24 August 2017
The new field of gravitational wave astronomy, which started with the first gravitational wave detection two years ago, is already offering possible explanations of how black holes form.
A team of physicists from the UK and the United States has studied the landmark observations of gravitational waves by the LIGO gravitational wave detector in 2015 and again in 2017.
The UK’s Science and Technology Facilities Council provides grant funding to enable UK researchers, including those at the University of Birmingham, to be involved in the LIGO scientific collaboration.
In the paper published in Nature today, the team says the evidence gathered from these detections limit the possible explanations for the formation of black holes outside of our galaxy; either they are spinning more slowly than black holes in our own galaxy or they spin rapidly but are ‘tumbled around’ with spins randomly oriented to their orbit.
By ruling out other explanations and narrowing it down to two, researchers will now be able to carry out more specific research and get closer to a definite answer.
Professor Ilya Mandel, also from the University of Birmingham, said: “We will know which explanation is right within the next few years. This is something that has only been made possible by the recent LIGO detections of gravitational waves.
“This field is in its infancy; I’m confident that in the near future we will look back on these first few detections and rudimentary models with nostalgia and a much better understanding of how these exotic binary systems form.”
More information is available on the University of Birmingham website.
LIGO stands for Laser Interferometer Gravitational-wave Observatory. LIGO was designed and is operated by Caltech and MIT, with funding from the National Science Foundation (NSF). Advanced LIGO is funded by the NSF with financial and technical contributions from the UK Science and Technology Facilities Council (STFC), the Max Planck Society of Germany, and the Australian Research Council (ARC).
LIGO consists of two L-shaped interferometers, one in Hanford, Washington, and one in Livingston, Louisiana. Each arm of each L is 2½ miles (4 km) long. Lasers look for changes in each arm's length as small as a millionth the diameter of a proton. Passing gravitational waves might distort space-time by that much. See more at LIGO Laboratory.
The UK has been involved in gravitational wave research for over four decades, as key partners in a global collaboration led by the US. With the help of funding from STFC, UK scientists and engineers have pioneered key aspects of the technology behind gravitational-wave detection, and played a leading role in analysis of the data that allowed scientists to identify the source of gravitational waves.
The LIGO Scientific Collaboration comprises over 1000 scientists from 17 countries, and includes researchers from ten UK universities (Glasgow, Birmingham, Cardiff, Strathclyde, West of Scotland, Sheffield, Edinburgh, Cambridge, King College London and Southampton).