Astronomers have taken clearest pictures but of “odd radio circles” – mysterious radio waves one million gentle years throughout – and so they all appear to have central galaxies containing energetic supermassive black holes
22 March 2022
We lastly have a sharper picture of one of many weirdest phenomena in area. These aptly named odd radio circles, or ORCs, are circles of radio waves that don’t appear to emit any radiation in different wavelengths, in contrast to many different objects seen in radio waves.
A group of researchers led by Ray Norris on the Australian Commonwealth Scientific and Industrial Research Organisation first noticed these unusual circles in 2020 utilizing the Australian Square Kilometre Array Pathfinder radio telescope. Astronomers have now definitively noticed 5 of them, with a number of extra unconfirmed candidates. Now Norris and his colleagues have used the MeerKAT telescope in South Africa to take the sharpest picture but of an ORC.
Odd radio circles are about a million gentle years throughout, bigger than even the most important spiral galaxies. Of the 5 confirmed ORCs, astronomers had seen galaxies on the centres of three of them, which hinted that the circles could be fashioned by some galactic course of.
The new observations from MeerKAT have revealed that every one ORCs appear to have central galaxies containing energetic supermassive black holes. That considerably narrows down the choices for what ORCs might be. According to Norris, there at the moment are three major choices: they might be particles from a big explosion of their host galaxies, they may come from jets of fabric spewed out by supermassive black holes, or they may come from residual power from bursts of star formation.
It will take extra observations with extra delicate radio telescopes to determine which of those explanations is the right one. The Square Kilometre Array, an enormous array of radio telescopes with sections in each Australia and South Africa, is predicted to search out many extra ORCs and assist shut the e book on what they are surely as soon as it’s absolutely constructed in 2028.
Journal reference: Monthly Notices of the Royal Astronomical Society, DOI: 10.1093/mnras/stac701
Sign as much as our free Launchpad e-newsletter for a voyage throughout the galaxy and past, each Friday
More on these matters: