¹²CO quadratic velocity residuals. Here we use the bettermoments “quadratic” centroid moment, which fits a quadratic function to the peak of the line and its two neighboring pixel to determine the line centroid (Teague 2019b). The employed ¹²CO robust 0.5 cube, Keplerian discminer model, and layout is the same as in Fig. 7. The quadratic LoS velocity map of the data differs from the Gaussian one of Fig. 7. The “quadratic” line centroid traces more closely the peak of the emission, hence leading to strong bending of the iso-velocity contours coinciding with the regions of broadened line-profiles, as highlighted in the map of Fig. 6. In particular, at the location of the infalling material in the southeast, this leads to a strong blue- or redshifted residual due to the double-peaked line profile at this location.