Dynamical scaling relations with radio and integral-field spectroscopy dat

Dynamical scaling relations such as the Tully-Fisher relation (TFR) link the baryonic and dark matter content of galaxies, and their slope and scatter encode important information on how galaxies assembled. Traditionally, most TFR work has been based on velocity widths obtained with 21 cm observations, but the advent of large integral-field spectroscopy (IFS) surveys has allowed us to revisit this important relation with new eyes. Interestingly, IFS studies seem to find more scatter at low stellar masses, compared to radio studies, which might be associated to the increasing importance of turbulent motions in these systems. The lack of overlapping samples with both IFS and 21 cm data has prevented a direct comparison until now. We present here the first results of SAMI-HI, a dedicated followup of galaxies with SAMI IFS data using the Arecibo radio telescope, and discuss the potential of the synergy between surveys of cold hydrogen gas and spatially-resolved optical spectroscopy.