Rotation curve of M 33 (filled triangles) and best-fitting dynamical models (solid line) for NFW dark matter halo profiles (dot-dashed line). The small and large dashed lines (red and blue in the online version) show the gas and stellar disk contributions to the rotation curve, respectively. In the bottom panel, the highest stellar contribution and lowest dark halo curve are for the best-fitting dynamical model using the BVIgi mass map, the other curves are for the BVI mass map. The top panel shows the most likely dynamical models for the two mass maps when the likelihood of the dynamical fit is combined with that of the stellar mass surface density and of the C − M_h relation resulting from simulations of structure formation in a ΛCDM cosmology.