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tokens: are from MERLIN 5 GHz observations of the radio jet (Gallimore et al. 2004 ); the MERLIN beam is 4.2 pc FWHM. Upper right: spectral map from a simulation of a bipolar outflow with the axis tilted 5° from the plane of the sky and rotated to PA 33° (see the text for details). Colors are as for the left panel. The outflow axis of ionized gas traced by optical emission lines in the narrow-line region is inclined 5° out of the plane of the sky (Crenshaw Kraemer 2000 ), and we assume the same for the CO outflow. Can such a small inclination produce the red–blue spatial separation observed in CO? To test this possibility we conducted a numerical simulation of a bipolar outflow. We employ a truncated cone geometry with a disk base diameter of 1 pc (comparable to the H 2 O maser disk), 4.4 pc total bicone height (based on the spread of CO features in Figure 2 ), and half-opening angle of 30°. To model the outflow, we randomly placed a total of 10 4 clumps inside the cone. Clumps were evenly distributed in cylindrical radius ρ (i.e., radius projected onto the disk plane) and distance along the polar axis. The direction of motion for a clump is vertical for clumps directly above and below the disk (i.e., clumps with ρ ≤ 0.5 pc) and radial from the edge of the disk for clumps with ρ > 0.5 pc. We further assume uniform acceleration from 30 km s −1 at the molecular disk to 800 km s −1 at the cone height; these values were selected from interactive trials to give a reasonable match to the observations. Finally, all clumps are equally luminous point sources of CO emission, added as beam-shaped, two-dimensional Gaussians to the planes of a simulated data cube. The cone was then inclined by 5°, and we repeated the cube analyses on the simulated data. To simulate the effects of measurement uncertainty, each measured peak position was displaced randomly, assuming 0.5 pc errors, comparable to the relative, observed position uncertainties. The simulation results shown in the right panel of Figure 2 broadly reproduce a parsec-scale asymmetry of redshifted and blueshifted peaks similar to that observed (left panel). This simple simulation was not meant to replicate any physical model or explain every aspect of the data; in particular, the systemic-velocity emission is concentrated to the east, at odds with the random distribution we use. Our simulation is only meant to demonstrate that the small 5° tilt detected in narrow-line observations is sufficient to produce the red–blue asymmetry of the excited CO emission. In addition to the outflow component described above, we also find evidence for rotation consistent with the compact H 2 O maser disk. Figure 3 shows the position–velocity ( p – v ) diagram constructed by slicing the CO spectral line cube along the axis tracing the extended systemic emission. Surface brightnesses were averaged within the three-pixel extraction width (green dashed lines in Figure 1 ). The data were smoothed using a Savitzky–Golay