Moment-9 maps of the CH₃CN(12–11) K=3 (panel a) and ¹³CH₃CN(13–12) K=3 (panel b) lines. The systemic velocity is ~−3.9 km s⁻¹. The solid line shows the deconvolved direction of the major axis of the continuum emission, while the dashed lines give the errors on this direction. The blue and red arrows indicate the directions of the blue- and redshifted lobes of the jet shown in Fig. 1. The ellipses in the bottom right corners denote the synthesized beams.