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ESA Finds a Black-Hole Flywheel in the Milky Way
Friday, April 26, 2002
The European Space Agency

A black hole whirls space around it -- and radiates energy in the form of X-rays.
Image Credit: ESA.

Far away among the stars, in the Ara constellation of the southern sky, a small black hole is whirling space around it. If you tried to stay still in its vicinity, you couldn't. You'd be dragged around at high speed as if you were riding on a giant flywheel. In reality, gas falling into the black hole is whirled in that way. It radiates energy, in the form of X-rays, more intensely than it would do if space were still by tapping into the black hole's internal energy stream.

XMM-Newton showed that energy can escape from a black hole. This artist's impression illustrates how a black hole system, MCG-6-30-15, may look.
Image Credit: ESA.

ESA's big X-ray detecting satellite, XMM-Newton, was specifically designed to detect this form of energy. With this finding it has chalked up another notable success in its investigations of the black holes -- mysterious regions of space where gravity is so strong that light can't escape. High speeds and intense gravity affect the energy of X-rays emitted from iron atoms very close to a black hole. By detecting the resulting spread of energies, with XMM-Newton, astronomers can diagnose the conditions there.

The weird effect of a spinning black hole on its surroundings is linked to Albert Einstein's theory of gravity, in which the fabric of space itself becomes fluid. XMM-Newton first discovered such black-hole flywheels in galaxies many millions of light-years away. Now, in findings to be formally reported next month, it sees the same thing much closer to home, in our own Galaxy, the Milky Way.
(More: ESA News Source)
2002 © The European Space Agency.

Dan