Deviations ⟨δv_rot⟩ from the Keplerian velocity for the GASGAPS S model. Here we show the individual contributions to ⟨δv_rot ⟩ from the height of the ¹²CO J = 2−1 emission layer (grey solid line), the density gradient (brown solid line), and the temperature gradient (pink solid line). The green solid line shows ⟨δv_rot⟩ including allthe components (same as in the bottom panel of Fig. 6).