Scientists report that they have discovered gravitational waves from 10 black holes so far, but they are still trying to explain the origin of these mergers. The largest merger detected so far seems to have overturned previous models as it has a higher rotating mass and mass than the range is possible. A team of researchers, including Assistant Professor at Rochester Institute of Technology, Richard O Shaughnessy, have created simulations that could explain how the merger happened.
In a new document published in Physical Examination Letters published November 1, 2019, researchers suggest that such large mergers could occur just outside the supermassive black holes at the center of the active galactic cores. Gas, stars, dust and black holes are trapped in a region surrounding the supermassive black holes known as the accretion disk. Researchers suggest that as black holes circumnavigate the accumulation disk, they eventually collide and merge to form a larger black hole that continues to swallow smaller black holes, becoming larger in this, what O’Shaughnessy calls “Pac-Man-like”
“This is a very harrowing prospect for those of us who work in the field,” says O’ Shaughnessy, a member of the Center for Computational Relativity and RIT Gravity (CCRG). "It offers a natural way of explaining high mass, high rotating binary mergers with a black hole and creating binaries in parts of the parameter space that other models cannot fill. There is no way to extract certain types of black holes from these other formation channels. ”
As the collaboration of LIGO and Virgo continues to search for gravitational waves, Shawnessy and his fellow researchers hope to find signatures of large, rotating black holes that could help to validation of their models. If their assumptions are correct, this could help us better understand how the galaxy's cosmic web gathers.
"This could be a unique way to study the physics around these supermassive black holes in a way that could not be investigated in any other way," said Shaughnessy. "It offers a unique perspective on how galaxy centers develop, which, of course, is important for understanding how galaxies grow as a whole, which explains most of the structure in the universe."
###  Reference: Hierarchical mergers with a black hole in active galactic nuclei
Y. Yan, I. Bartos, V. Gayatri, K. E. S. Ford, Z. Hyman, S. Klimenko, B. Kochis, S. Mark, Z. Mark, B. McKernan, and R. O Shaughnessy
Phys. Reverend Let. 123, 181101 – Published November 1, 2019
The CCRG of RIT has a large and active group of 18 faculty, students and doctoral students participating in LIGO scientific collaboration.