Continuum-subtracted I20210S off-axis Hβ+[O III] spectra extracted at a 5 px offset in the northern direction (left panel) and at an 8 px offset in the southern direction (right panel). In each panel, the best-fit model is shown (red solid line) along with the profiles of the narrow (green short-dashed line) and broad components (blue dotted line), and the zero-flux level is indicated (black long-dashed line). The standardized residuals after the best-fit subtraction are also shown in separate windows below each spectral region. The fit to the Hβ emission is not accounted for the calculations of χ² and p_F, which are performed on the [O III] doublet only (see text), and is shown here for visual purposes only.