Dying radio galaxies fade faster than scientists expected

Astronomers have identified a surprisingly young population of fading radio galaxies whose supermassive black holes have already switched off their powerful jets. The confirmed remnants range from about 8 to 42 million years old, suggesting many may disappear from view much faster than previously recognized. More distant remnants also seem to fade especially quickly, helping explain why they have been so difficult to detect.

Dying radio galaxies fade faster than scientists expected. Dying radio galaxies fade faster than scientists expected Science News from research organizations Dying radio galaxies fade faster than scientists expected Faint galactic ghosts are revealing that the afterlife of powerful black hole jets may be much shorter than astronomers realized. Com Astronomers have identified a little-studied population of faint remnant radio galaxies that appear to fade quickly after their central supermassive black holes stop producing powerful radio jets.

The findings provide a closer look at what happens during the final stages of a radio galaxy’s evolution. Researchers from the University of Cape Town (UCT) and the Inter-University Institute for Data Intensive Astronomy (IDIA) led the study, which investigated 14 possible remnant radio galaxies in the XMM-Newton Large-Scale Structure (XMM-LSS) field. Remnant radio galaxies are systems in which the jets produced by the central active galactic nucleus (AGN) have shut down.

Once those jets stop supplying energetic particles to the galaxy’s large radio lobes, the particles already inside the lobes gradually lose energy, and the radio emission becomes fainter.