Lyα emission and N_HI values in LGRB host galaxies. Left panel: N_HI distribution of the 140 LGRBs reported in Tanvir et al. (2019) (gray). The 22 of the 29 LAE-LGRBs that contain this information are shown in light blue, except for the GRB in the golden sample, which are represented in dark blue. The different histograms are superimposed and not cumulative. Right panel: Lyα luminosity distribution as function of N_HI column density. The symbols are the same as in Fig. 1.