Example pdf-file created by aperpol to inspect each source by eye. The panels show, from left to right, top to bottom: PI map with TP contours, the TP map with PI contours, RM map, FP map, WISE 3.4 μm map with TP contours, WISE 4.6 μm map with TP contours, SDSS g-band map with TP contours, WISE 12 μm map with TP contours, and the WISE 22 μm map with TP contours. Small green x-marks locate the coordinates of the individual components of PI and TP sources in the first two panels, respectively. Large green x-marks locate the position of other PI sources in the first panel and non-cross-matched TP sources in the second panel, whereas large turquoise x-marks locate the coordinate of the PI source in the first or the cross-matched TP source in the second panel. Large red x-marks in the second panel mark the position of NVSS counterparts. Small green and yellow x-marks identify the position of crossmatched WISE and SDSS sources in the corresponding panels.