Maps of the main indicators of the gas heating and cooling: the uncorrected [Cii] emission divided by the total infrared flux, [Cii]/F_TIR (left), the sum of the [Cii] emission, corrected for the contribution from ionised gas, and [Oi] 63 emission divided by the total infrared flux, ([Cii]+[Oi]63)/F_TIR (middle), and the [Cii]/[Oi]63 ratio, where the [Cii] emission is also just the component from neutral gas (right). The maps are centred on , (J2000.0) and are presented in the resolution and pixel size of the PACS 160 μm map. Contours from the F_TIR map (see Fig. 1) are superimposed on each image as a visual aid with levels as listed in Fig. 4.