Correlations between the shifts of the [N II], [S II], and Hα wing components in the unblended subsample (r – coefficient of correlation, and appropriate P-value are given). The data are fitted with a linear function Y = k ⋅ X + n (solid line), where k is the slope and n the intercept of the best linear fit. The one-to-one relation is denoted with a dashed line. The shaded region corresponds to the 95% confidence interval.