Closer look at five representative images with distinctly different shapes. The first row shows five hand-picked representative images from the trained SOM. The location of each representative image on the SOM is indicated by (column, row), thus the first highlighted representative image in this figure is positioned in the seventh column, second row of the SOM in Fig. 4. In each column, we show five (randomly selected) radio sources that have been mapped to the representative images in the first row.