An almost record-breaking, supermassive black hole located in a cosmic backwater has left scientists astonished, prompting them to rethink their existing black hole models.
Recent discoveries of monster black holes tend to be located in dense galaxy clusters, so imagine the surprise of astronomers from University of California, Berkeley when they located the supermassive black hole in a "relative desert."
Out Of Place?
The newly-detected gigantic black hole sits at the center of Galaxy NGC 1600 like a lofty skyscraper in a small town -- a massive distinction that experts never thought would occur.
The black hole contains 17 billion solar masses, only faintly smaller than the current record-holder which weighs in at 21 billion times the mass of the sun and lies in the Coma Cluster.
The study's lead scientist Chung-Pei Ma said the supermassive black hole they found is much bigger than the expected size for its galaxy.
"That's the puzzling part -- or the intriguing part -- of the result," Ma told Space.com.
The black hole's home, NGC 1600, is a galaxy 200 million light years away from our planet. It was unusual to find the supermassive black hole in this galaxy because NGC 1600 belongs to an average-size galaxy group.
Ma said rich galaxy clusters such as the Coma Cluster are very rare, but average-size galaxy groups such as NGC 1600 are not.
Although initial observations of the 17-million-solar-mass black hole were not detailed enough to see clearly the spectrum of light from the galaxy's center, Ma and her team could immediately tell that it was extraordinary.
Ma said looking at the black hole was like looking at a hurricane from far away.
"We couldn't quite tell how big this hurricane was, this black hole was," said Ma. "But the hurricane was so big that we already started to feel the wind using this coarser data."
What's more interesting is the fact that the surrounding stars in NGC 1600 are moving as if the black hole were a binary black hole, which is expected to be more common in large galaxies.
It is more common because galaxies are thought to grow by merging with other galaxies. Each would theoretically bring a central black hole with it.
The black holes would possibly sink to the new galaxy's core, and after an orbital dance, would merge with the gravitational wave emissions.
Monster Black Holes in Unlikely Places
With their discovery, scientists may have to reconsider their ideas about the location of black holes and their population in the known universe.
"The question now is, 'Is this the tip of an iceberg?" said Ma, who is head of a multitelescope effort called MASSIVE survey that began in 2014 which aims to catalogue and identify the most massive nearby black holes and galaxies.
Ma believes that perhaps there are further monster black holes out there that do not reside like "a skyscraper in Manhattan," but like "a tall silo" found in cosmic small towns. She and her colleagues will then help refine the MASSIVE survey and find more supermassive black holes in the vicinity of Earth.
The team's findings are featured in the journal Nature.
