|
. | . |
|
by Staff Writers Sheffield, UK (SPX) Jul 11, 2014
New research by academics at the University of Sheffield has solved a long-standing mystery surrounding the evolution of galaxies, deepening our understanding of the future of the Milky Way. The supermassive black holes in the cores of some galaxies drive massive outflows of molecular hydrogen gas. As a result, most of the cold gas is expelled from the galaxies. Since cold gas is required to form new stars, this directly affects the galaxies' evolution. The outflows are now a key ingredient in theoretical models of the evolution of galaxies, but it has long been a mystery as to how they are accelerated. A study led by researchers in the University's Department of Physics and Astronomy, with partners from the Netherlands Institute of Radio Astronomy and the Center for Astrophysics, Harvard, provides the first direct evidence that the molecular outflows are accelerated by energetic jets of electrons that are moving at close to the speed of light. Such jets are propelled by the central supermassive black holes. Using the Very Large Telescope of the European Southern Observatory in Chile to observe the nearby galaxy IC5063, researchers found that the molecular hydrogen gas is moving at extraordinary speeds - 1 million kilometers per hour - at the locations in the galaxy where its jets are impacting regions of dense gas. These findings help us further understand the eventual fate of our own galaxy, the Milky Way, which will collide with neighbouring galaxy Andromeda in about 5 billion years. As a result of this collision, gas will become concentrated at the centre of the system, fuelling its supermassive black hole, and potentially leading to the formation of jets that will then eject the remaining gas from the galaxy - just as we already observe in IC5063. Professor Clive Tadhunter, from the University's Department of Physics and Astronomy, said: "Much of the gas in the outflows is in the form of molecular hydrogen, which is fragile in the sense that it is destroyed at relatively low energies. It is extraordinary that the molecular gas can survive being accelerated by jets of electrons moving at close to the speed of light." The results of the study have been published in the journal Nature.
Related Links University of Sheffield Understanding Time and Space
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service. |