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Red quasars are quasars with optical colors that are redder than normal quasars, thought to be the result of moderate levels of dust extinction within the quasar host galaxy. Infrared surveys have demonstrated that red quasars make up a substantial fraction of the total quasar population.
Size comparison of the event horizons of the black holes of TON 618 and Phoenix A.The orbit of Neptune (white oval) is included for comparison. As a quasar, TON 618 is believed to be the active galactic nucleus at the center of a galaxy, the engine of which is a supermassive black hole feeding on intensely hot gas and matter in an accretion disc.
3C 279 (also known as 4C–05.55, NRAO 413, and PKS 1253–05) is an optically violent variable quasar (OVV), which is known in the astronomical community for its variations in the visible, radio and X-ray bands. [2] The quasar was observed to have undergone a period of extreme activity from 1987 until 1991. [3]
Quasars, Redshifts and Controversies is a 1987 book by Halton Arp, an astronomer famous for his Atlas of Peculiar Galaxies (1966). [1] Arp argued that many quasars with otherwise high redshift are somehow linked to close objects such as nearby galaxies .
Most have been observationally associated with central black holes of some active galaxies, radio galaxies or quasars, and also by galactic stellar black holes, neutron stars or pulsars. Beam lengths may extend between several thousand, [ 6 ] hundreds of thousands [ 7 ] or millions of parsecs. [ 2 ]
The long-term effects from a nearby burst are more dangerous. Gamma rays cause chemical reactions in the atmosphere involving oxygen and nitrogen molecules, creating first nitrogen oxide then nitrogen dioxide gas. The nitrogen oxides cause dangerous effects on three levels.
There is a correlation between the quasar's luminosity and the mass of its host galaxy, in that the most luminous quasars inhabit the most massive galaxies (ellipticals). 'Quasar 2s'. By analogy with Seyfert 2s, these are objects with quasar-like luminosities but without strong optical nuclear continuum emission or broad line emission.
Any quasar with z > 1 is receding faster than c, while z exactly equal to 1 indicates recession at the speed of light. [33] Early attempts to explain superluminal quasars resulted in convoluted explanations with a limit of z = 2.326, or in the extreme z < 2.4. [34] The majority of quasars lie between z = 2 and z = 5.