LIGO and Virgo detect most massive gravitational-wave source yet
This artist’s impression shows binary black holes about to collide. (Mark Myers, ARC Centre of Excellence for Gravitational Wave Discovery - OzGrav)
Researchers have detected a signal from what may be the most massive black hole merger yet observed in gravitational waves, an event that created a behemoth 142 times that of the sun.
Scientists think that these black holes may have themselves formed from the earlier mergers of two smaller black holes, as indicated in the illustration. (LIGO/ Caltech/MIT/R. Hurt – IPAC)
Produced by extreme events in the universe and first detected by the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015, gravitational waves reverberate through the fabric of space-time, like the clang of a cosmic bell.
Almost every confirmed gravitational-wave signal to date has been from a binary merger, either between two black holes or two neutron stars. This newest merger appears to be the most massive yet, involving two black holes with masses about 85 and 65 times the mass of the sun.
This signal, which scientists have labeled GW190521, was detected on May 21, 2019, by LIGO and Virgo, a 3-kilometer-long detector in Italy.
Their collision released an enormous amount of energy, equivalent to around eight solar masses – or eight times the mass of our sun – that spread across the universe in the form of gravitational waves.
Using a suite of state-of-the-art computational and modeling tools, scientists think that GW190521 was most likely generated by a binary black hole merger with unusual properties, said Patrick Brady, UWM professor of physics and spokesperson of the LIGO Scientific Collaboration (LSC), the international group representing 1,300 scientists – including those at UWM – that is engaged in gravitational wave research with data from the LIGO observatories.
10 • IN FOCUS • October, 2020
“This [signal] doesn’t look much like a chirp, which is what we typically detect,” said Virgo member Nelson Christensen, a researcher at the French National Centre for Scientific Research. “This is more like something that goes ‘bang,’ and it’s the most massive signal LIGO and Virgo have seen.”
