The Shapley Supercluster or Shapley Concentration (SCl 124) is the largest concentration of galaxies in our nearby universe that forms a gravitationally interacting unit, thereby pulling itself together instead of expanding with the universe. It appears as a striking overdensity in the distribution of galaxies in the constellation of Centaurus. It is 650 million light-years away (z=0.046).
History
In 1930,[3] Harlow Shapley and his colleagues at the Harvard College Observatory started a survey of galaxies in the southern sky, using photographic plates obtained at the 24-inch Bruce telescope at Bloemfontein, South Africa. By 1932, Shapley reported the discovery of 76,000 galaxies brighter than 18th apparent magnitude in a third of the southern sky, based on galaxy counts from his plates. Some of this data was later published as part of the Harvard galaxy counts, intended to map galactic obscuration and to find the space density of galaxies.
In this catalog, Shapley could see most of the 'Coma-Virgo cloud' (now known to be a superposition of the Coma Supercluster and the Virgo Supercluster), but found a 'cloud' in the constellation of Centaurus to be the most striking concentration of galaxies. He found it particularly interesting because of its great linear dimension, the numerous population and distinctly elongated form. This can be identified with what we now know as the core of the Shapley Supercluster. Shapley estimated the distance to this cloud to be 14 times that to the Virgo Cluster, from the average diameters of the galaxies. This would place the Shapley Supercluster at a distance of 231 Mpc, based on the current estimate of the distance to Virgo.
In recent times, the Shapley Supercluster was named by Somak Raychaudhury,[4] from a survey of galaxies from UK Schmidt Telescope Sky survey plates, using the Automated Plate Measuring Facility (APM) at the University of Cambridge in England. In this paper, the supercluster was named after Harlow Shapley, in recognition of his pioneering survey of galaxies in which this concentration of galaxies was first seen. Around the same time, Roberto Scaramella and co-workers had also noticed the Shapley Supercluster in the Abell catalogue of clusters of galaxies: they had named it the Alpha concentration.[5]
Current interest
The Shapley Supercluster lies very close to the direction in which the Local Group of galaxies (including our galaxy) is moving with respect to the Cosmic Microwave Background (CMB) frame of reference. This has led many to speculate that the Shapley Supercluster may indeed be one of the major causes of our galaxy's peculiar motion—the Great Attractor may be another—and has led to a surge of interest in this supercluster. It has been found that the Great Attractor and all the galaxies in our corner of the universe (including our galaxy, the Milky Way) are moving toward the Shapley Supercluster.[6]
In 2017 it was proposed that the movement towards attractors like the Shapley Supercluster attractor creates a relative movement away from underdense areas, that may be visualized as a virtual repeller. This approach enables new ways of understanding and modelling variations in galactic movements. The nearest large underdense area has been labelled the dipole repeller.[7]
See also
Dark flow – A possible non-random component of the peculiar velocity of galaxy clusters
Great Attractor – An apparent gravitational anomaly at the center of the local Laniakea Supercluster
Hydra-Centaurus Supercluster
Large-scale structure of the universe – all matter that can be observed from the Earth at the present time
Supercluster – Large group of smaller galaxy clusters or galaxy groups
Norma Cluster
References
http://www.eso.org/sci/publications/messenger/archive/no.124-jun06/messenger-no124-30-31.pdf
http://www.eso.org/sci/publications/messenger/archive/no.124-jun06/messenger-no124-30-31.pdf
"The Shapley Supercluster". www.atlasoftheuniverse.com. Retrieved 2020-09-23.
The distribution of galaxies in the direction of the 'Great Attractor' Somak Raychaudhury Nature 342, 251-255 (1989)
A marked concentration of galaxy clusters: is this the origin of large-scale motions? R. Scaramella et al. Nature 338, 562 (1989)
http://www.universetoday.com/113150/what-is-the-great-attractor/
Hoffman, Yehuda; Pomarède, Daniel; Tully, R. Brent; Courtois, Hélène M. (30 January 2017). "The dipole repeller". Nature Astronomy. 1 (2): 0036. arXiv:1702.02483. Bibcode:2017NatAs...1E..36H. doi:10.1038/s41550-016-0036.
External links
Shapley Supercluster at Atlas of the Universe
"The Shapley Concentration". Consiglio Nazionale delle Ricerche (CNR). Istituto di Radioastronomia (IRA). Archived from the original on March 26, 2007.
Harvard College Observatory (HCO)
"X-rays Reveal What Makes the Milky Way Move". University of Hawaii. IFA. Jan 11, 2006. "Part of Abell 3558, the galaxy cluster at the center of the Shapley Supercluster, the largest mass concentration in the observable Universe"
"A Complete CEnsus of Star formation in the Shapley supercluster". Istituto Nazionale di Astrofisica. Osservatorio Astronomico di Capodimonte.
"Dipole Repeller". Nature Astronomy. 1 (36): 0036. Jan 30, 2017. arXiv:1702.02483. Bibcode:2017NatAs...1E..36H. doi:10.1038/s41550-016-0036.
Coordinates: Sky map 13h 25m 0s, −30° 0′ 0″
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Constellation of Centaurus
List of stars in Centaurus Centaurus in Chinese astronomy
Stars
Bayer
α (Rigil Kentaurus [A], Toliman [B]) β (Hadar) γ δ ε ζ η θ (Menkent) ι κ λ μ ν ξ1 ξ2 ο1 ο2 π ρ σ τ υ1 υ2 φ χ ψ
Flamsteed
1 (i) 2 (g) 3 (k) 4 (h)
Variable
R T V Y RR SV SX BV DY V744 V752 V761 (a) V763 (C1) V766 V803 V810 V816 (Przybylski's Star) V831 V842 V885 V863 V945 (H) V1032 V1400
HR
4460 (A) 4466 (C2) 4476 (C3) 4499 4522 4523 4537 (j) 4546 (B) 4620 (E) 4652 (D) 4682 (F) 4712 (x1) 4721 4724 (x2) 4732 (G) 4748 (u) 4796 4817 (l) 4831 (w) 4874 (p) 4888 (e) 4889 (n) 4940 (f) 4979 4989 5006 (r) 5035 (J) 5041 (m) 5071 (K) 5089 (d) 5141 (Q) 5172 (M) 5174 (z) 5207 (N) 5222 (y) 5241 5297 5358 (v) 5371 5471 (b) 5485 (c1) 5489 (c2)
HD
96660 97413 98176 101930 102117 (Uklun) 103197 107914 109749 113538 113766 114386 114729 117207 117618 (Dofida) 121228 121504 125072 125595 131399
Other
2MASS J1126−5003 2M1207 BPM 37093 Centaurus X-3 (Krzeminski's Star) GJ 3737 Proxima Centauri (α C) WASP-15 (Nyamien)
Exoplanets
2M1207b HD 102117 b HD 103197 b HD 109749 b HD 101930 b HD 113538 b, c HD 114386 b HD 114729 b HD 117207 b HD 117618 b HD 121504 b HD 131399 Ab HIP 65426 b Proxima Centauri b, c WASP-15b
Star clusters
IC 2944 NGC 3766 NGC 4230 NGC 5286 NGC 5281 NGC 5316 NGC 5460 NGC 5617 NGC 5662 Omega Centauri Scorpius–Centaurus Association Stock 16
Nebulae
Boomerang Nebula Fleming 1 G292.0+1.8 H II IC 2944 NGC 3918 NGC 5307 RCW 79 Southern Crab Nebula SN 185 (RCW 86)
Galaxies
NGC
3783 4444 4603 4622 4650A 4683 4696 4706 4709 4729 4730 4743 4744 4945 4976 5011 5011A 5026 5090 5091 5102 5114 5128 (Centaurus A) 5161 5253 5291 5398 5408
Other
ESO 269-57 ESO 325-G004 ESO 444-46 IRAS 13224-3809
Galaxy clusters
Abell S740 Shapley Supercluster
Astronomical events
Nova Centauri 2013 SN 185 SN 1895B SN 1986G
Hellenica World - Scientific Library
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