Gravitational wave detectors have detected a fusion of black holes that are never seen. This calls into question theories on the formation of these mysterious objects.
It’s a record! A fusion between two black holes has been detected and the object created has a mass of around 225 solar masses. The signal called GW231123 was found thanks to the Ligo-Virgo-Kagra collaboration, an alliance between several detectors ofgravitational wavesgravitational waves based in the United States (LigoLigo), in Italy (VirgoVirgo) and in Japan (Kagra).
The results are the subject of a study presented at the International Conference on General Relativity and Gravitation, in Scotland
“A real challenge”
« It is the binary systembinary system of the most massive black holes that we have observed through the gravitational waves, Assures one of the members of the collaboration, Mark Hannam, of the University of Cardiff. This represents a real challenge in our understanding of the formation of black holes ».
Indeed, previous observations had never affected such important objects. The very first detection carried out by Ligo in 2015 appointed an object of 62 solar masses. And the previous record dated from 2021, with a merged black hole reaching a total of 140 solar masses, the GW190521 signal.
A landing now widely exceeded since this impressive mass would represent only one of the two objects involved in this GW231123. But then why are they so massive?
Stellar training models cannot explain alone how nature can lead to the creation of objects that exceed 100 solar masses. For this, it would take a star of a considerable mass, such as none has never been observed. Here, the authors of the study think that the two black holes at the origin of the merger are already formed from a previous rapprochement. It would therefore not be a question of stellar black holesstellar black holes But indeedAstresAstres already merged from other smaller objects.
Years of data to peel
But in addition, beyond this mass issue, the black holes observed present another interesting characteristic: they have a spinspin (an extremely fast rotation). So much so that it is difficult to measure it well with gravitational wave detectors because the theoretical models only provide for this kind of behavior in extreme cases. They would approach the limit of vitessevitesse proposed by the theory of general relativity of Einstein.
On the other hand, no satisfactory explanation has been advanced to explain this behavior. THE spin is so fast that the instruments fail to interpret this extreme signal correctly. For Gregorio Carullo of the University of Birmingham which is also part of the collaboration: ” It will take years so that the community can completely clear this signal and all its implications ».
In any case, there will be many scientists on the subject since the data will be placed in free access through the Gravitational Wave Open Science Center Who makes all these finds accessible to the community, so that everyone can help unravel this discovery.
