Supercluster

A supercluster is a large group of smaller galaxy clusters or galaxy groups;[1] it is among the largest known structures of the universe. The Milky Way is part of the Local Group galaxy group (which contains more than 54 galaxies), which in turn is part of the Virgo Supercluster, which is part of the Laniakea Supercluster.[2] The large size and low density of superclusters means that they, unlike clusters, expand with the Hubble expansion. The number of superclusters in the observable universe is estimated to be 10 million.[3]

A map of the Superclusters and voids nearest to Earth

Existence

The Abell 901/902 supercluster is located a little over two billion light-years from Earth.[4]

The existence of superclusters indicates that the galaxies in the Universe are not uniformly distributed; most of them are drawn together in groups and clusters, with groups containing up to some dozens of galaxies and clusters up to several thousand galaxies. Those groups and clusters and additional isolated galaxies in turn form even larger structures called superclusters.

Their existence was first postulated by George Abell in his 1958 Abell catalogue of galaxy clusters. He called them "second-order clusters", or clusters of clusters.[5]

Superclusters form massive structures of galaxies, called "filaments", "supercluster complexes", "walls" or "sheets", that may span between several hundred million light-years to 10 billion light-years, covering more than 5% of the observable universe. These are the largest structures known to date. Observations of superclusters can give information about the initial condition of the universe, when these superclusters were created. The directions of the rotational axes of galaxies within superclusters are studied by those who believe that they may give insight and information into the early formation process of galaxies in the history of the Universe.[6]

Interspersed among superclusters are large voids of space where few galaxies exist. Superclusters are frequently subdivided into groups of clusters called galaxy groups and clusters.

Although superclusters are supposed to be the largest structures in the universe, according to the Cosmological principle, larger structures have been observed in surveys, including the Sloan Great Wall.[7]

List of superclusters

Galaxy supercluster	Data	Notes
Laniakea Supercluster	z = 0.000 Length = 153 Mpc (500 million light-years)	The Laniakea Supercluster is the supercluster that contains the Virgo Cluster, Local Group, and by extension on the latter, our galaxy; the Milky Way.[2]
Virgo Supercluster	z= 0.000 Length = 33 Mpc (110 million light-years)	It contains the Local Group with our galaxy, the Milky Way. It also contains the Virgo Cluster near its center, and is sometimes called the Local Supercluster. It is thought to contain over 47,000 galaxies. In 2014, the newly announced Laniakea Supercluster subsumed the Virgo Supercluster, which became a component of the new supercluster.[8]
Hydra-Centaurus Supercluster		It is composed of two lobes, sometimes also referred to as superclusters, or sometimes the entire supercluster is referred to by these other two names Hydra Supercluster Centaurus Supercluster In 2014, the newly announced Laniakea Supercluster subsumed the Hydra-Centaurus Supercluster, which became a component of the new supercluster.[8]
Pavo-Indus Supercluster		In 2014, the newly announced Laniakea Supercluster subsumed the Pavo-Indus Supercluster, which became a component of the new supercluster.[8]
Southern Supercluster		Includes Fornax Cluster (S373), Dorado and Eridanus clouds.
Saraswati Supercluster	Distance = 4000 Million light years (1.2 Gpc) Length = 652 Million light-years	The Saraswati Supercluster consists of 43 massive galaxy clusters such as Abell 2361 and has a mass of about 2 x 10^16 M☉ and is seen in the Pisces constellation

Nearby superclusters

Galaxy supercluster	Data	Notes
Perseus-Pisces Supercluster
Coma Supercluster		Forms most of the CfA Homunculus, the center of the CfA2 Great Wall galaxy filament
Sculptor Superclusters		SCl 9
Hercules Superclusters		SCl 160
Leo Supercluster		SCl 93
Ophiuchus Supercluster	17^h 10^m −22° cz=8500–9000 km/s (centre) 18 Mpc x 26 Mpc	Forming the far wall of the Ophiuchus Void, it may be connected in a filament, with the Pavo-Indus-Telescopium Supercluster and the Hercules Supercluster. This supercluster is centered on the cD cluster Ophiuchus Cluster, and has at least two more galaxy clusters, four more galaxy groups, several field galaxies, as members.[9]
Shapley Supercluster	z=0.046.(650 Mly away)	The second supercluster found, after the Local Supercluster.

Distant superclusters

Galaxy supercluster	Data	Notes
Pisces-Cetus Supercluster
Boötes Supercluster		SCl 138
Horologium-Reticulum Supercluster	z=0.063 (700 Mly) Length = 550 Mly
Corona Borealis Supercluster	z=0.07[10]
Columba Supercluster
Aquarius Supercluster
Aquarius B Supercluster
Aquarius-Capricornus Supercluster
Aquarius-Cetus Supercluster
Bootes A Supercluster
Caelum Supercluster	z=0.126 (1.4 Gly) Length = 910 Mly	The largest galaxy supercluster.
Draco Supercluster
Draco-Ursa Major Supercluster
Fornax-Eridanus Supercluster
Grus Supercluster
Leo A Supercluster
Leo-Sextans Supercluster
Leo-Virgo Supercluster		SCl 107
Microscopium Supercluster		SCl 174
Pegasus-Pisces Supercluster		SCl 3
Perseus-Pisces Supercluster		SCl 40
Pisces-Aries Supercluster
Ursa Majoris Supercluster
Virgo-Coma Supercluster		SCl 111

Incredibly distant superclusters

Galaxy supercluster	Data	Notes
Hyperion proto-supercluster	z=2.45	This supercluster at the time of its discovery in 2018 was the earliest and largest proto-supercluster found to date.[11][12]
Lynx Supercluster	z=1.27	Discovered in 1999[13] (as ClG J0848+4453, a name now used to describe the western cluster, with ClG J0849+4452 being the eastern one),[14] it contains at least two clusters RXJ 0848.9+4452 (z=1.26) and RXJ 0848.6+4453 (z=1.27) . At the time of discovery, it became the most distant known supercluster.[15] Additionally, seven smaller groups of galaxies are associated with the supercluster.[16]
SCL @ 1338+27 at z=1.1	z=1.1 Length=70Mpc	A rich supercluster with several galaxy clusters was discovered around an unusual concentration of 23 QSOs at z=1.1 in 2001. The size of the complex of clusters may indicate a wall of galaxies exists there, instead of a single supercluster. The size discovered approaches the size of the CfA2 Great Wall filament. At the time of the discovery, it was the largest and most distant supercluster beyond z=0.5 [17][18]
SCL @ 1604+43 at z=0.9	z=0.91	This supercluster at the time of its discovery was the largest supercluster found so deep into space, in 2000. It consisted of two known rich clusters and one newly discovered cluster as a result of the study that discovered it. The then known clusters were Cl 1604+4304 (z=0.897) and Cl 1604+4321 (z=0.924), which then known to have 21 and 42 known galaxies respectively. The then newly discovered cluster was located at  16^h 04^m 25.7^s, +43° 14′ 44.7″[19]
SCL @ 0018+16 at z=0.54 in SA26	z=0.54	This supercluster lies around radio galaxy 54W084C (z=0.544) and is composed of at least three large clusters, CL 0016+16 (z=0.5455), RX J0018.3+1618 (z=0.5506), RX J0018.8+1602 .[20]
MS 0302+17	z=0.42 Length=6Mpc	This supercluster has at least three member clusters, the eastern cluster CL 0303+1706, southern cluster MS 0302+1659 and northern cluster MS 0302+1717.[21]

Diagram

A diagram of Earth's location in the observable Universe and neighbouring superclusters of galaxies. (Alternative image.)

See also

• Lists of astronomical objects
• List of largest cosmic structures
• Galaxy
• Galaxy cloud
• Galaxy cluster
• Galaxy filament
• Galaxy group
• Illustris project
• Large-scale structure of the cosmos

References

1. Cain, Fraser (4 May 2009). "Local Group". Universe Today. Retrieved 6 December 2015.
2. Earth's new address: 'Solar System, Milky Way, Laniakea' / Nature
3. "The Universe within 14 billion Light Years". Atlas of the Universe. Retrieved 6 December 2015.
4. "An Intergalactic Heavyweight". ESO Picture of the Week. Retrieved 12 February 2013.
5. Abell, George O. (1958). "The distribution of rich clusters of galaxies. A catalogue of 2,712 rich clusters found on the National Geographic Society Palomar Observatory Sky Survey" (PDF). The Astrophysical Journal Supplement Series. 3: 211–88. Bibcode:1958ApJS....3..211A. doi:10.1086/190036.
6. Hu, F. X.; et al. (2006). "Orientation of Galaxies in the Local Supercluster: A Review". Astrophysics and Space Science. 302 (1–4): 43–59. arXiv:astro-ph/0508669. Bibcode:2006Ap&SS.302...43H. doi:10.1007/s10509-005-9006-7.
7. Nurmi, P.; Heinamaki, P.; Martinez, V. J.; Einasto, J.; Enkvist, I.; Einasto, P.; Tago, E.; Saar, E.; Tempel, E. (2011-05-09). "The Sloan Great Wall. Morphology and galaxy content". The Astrophysical Journal. 736 (1): 51. arXiv:1105.1632v1. Bibcode:2011ApJ...736...51E. doi:10.1088/0004-637X/736/1/51.
8. R. Brent Tully; Helene Courtois; Yehuda Hoffman; Daniel Pomarède (2 September 2014). "The Laniakea supercluster of galaxies". Nature (published 4 September 2014). 513 (7516): 71–3. arXiv:1409.0880. Bibcode:2014Natur.513...71T. doi:10.1038/nature13674. PMID 25186900.
9. Hasegawa, T.; et al. (2000). "Large-scale structure of galaxies in the Ophiuchus region". Monthly Notices of the Royal Astronomical Society. 316 (2): 326–344. Bibcode:2000MNRAS.316..326H. doi:10.1046/j.1365-8711.2000.03531.x.
10. Postman, M.; Geller, M. J.; Huchra, J. P. (1988). "The dynamics of the Corona Borealis supercluster". Astronomical Journal. 95: 267–83. Bibcode:1988AJ.....95..267P. doi:10.1086/114635.
11. Natalia A. Ramos Miranda (October 17, 2018), Scientists in Chile unveil 'A Cosmic Titan' cluster of galaxies, Reuters
12. Cucciati, O.; Lemaux, B. C.; Zamorani, G.; Le Fevre, O.; Tasca, L. A. M.; Hathi, N. P.; Lee, K-G.; Bardelli, S.; Cassata, P.; Garilli, B.; Le Brun, V.; Maccagni, D.; Pentericci, L.; Thomas, R.; Vanzella, E.; Zucca, E.; Lubin, L. M.; Amorin, R.; Cassara', L. P.; Cimatti, A.; Talia, M.; Vergani, D.; Koekemoer, A.; Pforr, J.; Salvato, M. (2018). "The progeny of a Cosmic Titan: a massive multi-component proto-supercluster in formation at z=2.45 in VUDS". Astronomy & Astrophysics. 619: A49. arXiv:1806.06073. Bibcode:2018A&A...619A..49C. doi:10.1051/0004-6361/201833655.
13. Rosati, P.; et al. (1999). "An X-Ray-Selected Galaxy Cluster at z = 1.26". The Astronomical Journal. 118 (1): 76–85. arXiv:astro-ph/9903381. Bibcode:1999AJ....118...76R. doi:10.1086/300934.
14. "Lynx Supercluster". SIMBAD.
15. Nakata, F.; et al. (2004). Discovery of a large-scale clumpy structure of the Lynx supercluster at z∼1.27. Proceedings of the International Astronomical Union. 2004. Cambridge University Press. pp. 29–33. Bibcode:2004ogci.conf...29N. doi:10.1017/S1743921304000080. ISBN 0-521-84908-X.
16. Ohta, K.; et al. (2003). "Optical Identification of the ASCA Lynx Deep Survey: An Association of Quasi-Stellar Objects and a Supercluster at z = 1.3?". The Astrophysical Journal. 598 (1): 210–215. arXiv:astro-ph/0308066. Bibcode:2003ApJ...598..210O. doi:10.1086/378690.
17. Tanaka, I. (2004). "Subaru Observation of a Supercluster of Galaxies and QSOS at Z = 1.1". Studies of Galaxies in the Young Universe with New Generation Telescope, Proceedings of Japan-German Seminar, held in Sendai, Japan, July 24–28, 2001. pp. 61–64. Bibcode:2004sgyu.conf...61T.
18. Tanaka, I.; Yamada, T.; Turner, E. L.; Suto, Y. (2001). "Superclustering of Faint Galaxies in the Field of a QSO Concentration at z ~ 1.1". The Astrophysical Journal. 547 (2): 521–530. arXiv:astro-ph/0009229. Bibcode:2001ApJ...547..521T. doi:10.1086/318430.
19. Lubin, L. M.; et al. (2000). "A Definitive Optical Detection of a Supercluster at z ≈ 0.91". The Astrophysical Journal. 531 (1): L5–L8. arXiv:astro-ph/0001166. Bibcode:2000ApJ...531L...5L. doi:10.1086/312518. PMID 10673401.
20. Connolly, A. J.; et al. (1996). "Superclustering at Redshift z = 0.54". The Astrophysical Journal Letters. 473 (2): L67–L70. arXiv:astro-ph/9610047. Bibcode:1996ApJ...473L..67C. doi:10.1086/310395.
21. University of Hawaii, "The MS0302+17 Supercluster", Nick Kaiser. Retrieved 15 September 2009.

• Freedman, Roger; Gellar, Robert M.; Kaufmann, William III (2015). "Galaxies". Universe (10th ed.). New York: W.H. Freedman. ISBN 978-1-319-04238-7.

External links

• Overview of local superclusters
• The Nearest Superclusters
• Universe family tree: Supercluster
• Superclusters - Large Scale Structures