Stack physical properties vs. Lyα properties. From the top row: the plots show Δv, rest-frame UV concentration, rest-frame UV magnitude, EW(CIII]1908), and stellar mass vs. EW(Lyα) (first column), Ext(Lyα-C) (second column), and Lyα peak shift (third column). Symbols are as in Fig. 6. For each subset, Δv, EW(Lyα), EW(CIII]1908), and Lyα peak shift are measured in the stacks, while C_UV, R, and M_∗ correspond to the median values of the galaxies within the subset. The black star represents a subset of sources with extreme Ext(Lyα-C) in the individual spectra. These sources are characterized by moderate EW(Lyα), Lyα peak shift larger than 300 km s^-1 and Δv consistent with zero.