June 17, 2011
Black Hole Rips Apart Star In A Flash
According to new research, the flash from one of the biggest and brightest bangs ever recorded by astronomers is derived from a massive black hole at the center of a distant galaxy.
The researchers found that the black hole appears to have ripped apart a star that wandered too close, which helped create a powerful beam of energy that crossed the 3.8 billion lights years to Earth.The astronomers reported in the journal Science in a paper entitled "An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy" that high energy X-rays and gamma-rays persisted at an extremely bright level for weeks after the event.
The extreme brightness, according to the researchers, comes from the fact that it illuminated only a small fraction of the sky, pointing a jet of light towards the Milky Way.
Dr Andrew Levan, lead researcher on the paper from the University of Warwick, said in a statement: "Despite the power of this the cataclysmic event we still only happen to see this event because our solar system happened to be looking right down the barrel of this jet of energy".
"The only explanation that so far fits the size, intensity, time scale, and level of fluctuation of the observed event, is that a massive black at the very centre of that galaxy has pulled in a large star and ripped it apart by tidal disruption. The spinning black hole then created the two jets one of which pointed straight to earth."
The team analyzed data from the Swift satellite, the Hubble Space Telescope and the Chandra X-ray Observatory to help confirm the finding.
"This is truly different from any explosive event we have seen before," Joshua Bloom, an associate professor of astronomy at UC Berkeley, said in a statement.
The team said that about 10 percent of the mass from the star ripped up by the black hole is turned into energy and irradiated as X-rays from the swirling accretion disk or as X-rays and higher energy gamma rays from a relativistic jet that punches out along the rotation axis.
"We think this event was detected around the time it was as bright as it will ever be, and if it's really a star being ripped apart by a massive black hole, we predict that it will never happen again in this galaxy," he said.
Image 1: What University of Warwick researchers think the star may have looked like at the start of its disruption by a black hole at the center of a galaxy 3.8 billion light years distant resulting in the outburst known as Sw 1644+57. Credit: University of Warwick / Mark A. Garlick
Image 2: What University of Warwick researchers think the aftermath of a large star being consumed by a black hole at the center of a galaxy 3.8 billion light years distant may have looked like. The event blasted jets of energy from the black hole, one of which pointed directly at our own galaxy, allowing us to be aware of this event- an outburst now known as Sw 1644+57. Credit: University of Warwick / Mark A. Garlick
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