Magnitude completeness. Continuous and dot-dash histograms in black represent the G2 and the ‘good’ samples, respectively. Dashed histogram in black shows the distribution of the sources removed from the G2 sample after the cleaning-out process (see Sect. 4.1). Red histogram shows the distribution of the morphological sample (see Sect. 4.2). Magnitudes indicated in the legend are 50% completeness magnitudes for each sample.