Schematic showing the different parts to the proposed interpretation. The top left panel shows the cooling of atomic to molecular gas, along with the dominant constituents and coolants at each stage. Top right shows a cartoon HIFI CO 16–15 profile centered at zero velocity, with the broad outflow cavity shock component shown in green, and the offset spot shock component in orange. Bottom left is a CO rotational diagram with the different temperature components highlighted. Finally, bottom right shows where these different components may be located in the protostellar system. The top part shows the scenario where the broad component is caused by outflow cavity shocks, and the lower part shows the scenario where the broad component arises in the disk wind.