Moment 1 (left) and position-velocity (PV) maps for molecular gas around W3 IRS4. From top to bottom, each row shows the moment 1 map and PV cuts along three different axes (middle-left, middle-right and right), for H₂CO 3_2,2 −2_2,1, OCS 18-17, HNCO 10_1,9−9_1,8, CH₃ CN 12₃ −11₃, and CH₃CN 12₆ −11₆. The three PV cuts, taken along the outflow axis (1), rotated by 45° (2), and perpendicular to it (3), are shown on the moment 1 maps with grey lines numbered in red, where each cut is averaged over a width similar to the beam perpendicular to the cut. The 5σ contour of the data in each PV diagram is indicated with a white solid contour, while white dashed horizontal and vertical lines indicate the v_LSR and zero offset from the continuum peak. The spatial and spectral resolution of the PV diagrams is indicated with a white cross in the lower-left corner of PV diagram 1 in each row. The black dashed lines indicate the results of the same cut through the moment 1 map, while the red dashed lines indicate what would be expected for Keplerian motion with a central mass of 10 and 20 M_⊙. The black contours in the moment 1 maps show the continuum, as in Fig. 11.