PGC 1000714: The rare galaxy 'nobody has ever seen before'
Karolyn Coorsh , CTVNews.ca
Published Wednesday, January 4, 2017 8:45AM EST
Researchers are getting a first look at a new, extremely rare, galaxy approximately 359 million light-years away. The scientists who discovered it say it’s unlike anything they’ve seen before.
Newly published research by scientists at the University of Minnesota Duluth and at the North Carolina Museum of Natural Sciences provided an initial description of the galaxy, named PGC 1000714.
Images show its defined elliptical-like core surrounded by two circular rings, indicating that it belongs to the rarely observed class of Hoag-type galaxies.
Study co-author and astrophysicist Patrick Treuthardt says Hoag-types, which feature an elliptical core and a circular ring with “nothing connecting the two,” are so rare that they comprise just 0.1 per cent of all the galaxies in the “observable” universe.
Treuthardt said he first spotted PGC 1000714 while analyzing “a bunch” of other galaxies.
“This was actually off to the side of the galaxy I was actually doing research on,” he told CTV’s Your Morning on Wednesday. On closer inspection, Treuthardt says he saw a “blue ring around it. When I saw that I already knew I had something there.”
After some analysis, Treuthardt and his colleagues were able to “subtract out the core,” and found another circular ring underneath the core’s light. “That’s unique,” he said. “That’s something nobody has ever seen before.”
The second red inner ring appears to be older than the blue ring, which is what makes it unique.
Researchers collected “multi-waveband” images of the galaxy using a large diameter telescope in the Chilean mountains. Those images were able to help researchers determine the ages of the galaxy’s outer ring and central body.
Because of the still-limited data on the galaxy, Treuthardt says he and his colleagues are still a little confused by it.
“What we really need to do is actually probe the interior more,” he said. “Maybe something came by and interacted with the galaxy to form these rings so we need to probe the gas that surrounds the galaxy as well.”
But he’s hoping the discovery will be a “really good test” of the overall understanding of how galaxies form and evolve.
“Right now there’s a pretty good understanding of how galaxies form, maybe how they evolve, through the history of the universe,” Treuthardt said. “But these outlying galaxies, these galaxies that are strange and unusual, they actually really push the boundaries of our theories.”