In environments rich in carbon monoxide ($ ext{CO}$), how does it aid the early stages of core contraction?

$ ext{CO}$ emits radio waves that efficiently escape, allowing the gas to shed gravitational energy as heat

Cooling efficiency is paramount for allowing a contracting core to proceed toward star formation, as contraction releases gravitational energy as heat, which would otherwise raise the pressure and halt collapse. In the early stages of contraction, the core is transparent, allowing photons to escape. In regions where carbon monoxide ($ ext{CO}$) is present, this molecule is particularly effective at cooling because it can emit photons in the radio wave range. These radio photons escape the cloud material much more readily than photons at other wavelengths. This efficient radiative energy loss prevents the temperature from rising too quickly, ensuring the thermal pressure remains low enough for gravity to continue driving the collapse past this initial critical stage.