NGC 4636 line-of-sight velocity distributions. From top to bottom, the panels show the velocity distribution for the entire sample, the blue, and the red subsample, as defined in Sect. 5.2. In all panels, the vertical dashed line shows the systemic velocity of NGC 4636. The unfilled histograms show the respective velocity distributions prior to any quality selection and outlier rejection. The filled histograms show the final samples. In all panels, the dashed curve shows the Gaussian corresponding to the dispersion value for the respective final sample as given in Table 4. The thin solid line is the corresponding Gaussian kernel density estimate (for a bandwidth of 50   km   s^-1, same as the bin width).