Median of the line ratios plotted as a function of gas density, temperature, metallicity, UV field, and absolute velocity of the gas cells. The ratios are divided into the total halo (black), the disc (indigo), the merger components (magenta), and the CGM (orange), except for the absolute velocity panel, in which we divide the gas into inflowing (blue) and outflowing (red) gas. The shaded areas correspond to the 25th and 75th percentiles.