A research group led by Stefanie Komossa (MPIfR Bonn, Germany) presents new results on the galaxy OJ 287, based on the most dense and longest radio-to-high-energy observations to date with telescopes like the Effelsberg telescope and the Swift Observatory.

The results favor a pair of black holes in the center of the galaxy with a smaller mass of 100 million solar masses for the primary black hole. Several outstanding mysteries, including the apparent absence of the latest big outburst of OJ 287 and the much-discussed emission mechanism during the main outbursts, can be solved this way.

Blazars are galaxies that host powerful, long-lived jets of relativistic particles that are launched in the immediate vicinity of their central supermassive black hole.

When two galaxies collide and merge, supermassive binary black holes are formed. These binaries are of great interest because they play a key role in the evolution of galaxies and the growth of supermassive black holes. Furthermore, coalescing binaries are the universe's loudest sources of gravitational waves. The future ESA cornerstone mission LISA (Laser Interferometer Space Antenna) aims to directly detect such waves in the gravitational wave spectrum. The search for supermassive binary black hole systems is currently in full swing.