Coma Supercluster
{{Short description|Supercluster of galaxies}}
{{Infobox galaxy cluster
| name = Coma Supercluster
| image = Com01.png
| image_scale = 2
| caption = A map of the Coma Supercluster
| constellation = Coma Berenices
| distance = {{convert|92|Mpc|Mly|0|abbr=on|lk=on}}{{Cite web |title=NED results for object Coma Supercluster |url=https://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=Coma+Supercluster&extend=no |access-date=2025-02-03 |website=NASA/IPAC Extragalactic Database}}
|epoch=J2000}}
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,{{cite web|title=Superclusters - A Review of the Universe|url=https://universe-review.ca/F03-supercluster.htm|accessdate=1 January 2016}} it is in the center of the Great Wall and a part of the Coma Filament.'Astronomy and Astrophysics' ({{ISSN|0004-6361}}), vol. 138, no. 1, Sept. 1984, pp. 85-92. Research supported by Cornell University "The Coma/A 1367 filament of galaxies" 09/1984 {{bibcode|1984A&A...138...85F}} It is roughly spherical, about 98 mega light-years in diameter,{{Cite journal |last1=Seth |first1=Ruchika |last2=Raychaudhury |first2=Somak |date=2020-09-01 |title=Evolution of galaxies in groups in the Coma Supercluster |url=https://academic.oup.com/mnras/article/497/1/466/5860776 |journal=Monthly Notices of the Royal Astronomical Society |volume=497 |issue=1 |pages=466–481 |doi=10.1093/mnras/staa1779 |doi-access=free |issn=0035-8711|arxiv=2006.09898 }} and contains more than 3,000 galaxies.
Although the extent of the Coma Cluster has been understood since around 1900,{{Citation |last=Steinicke |first=Wolfgang |title=The Discovery of the Coma Cluster of Galaxies |date=2023 |work=Essays on Astronomical History and Heritage: A Tribute to Wayne Orchiston on his 80th Birthday |series=Historical & Cultural Astronomy |pages=225–238 |editor-last=Gullberg |editor-first=Steven |url=https://link.springer.com/chapter/10.1007/978-3-031-29493-8_10 |access-date=2025-02-18 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-031-29493-8_10 |bibcode=2023eahh.book..225S |isbn=978-3-031-29493-8 |editor2-last=Robertson |editor2-first=Peter|url-access=subscription }} 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.{{Cite journal |last1=Gregory |first1=S. A. |last2=Thompson |first2=L. A. |date=1978-06-01 |title=The Coma/A1367 supercluster and its environs. |url=https://ui.adsabs.harvard.edu/abs/1978ApJ...222..784G/abstract |journal=The Astrophysical Journal |volume=222 |pages=784–799 |bibcode=1978ApJ...222..784G |doi=10.1086/156198 |issn=0004-637X}} 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.
= Core population =
Galaxies found at the cores of clusters are high in density and have a high velocity dispersion: around 1000 km/s in Abell 1656, and slightly lower than this in Abell 1367. These galaxies tend to be either elliptical or lenticular galaxies, suggesting that they have undergone mergers or tidal stripping.
= Low-mass groups =
= Isolated galaxies =
Kinematics
Multiple peaks in the distribution of the redshifts of the galaxies in the Coma Supercluster suggest that the system is not gravitationally relaxed, which would result in many galaxy groups maintaining their own individual velocities. This implies that they still have not yet fully merged into the supercluster, but are expected to eventually.
This is supported by the general motion of the galaxies, which is moving inwards towards the core of the cluster.{{Cite journal |last1=Tago |first1=Erik |last2=Einasto |first2=Jaan |last3=Saar |first3=Enn |date=1984-02-01 |title=Structure of superclusters and superclusters formation – IV. Spatial distribution of clusters of galaxies in the Coma Supercluster and its large-scale environment |url=https://academic.oup.com/mnras/article/206/3/559/958968?login=false |journal=Monthly Notices of the Royal Astronomical Society |volume=206 |issue=3 |pages=559–587 |doi=10.1093/mnras/206.3.559 |doi-access=free |issn=0035-8711|url-access=subscription }}
See also
References
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