Nature 477, 185–187 (2011); 10.1038/nature10387

In Fig. 3 of this Letter, the axes labels were inadvertently exchanged. The y-axis label should read “Declination offset from 43-GHz core (mas)” and the x-axis label should read: “RA offset from 43-GHz core (mas)”. The PDF and HTML versions have been corrected online.