(2005) The luminosity dependence of the type 1
active galactic nucleus fraction.
The visible light does not come from the
active galactic nucleus, but from the gas that fills the space between the stars in the galaxy.
A central black hole, also called an
active galactic nucleus, may grow by swallowing material from the surrounding interstellar gas, releasing energy in the process.
Any bright galactic core not powered by starlight is known as an
active galactic nucleus. The most luminous of these are called quasars, and they are thought to be fueled by massive black holes.
Interestingly, the light of material gobbled up by a supermassive black hole sitting at the center of a galaxy or
active galactic nucleus (AGN) varies a lot.
Barro's team found X-ray evidence for an
active galactic nucleus (AGN) in 7 of the 13 galaxies it studied, while Nelson's team saw no sign of an AGN in the galaxy it analyzed.
"They strengthen the case for an
active galactic nucleus in the Milky Way's relatively recent past," he said.
Other observations have revealed that NGC 4945 has an
active galactic nucleus, meaning its central bulge emits far more energy than calmer galaxies like the Milky Way.
Jaffe of the State University of Leiden in the Netherlands, the Hubble image provides the closest look yet at the center of a type of galaxy -- called an
active galactic nucleus (AGN) -- that has a luminous, energetic core.
Sometimes, however, it can also be observed by looking at the energetic radiation from the
active galactic nucleus. Simply put, the energy radiating from the AGN could be responsible for heating and dissipating the gas that would have otherwise cooled and condensed into stars.
On July 3rd in Nature, astronomers reported that the double ACN SDSS J1502+1115 is actually a highly compact triple
active galactic nucleus (ACN).