The black hole at the center of Mrk 501 ejects a powerful jet of particles traveling at nearly the speed of light into space. For the study, the team analyzed high-resolution observations of the region. These cover various radio frequencies and were collected on dozens of days over a period of approximately 23 years. This long-term data reveals not only a single jet, but a second one as well. It is the first direct image of such a system at the center of a galaxy, and a clear indication of the existence of a second supermassive black hole. “We searched for it for so long, and then it came as a complete surprise that we could not only see a second jet, but even track its movement,” reports Britzen.
https://phys.org/news/2026-04-pair-supermassive-black-holes.html