What allows the initial, rapid collapse phase of a gas cloud to proceed before significant slowing occurs?

Answer

Efficient radiation of heat away due to the cloud remaining transparent.

The initial rapid collapse, sometimes called free-fall, continues as long as the gas cloud is tenuous enough to efficiently radiate away the thermal energy generated by compression, keeping the temperature low.

What allows the initial, rapid collapse phase of a gas cloud to proceed before significant slowing occurs?
gravitystar formationpressurecollapseinterstellar cloud