New insights into the early universe’s galaxy clusters
Molecular gas is the raw material which fuels star formation throughout the universe. Now, using the revolutionary Atacama Large Millimeter Array (ALMA) telescope, an international team of scientists has conducted one of the largest studies of molecular gas in distant galaxy clusters — rare conglomerations containing hundreds of galaxies, trillions of stars, and dark matter. Scientists from the Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) collaboration observed the galaxies within these distant clusters as they were when the universe was only 4 billion years old. They found that they harbor larger molecular gas reservoirs compared to galaxies in found in more typical isolated environments with fewer galaxy neighbors, known as field galaxies. “We expected to find molecular gas deficiencies in these cluster galaxies compared to the field,” says lead author Allison Noble, a postdoc at the MIT Kavli Institute for Astrophysics and Space Research. “Galaxies in nearby clusters are dead, lacking star formation activity and with...