Brγ displacement for different (radial) velocity channels (with velocity bins from −550 to 550 km s^-1) derived from the measured differential phases, after correcting for the continuum contribution. Different colours indicate different velocity bins. Black solid and red dashed ellipses indicate the extent of the K-band continuum with its uncertainty (1.94 ± 0.37 mas Kraus et al. 2010), whereas the red line shows the position of the jet axis (Caratti o Garatti et al. 2015a).