Record-breaking cosmic object seen

A galaxy cluster, one of the largest objects in the universe, is breaking several cosmic records for star formation and energy output, U.S. astronomers say. The Phoenix cluster, located about 5.7 billion light years from Earth, is forming stars at the highest rate ever observed for the middle of a galaxy cluster and is the most powerful producer of X-rays of any known cluster, NASA's Chandra X-ray Observatory in Cambridge, Mass., reported Wednesday. The cluster, one of the largest in the universe, is named not only for the constellation in which it is located but also for its remarkable properties, astronomers said. "While galaxies at the center of most clusters may have been dormant for billions of years, the central galaxy in this cluster seems to have come back to life with a new burst of star formation," Michael McDonald, a Hubble Fellow at the Massachusetts Institute of Technology, said. "The mythology of the Phoenix, a bird rising from the dead, is a great way to describe this revived object." The Phoenix cluster and its central galaxy and supermassive black hole are crucial objects for studying cosmology and galaxy evolution, scientists said. "This spectacular star burst is a very significant discovery because it suggests we have to rethink how the massive galaxies in the centers of clusters grow," said Martin Rees of Cambridge University, a world-renowned cosmologist who was not involved in the study.