Astronomers: A supermassive black hole rotates far slower than expected
The uncertainty of science: Using Chandra astronomers have measured the rotation of a supermassive black hole in a distant quasar about 3.4 billion light years away and found that it spins at about half the speed of other less massive black holes.
Because a spinning black hole drags space around with it and allows matter to orbit closer to it than is possible for a non-spinning one, the X-ray data can show how fast the black hole is spinning. The spectrum — that is, the amount of energy as a function wavelength — of H1821+643 indicates that the black hole is rotating at a modest rate compared to other, less massive ones that spin close to the speed of light. This is the most accurate spin measurement for such a massive black hole.
The black hole, thought to weigh between 3 to 30 billion times more than the Sun and is the heaviest such object measured in this way, rotates at about half the speed of light. Why that rotation is less than other smaller black holes remains a question not yet answered, though astronomers suspect it is related to its formation history.
The image above is a composite showing this quasar across multiply wavelengths. X-rays are shown in blue, radio in red, and optical in white.
The uncertainty of science: Using Chandra astronomers have measured the rotation of a supermassive black hole in a distant quasar about 3.4 billion light years away and found that it spins at about half the speed of other less massive black holes.
Because a spinning black hole drags space around with it and allows matter to orbit closer to it than is possible for a non-spinning one, the X-ray data can show how fast the black hole is spinning. The spectrum — that is, the amount of energy as a function wavelength — of H1821+643 indicates that the black hole is rotating at a modest rate compared to other, less massive ones that spin close to the speed of light. This is the most accurate spin measurement for such a massive black hole.
The black hole, thought to weigh between 3 to 30 billion times more than the Sun and is the heaviest such object measured in this way, rotates at about half the speed of light. Why that rotation is less than other smaller black holes remains a question not yet answered, though astronomers suspect it is related to its formation history.
The image above is a composite showing this quasar across multiply wavelengths. X-rays are shown in blue, radio in red, and optical in white.