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New Energy Source Wrings Power From Black Hole Spin

Scientists for the first time have seen energy being extracted from a black hole. Like an electric dynamo, this black hole spins and pumps energy out through cable-like magnetic field lines into the chaotic gas whipping around it, making the gas ? already infernally hot from the sheer force of crushing gravity ? even hotter.

Joern Wilms of Tuebingen University, Germany, and an international team of astronomers observed the novel "power tapping" with the European Space Agency's x-ray Multi-Mirror Mission (XMM-Newton) satellite by watching a supermassive black hole in the core of galaxy named MCG-6-30-15. The observation also may explain the origin of particle jets in quasars.

"Never before have we seen energy extracted from a black hole," said co-author Christopher Reynolds of the University of Maryland, College Park. "We always see energy going in, not out."

"The gravity in this region appears to be so intense that the very fabric of space twists around the black hole, dragging magnetic field lines along with it," said Wilms. "The magnetic fields tighten about the black hole, slowing its spin. This ?friction' heats the region to even higher temperatures."

Scientists say most galaxies, including our Milky Way galaxy, have a supermassive black hole at their core. A supermassive black hole contains the mass of millions to billions of Suns compressed within a region smaller than our solar system. The black hole in MCG-6-20-15, over 100 million light-years from Earth, has the mass of about 100 million Suns.

Co-author Mitchell Begelman of the University of Colorado, Boulder, said this finding may be observational evidence of a theory by Prof. Roger Blandford, currently at the California Institute of Technology, Pasadena, and Dr. Roman Znajek, when he was at Cambridge University in England, over 25 years ago. According to the theory, rotational energy can be extracted from the black hole as it is braked by magnetic fields. The first law of thermodynamics (conservation of energy) states that energy lost from the black hole must be absorbed by the region.

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