Active Galactic Nuclei (AGN)

3D ModelNoAI

Galaxies are gravitationally bound systems made of stars, gas, dust, remnants of stellar explosions (the so-called supernova remnants), star forming regions, and dark matter. The Milky Way is the galaxy hosting our solar system. In some cases, a galaxy can be characterized by a very bright central region, much more luminous than the rest of the hosting galaxy. These regions are called Active Galactic Nuclei (AGN). AGN are strong emitters of non-thermal radiation basically at all wavelength bands, from radio, to optical, ultraviolet, and X-rays. According to most recent studies, AGN have a supermassive black hole at the center, with an accretion disk of hot gas in the immediate surrounding, and a more extended torus of colder gas at larger distances. Collimated bipolar jets mainly emitting in the radio band propagate perpendicularly to the plane of the disk and the torus.

Credits: INAF - Osservatorio Astronomico di Palermo.