Scientists have discovered a new way to measure the spin of extremely large black holes, which could help them understand their evolution and growth, according to a press release.
Researchers from the U.K.'s Durham University analyzed a black hole 10 million times larger than our sun in a galaxy 500 million light years away from Earth. They were able to watch it feed on a surrounding disc of material, strengthening and fueling its growth.
"We know the black hole in the center of each galaxy is linked to the galaxy as a whole, which is strange because black holes are tiny in relation to the size of a galaxy," lead researcher Chris Done, a Durham professor of Physics, said in the release. "This would be like something the size of a large boulder (ten meters), influencing something the size of the Earth."
Done and her team were able to measure the distance between the disc from the black hole by viewing optical, ultra-violet and soft x-ray images captured by the European Space Agency's XMM-Newton satellite. By using the distance of the black hole from the disc, the researchers were able to determine the spin of the black hole.
Understanding more about the spin of a black hole, Done said, could help researchers better understand how galaxies grow over billions of years, as black holes often sit in the middle of most galaxies.
"Understanding this connection between stars in a galaxy and the growth of a black hole, and vice-versa, is key to understanding how galaxies form throughout cosmic time, she said. "If a black hole is spinning it drags space and time with it and that drags the accretion disc, containing the black hole's food, closer towards it. This makes the black hole spin faster, a bit like an ice skater doing a pirouette."
Further research will be needed to lower the effect of black hole mass on their results, Done said. "We hope to be able to understand more about the link between black holes and their galaxies."
