The analysis of an unusual “gravitational signal” revealed the collision of two remarkably massive black holes, upsetting our understanding of these extreme objects.
Record event
As its name suggests, the Observatory of Gravitational Waves by Laser Interferometry (LIGO) focuses on the detection of these undulations in the very fabric of space-time, created by cataclysmic cosmic events, such as stellar explosions (supernovas) or collisions of black holes.
« We could compare them to those produced when you throw a stone in a lake », Illustrates Samar Safi-harb, astrophysicist at the University of Manitoba. In the case of objects as dense as black holes, their rapprochement will generate gravitational waves Remarkably powerful.
On 23 November 2023, a Signal ” extraordinary and confusing Had been captured. Led by Sophie Bini, of the California Institute of Technology, and her colleagues, the GW231123 exam linked it to the merger ” impossible “Of two cosmic monsters, having led to the formation of a black hole of 225 solar masses.
Respectively 100 and 140 times more massive than our star, the two extreme objects having given it proved to be about twice as heavy as previous record holders. They also turned at a breathtaking speed, close to the physical limits set by the general relativity of Einstein.
Chain mergers
According to the researchers, their mass was too large for them to be directly born from the collapse of old massive stars. “” Current stellar evolution models do not predict existence “Explains Ed Porter, researcher at the Astroparticles and Cosmology of the CNRS laboratory.
At this stage, the main hypothesis is that these intermediate objects result from “chain” mergers involving smaller black holes, in dense regions of the cosmos. The in -depth analysis of Ligo data, free access, and observations of other similar events will prove to be essential to support it, and thus advance our understanding of the global dynamics of the cosmos.
« It will take years so that the community is entirely shedding light on this signal and its implications “, Esides Gregorio Carullo of the University of Birmingham, having contributed to this work presented on the occasion of the Edoardo Amaldi conference on gravitational waves.
At the start of the year, a study suggested that a black hole 600,000 times more massive than the sun could hit the Milky Way.