Latest detection of gravitational waves confirms new population of black holes
An international team of scientists has today (Thursday 1 June 2017) announced the third detection of gravitational waves – ripples in space and time – demonstrating that a new window in astronomy has been firmly opened.
As was the case with the first two detections, the waves were generated when two black holes collided to form a larger black hole.
The newfound black hole, detected by the Laser Interferometer Gravitational-wave Observatory (LIGO), formed by the merger, has a mass about 49 times that of our sun. This fills in a gap between the masses of the two merged back holes detected previously by LIGO, with solar masses of 62 (first detection) and 21 (second detection).
The new observation was made by the LIGO Scientific Collaboration together with the European-based Virgo Collaboration, which includes Dr Ed Daw from the University of Sheffield’s Department of Physics and Astronomy.
“Because black holes don't emit light, we don't know as much about them as we do about stars that shine,” said Dr Daw.
“By observing the waves of gravity that some black hole systems emit, we can infer the physics driving the emission of the gravitational waves, and probe the ideas of Einstein and others of how gravity works.
“We can also start to conduct a sort of black hole census - how many black holes are in your average galaxy and how massive are they?
“We currently don't really understand how the universe produced so many black hole binaries tens of times as massive as our sun, and the quest to understand how they came about is an interesting one in its own right.”
He added: "LIGO continues to probe the dark universe with this latest discovery of another binary black hole system.
“Our group at Sheffield works on running and maintaining searches for longer duration signals, on interferometer diagnostics that will improve the performance of LIGO at high laser power, and on applying technology we invented for LIGO to industrial applications.
“This latest discovery is further evidence of LIGO developing from a first-discovery instrument to an observatory that explores our mysterious universe."
The new detection occurred during LIGO's current observing run, which began 30 November 2016, and will continue through the summer.
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