Supermassive Black Holes Spin at the Limits of Relativity
Written by Fraser Cain
You know the saying: nothing, not even light can escape a black hole. That makes them invisible. Amazingly, researchers from the University of Maryland have determined how fast a supermassive black hole is spinning. You won't be surprised to know it's spinning insanely fast, at the limits predicted by relativity.
The researchers used ESA's XMM-Newton X-Ray telescope to examine the quantity of iron in an accretion disk around a supermassive black hole at the centre of galaxy MCG-06-30-15. Because the disk is spinning so rapidly, the light from the disk is warped relativistically. According to their calculation, the black hole must be spinning at least 98.7% of the maximum spin rate allowable by Einstein's Theory of General Relativity.
This result helps astronomers understand how black holes grow over time. If supermassive black holes formed by slowly pulling in surrounding matter, they would be expected to spin faster and faster, until they reach this relativistic limit. If the supermassive black holes were instead formed by colliding smaller black holes, they'd be spinning much more slowly.
Original Source: UM News Release
Filed under: Black Holes
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