Position velocity diagrams for DF Tau; the two components of the binary are not resolved.T he x-axis shows the velocity with respect to the feature rest wavelength in the velocity frame of the star (which one? Or do they have the same radial velocity?) and the y-axis the distance along the slit. In the left panel, resolved emission is visible around \(\pm200\ \mathrm{km\ s^{-1}}\).