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> Active galaxy M77 (NGC 1068) in Cetus
Active galaxy M77 (NGC 1068) in Cetus
author: R.Gendler/Novapix
reference: a-gax10-68002
Image Size 300 DPI: 14 * 12 cm
M77 is an archetypical example of a Seyfert type II galaxy and the brightest galaxy of its class. Galaxies of this type are named after the American astronomer Carl K. Seyfert (1911-1960) who in 1943 first described their characteristics, namely a brilliant starlike nucleus, faint spiral arms, and specific emission line spectra from their nucleus. M77 is a large galaxy and together with its faint outer spiral arms may extend up to 170,000 light years across. It is located about 50 millions light years away in Cetus constellation. Seyfert galaxies are a subclass of galaxies known as active galaxies. Active galaxies are distinguished from normal galaxies by virtue of their "active galactic nucleus" or AGN. Galaxies with an AGN include other subclasses such as quasars and radio galaxies. The Seyfert type nucleus releases prodigious amounts of energy at a wide range of wavelengths, but is especially strong at infrared and radio wavelengths. In contrast to a normal galactic nucleus the energy released from the Seyfert nucleus arises from a nonstellar source. The central engine of the Seyfert nucleus (and all AGN) is believed to be an accretion disk that continuously drops matter into a supermassive black hole.
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