Physicists with the Ligo/Virgin/Kagra collaboration have detected the gravity wave signal (called GW231123) of the most massive merger between two black holes, resulting in a new black hole that is 225 times massier than our sun. The results were presented at the Edoardo Amaldi conference on gravitational waves in Glasgow, Scotland.
The Ligo/Virgin/Kagra collaboration searches the universe for gravitational waves produced by the mergers of black holes and neutron stars. Ligo detects gravitational waves via laser interferometry, using powerful lasers to measure small changes in the distance between two objects kilometers apart. Ligo has detectors in Hanford, Washington and in Livingston, Louisiana. A third detector in Italy, advanced Virgin, came online in 2016. In Japan, Kagra is the first gravitational-wave detector in Asia and the first to be built underground. The construction started on Ligo-India in 2021, and physicists expect it to be engaged somewhere after 2025.
To date, the collaboration has discovered dozens of merger events since the first Nobel Prize-winning discovery. Early detected mergers include two black holes or two neutron stars. In 2021, Ligo/Virgin/Kagra confirmed the detection of two separate “mixed” mergers between black holes and neutron stars.
A tour of Virgo. Credit: ego-virgo
Ligo/Virgin/Kagra started his fourth observation run in 2023 and the following year had announced the detection of a signal that a merger between two compact objects indicates, one of which was probably a neutron star. The other had an intermediate mass – heavier than a neutron star and lighter than a black hole. It was the first detection of gravitational waves of a massage object combined with a neutron star and hinted that the mass globe might be less empty than astronomers thought.
