Scientists have detected ripples in space-time from the collision of two massive black holes, marking the most powerful black hole merger ever recorded by gravitational wave detectors, and prompting a re-evaluation of how such massive objects form.
The two black holes, located about 10 billion light years from Earth, were each over 100 times the mass of the sun and spiralled into one another before merging into a single black hole weighing around 265 times the mass of the sun, The Guardian reported.
The violent event generated gravitational waves that travelled across the cosmos and were picked up on 23 November 2023 by the twin detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) in Washington and Louisiana. These detectors recorded the subtle stretching and squeezing of space-time for a tenth of a second, capturing the final ringdown phase as the newly formed black hole settled.
Analysis revealed that the original black holes were 103 and 137 times the mass of the sun and were spinning at a rate about 400,000 times faster than Earth, which is near the theoretical maximum for such objects. These unusual masses place them in a range previously believed to be uninhabitable for black holes due to the instability in stellar collapse processes, challenging long-standing assumptions in astrophysics.
Researchers now suspect that the colliding black holes may have themselves been the products of earlier black hole mergers, which would account for their extreme mass and high spin. Although earlier observations had hinted at such hierarchical mergers, this event is the most convincing evidence to date.
Since the advent of gravitational wave astronomy in the 1990s, scientists have detected around 300 black hole mergers, but this event stands out due to its unprecedented scale. With plans underway for more advanced detectors in the next decade, scientists anticipate observing not only all black hole mergers across the universe but also unexpected phenomena that could transform current cosmological theories. The findings are scheduled for presentation at the GR-Amaldi meeting in Glasgow.