The Coma Supercluster (SCl 117) is a nearby supercluster of galaxies that includes the Coma Cluster (Abell 1656) and the Leo Cluster (Abell 1367).
Located 300 million light-years from Earth in the constellation Coma Berenices, it is in the center of the Great Wall and a part of the Coma Filament. It is roughly spherical, about 98 mega light-years in diameter, and contains more than 3,000 galaxies.
Although the extent of the Coma Cluster has been understood since around 1900, it took several decades for the existence of the supercluster to be discovered; this was due to the very large physical separation (around 21 Mpc) and angular separation (around 20°) between the Coma and Leo Clusters. In 1977, further analysis of the redshifts of hundreds of galaxies within the supercluster confirmed that these were all part of a larger group of clusters. Despite this, it was still one of the first superclusters to be discovered, and helped astronomers understand the large-scale structure of the universe.
Composition
The Coma Supercluster contains three distinct populations of galaxies: galaxies in the cores of the two main clusters (Coma and Leo), galaxies in low mass groups, and a few isolated galaxies. The dominant structure of the supercluster is four distinct chains of clusters, each one roughly 80 Mpc long. Between each cluster chain is a relatively empty region of space.
See also
- Abell catalogue
- Large-scale structure of the universe
- List of Abell clusters