A global team of astronomers including researchers from The University of Western Australia has detected two gravitational wave black holes colliding into a big black hole, more than 150 times the weight of the sun.

UWA researchers were among the fastest to detect the black holes, within seconds, making a discovery that has changed scientists’ understanding of the Universe. 

A black hole is one of the most mysterious objects in the Universe. Scientists do not know what is inside black holes – the region where gravity becomes so strong that not even light can escape its pull.

For this reason, telescopes that see electromagnetic radiation such as optical light and radio waves  can only see the hot material surrounding the black hole. Last year, the Event Horizon Telescope imaged this material and the shadow cast by the black hole where light cannot escape.

"To be among the first to detect gravitational wave signals, we rely heavily on innovative high-performance computing technologies."

Professor Linqing Wen

What makes this discovery most interesting is that the origin of the two colliding black holes is not currently understood: black holes with masses of between 65 and 130 times the mass of the sun cannot be formed by a collapsing star, according to current theories. The larger black hole in this binary system requires a complementary or a new theory for its formation.

Professor Linqing Wen from UWA’s School of Physics, Mathematics and Computing, who led the team of the Gravitational Wave Astronomy group, and a Chief Investigator of OzGrav, said the waves were detected on 21 May 2019 through the LIGO-Virgo mission that had led to public alerts generated through the LIGO scientific collaboration. 

“It is excellent that our team contributed directly to the detection of this unusual system,” she said. 

“To be among the first to detect gravitational wave signals, we rely heavily on innovative high-performance computing technologies.  

“The UWA team has received substantial HPC support from the LSC DataGrid, the OzSTAR National Facility at Swinburne University of Technology, the WA’s Pawsey Supercomputing Centre, and the Pople HPC Cluster of the Faculty of Science at UWA.”

UWA PhD student and co-author Manoj Kovalam who was directly involved in the search for gravitational waves said it was exciting to be part of a team that had made such a significant scientific discovery.

“It was thrilling to see our program detect this rare event in real-time. Discoveries like these are very essential to understand the formation channels of such unusual black holes.” he said.

UWA Research Fellow and a member of OzGrav, Qi Chu said the finding was groundbreaking, not just in one way.

“What makes this discovery so interesting is that black holes between 100 to about 100,000 times the weight of the Sun, were an uncharted region. This remnant black hole was the first to fill the observation gap,” she said.

“This, with future observations in this region, might bring the answer to the ever-lasting question that how black holes, beyond stellar masses, are formed.”