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Photo:
Artist's conception shows two supermassive black holes, similar to those observed by researchers, orbiting one another. (Supplied: Josh Valenzuela/UNM)
In what is being hailed as a "groundbreaking
discovery", astronomers have for the first time observed two
supermassive black holes orbiting around each other in a distant galaxy,
according to new research.
In an article published in the
Astrophysical Journal, researchers have detailed how they used radio
telescopes to detect what appeared to be two black holes moving in
relation to each other in radio galaxy 0402+379 ."For a long time, we've been looking into space to try and find a pair of these supermassive black holes orbiting as a result of two galaxies merging," University of New Mexico's professor of physics and astronomy Greg Taylor said.
"Even though we've theorised that this should be happening, nobody had ever seen it until now."The research team has been studying the two objects, which lie at the centre of the bulging galaxy, since 2003.
Photo:
A false colour VLBA map of 0402+379 shows two supermassive black holes, represented by accretion discs with twin jets. (Supplied: University of New Mexico)
The galaxy itself was discovered in 1995 and is approximately 750 million light years away from Earth.The lead author of the paper, Karishma Bansal, said the black holes are at a "separation of about seven parsecs," or 217 trillion kilometres.
"[This] is the closest together that two supermassive black holes have ever been seen before," she said.
The black holes are among the largest ever found, with a combined mass 15 billion times that of the sun, the study says.
Photo:
Observations from radio telescopes indicate that two black holes are orbiting each other. (Supplied: National Radio Astronomy Observatory)
If confirmed, it will be the smallest ever recorded
movement of an object across the sky — at a rate of just over one
micro-arc second per year, an angle about 1 billion times smaller than
the smallest thing visible with the naked eye.That means one black hole is believed to be orbiting around the other over a period of 30,000 years, the researchers said.
"If you imagine a snail on the recently discovered Earth-like planet orbiting Proxima Centauri — a bit over four light years away — moving at one centimetre a second, that's the angular motion we're resolving here," Stanford's professor of physics and co-author of the paper, Roger W Romani, said.
Photo:
The galaxy hosts two supermassive black holes at its centre, being denoted as C1 and C2. (Supplied: University of New Mexico)
The researchers are hoping the finding will offer
insight into "how black holes merge, how these mergers affect the
evolution of the galaxies around them and ways to find other binary
black-hole systems".Large galaxies often have supermassive black holes at their centre and astronomers argue, if large galaxies combine, their black holes eventually follow suit.
As a result, the researchers have suggested that it is possible the apparent orbit of the black hole in 0402+379 is an "intermediary stage in this process".
But, given how slowly the pair is orbiting, the team thinks the black holes are too far apart to come together within the estimated remaining age of the universe, unless there is an added source of friction, they argue.
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