New insight into why galaxies stop forming stars

Galaxy clusters are rare regions of the universe consisting of hundreds of galaxies containing trillions of stars. It has long been known that when a galaxy falls into a cluster, star formation is fairly rapidly shut off in a process known as ‘quenching.’ A new study has made the best measurement yet of the quenching timescale, measuring how it varies across 70 percent of the history of the universe. https://www.sciencedaily.com/releases/2018/10/181023185443.htm