Ratio of column densities in the same output and direction as in Figs. 1 and 14. Upper panel: ratio of carbon to hydrogen column densities. Lower panel: ratio of C⁺ to H⁰ column densities. The column densities are computed from the stellar particles to the virial radius. In every pixel, the ratio is averaged over all stellar particles in this pixel and weighted by the luminosity of the stellar particle at 1334 Å. The black pixels have no stellar particles in them.