Stellar mass versus dynamical mass (Eq. (4)) as inferred from the prism and high-resolution spectroscopy, respectively. The dashed line shows the one-to-one relation between the two masses. The data points from the literature (circles, squares) are as described in Fig. 5. As is to be expected, the dynamical masses are higher than the stellar masses for all objects in our sample. Surprisingly, however, the dynamical masses are substantially higher (up to a factor of ∼40), most likely indicating high gas masses or large systematic uncertainties in the stellar mass estimates.