Best-fit profiles of the emission lines from the South Nebula in the rest frame. Left panel: the Hβ+[O III] spectral region. Right panel: the Hα+[N II] and [S II] spectral region. In both panels, the global emission profile (red solid line) is shown superimposed to the line spectrum (black histogram) along with the single components of the Hα+[N II] and [S II] blended profiles (green short-dashed lines), and the zero-flux level (black long-dashed line) is indicated. The standardized residuals after the best-fit subtraction are also shown in separate windows below each spectral region.