In the boundless expanses of space, phenomena occasionally appear that baffle even the most experienced scientists. One such example is “Odd Radio Circles” (ORC) – giant circular structures visible only in the radio spectrum. Discovered in 2019, they resemble cosmic ghosts, and their origin remains a mystery. But now scientists have taken an important step toward solving it.
The advent of powerful new telescopes often opens the door to phenomena we never even suspected about. This is what happened with the Australian ASKAP radio telescope, which discovered strange radio rings during its first survey of the sky. They were so unusual that they were given their own category. To date, only about a dozen such objects are known. They are invisible to optical, infrared, or X-ray telescopes, which makes them even more mysterious.
Universal ghosts
An international team led by German scientists from Ruhr University Bochum decided to thoroughly study one such object – ORC J0356-4216. Researchers used powerful ASKAP and MeerKAT radio telescopes to analyze its structure and radiation properties. The results were impressive. It turned out that this was not a simple ring, but a complex structure consisting of two symmetrical arcs with a total diameter of more than 2 million light-years. Such a formation could easily encompass several galaxies similar to the Milky Way.
Who is the architect of these giants?
Analysis showed that the radio emissions from the rings were strongly polarized, and the magnetic field within them was oriented along the arcs themselves. This key detail, together with the location of ORCs in the center of the galaxy, points to the likely source of their origin. Scientists suggest that we are observing a relic shock wave from a colossal event in the past of this galaxy. The most plausible scenarios are cataclysms such as the merger of two galaxies, a powerful starburst, or a phase of incredible activity of a supermassive black hole at the core of the galaxy. In the latter case, the substance falling into the black hole ejected powerful jets of plasma, which formed these giant radio rings.
The study, which is awaiting peer review, offers the most comprehensive explanation of the nature of these mysterious “cosmic ghosts.” Although the mystery of ORCs has not yet been fully solved, science has come closer to understanding one of the most amazing formations in the Universe.
We previously reported on how MeerKAT found a double relic and ORC.
According to sciencealert.com
