Astrophysicists from Poland and the United States have clarified the past of black holes, the collision of which led to the detection of the event GW150914 on September 14, 2015 - the first detection of gravitational waves in the history of science. The research is published in the journal Nature.
Using numerical simulations, scientists have shown that in the distant past, black holes were massive stars (40-100 times heavier than the Sun). These objects are believed by astrophysicists to have formed about two billion years after the Big Bang.
Scientists have also estimated the speed of gravitational wave detectors, which can register gravitational waves. Once optimum sensitivity has been achieved, these ground-based observatories should be able to detect one merging event of black holes each year, each 20 to 80 times heavier than the Sun.
For the first time, gravitational waves were recorded on September 14, 2015 at two twin detectors of the LIGO laser interferometric gravitational-wave observatory located in Livingston (Louisiana) and Hanford (Washington) in the USA. The disturbances were created by a pair of black holes (29 and 36 times heavier than the Sun) before they merged into a massive rotating gravitational object.
The second time the waves of space-time were registered by the same scientists on December 26, 2015.