Chrome-plated Universe

Recently astronomers used the Suzaku orbiting X-ray observatory, operated jointly by NASA and the Japanese space agency, to discover the largest known reservoir of rare metals in the universe. Suzaku detected the elements chromium and manganese while observing the central region of the Perseus galaxy cluster. The metallic atoms are part of the hot gas, or "intergalactic medium," that lies between galaxies. Thumbnail: "The Robot (3) 20102007 Inspired by Hajime Sorayama by Emile Noordeloos." Exploding stars, or supernovas, forge the heavy elements. The supernovas also create vast outflows, called superwinds. These galactic gusts transport heavy elements into the intergalactic void. What is the universe made of? The vast majority of it consists of the wispy cosmic lightweights hydrogen and helium. Everything else on the periodic table contributes only a small fraction of the whole. Elements heavier than hydrogen and helium are forged in stars, and during their explosive deaths as supernovas. Type 1a supernovas are nature s most productive foundries. An old white dwarf star pulls gas off its giant neighbor. The dwarf gains mass until it becomes unstable and blows itself to bits. The explosion creates vast amounts of heavy elements and blasts them into space. Suzaku is an orbiting X-ray observatory, operated jointly by NASA and the Japanese Space Agency. And it recently spotted the metals chromium and manganese in intergalactic space for the first time. It s the largest known concentration of rare metals in the universe. Suzaku was looking at X-rays shining from the core region of the Perseus galaxy cluster and detected the metals in hot, thin intergalactic gas. The gas is so thin it s close to a vacuum, but it fills a volume of space in the cluster about 1.4 million light years across. [ Supernovas forged the metals and blasted them out of the galaxies, but a single stellar explosion wasn t powerful enough to get the job done. That requires periods of higher than normal star birth and death. These so-called starbursts stirred up vast outflows of matter called superwinds. Heavy elements forged by supernovas rode the superwinds to intergalactic space. A single supernova can produce thousands of times Earth s mass in chromium. The Suzaku astronomers estimate that it took some three billion supernovas to forge the treasure trove they found in the Perseus Cluster. The total reservoir of heavy metal discovered by Suzaku is even more staggering. The Perseus core region holds 30 millions times the Sun s mass in chromium. About 10 trillion times the mass of Earth. Suzaku s chemical census of the universe is just beginning, but it s already revealed just how rare and precious some corners of the cosmos are.