Continuum images from (left to right) the VLA S, C, and X bands. The three panels in each row present the VLA three-band images for one target. Each panel has an image size of 3″ × 3″. The black crosses mark the published optical positions (Sharp et al. 2001; McGreer et al. 2009; SDSS); in the case of J0131−0321, J1146+4037, and J2228+0110 we adopt the position from EVN observations (Frey et al. 2010; Cao et al. 2014; Gabányi et al. 2015). The shapes of the synthesized beams are plotted in the bottom left corner of each sub-figure. The beam sizes are presented in Table 2, where the flux density for each target is also listed. The contour levels are [−4, 4, 16, 64, 256, 1024] × rms (the 1σ off-source noise level listed in Table 2).