A team of international astronomers has made one of the most detailed observations yet of a spectacular jet emerging from the heart of a distant galaxy, OJ 287. Using the RadioAstron space telescope in combination with a global network of radio observatories, they have shed new light on extreme environments surrounding supermassive black holes.
Located about 5 billion light-years from Earth, OJ 287 has long intrigued scientists due to its dramatic bursts of light and enigmatic behavior. It is suspected to hold a binary system of two supermassive black holes with a total mass exceeding a billion Solar masses. For the first time, researchers have peered into its core with high spatial resolution, revealing a sharply bent “ribbon” of plasma twisting and turning as it streams from the galaxy’s center.
The findings, published in Astronomy & Astrophysics, have provided new insights into how two gigantic black holes interact. By combining a spaceborne radio telescope with 27 ground-based radio telescopes worldwide, researchers created a virtual telescope five times the diameter of Earth. This remarkable clarity revealed intricate details, including regions within the jet hotter than 10 trillion Kelvin.
The study has also offered clues about how jets are launched and shaped. Polarisation measurements showed the jet’s magnetic field aligned along its length, providing new information on this phenomenon. The team witnessed the birth of a shock wave in the jet, which later collided with a stationary shock, an event that coincided with the historic detection of trillion-electron-volt gamma rays from OJ 287 in early 2017.
The observations may also shed light on the mystery surrounding OJ 287’s unusual brightness variations. The newly imaged jet structure supports the idea that two massive black holes are orbiting each other in the galaxy’s core, their motion potentially twisting and reorienting the jet. This effect is now becoming detectable with highly accurate radio recordings.
The study has significant implications for studying binary supermassive black hole systems and their potential mergers, which could generate powerful gravitational waves. The RadioAstron project marks an important step towards multi-messenger astronomy, a new approach that combines signals such as electromagnetic radiation, gravitational waves, and neutrinos to explore the Universe in unprecedented detail.
Source: https://www.tudelft.nl/en/2025/lr/ribbons-in-the-sky-space-radio-telescope-reveals-plasma-jet-in-a-supermassive-black-hole-binary-candidate