Largest ever black hole collision detected by scientists

An international team of scientists have detected the largest ever black hole collision through the ripples it made in space-time.

US scientists discovered the space-time ripples - officially known as gravitational waves - in a breakthrough in 2016 , although their existence was predicted by Albert Einstein roughly a century ago.

Now academics at the Australian National University (ANU) have detected the collision between two black holes, which are believed to have formed a new black hole about 80 times larger than the Sun.

The ANU team worked in partnership with other academic institutions through the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO), which is based in the US.

ANU Professor Susan Scott said the team discovered four collisions in total by re-analysing data captured during Advanced LIGO's first two observing runs.

Among these was the formation of the biggest known black hole, created in the collision and merger of a binary system of black holes on 29 July 2017 - about nine billion light years away from Earth.

Professor Scott said: "This event also had black holes spinning the fastest of all mergers observed so far. It is also by far the most distant merger observed."

The team published computer calculations modelling the gravitational waves it observed and the black holes that emitted waves.

Astrophysicists currently believe there are about 10,000 black holes at the centre of our own galaxy, the Milky Way, all of which surround a supermassive black hole at its core.

The three other black hole collisions detected by ANU occurred between 9 and 23 August 2017.

These were between three and six billion light years away, and the black holes they produced between 56 and 66 times larger than our Sun.

"These were from four different binary black hole systems smashing together and radiating strong gravitational waves out into space," said Professor Scott.

"These detections of black hole collisions greatly improve our understanding of how many binary black hole systems there are in the universe, as well as the range of their masses and how fast the black holes spin during a merger."

The academics intend to continually develop and improve the gravitational wave detectors so they can spot cataclysmic events much further out in space.

One day they hope to be able to reach back to the beginning of time just after the Big Bang, something which cannot be done with light.

Professor Scott will present the results of the team's work at the Australian Institute of Physics Congress in Perth later in December.

They will also be published in Physical Review X.