Bautz–Morgan classification explained
The Bautz–Morgan classification was developed in 1970 by Laura P. Bautz and William Wilson Morgan to categorize galaxy clusters based on their morphology.[1] It defines three main types: I, II, and III. Intermediate types (I-II, II-III) are also allowed. A type IV was initially proposed, but later redacted before the final paper was published.[2]
Classification
- A type I cluster is dominated by a bright, large, supermassive cD galaxy; for example Abell 2029 and Abell 2199.
- A type II cluster contains elliptical galaxies whose brightness relative to the cluster is intermediate to that of type I and type III. The Coma Cluster is an example of a type II.
- A type III cluster has no remarkable members, such as the Virgo Cluster. Type III has two subdivisions, type IIIE and type IIIS
- Type IIIE clusters do not contain many giant spirals
- Type IIIS clusters contain many giant spirals
- The deprecated type IV was for clusters whose brightest members were predominantly spirals.[2]
Examples
See also
Notes and References
- Bautz . L. P. . Laura P. Bautz . Morgan . W. W. . William Wilson Morgan . December 1970 . On the Classification of the Forms of Clusters of Galaxies . Astrophysical Journal . 162 . L149 . A&AA ID. AAA004.160.015 . 1970ApJ...162L.149B . 10.1086/180643 . March 10, 2012 .
- Bautz . Laura P. . Laura P. Bautz . Morgan . W. W. . William Wilson Morgan . September 1970 . Preliminary Classification of Clusters of Galaxies . Bulletin of the American Astronomical Society . 2 . 294 . A&AA ID. AAA004.160.006 . 1970BAAS....2R.294B . March 10, 2012 .