A rich (high-concentration density) cluster of galaxies as characterized by the American astronomer GEORGE O. ABELL (1927–83). In 1958 Abell produced a catalog describing over 2,700 of such high-density galactic clusters using photographic data from the Palomar Observatory. Abell required that each cluster of galaxies satisfy certain criteria before he included them in this catalog. His selection criteria included population (each Abell cluster had to contain 50 or more galaxies) and high-concentration density (richness). Abell also characterized such rich galactic clusters by their appearance—listing them as either regular or irregular.
Senin, 03 November 2008
Abell cluster
A rich (high-concentration density) cluster of galaxies as characterized by the American astronomer GEORGE O. ABELL (1927–83). In 1958 Abell produced a catalog describing over 2,700 of such high-density galactic clusters using photographic data from the Palomar Observatory. Abell required that each cluster of galaxies satisfy certain criteria before he included them in this catalog. His selection criteria included population (each Abell cluster had to contain 50 or more galaxies) and high-concentration density (richness). Abell also characterized such rich galactic clusters by their appearance—listing them as either regular or irregular.
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