Comparison of s₁ and s₃ terms normalized by the circular rotation term c₁ derived from the adopted best fit of the CO(3–2) velocity field. The continuous line represents the least-squares fit to the data points, and the dashed line represents the expected warp line location predicting a relation between the s₁ and s₃ terms for an error in the position angle adopted throughout the disk (PA = 289°) (see discussion in Wong et al. 2004). The sign of s₁ is taken as a signature of inflow or outflow as shown, for the assumed geometry of the galaxy. Black symbols correspond to points at radii > 3″, while red symbols correspond to radii ≤ 3″.