Active Galactic Nucleus

An Active Galactic Nucleus (AGN) is a compact region at the center of a galaxy that is thought to contain a supermassive black hole and is characterized by its high levels of radiation across the electromagnetic spectrum, from radio waves to gamma rays. AGNs are some of the most energetic and luminous objects in the universe and are believed to play a major role in the evolution and growth of galaxies.

There are two main types of AGN: Seyfert galaxies and Quasars. Seyfert galaxies have lower luminosities and are relatively nearby, while Quasars are extremely luminous and can be located billions of light-years away.

The high luminosity of AGNs is thought to be powered by the accretion of matter onto the central supermassive black hole. As matter spirals towards the black hole, it heats up and radiates energy, producing the observed high levels of radiation. The intense radiation from AGNs can have a significant impact on their host galaxies, influencing the evolution of stars and the distribution of gas and dust.

The study of AGNs is important for understanding the processes that govern the growth and evolution of black holes and galaxies. By observing the properties of AGNs, such as their luminosity, spectrum, and variability, scientists can probe the physical conditions near supermassive black holes and gain insight into the processes that drive accretion and the emission of radiation from these objects.