For decades, astronomers have described the galaxy cluster Abell 2029, a vast city of galaxies in the Virgo constellation, as "the most relaxed clusters in the universe." But beneath that placid exterior, scientists have now found, the cluster is still reverberating from an ancient cosmic collision.
New observations from the Chandra X-ray Observatory suggest giant "sloshing" motions in the cluster's gas — triggered by a merger roughly 4 billion years ago — may help heat the cluster alongside energy released by the supermassive black hole at its center. That could help explain why the gas in galaxy clusters does not cool as quickly as expected, the researchers say. But of note, Chandra's new data also revealed massive substructures still visible today, including gigantic spirals, shock fronts and waves of superheated gas rippling through the cluster, according to a statement released last week by Chandra X-ray Observatory.
