The most massive black hole merger so far has been detected: 225 times that of our Sun.
Scientists from the United States, Italy, and Japan achieve a new milestone in gravitational wave astronomy.
BarcelonaA black hole with a mass 225 times that of our Sun. This is the result of the powerful merger of several black holes detected by scientists from the United States, Italy, and Japan through the international LIGO-VIRGO-KAGRA (LIGO-VIRGO-KAGRA) consortium. This is the most massive merger of black holes ever observed, and they were able to detect it through gravitational waves, which are tiny distortions in space-time in the form of ripples caused by violent cosmic events like this one. They have named the signal they detected from the observatories GW231123 and will present it at the 24th International Conference on General Relativity and Gravitation (GR24) and the 16th Edoardo Amaldi Conference on Gravitational Waves, which are being held in the United Kingdom until Friday.
The calibrated data used to detect and study the signal will be made available for other researchers to analyze. "This event pushes our instrumentation and data analysis capabilities to the limits of what's currently possible," says Sophie Bini, a postdoctoral researcher at Caltech and a member of the LVK. "It's a powerful example of how much we can learn from gravitational-wave astronomy and how much there is still to discover."
More black hole mergers
Scientists at the US Laser Interferometer Gravitational-Wave Observatory (LIGO) made history in 2015 by directly detecting gravitational waves for the first time. In that case, the waves came from a black hole merger that resulted in a final black hole with a mass 62 times that of our Sun. The signal was jointly detected by LIGO’s twin detectors, one located in Livingston, Louisiana, and the other in Hanford, Washington.
Since then, the LIGO team has joined with partners at the VIRGO detector in Italy and the Kamioka Gravitational-Wave Detector (KAGRA) in Japan to form the LVK collaboration. These detectors have together observed more than 200 black hole mergers during their fourth analysis cycle and around 300 in total since the start of the first cycle in 2015. Sun. This time the 225 solar mass black hole was created by the coalescence of black holes, each about 100 and 140 times the mass of the Sun.
Understanding Black Holes
In addition to their large masses, black holes also spin rapidly. “This is the most massive binary black hole system we’ve observed using gravitational waves, and it represents a real challenge to our understanding of black hole formation,” says Mark Hannam of Cardiff University and a member of the KLV Collaboration. “Black holes of this mass are forbidden in standard models of stellar evolution. One possibility is that the two black holes in this binary system formed through previous mergers of smaller black holes.”
“The black holes appear to be spinning very quickly, close to the limit allowed by Einstein’s theory of general relativity,” explains Charlie Hoy of the University of Portsmouth, UK, a member of the KLV Collaboration. “While a black hole merger remains the most likely explanation, their unexpected characteristics are not entirely clear.”
