Potential polar ring galaxy NGC 4632. The picture shows a gaseous ring perpendicularly circulating ... [+]
Scientists using a radio observatory in Western Australia have stumbled upon two rare “polar ring galaxies” that resemble giant eyes with entire galaxies within.
PRGs are unusual galaxies that have a beautiful gas ring perpendicular to a spiral disk of stars.
Discovered during a study of hydrogen gas in 600 galaxies, the two galaxies—known as NGC 4632 and NGC 6156—are both spiral galaxies in the constellations Virgo and Ara, respectively.
The image, above, shows NGC 4632, among the first-ever galaxies revealed to have a polar ring by a radio telescope. The image is a composite of two images—a visible light image of the galaxy from the Subaru telescope in Hawaii and a radio image from the ASKAP telescope in Western Australia.
Most Spectacular In The Universe
“Polar ring galaxies are some of the most spectacular looking galaxies in the universe,” said Dr. Nathan Deg, researcher, Department of Physics, Engineering Physics and Astronomy, Queen’s University, Canada, and lead author of a paper published in the Monthly Notices of the Royal Astronomical Society. “These findings suggest that one to three per cent of nearby galaxies may have gaseous polar rings, which is much higher than suggested by optical telescopes.”
The rare galaxies were found as part of the WALLABY survey, which is now expected to detect hundreds of new polar ring galaxies, according to the authors. Overall it will detect atomic hydrogen emission from around half a million galaxies.
CSIRO's ASKAP radio telescope under the Milky Way on Wajarri Yamaji Country. Western Australia.
Serendipity At Its Best
“This is serendipity at its best—we found things we certainly didn’t expect to find,” said Dr. Kristine Spekkens, Professor (cross-appointed from Royal Military College), Department of Physics, Engineering Physics and Astronomy, Queen’s University, Canada. “These results are a really nice illustration of the tremendous value of mapping the sky more deeply and more widely than has ever been done before.”
It’s hoped that by investigating PRGs astronomers will better understand how galaxies evolve. However, it’s also thought that they can be used to investigate the shape of dark matter in a host galaxy. Accounting for about 85% of matter in the entire universe and only interacting with gravity, dark matter doesn’t absorb, reflect or emit light or energy.
ASKAP—a radio telescope owned and operated by CSIRO, Australia’s national science agency—is at Inyarrimanha Ilgari Bundara, CSIRO’s Murchison radio astronomy observatory on Wajarri Yamaji Country in Western Australia.
The scientists now hope to confirm their findings using the MeerKAT radio telescope in South Africa.
Wishing you clear skies and wide eyes.
