Black holes are collapsed stars with such intensely powerful gravitational fields that it was believed not even light can escape them – but scientists have detected a “flare” for the first time.
A Brit-led team of scientists has detected light from a black hole after two of the ultra-dense celestial objects slammed into each other in the far reaches of space.
It emitted huge “flares” of light across the darkness of space.
Now an international team has witnessed these massive “flares” created by the colossal cosmic crash.
Project collaborator Dr Nicholas Ross, of the Institute for Astronomy, University of Edinburgh, said: “This result, the optical flash resulting from two black holes colliding and crushing the gas around them, is so exciting.”
“As a wee kid, I was hooked by the idea of black holes and now, as a big kid, the fact that we have ‘seen’ as well as ‘heard’ these black hole mergers, is an amazing discovery that has deep implications for astrophysics.”
The event involved a supermassive black hole, like the one at the centre of our galaxy, and a smaller one.
It was picked up by gravitational wave detectors LIGO in Louisiana and its European counterpart VIRGO in Cascina, Italy.
The observation was confirmed by the California Institute of Technology’s (Caltech) Zwicky Transient Facility (ZTF), located at the Palomar Observatory near San Diego.
Previous observations have shown when two black holes spiral around each other and ultimately merge they generate ripples, or “gravitational waves”.
The phenomena, a direct consequence of Einstein’s theory of gravity, was only realised in 2015 and won three US scientists the Nobel Prize in Physics.
Lead author Professor Matthew Graham, project scientist at ZTF, said: “This supermassive black hole was burbling along for years before this more abrupt flare.
“The flare occurred on the right timescale, and in the right location, to be coincident with the gravitational-wave event.
“In our study, we conclude that the flare is likely the result of a black hole merger, but we cannot completely rule out other possibilities.”
Supermassive black holes lurk at the centre of most galaxies, including the Milky Way.
They can be surrounded by a disc of flowing gas which contains swarms of stars and smaller black holes.
The flow of the gas helps to bring the smaller black holes together, enabling them to merge, and creates a larger black hole within the disk.
Upon creation, the new black hole has a large velocity and it is given what scientists described as “a kick” through the gas disk.
Experts said it is the reaction of the gas to the new speeding black hole that creates a bright light flare, visible with telescopes.
Co author Prof Saavik Ford, of the City University of New York, added: “At the centre of most galaxies lurks a supermassive black hole. It’s surrounded by a swarm of stars and dead stars, including black holes.
“These objects swarm like angry bees around the monstrous queen bee at the centre. They can briefly find gravitational partners and pair up but usually lose their partners quickly to the mad dance.
“But in a supermassive black hole’s disk, the flowing gas converts the mosh pit of the swarm to a classical minuet, organising the black holes so they can pair up.”
The newly formed larger black hole, described in Physical Review Letters, should cause another burst of light in the next few years.