Tuesday, 26 June 2012

Black Holes

Perseus Black Hole

Photograph courtesy NASA/CXC/IoA/A. Fabian et al.
A view of the central region of the Perseus galaxy cluster, one of the most massive objects in the universe, shows the effects that a relatively small but supermassive black hole can have millions of miles beyond its core. Astronomers studying this photo, taken by the Chandra X-ray Observatory, determined that sound waves emitted by explosive venting around the black hole are heating the surrounding area and inhibiting star growth some 300,000 light-years away. "In relative terms, it is as if a heat source the size of a fingernail affects the behavior of a region the size of Earth," said Andrew Fabian of Cambridge University.

Black Hole Wind

Photograph courtesy NASA/CXC/MIT/UCSB/P. Ogle et al./STScI/A. Capetti et al.
A composite x-ray/optical image of the active NGC 1068 galaxy reveals an enormous plume of hot gas emanating from the supermassive black hole at the galaxy's center. Scientists think the shape and speed of the plume, which moves at about 1 million miles an hour (1.6 million kilometers an hour), are caused by the funneling effect of a doughnut-shaped ring of cooler gas and dust that surrounds the black hole.

Unexpected X-Rays

Photograph courtesy NASA/CXC/OCIW/P. Martini et al.
In 2000, astronomers studying the A2104 galaxy cluster (in blue) discovered powerful x-rays emanating from several black holes in regions previously thought too old and devoid of gas to create such radiation. They had expected to find perhaps one such x-ray source in the area, but instead found six. The discovery, made using the Chandra X-ray Observatory, changed many of the assumptions scientists had made about the life cycles of galaxies and black holes.

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