The recent third detection of gravitational waves was made possible partly because of the work carried out by Rochester Institute of Technology researchers through their black hole computer simulation.
Researchers at the institute not only helped with the third detection of gravitational waves, they also helped identify a new black hole 49 times the size of our Sun. The team at RIT helped the collaboration measure and interpret black hole spins and alignment. These measurements can tell scientists what happens when massive stars die and transform into black holes.
The gravitational wave signal was produced from the collision of black holes. The newly found black hole, formed by the merger, has a mass about 49 times that of our Sun. This fills in a gap between the masses of the two merged black holes detected previously by LIGO, with solar masses of 62 (first detection) and 21 (second detection).
“We can see the outlines of a population of black holes emerge,” Richard O’Shaughnessy, associate professor in RIT’s School of Mathematical Sciences.
The new observations rule out the possibility that pairs of heavy black holes have a lot of net-aligned spin and agree with LIGO’s 2015 breakthrough observation, he noted. Research at RIT’s Center for Computational Relativity and Gravitation is advancing techniques for understanding that crucial astrophysical parameter — spin, said Carlos Lousto, professor in RIT’s School of Mathematical Sciences.
Researchers in RIT’s Center for Computational Relativity and Gravitation directly compared gravitational wave signals to their computer simulations based on Albert Einstein’s equations. The recent observations further tested Einstein’s general theory of relativity and prediction that gravitational waves always move at the speed of light. LIGO saw no evidence that the waves travelled at different speeds.
“This third event lies in an mass range intermediate to the previous two events and shows that black hole mergers are common in the universe,” said Manuela Campanelli, director of RIT’s Center for Computational Relativity and Gravitation and Frontier in Gravitational Astrophysics, an RIT signature research area.
The new detection occurred during LIGO’s current observing run, which began Nov. 30, 2016, and will continue through the summer. LIGO observations are carried out by twin detectors — one in Hanford, Wash., and the other in Livingston, La. — operated by Caltech and Massachusetts Institute of Technology with funding from the National Science Foundation.
LIGO made the first-ever direct observation of gravitational waves in September 2015 and a second detection in December 2015. The breakthrough LIGO paper prominently cites 2005 landmark research done by Campanelli and her team on binary black hole mergers. Based on this milestone work, Lousto and Healy numerically modeled the merger of a pair of black holes and simulated gravitational waveforms that match the first LIGO detection.