the average of the deconvolved angular dimensions given in Table 1, we then estimate the opening angle of the thermal jet to be $\sim$15$^\circ$ (as opposed to the value of $\sim$25$^\circ$ derived by Rodríguez et al.), indicating significant collimation in this massive protostar. This result suggests that jets from high mass young stars can be as collimated as those found in lower mass objects, where HST studies indicate opening angles in the range of tens of degrees in scales of tens of AU from the star (Ray et al. 2007). On larger physical scales the optical jets from low mass young stars are known to show recollimation, resulting in opening angles of a few degrees (Ray et al. 2007). This recollimation is not evident in the thermal radio jets, which are usually detected only close to the star.

The northern lobe
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As noted before, we identify two additional components (N-4 and N-5) in this lobe, indicating an almost continuous sequence of knots between the central jet and the outermost N-1 component (see Fig. 2). The sequence of five knots, N-1 to N-5, shows a gentle monotonic curvature that may be indicative of precession (see Section 5). Four of the 