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XMM-Newton Spots Greatest Ball Of Fire
Baltimore MD (SPX) Jun 13, 2006 Thanks to data from ESA's XMM-Newton X-ray satellite, a team of international scientists has found a comet-like ball of gas over a billion times the mass of the Sun hurling through a distant galaxy cluster at more than 750 kilometers (465 miles) per second. This colossal 'ball of fire' is by far the largest object of this kind ever identified, the scientists said. The gas ball is about 3-million light-years across, or about 5 billion times the size of the solar system. The object appears as a circular X-ray glow with a comet-like tail nearly half the size of the Moon. "The size and velocity of this gas ball is truly fantastic," lead researcher Alexis Finoguenov, of the University of Maryland, Baltimore County, and the Max Planck Institute for Extra-Terrestrial Physics in Garching, Germany. "This is likely a massive building block being delivered to one of the largest assembly of galaxies we know." The gas ball is in a galaxy cluster called Abell 3266, millions of light years from Earth - so it poses no danger to the solar system. Abell 3266 contains hundreds of galaxies and great amounts of hot gas at a temperature of nearly 100- million degrees. Both the cluster gas and the giant gas ball are held together by the gravitational attraction of unseen dark matter. "What interests astronomers is not just the size of the gas ball but the role it plays in the formation and evolution of structure in the universe," said Francesco Miniati, who worked on the data at UMBC while visiting from the Swiss Federal Institute of Technology in Zurich. Abell cluster 3266 is part of the Horologium-Reticulum super-cluster and is one of the most massive galaxy clusters in the southern sky. It still is actively growing in size, as indicated by the gas ball, and will become one of the largest mass concentrations in the nearby universe. Using XMM-Newton data, the science team produced what scientists call an entropy map, which is a measure of disorder. The map allows for the separation of the cold and dense gas of the comet from the hotter and more rarefied gas of the cluster. This is based on X-ray spectra. The data show in detail the process of gas being stripped from the comet's core and forming a large tail containing lumps of colder and denser gas. The researchers estimate a Sun's worth of mass is lost every hour. "In Abell 3266 we are seeing structure formation in action," said co-researcher Mark Henriksen of UMBC. "Dark matter is the gravitational glue holding the gas ball together, but as it races through the galaxy cluster, a tug-of-war ensues, where the galaxy cluster eventually wins, stripping off and dispersing gas that perhaps one day will seed star and galaxy growth within the cluster." Community Email This Article Comment On This Article Related Links XMM-Newton Stellar Chemistry, The Universe And All Within It
Astronomers Find Most Distant Galaxy Cluster Yet
Calgary, Alberta (SPX) Jun 7, 2006Astronomers have found the most distant cluster of galaxies to date and possibly the most massive one yet seen at such an early era in the universe. |
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