Example of one-velocity (top) and two-velocity (bottom) component fits to two different spectra; the former (later) corresponds to a spectrum extracted from the blue (orange) areas in Fig. 5. In both panels: the data are represented on the top (solid black histograms) with their corresponding fits (colored curves), and the residuals are shown on the bottom, here the orange line refers to the nil value. The S/N of each spectrum, as well as the best-fit parameter values, are listed in each panel. In the bottom panel, the red curve represents the sum over the two velocity components.