LEICESTER, England, March 23 (UPI) -- Black holes a billion times heavier than our sun may have gotten that big by being gluttons and eating several "meal courses" at once, U.K. researchers say.
Researchers from the University of Leicester and Australian colleagues from Monash University studied how some black holes could grow so big so fast.
"Almost every galaxy has an enormously massive black hole in its center," Leicester researcher Andrew King said. "Our own galaxy, the Milky Way, has one about 4 million times heavier than the sun. But some galaxies have black holes a thousand times heavier still. We know they grew very quickly after the Big Bang."
Black holes grow by sucking in gas that forms a disc around the hole and spirals in, but usually so slowly the largest black holes could not have grown to these huge masses in the entire age of the universe, researchers said.
"We needed a faster mechanism," Chris Nixon, also at Leicester, said, "so we wondered what would happen if gas came in from different directions."
The researchers did computer simulations of two gas discs orbiting a black hole at different angles and found after a short time the discs spread and collide, and large amounts of gas fall into the hole.
The calculations show black holes can grow 1,000 times faster when this happens, they said.
"If two guys ride motorbikes on a Wall of Death and they collide, they lose the centrifugal force holding them to the walls and fall," King said, the same thing that happens to the gas in the discs causing it to fall in toward the black hole.
"We don't know exactly how gas flows inside galaxies in the early universe," King said in a Leicester release Friday, "but I think it is very promising that if the flows are chaotic it is very easy for the black hole to feed."