Astronomers may finally be able to detect hundreds of black holes, thanks to new research by a team of scientists from Cardiff University, as two new detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) are to be turned on next year.
Black holes are dense objects exerting huge gravitational forces that are strong enough to suck in light. In other words they cannot be seen, but scientists hope the revamped detectors, which act like giant microphones, will find remnants of black hole collisions.
They have devised a model of how black holes distort waves of energy around them when they collide.
Led by Dr Mark Hannam from the School of Physics and Astronomy, the researchers have built a theoretical model which aims to predict all potential gravitational-wave signals that might be found by the detectors. The Cardiff team, which includes postdoctoral researchers, PhD students, and collaborators from universities in Europe and the United States, will work with scientists across the world as they attempt to unravel the origins of the Universe. They started the observations for gravitational waves back in 2002 but stopped in 2010 because they didn’t find any.
“The rapid spinning of black holes will cause the orbits to wobble, just like the last wobbles of a spinning top before it falls over. These wobbles can make the black holes trace out wild paths around each other, leading to extremely complicated gravitational-wave signals. Our model aims to predict this behaviour and help scientists find the signals in the detector data,” Dr Hannam said.
“Sometimes the orbits of these spinning black holes look completely tangled up, like a ball of string,” says Hannam. “But if you imagine whirling around with the black holes, then it all looks much clearer, and we can write down equations to describe what is happening.” These equations virtually set us inside the black hole. He compared it to a child riding a merry-go-round: for all those watching the child turn around, if the child raises up a hand, it looks like a blur. However, someone riding beside the kid views the hand clearly.
Supermassive balck holes are in the centre of most galaxies, including ours.