New Delhi: An international team of researchers have used data from the LIGO-Virgo-KAGRA gravitational wave observatory network to measure the properties of black holes in the forbidden range. In theory, scientists have predicted that black holes containing between 50 and 130 solar masses cannot form directly from the gravitational collapse of a massive star. Such a star would become so hot, that it would be blown away entirely, along with the core, leaving behind no stellar remnant, the nuclear heart of a dead star.
These extreme stellar explosions, known as pair instability supernovae, are predicted to exist by theory, but are difficult to observe. The new research may have provided indirect evidence. The data from black holes in the forbidden range confirm that black holes with masses greater than 45 times that of the Sun are result from mergers between two smaller black holes, rather than the collapse of exceptionally massive dying stars. The research indicate that pair instability supernovae are indeed occurring. The detection of gravitational waves allows scientists to probe the life cycles of stars, and better understand the eventual, violent deaths of the most massive stars in the universe.
The complex lives of dead stars
Being able to demonstrate the existence of pair instability supernvae was one of the long-standing promises of the field of gravitational wave astronomy, which has now been fulfilled. A paper describing the research has been published in Nature. The research also confirms that black holes increase in size, merging with others that were spawned from previous deaths of stars. Astronomers are now investigating how these objects interact within extremely crowded regions of the cosmos. This is because a number of black hole binary systems with a black hole in the forbidden range is most likely a product of past mergers, indicating that there is a whole population of very interesting black holes waiting to be discovered.