An active Seyfert Galaxy

3D ModelNoAI

About 10% of all known galaxies belong to the class of Seyfert galaxies, named after the astronomer who first studied these objects in 1943, Carl Seyfert. These galaxies look like normal spiral galaxies but have active nuclei with very high surface brightness and properties similar to those of quasars (another class of active but brighter and more distant galaxies). According to recent studies, supermassive black holes are located at the center of these objects. Accretion disks surround the black holes and the infalling plasma from the disks to the black holes determines the high level of activity and brightness of the nuclei. In a few cases (the so-called radio-loud Seyfert galaxies), jets of relativistic particles (such as electrons) are launched by the active nuclei, producing synchrotron emission. An example is the Seyfert galaxy IC 5063 (Tadhunter et al. 2014, Nature 511, 440).

Credit: INAF-Osservatorio Astronomico di Palermo.