Example image of the THOR source G32.744+0.770, which is most likely an extragalactic jet. The large image represents an averaged image of the two spectral windows around 1.4 and 1.8 GHz, which we used for the source extraction (see Sects. 3.1 and 3.3). The white contours shows the extent of the source determined by the BLOBCAT algorithm. The black cross marks the peak position, which we used to determine the spectral index. The small images show each spectral window separately, and the top panel presents the peak intensity for each spectral window and the corresponding spectral index fit. In each image the synthesized beam is given in the lower left corner.