Line luminosities plotted as a function of gas number density (left column), gas temperature (middle column) and incident radiation field (right column). The lines are also divided into the contribution from different halo components, where the black solid line shows the total emission from the whole simulation box, the dashed purple line shows the main disc emission, the two mergers are plotted using a magenta dashed line, and the CGM is plotted using a dashed orange line.