectrum.
Since blend lines affect the shapes of the neighboring spectral lines they have to be
treated in a sophisticated manner in order to efficiently model a given spectral line of
interest. The depolarizing blend lines – mostly considered to be formed under LTE
conditions – depolarize the background continuum and thereby affect the absolute scale
of the polarization measurement. An understanding of the influence of the blend lines
leads to a proper determination of the zero-point of the polarization scale. With this
motivation we extend a previously developed framework to include many blend lines
formed under NLTE conditions, in the radiative transfer equation. The results are shown
for the particular case of two blend lines situated on either side of the main spectral line.
