"Local Supercluster" redirects here. For the supercluster discovered in 2014, where Virgo SC is the local concentration of clusters component of the Local Supercluster, see Laniakea Supercluster.
A 2014 study indicates that the Virgo Supercluster is only a lobe of an even greater supercluster, Laniakea, a larger, competing referent of the term Local Supercluster centered on the Great Attractor.[2]
Beginning with the first large sample of nebulae published by William and John Herschel in 1863, it was known that there is a marked excess of nebular fields in the constellation Virgo (near the north galactic pole). In the 1950s, French–American astronomer Gérard de Vaucouleurs was the first to argue that this excess represented a large-scale galaxy-like structure, coining the term "Local Supergalaxy" in 1953, which he changed to "Local Supercluster" (LSC[3]) in 1958. (Harlow Shapley, in his 1959 book Of Stars and Men, suggested the term Metagalaxy.[4]) Debate went on during the 1960s and 1970s as to whether the Local Supercluster (LS) was actually a structure or a chance alignment of galaxies.[5] The issue was resolved with the large redshift surveys of the late 1970s and early 1980s, which convincingly showed the flattened concentration of galaxies along the supergalactic plane.[6]
Structure
In a comprehensive 1982 paper, R. Brent Tully presented the conclusions of his research concerning the basic structure of the LS. It consists of two components: an appreciably flattened disk containing two-thirds of the supercluster's luminous galaxies, and a roughly spherical halo containing the remaining one-third.[7] The disk itself is a thin (~1 Mpc) ellipsoid with a long axis / short axis ratio of at least 6 to 1, and possibly as high as 9 to 1.[8] Data released in June 2003 from the 5-year Two-degree-Field Galaxy Redshift Survey (2dF) has allowed astronomers to compare the LS to other superclusters. The LS represents a typical poor (that is, lacking a high density core) supercluster of rather small size. It has one rich galaxy cluster in the center, surrounded by filaments of galaxies and poor groups.[1] The Local Group is located on the outskirts of the LS in a small filament extending from the Fornax Cluster to the Virgo Cluster.[6] The Virgo Supercluster's volume is very approximately 7000 times that of the Local Group or 100 billion times that of the Milky Way.
Galaxy distribution
The number density of galaxies in the LS falls off with the square of the distance from its center near the Virgo Cluster, suggesting that this cluster is not randomly located. Overall, the vast majority of the luminous galaxies (less than absolute magnitude −13) are concentrated in a small number of clouds (groups of galaxy clusters). Ninety-eight percent can be found in the following 11 clouds (given in decreasing order of number of luminous galaxies): Canes Venatici, Virgo Cluster, Virgo II (southern extension), Leo II, Virgo III, Crater (NGC 3672), Leo I, Leo Minor (NGC 2841), Draco (NGC 5907), Antlia (NGC 2997), and NGC 5643. Of the luminous galaxies located in the disk, one third are in the Virgo Cluster, while the remainder are found in the Canes Venatici Cloud and Virgo II Cloud, plus the somewhat insignificant NGC 5643 Group.
The luminous galaxies in the halo are also concentrated in a small number of clouds (94% in 7 clouds). This distribution indicates that "most of the volume of the supergalactic plane is a great void."[8] A helpful analogy that matches the observed distribution is that of soap bubbles. Flattish clusters and superclusters are found at the intersection of bubbles, which are large, roughly spherical (on the order of 20–60 Mpc in diameter) voids in space.[9] Long filamentary structures seem to predominate. An example of this is the Hydra–Centaurus Supercluster, the nearest supercluster to the LS, which starts at a distance of roughly 30 Mpc and extends to 60 Mpc.[10]
Cosmology
Large-scale dynamics
Since the late 1980s it has been apparent that not only the Local Group, but all matter out to a distance of at least 50 Mpc is experiencing a bulk flow on the order of 600 km/s in the direction of the Norma Cluster (Abell 3627).[11] Lynden-Bell et al. (1988) dubbed the cause of this the "Great Attractor". The Great Attractor is now understood to be the center of mass of an even larger structure of galaxy clusters, dubbed "Laniakea", which includes the Virgo Supercluster (including the Local Group) as well as the Hydra-Centaurus Supercluster, the Pavo-Indus Supercluster, and the Fornax Group.
The LS has a total mass M ≈ 1015M☉ and a total optical luminosity L ≈ 3×1012L☉.[1] This yields a mass-to-light ratio of about 300 times that of the solar ratio (M☉/L☉ = 1), a figure that is consistent with results obtained for other superclusters.[13][14] By comparison, the mass-to-light ratio for the Milky Way is 63.8 assuming a solar absolute magnitude of 4.83,[15] a Milky Way absolute magnitude of −20.9,[16] and a Milky Way mass of 1.25×1012M☉.[17] These ratios are one of the main arguments in favor of the presence of large amounts of dark matter in the universe; if dark matter did not exist, much smaller mass-to-light ratios would be expected.
Maps
Map of the nearby universe within 100 million light-years from Earth, including a portion of the Southern Supercluster at the bottom left and the Virgo Supercluster on the right in supergalactic coordinates (click on feature names for more information)
The nearest galaxy groups projected onto the supergalactic plane (click on feature names for more information)
^ abcd Einasto, M.; et al. (December 2007). "The richest superclusters. I. Morphology". Astronomy and Astrophysics. 476 (2): 697–711. arXiv:0706.1122. Bibcode:2007A&A...476..697E. doi:10.1051/0004-6361:20078037. S2CID 15004251.
^R. Brent Tully; Hélène Courtois; Yehuda Hoffman; Daniel Pomarède (2 September 2014). "The Laniakea supercluster of galaxies". Nature (published 4 September 2014). 513 (7516): 71–73. arXiv:1409.0880. Bibcode:2014Natur.513...71T. doi:10.1038/nature13674. PMID 25186900. S2CID 205240232.
^ cfa.harvard.edu, The Geometry of the Local Supercluster, John P. Huchra, 2007 (accessed 12-12-2008)
^ de Vaucouleurs, G. (March 1981). "The Local Supercluster of Galaxies". Bulletin of the Astronomical Society of India. 9: 6 (see note). Bibcode:1981BASI....9....1D.
^ ab Klypin, Anatoly; et al. (October 2003). "Constrained Simulations of the Real Universe: The Local Supercluster". The Astrophysical Journal. 596 (1): 19–33. arXiv:astro-ph/0107104. Bibcode:2003ApJ...596...19K. doi:10.1086/377574. S2CID 1830859.
^ Hu, F. X.; et al. (April 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. S2CID 18837475.
^ ab Tully, R. B. (15 Jun 1982). "The Local Supercluster". Astrophysical Journal. 257 (1): 389–422. Bibcode:1982ApJ...257..389T. doi:10.1086/159999.
^ Carroll, Bradley; Ostlie, Dale (1996). An Introduction to Modern Astrophysics. New York: Addison-Wesley. p. 1136. ISBN0-201-54730-9.
^ Fairall, A. P.; Vettolani, G.; Chincarini, G. (May 1989). "A wide angle redshift survey of the Hydra-Centaurus region". Astronomy and Astrophysics Supplement Series. 78 (2): 270. Bibcode:1989A&AS...78..269F. ISSN 0365-0138.
^ Plionis, Manolis; Valdarnini, Riccardo (March 1991). "Evidence for large-scale structure on scales about 300/h MPC". Monthly Notices of the Royal Astronomical Society. 249: 46–61. Bibcode:1991MNRAS.249...46P. doi:10.1093/mnras/249.1.46.
^ Small, Todd A.; et al. (Jan 1998). "The Norris Survey of the Corona Borealis Supercluster. III. Structure and Mass of the Supercluster". Astrophysical Journal. 492 (1): 45–56. arXiv:astro-ph/9708153. Bibcode:1998ApJ...492...45S. doi:10.1086/305037. S2CID 119451873.
^ Heymans, Catherine; et al. (April 2008). "The dark matter environment of the A901 abell A901/902 supercluster: a weak lensing analysis of the HST STAGES survey". Monthly Notices of the Royal Astronomical Society. 385 (3): 1431–1442. arXiv:0801.1156. Bibcode:2008MNRAS.385.1431H. doi:10.1111/j.1365-2966.2008.12919.x. S2CID 59057342.
^ Williams, D. R. (2004). "Sun Fact Sheet". NASA. Retrieved 2012-03-17.
^McMillan, Paul J. (July 2011), "Mass models of the Milky Way", Monthly Notices of the Royal Astronomical Society, 414 (3): 2446–2457, arXiv:1102.4340, Bibcode:2011MNRAS.414.2446M, doi:10.1111/j.1365-2966.2011.18564.x, S2CID 119100616
Further reading
Tully, Brent (1982). "The Local Supercluster". Astrophys. J. 257: 389–422. Bibcode:1982ApJ...257..389T. doi:10.1086/159999.
Lynden-Bell, D.; et al. (1988). "Spectroscopy and photometry of elliptical galaxies. V — Galaxy streaming toward the new supergalactic center". Astrophysical Journal. 326: 19–49. Bibcode:1988ApJ...326...19L. doi:10.1086/166066.
External links
The Atlas of the Universe, a website created by astrophysicist Richard Powell that shows maps of our local universe on a number of different scales (similar to above maps).
virgo, supercluster, local, supercluster, redirects, here, supercluster, discovered, 2014, where, virgo, local, concentration, clusters, component, local, supercluster, laniakea, supercluster, virgo, local, supercluster, mass, concentration, galaxies, containi. Local Supercluster redirects here For the supercluster discovered in 2014 where Virgo SC is the local concentration of clusters component of the Local Supercluster see Laniakea Supercluster The Virgo Supercluster Virgo SC or the Local Supercluster LSC or LS is a mass concentration of galaxies containing the Virgo Cluster and Local Group which itself contains the Milky Way and Andromeda galaxies as well as others At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs 110 million light years The Virgo SC is one of about 10 million superclusters in the observable universe and is in the Pisces Cetus Supercluster Complex a galaxy filament Virgo SuperclusterDistances from the Local Group for selected groups and clusters within the Local SuperclusterObservation data Epoch J2000 Parent structureLaniakea SuperclusterRedshiftDoppler shiftBinding mass 1 48 1015 1 M Luminosity specify 3 1012 L 1 total Other designationsLocal Supercluster LSC LSSee also Galaxy group Galaxy cluster List of galaxy groups and clustersA 2014 study indicates that the Virgo Supercluster is only a lobe of an even greater supercluster Laniakea a larger competing referent of the term Local Supercluster centered on the Great Attractor 2 Contents 1 Background 2 Structure 3 Galaxy distribution 4 Cosmology 4 1 Large scale dynamics 4 2 Dark matter 5 Maps 6 Diagrams 7 See also 8 References 9 Further reading 10 External linksBackground EditBeginning with the first large sample of nebulae published by William and John Herschel in 1863 it was known that there is a marked excess of nebular fields in the constellation Virgo near the north galactic pole In the 1950s French American astronomer Gerard de Vaucouleurs was the first to argue that this excess represented a large scale galaxy like structure coining the term Local Supergalaxy in 1953 which he changed to Local Supercluster LSC 3 in 1958 Harlow Shapley in his 1959 book Of Stars and Men suggested the term Metagalaxy 4 Debate went on during the 1960s and 1970s as to whether the Local Supercluster LS was actually a structure or a chance alignment of galaxies 5 The issue was resolved with the large redshift surveys of the late 1970s and early 1980s which convincingly showed the flattened concentration of galaxies along the supergalactic plane 6 Structure EditIn a comprehensive 1982 paper R Brent Tully presented the conclusions of his research concerning the basic structure of the LS It consists of two components an appreciably flattened disk containing two thirds of the supercluster s luminous galaxies and a roughly spherical halo containing the remaining one third 7 The disk itself is a thin 1 Mpc ellipsoid with a long axis short axis ratio of at least 6 to 1 and possibly as high as 9 to 1 8 Data released in June 2003 from the 5 year Two degree Field Galaxy Redshift Survey 2dF has allowed astronomers to compare the LS to other superclusters The LS represents a typical poor that is lacking a high density core supercluster of rather small size It has one rich galaxy cluster in the center surrounded by filaments of galaxies and poor groups 1 The Local Group is located on the outskirts of the LS in a small filament extending from the Fornax Cluster to the Virgo Cluster 6 The Virgo Supercluster s volume is very approximately 7000 times that of the Local Group or 100 billion times that of the Milky Way Galaxy distribution EditThe number density of galaxies in the LS falls off with the square of the distance from its center near the Virgo Cluster suggesting that this cluster is not randomly located Overall the vast majority of the luminous galaxies less than absolute magnitude 13 are concentrated in a small number of clouds groups of galaxy clusters Ninety eight percent can be found in the following 11 clouds given in decreasing order of number of luminous galaxies Canes Venatici Virgo Cluster Virgo II southern extension Leo II Virgo III Crater NGC 3672 Leo I Leo Minor NGC 2841 Draco NGC 5907 Antlia NGC 2997 and NGC 5643 Of the luminous galaxies located in the disk one third are in the Virgo Cluster while the remainder are found in the Canes Venatici Cloud and Virgo II Cloud plus the somewhat insignificant NGC 5643 Group The luminous galaxies in the halo are also concentrated in a small number of clouds 94 in 7 clouds This distribution indicates that most of the volume of the supergalactic plane is a great void 8 A helpful analogy that matches the observed distribution is that of soap bubbles Flattish clusters and superclusters are found at the intersection of bubbles which are large roughly spherical on the order of 20 60 Mpc in diameter voids in space 9 Long filamentary structures seem to predominate An example of this is the Hydra Centaurus Supercluster the nearest supercluster to the LS which starts at a distance of roughly 30 Mpc and extends to 60 Mpc 10 Cosmology EditLarge scale dynamics Edit Since the late 1980s it has been apparent that not only the Local Group but all matter out to a distance of at least 50 Mpc is experiencing a bulk flow on the order of 600 km s in the direction of the Norma Cluster Abell 3627 11 Lynden Bell et al 1988 dubbed the cause of this the Great Attractor The Great Attractor is now understood to be the center of mass of an even larger structure of galaxy clusters dubbed Laniakea which includes the Virgo Supercluster including the Local Group as well as the Hydra Centaurus Supercluster the Pavo Indus Supercluster and the Fornax Group The Great Attractor together with the entire supercluster is found to be moving toward Shapley Supercluster with center of Shapley Attractor 12 Dark matter Edit The LS has a total mass M 1015 M and a total optical luminosity L 3 1012 L 1 This yields a mass to light ratio of about 300 times that of the solar ratio M L 1 a figure that is consistent with results obtained for other superclusters 13 14 By comparison the mass to light ratio for the Milky Way is 63 8 assuming a solar absolute magnitude of 4 83 15 a Milky Way absolute magnitude of 20 9 16 and a Milky Way mass of 1 25 1012 M 17 These ratios are one of the main arguments in favor of the presence of large amounts of dark matter in the universe if dark matter did not exist much smaller mass to light ratios would be expected Maps Edit Map of the nearby universe within 100 million light years from Earth including a portion of the Southern Supercluster at the bottom left and the Virgo Supercluster on the right in supergalactic coordinates click on feature names for more information The nearest galaxy groups projected onto the supergalactic plane click on feature names for more information Diagrams Edit A diagram of our location in the observable universe Alternative image See also EditAbell catalogue Large scale structure of the universe List of Abell clusters Supercluster KBC VoidReferences Edit a b c d Einasto M et al December 2007 The richest superclusters I Morphology Astronomy and Astrophysics 476 2 697 711 arXiv 0706 1122 Bibcode 2007A amp A 476 697E doi 10 1051 0004 6361 20078037 S2CID 15004251 R Brent Tully Helene Courtois Yehuda Hoffman Daniel Pomarede 2 September 2014 The Laniakea supercluster of galaxies Nature published 4 September 2014 513 7516 71 73 arXiv 1409 0880 Bibcode 2014Natur 513 71T doi 10 1038 nature13674 PMID 25186900 S2CID 205240232 cfa harvard edu The Geometry of the Local Supercluster John P Huchra 2007 accessed 12 12 2008 Shapley Harlow Of Stars and Men 1959 de Vaucouleurs G March 1981 The Local Supercluster of Galaxies Bulletin of the Astronomical Society of India 9 6 see note Bibcode 1981BASI 9 1D a b Klypin Anatoly et al October 2003 Constrained Simulations of the Real Universe The Local Supercluster The Astrophysical Journal 596 1 19 33 arXiv astro ph 0107104 Bibcode 2003ApJ 596 19K doi 10 1086 377574 S2CID 1830859 Hu F X et al April 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 amp SS 302 43H doi 10 1007 s10509 005 9006 7 S2CID 18837475 a b Tully R B 15 Jun 1982 The Local Supercluster Astrophysical Journal 257 1 389 422 Bibcode 1982ApJ 257 389T doi 10 1086 159999 Carroll Bradley Ostlie Dale 1996 An Introduction to Modern Astrophysics New York Addison Wesley p 1136 ISBN 0 201 54730 9 Fairall A P Vettolani G Chincarini G May 1989 A wide angle redshift survey of the Hydra Centaurus region Astronomy and Astrophysics Supplement Series 78 2 270 Bibcode 1989A amp AS 78 269F ISSN 0365 0138 Plionis Manolis Valdarnini Riccardo March 1991 Evidence for large scale structure on scales about 300 h MPC Monthly Notices of the Royal Astronomical Society 249 46 61 Bibcode 1991MNRAS 249 46P doi 10 1093 mnras 249 1 46 What is the Great Attractor 14 July 2014 Small Todd A et al Jan 1998 The Norris Survey of the Corona Borealis Supercluster III Structure and Mass of the Supercluster Astrophysical Journal 492 1 45 56 arXiv astro ph 9708153 Bibcode 1998ApJ 492 45S doi 10 1086 305037 S2CID 119451873 Heymans Catherine et al April 2008 The dark matter environment of the A901 abell A901 902 supercluster a weak lensing analysis of the HST STAGES survey Monthly Notices of the Royal Astronomical Society 385 3 1431 1442 arXiv 0801 1156 Bibcode 2008MNRAS 385 1431H doi 10 1111 j 1365 2966 2008 12919 x S2CID 59057342 Williams D R 2004 Sun Fact Sheet NASA Retrieved 2012 03 17 Jerry Coffey Absolute Magnitude Retrieved 2010 04 09 McMillan Paul J July 2011 Mass models of the Milky Way Monthly Notices of the Royal Astronomical Society 414 3 2446 2457 arXiv 1102 4340 Bibcode 2011MNRAS 414 2446M doi 10 1111 j 1365 2966 2011 18564 x S2CID 119100616Further reading EditTully Brent 1982 The Local Supercluster Astrophys J 257 389 422 Bibcode 1982ApJ 257 389T doi 10 1086 159999 Lynden Bell D et al 1988 Spectroscopy and photometry of elliptical galaxies V Galaxy streaming toward the new supergalactic center Astrophysical Journal 326 19 49 Bibcode 1988ApJ 326 19L doi 10 1086 166066 External links EditThe Atlas of the Universe a website created by astrophysicist Richard Powell that shows maps of our local universe on a number of different scales similar to above maps Portals Stars Spaceflight Solar System Science Retrieved from https en wikipedia org w index php title Virgo Supercluster amp oldid 1129941641, wikipedia, wiki, book, books, library,
