Distribution of the simulated observed-frame coming from foreground sources for the sub-sample with Lyα_ext ≤ 5.7 kpc imposing U_max = 25 (magenta histogram) and U_max = 26 (blue histogram). The continuum vertical lines are the median of the distributions and the dashed and dotted lines are the 1σ and 2σ confidence intervals, respectively. The symbol in the figure is the average observed-frame obtained forthe sub-sample.