active galactic nucleus (AGN)
Chandra X-ray image of Centaurus A showing a bright central source: the active galactic nucleus suspected of harboring a supermassive black hole ...
Active galactic nucleus
An active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas.
Active galactic nucleus
Wikipedia, the free encyclopedia - Cite This Source ...
galactic nucleus Small central high-density region of a galaxy. Nearly all of the radiation from an active galaxy is emitted from the nucleus.
galactic nucleus
the central region of a galaxy; often contains a high density of stars and gas, and a supermassive black hole
galactic plane ...
Galactic Nucleus
In the innermost region of a galaxy, there is often a concentration of stars and gas, sometimes extending over thousands of light-years from the center of the galaxy.
Galactic Plane ...
Galactic Nucleus
a tight concentration of stars and gas found at the innermost regions of a galaxy. Astronomers now believe that massive black holes may exist in the center of many galaxies.
Galactic Nucleus - The central region of the Milky Way
Galaxy - A massive system of stars, gas, and dark matter held together by its own gravity
Gamma Ray - The part of the electromagnetic spectrum having the shortest wavelengths ...
active galactic nucleus (AGN): The central energy source of an active galaxy.
active galaxy: A galaxy that is a source of excess radiation, usually radio waves, X rays, gamma rays, or some combination.
galactic nucleus Small central high-density region of a galaxy. Most galactic nuclei are thought to harbor a supermassive black hole.
galaxy A gravitationally-bound system of stars, gas, dust and dark matter. [More Info: Field Guide] ...
Galactic Nucleus
The central concentration of matter (stars, gas, dust, and perhaps a black hole) in a galaxy, typically spanning no more than a few light-years in diameter.
Galactic Plane ...
Active Galactic Nucleus (AGN)
A very bright, compact region found at the center of certain galaxies. The brightness of an active galactic nucleus is thought to come from an accretion disk around a supermassive black hole.
Active Galactic Nucleus (AGN): The central region of an active galaxy where the energtic activity is concentrated.
two separated bodies are said to directly exert forces on each other. In the modern description, the bodies produce a gravitational field, which in turn exerts forces on the two bodies. see Gravitational Field [G97]
Active Galactic Nucleus ...
accretion disks (NASA Thesaurus) Rotating disks of matter surrounding an astronomical object, such as a star, galactic nucleus, black hole, etc., which is accumulated gravitationally by the object.
As mentioned repeatedly, the galactic nucleus is not visible in optical light. It can be studied, however, in light from other parts of the electromagnetic spectrum. Recall that dust affects blue light more than red light.
Recent detailed pictures of radio galaxies, obtained with high resolution radio telescopes such as the VLA, often show a prominent jet of material connecting a bright, compact radio source at the galactic nucleus to the more extended radio lobes ...
For example, the active galactic nucleus of NGC 1068 is shown at X-ray (blue/green) and optical (red) wavelengths.
The standard model for an active galactic nucleus is based upon an accretion disc that forms around a supermassive black hole (SMBH) at the core region.
An AGN is short for "Active Galactic Nucleus." Some galaxies have nuclei (centers) that are 'active', meaning they emit large amounts of radiation (radio, optical, X-rays, gamma-rays, particle jets, etc.), and/or are highly variable.
One unsolved mystery that has left astronomers puzzled is where the material comes from to disturb a black hole from its slumber, triggering angry outbursts as it is awoken and becoming an active galactic nucleus.
Firstly X-rays are emitted by black holes in active galactic nucleus, or AGN for short, galaxy clusters, supernova remnants, stars, binary stars containing a white dwarf (cataclysmic variable stars), neutron star or a black hole (X-ray binaries), ...
Definition: jets: Beams of particles, usually coming from an active galactic nucleus or a pulsar. Unlike a jet airplane, when the stream of gas is in one direction, astrophysical jets come in pairs with each jet aiming in opposite directions.
A Quasi-stellar radio source is a powerfully energetic and distant active galactic nucleus.
From it pours a variable jet at nearly the speed of light, making M 87 an "active galaxy" and the core an "active galactic nucleus," or "AGN.
If this cloud can be excited by a nearby source of energy such as hot, young stars or an active galactic nucleus then the electrons in atoms of the gas cloud can get excited. When they de-excite they emit photons of specific frequency and wavelength.
active galaxy, active galactic nucleus, AGN
radio wavelengths, radiowaves
bremsstrahlung radiation ...
JETS
Jets are blasts of particles that are emitted by an active galactic nucleus or a pulsar. Jets only occur in pairs, going in opposite directions.
Jets: A pair of beams of particles, usually coming from an active galactic nucleus or a pulsar.
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The Hourglass Milky Way Thunderbolts - June 28, 2010
A dipolar "bubble" of gamma radiation from the galactic nucleus
charged dust into a z-pinch compression zone.
Andromedia: Galaxy, Constellation, Mythology ...
The central region of an active galaxy is called an "active galactic nucleus" (AGN) where energetic activity is concentrated.
there are many cluster located there, the main reason for Lacerta's fame is BL Lacertae. This object, originally identified as an irregular variable star, is now known to correspond to a quasi-stellar object a.k.a. an active galactic nucleus ...
While halo stars are only very weakly concentrated towards the galactic plane, they exhibit a strong concentration towards and including the galactic nucleus but with highly eccentric orbits.
We are currently near this, at 27 700 light years from galactic centre, and will reach it in 15 million years, which is less than one twelfth of the Sun's period of revolution about the galactic nucleus (the galactic year).
Centaurus A is a nearby example of an extended radio galaxy that features two outer lobes 650,000 and 1,350,000 light-years in diameter. In contrast, compact radio galaxies emit radio lobes not much larger than the galactic nucleus.
active galactic nuclei are produced by material spiraling into a disk around the black hole, and being squashed out the top and bottom of the disk as it tries to enter the black hole. This explanation for the "engine'' in an active galactic nucleus ...
 See also: Nucleus, Galaxy, Black Hole, Galaxies, Distance
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