What event often consumes the cold fuel rapidly during the merger that forms massive elliptical galaxies?

Answer

A spectacular, short-lived burst of star formation (a 'starburst' event)

When two spiral galaxies merge, the resulting gravitational disruption often triggers an intense, short-lived burst of star formation that rapidly consumes the remaining cold fuel.

What event often consumes the cold fuel rapidly during the merger that forms massive elliptical galaxies?
galaxyastronomystarsgas