Mg II (left panels) and C IV (right panels) absorbers’ rest-frame equivalent width (top panels) and width in velocity space (bottom panels) as a function of the Lyα luminosity for isolated galaxies (red) and the closest member of each group (blue). Empty squares mark the case in which the closest galaxy of a group is also the brightest. The results from the Spearman rank test to assess the presence and the significance of possible correlations are listed in Table 2.