Latest Active galactic nucleus Stories
Researchers from several American institutes and agencies have developed a new model showing how an elusive type of black hole can be formed in the gas surrounding their supermassive counterparts.
Astronomers studying the galaxy NGC 4151 with ESA's XMM-Newton space observatory have detected X-rays emitted and then reflected by ionised iron atoms very close to the supermassive black hole hosted at the galaxy's core.
Gamma-ray beams seen in the Milky Way's central black hole suggest that the galaxy's center was much more active in the past, according to new research.
By combining the light of three powerful infrared telescopes, an international research team has observed the active accretion phase of a supermassive black hole in the center of a galaxy tens of millions of light years away.
A curious correlation between the mass of a galaxy's central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years.
Astronomers using the partially completed ALMA observatory have found compelling evidence for how star-forming galaxies evolve into 'red and dead' elliptical galaxies, catching a large group of galaxies right in the middle of this change.
An international team of astronomers has identified the moment when a black hole in our galaxy launched super-fast knots of gas into space.
Supermassive black holes millions to billions times the mass of our Sun lie at the heart of most, maybe all large galaxies.
Seyfert Galaxy -- Seyfert galaxies are spiral or irregular galaxies containing an extremely bright nucleus, most likely caused by a supermassive black hole, that can sometimes outshine the surrounding galaxy. The light from the central nucleus varies in less than a year, which implies that the emitting region must be less than one light year across. They are named for the astronomer Carl Seyfert, who studied them extensively in the 1940s. They are a subclass of active galactic nuclei....
Quasar -- A quasar (from quasi-stellar radio source) is an astronomical object that looks like a star in optical telescopes (i.e. it is a point source), but has a very high redshift. The general consensus is that this high redshift is cosmological, the result of Hubble's law and that their redshift indicates that they are typically very distant from Earth; we observe them as they were several billions of years ago. Since we can see them despite their distance, they must emit more...
Active Galaxy -- An active galaxy is a galaxy where a significant fraction of the energy output is not emitted from normal stellar populations or interstellar gas. This energy, depending on the active galaxy type, can be emitted across most of the electromagnetic spectrum, as infrared, radio waves, UV, X-ray and gamma rays. Frequently, the abbreviation AGN (Active Galactic Nuclei) is used, since most of the active galaxies emit most of their radiation from a narrow region in their...
Circinus Galaxy -- Resembling a swirling witch's cauldron of glowing vapors, the black hole-powered core of a nearby active galaxy appears in this colorful NASA Hubble Space Telescope image. The galaxy lies 13 million light-years away in the southern constellation Circinus. This galaxy is designated a type 2 Seyfert, a class of mostly spiral galaxies that have compact centers and are believed to contain massive black holes. Seyfert galaxies are themselves part of a larger class of objects...
- To swell, as grain or wood with water.