Orbiting telescope observes effects as giant galaxies collide Share This: UPI 4/30/2013 11:17:10 PM CAMBRIDGE, Mass., April 30 (UPI) -- Scientists say NASA's orbiting Chandra X-ray Observatory has yielded details of an enormous cloud of hot gas enveloping two large, colliding galaxies. With as much mass as 10 billion suns, the large reservoir of gas spans about 300,000 light years and radiates at a temperature of more than 12.5 million degrees F. This giant gas cloud, dubbed a "halo," surrounds two large spiral galaxies similar in size to the Milky Way, each with a supermassive black hole at its center, a release from Smithsonian's Astrophysical Observatory in Cambridge, Mass., which hosts the Chandra X-ray Center, said Tuesday. The black holes are spiraling toward one another and may eventually merge to form a larger black hole, the scientists said. A violent stirring of the surrounding gas caused by the merging of the galaxies had created a baby boom of new stars that has lasted for at least 200 million years, they said. Chandra X-ray Observatory scientist say the collision offers the opportunity to witness a relatively nearby version of an event that was common in the early Universe when galaxies were much closer together and merged more often.