Relation between hydrogen column density in the ISM and galaxy mass and half-mass radius at z = 6. Top panel: column density obtained integrating the column density from the position of the MBH to the host galaxy virial radius (“max” model). Bottom panel: column density obtained excluding the inner 80 pc around the MBH (“outmax80” model). The orange points show the mean column density for each galaxy, with size scaling with M_star. For a random subset of 24 galaxies we show the column density for 12 different lines of sight, with the grayscale proportional to M_star, as shown in the color bar.