Histogram of z_phot of galaxies populating each cell falling in the grey region of the z_phot, SOM–z_spec plane (bottom left panel of Fig. 2). The distribution is normalised by dividing the number of galaxies in each z_phot bin by the total number of z_phot populating the considered cell; the number is indicated with the letter N in the top left panel of the figures, and written at the same position in the others. Similarly, the cell number (Cell ID) and coordinates (Cell X, Cell Y) are also given inside each panel. The z_phot, SOM is represented by the dashed line, whereas dotted lines indicate z_spec measured during our KMOS programme. The horizontal bar centred on the mean z_phot is the rms of the histogram.