Hybrid RC is plotted using different symbol to represent Hα, [O II] and H I data. The resulting model, plotted using a red line, is the quadratic sum of the gas, disc, bulge, and dark halo components. The lines correspond to the BFM and the bottom and top of the filled area around these lines represent the first and the third percentile around the median (the second percentile) the χ² distribution ranging from to 1.10χ². The orange crosses represent the difference between the observed rotation velocities and the model for each point of the RC. Top panel (model a): both disc and bulge mass-to-light ratios are fixed by the colour indexes and M/L_Disc varies with the radius as shown in Fig. 9. The halo parameters are computed using a BFM. Bottom panel (model b): the disc, bulge, and halo parameters are fitted using a BFM, but M/L_Disc is not allowed to be larger than M/L_Bulge.