Vast Clouds of Hot Gas are Sloshing in Galaxy Cluster Abell 2052
Posted on January 30, 2012
Scientists recently discovered that vast clouds of hot gas are "sloshing" in Abell 2052, a galaxy cluster located in the constellation Serpens, about 480 million light years from Earth. The scientists are studying the hot (30 million degree) gas using X-ray data from NASA's Chandra X-ray Observatory and optical data from the Very Large Telescope.
U.S. Naval Research Laboratory's Dr. Tracy Clarke says, "The X-ray images were amazing. We were able to see gas sloshing like liquid in a glass. Of course this would be one enormous glass since we see the gas sloshing over a region of nearly a million light years across!"
Chandra data reveals the enormous spiral structure in the hot gas around the outside of the image. Zooming in on the cluster reveals "cavities" or "bubbles" surrounding the central giant elliptical galaxy. The spiral began when a small cluster of galaxies collided off-center with a larger one positioned around that central galaxy. The gravitational attraction of the smaller cluster drew the hot gas out of the central cluster toward the smaller cluster. Once the smaller cluster passed the central cluster core, the gas movement reversed and it was pulled back toward the center of the main cluster. The hot cluster gas overshot the cluster center, creating the "sloshing" effect that is like the sloshing that occurs when a glass holding a liquid is quickly jerked sideways.
Scientists say the "sloshing" motion in Abell 2052 is important for two reasons. The sloshing helps to move some of the cooler, dense gas in the center of the core farther away from the core. It also helps redistribute heavy elements like iron and oxygen, which are created out of supernova explosions.
The research was published in the August 20, 2011 issue of The Astrophysical Journal. The authors include Elizabeth Blanton of Boston University, Boston, MA; Scott Randall of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA; Tracy Clarke of the Naval Research Laboratory, Remote Sensing Division, in Washington DC; Craig Sarazin of the University of Virginia in Charlottesville, VA; Brian McNamara of the University of Waterloo in Waterloo, Canada; Edmund Douglass of Boston University and Michael McDonald of the University of Maryland, College Park, MD.