As reported by CSIRO.

First revealed by the ASKAP radio telescope, owned and operated by Australia’s national science agency CSIRO, odd radio circles quickly became objects of fascination. Theories on what caused them ranged from galactic shockwaves to the throats of wormholes.

A new detailed image, captured by the South African Radio Astronomy Observatory’s MeerKAT radio telescope and published today in Monthly Notices of the Royal Astronomical Society (DOI 10.1093/mnras/stac701 and available on arXive), is providing researchers with more information to help narrow down those theories.

There are now three leading theories to explain what causes ORCs:

·       They could be the remnant of a huge explosion at the centre of their host galaxy, like the merger of two supermassive black holes;

·       They could be powerful jets of energetic particles spewing out of the galaxy’s centre; or

·       They might be the result of a starburst ‘termination shock’ from the production of stars in the galaxy.

To date ORCs have only been detected using radio telescopes, with no signs of them when researchers have looked for them using optical, infrared, or X-ray telescopes.

Dr Jordan Collier of the Inter-University Institute for Data Intensive Astronomy, who compiled the image from MeerKAT data said continuing to observe these odd radio circles will provide researchers with more clues.

“People often want to explain their observations and show that it aligns with our best knowledge. To me, it’s much more exciting to discover something new, that defies our current understanding,” Dr Collier said.

The rings are enormous – about a million light years across, which is 16 times bigger than our own galaxy. Despite this, odd radio circles are hard to see.

Professor Ray Norris from Western Sydney University and CSIRO, one of the authors on the paper, said only five odd radio circles have ever been revealed in space.

Read the full media release.

Photo: Artist’s impression of odd radio circles. Credit – CSIRO.