Astrophysicists from Northwestern University have described the process by which X-shaped radio galaxies appeared. Study published In Astrophysical Journal Letters.
Scientists simulated conditions in which a supermassive black hole actively “feeds”, forming jets (large jets of plasma) and an accretion disk (a structure of gas and dust formed under the influence of gravity).
When the scientists ran the simulation, an X-shaped radio galaxy was formed. It turns out that the galaxy’s characteristic X-shaped shape is the result of the interaction between the jets and the gas falling into the black hole.
At the start of the simulation, the gas deflected the newly formed jets. They inflated pairs of cavities in different directions, forming a characteristic shape. Eventually, however, the jets stabilized, stopped swaying and spread along an axis.
Previously, scientists believed that X-shaped radio galaxies were formed when two galaxies collided, causing supermassive black holes to merge.