Artist's impression of a post-starburst galaxy

Post-starburst galaxies, or PSBs, were previously thought to expel all of their gas in violent outbursts, leading to dormancy, a time when galaxies stop forming stars. But scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) found that instead, PSBs condense and hold onto this turbulent gas, and then don't use it to form stars. This artist's impression highlights the compactness of molecular gas in a PSB and its lack of star formation. Credit: ALMA (ESO/NAOJ/NRAO)/S. Dagnello (NRAO/AUI/NSF)