Fitted Hα part from the polarized spectrum obtained with FORS/VLT. The data are marked in gray, and the model is marked in black. For each fit, we considered two components of Hα: a BC (red) and an NC (black). The blue line corresponds to the power-law continuum. The lower panels of each plot correspond to the residuals, in radial velocity in units of km s⁻¹. With an arrow, we mark the presence of an “absorption” in the fit of SDSS J080101. The “absorption” is meant to account for the low S/N of the data and to ease the fit of a symmetric Gaussian constrained by the blue side of the polarized flux profile.