active galactic nucleus

(redirected from Active galaxies)
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Related to Active galaxies: Quasars

active galactic nucleus

n.
A galactic nucleus that emits more radiation than can be accounted for solely by light from the stars it contains.
References in periodicals archive ?
One day 3C 279 was just one of many active galaxies we see, and the next day it was the brightest thing in the gamma-ray sky," said Sara Cutini, a Fermi Large Area Telescope scientist at the Italian Space Agency's Science Data Center in Rome.
K2 also will introduce new opportunities to observe star clusters, active galaxies and supernovae.
It tells us more about the powerful ionized winds that allow supermassive black holes in the nuclei of active galaxies to expel large amounts of matter.
Using data from NASA's Rossi X-ray Timing Explorer (RXTE) satellite, an international team has uncovered a dozen instances where X-ray signals from active galaxies dimmed as a result of a cloud of gas moving across our line of sight.
Examples of these phenomena include black holes at all scales, neutron stars, pulsars and their nebula, binaries, novae and supernovae, their remnants, active galaxies, and clusters.
Understanding how the first active galaxies (AGN) and quasars formed in the early Universe and how they evolved along Cosmic Time is a major observational and theoretical effort.
The identification of active galaxies as a class distinct from others began 15 years later in 1940-'42 with the work of Carl Seyfert, also working at the Mount Wilson Observatory.
Officials said the primary goals of the mission are to conduct a deep survey for supermassive black holes, study particle acceleration in active galaxies, and measure radioactive isotopes in young supernova remnants in our own galaxy.
Kevin Schawinski, of Yale University, said: "We just don't see such active galaxies today.
The time in Texas indeed shaped much of Tony's later research career; his interest in active galaxies and supernovae (valuable for measuring the scale of the universe) were strengthened from the time spent in California with Fritz Zwicky, whom Tony held in the highest regard.
Aimed at astronomy and physics majors, it offers thorough coverage of galactic structure and evolution, active galaxies, cosmology, and the history of the universe.
During the first five years - its original lifespan was only meant to be three to five years - cosmonauts and scientists pushed back the limits of knowledge on the physics of active galaxies, quasars and neutron stars, and acquired a wealth of information about living for long periods in space.