Distribution of the parent sample in the L_UV-z plane. Straight lines are lines of constant UV flux. Black circles represent objects in common with Vagnetti et al. (2010), empty circles are objects present only in this work. The straight lines are constant UV flux lines. The histogram on top shows the distribution of objects in the parent sample with respect to UV luminosity; the histogram on the right shows the redshift distribution of objects in the parent sample. The histogram inside the plot area (lower-right) shows the distribution of objects in the parent sample with respect to UV flux.