Velocity of model gas particles in the z‐direction vs. x‐coordinate value for comparison with observational velocity–right ascension plot. Note that we have rotated the model results by −10° in the x‐y plane, so that the x‐axis of the model more nearly corresponds to right ascension. The model velocities have been scaled as in Fig. 18, multiplying by a factor of 100 and adding a constant systemic velocity of 2800 km s⁻¹. The x‐axis values are in dimensionless code units. Text labels identify particle sets corresponding to those of the observational plot (Fig. 20). See text for details.