Left panel: CRIRES Brα spectrum (top panel) along with the spectro-astrometric signal (in mas) detected in the jet parallel (middle panel) and perpendicular slit (bottom panel). The spectro-astrometric signal is continuum-corrected. Right panel: spectro-astrometric signal on the plane of the sky (north is up and east is to the left). The red line is the linear fit to the points giving a PA for the line-emitting region of 216° ± 5°. Error bars shown in both plots are 3σ. Velocities are colour coded and are the same in both panels.