The mysterious circuit of radio waves is found again

Astronomers have once again discovered a strange circuit of radio waves in the sky. The cause of the circle is unclear: Are we seeing a galactic side view, or the result of the merger of supermassive black holes?

It is the fifth time that astronomers have seen a strange circuit of radio waves. (Single radio circuit Or ORC). In 2020, the astronomer found it Ray Norris From Western Sydney University and CSIRO in Australia, and colleagues Four strange circles of radio waves in the sky. No one has seen such circles before. The team had some ideas of what they could be, but they weren’t sure.

“After we published our research, I expected someone to say, ‘I missed this obvious answer,’” says Norris. But this did not happen.

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Now Norris and Barbel Koribalski From the Australian National Telescope Facility he found another ORC. Came to light thanks to the Australian Pathfinder Array’s Square Kilometer Telescope (ASKAP).

from New radio circuit It appears to be centered around an elliptical galaxy. This was also the case with two of the previously discovered ORCs. The circle is also as bright as these two regions, with a diameter of about a million light years.

Researchers believe that it is no coincidence that three of the ORCs have galaxies at their center. They expect galaxies to be bound to radio waves. The other two centers do not have galaxies in their center. This may be related to another phenomenon.

Candidates

Based on the age of the galaxies, the team says the three galaxies are over a million years old. Both Norris and Koribalski have their favorite candidates when it comes to the reason behind these ORCs.

Norris believes the circles are remnants of a galactic explosion, possibly the result of the merger of two supermassive black holes. “This stuff is so circular that it really looks like a ball around a volcanic eruption.”

He says these assets explain their size and shape, as well as why they are so difficult to find. “We know that supermassive black hole mergers do happen,” Norris says. “But they are very rare.”

Koribalski is not convinced that such a big bang would cause the ORC to be found. Instead, you think we are looking at the final face of a massive galaxy with a black hole in the center, where radio waves are shining from both sides. Then it will be a beam in the form of a dumbbell, one end of which is directed toward the ground. ORCs are rare, therefore, because it is unlikely that the galaxy will point completely in the direction of our telescopes, she says.

astronomer Jacinta Delhies From the University of Cape Town in South Africa, he says the idea of ​​the galaxy is “very reasonable”. But Norris is less confident that the ends of the dumbbell shape will actually look this way.

mystery

Both ideas are still entirely speculative. Koribalski says we haven’t found enough ORCs yet to be sure. She is confident that more will be found soon. Meanwhile, Norris is working on a 3D model of his blast hypothesis to see if it will hold.

“It’s the first time in my career – which has been going on for quite some time now – that I’ve got my hands on a puzzle that I have no idea what it is,” says Norris. “It is everyone’s dream to have such a puzzle.”