Faber-Jackson relation for the galaxies of our (larger symbols) and comparison sample (smaller symbols). The ellipticals (triangles) and bulges (squares) of the comparison sample are shown with filled (σ> 70 km s^-1) and empty symbols (σ< 70 km s^-1) according to their calculated velocity dispersion. Filled circles with and without error bars correspond to the galaxies in our sample with and without bulge, respectively. Open circles indicate the barred galaxies. The galaxies are divided according to their Sérsic index in the following bins: 1 <n< 2 (blue), 2 <n< 3 (red), 3 <n< 4 (orange), and n> 4 (green). The dashed line is the best-fitting relation for the comparison sample. The dotted lines show the rms deviation in log (σ_e) given in Fig. 6. The distribution of galaxies of the different bins of n as function of their absolute magnitude and effective velocity dispersion are also shown.