Infalling streamline model for the red-shifted southern arc structure (outlined in the green polygon), with the same disk orientation and rotation geometry used for the northern streamer model (Fig. B.1). Top: Streamline model, plotted in green, on top of the moment-1 map of CO, showing the model curvature with this rotation geometry is opposite to the spatial structure of the southern redshifted arc. Bottom: Velocity components of CO taken from inside the green polygon plotted as a function of projected distance from the central young stellar object, withvarying levels of kernel density estimation of the velocity plotted as filled contours and contours calculated as in Fig. B.1. The streamline model consistently under-predicts the velocity of the arc structure by ~3 km s⁻¹.