Selection of the isolated galaxy sample. Top: Evolution of the virial radius with redshift for different halo masses compared to the evolution of the size of the MUSE field of view. The solid red line represents the virial radius for the median halo mass of our sample (that we chose as our isolation radius). The vertical dashed lines indicate our redshift selection (0.4 < z < 1.5) for which the isolation radius is contained within the MUSE field of view. Bottom: Distribution of the stellar masses for MEGAFLOW galaxies at z < 1.5. We consider the MEGAFLOW survey reasonably complete for 0.4 < z < 1.5 down to log(M_⋆/M_⊙) = 9 (represented by the horizontal dashed line). Our volume-limited sample of isolated galaxies is represented by the blue dots.