Jet parameters obtained from the ridge line fitting of the Global 22 GHz and VLBA 15, 22, and 43 GHz images. Jet width (top) and apparent opening angle (bottom) along the jet ridge lines. The same parameters for the GMVA 86 GHz observation from 2004 are plotted on top, without being taken into account for the fit. Error bars are derived from a linear combination of the fitting and imaging error and are only plotted if exceeding the marker size. The values of R_S are computed assuming a black hole mass of 10^8.2 M_⊙.