Four galaxy clusters are in the process of merging into a single megacluster 3 billion light years from Earth. In this image, combining X-ray and optical data, the four clusters are grouped in two pairs, each embedded in vast clouds of hot gas (shown in blue) and unseen dark matter. Image: X-ray: NASA/CXC/SAO/G.Schellenberger et al.; Optical: SDSS
Four huge galaxy clusters, each with a mass of at least several hundred trillion times that of the sun, are in the process of merging to form one of the most massive systems in the known universe.
Known collectively as Abell 1758, the system consists of a northern pair of galaxy clusters and a southern pair some 3 billion light years from Earth, each embedded in vast clouds of hot gas and permeated by even larger amounts of unseen dark matter. The two galaxy clusters in each pair are themselves in the process of merging.
“Abell 1758 is a galaxy cluster system that was originally discovered as one single cluster, but follow-up observations showed it to consist of two separate clusters: one northern and one southern, separated by about 6 million light years,” astronomer Gerrit Schellenberger writes in a blog posting hosted by ...