A team of U.S. astronomers has found the closest pair of supermassive black holes ever discovered in the Universe.
Artist’s depiction of a black hole merger. Image credit: NASA / CXC / A. Hobart / Josh Barnes, University of Hawaii / John Hibbard, NRAO.
The black hole pair is in the center of a quasar called PKS 1302-102, approximately 3.5 billion light-years away.
These two black holes are only a light-week apart and are spiraling toward a cataclysmic collision.
By contrast, the closest previously confirmed black hole pair is separated by approximately 20 light-years.
“This is the closest we’ve come to observing two black holes on their way to a massive collision,” said team leader Dr Zoltán Haiman of Columbia University.
“Watching this process reach its culmination can tell us whether black holes and galaxies grow at the same rate, and ultimately test a fundamental property of space-time: its ability to carry vibrations called gravitational waves, produced in the last, most violent, stage of the merger.”
The black hole pair, according to Dr Haiman and his colleagues, is causing the rhythmic flashes of light coming from PKS 1302-102, also known as PG 1302-102.
The team predicts a smashup between 20,000 and 350,000 years from now with a best estimate of 100,000 years.
“The black holes are circling toward a collision so powerful it would send a burst of gravitational waves surging through the fabric of space-time itself,” the astronomers said.
“The detection of gravitational waves lets us probe the secrets of gravity and test Einstein’s theory in the most extreme environment in our Universe – black holes,” said team member Daniel D’Orazio of Columbia University.
“Getting there is a holy grail of our field.”
The discovery is reported September 16 in the online edition of the journal Nature.
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Daniel J. D’Orazio et al. 2015. Relativistic boost as the cause of periodicity in a massive black-hole binary candidate. Nature 525, 351-353; doi: 10.1038/nature15262
