The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System ...

containing the

Virgo Cluster The Virgo Cluster is a large cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the constellation Virgo. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies, the cluster forms the heart of the la ...

and Local Group, which itself contains the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

and Andromeda galaxies, as well as others. At least 100

galaxy group A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxie ...

s and clusters are located within its diameter of 33 megaparsecs (110 million light-years). The Virgo SC is one of about 10 million

supercluster A supercluster is a large group of smaller galaxy clusters or galaxy groups; they are among the largest known structures in the universe. The Milky Way is part of the Local Group galaxy group (which contains more than 54 galaxies), which in t ...

s in the

observable universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these ob ...

and is in the Pisces–Cetus Supercluster Complex, a galaxy filament. 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.

Background

Beginning with the first large sample of

nebula A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regio ...

e published by

William William is a male given name of Germanic origin.Hanks, Hardcastle and Hodges, ''Oxford Dictionary of First Names'', Oxford University Press, 2nd edition, , p. 276. It became very popular in the English language after the Norman conquest of Engl ...

and

John Herschel Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wo ...

in 1863, it was known that there is a marked excess of nebular fields in the constellation

Virgo Virgo may refer to: *Virgo (astrology), the sixth astrological sign of the zodiac * Virgo (constellation), a constellation *Virgo Cluster, a cluster of galaxies in the constellation Virgo *Virgo Stellar Stream, remains of a dwarf galaxy * Virgo Su ...

(near the north galactic pole). In the 1950s, French–American astronomer

Gérard de Vaucouleurs Gérard Henri de Vaucouleurs (25 April 1918 – 7 October 1995) was a French astronomer. Life and career Born in Paris, he had an early interest in amateur astronomy and received his undergraduate degree in 1939 at the Sorbonne in that city. ...

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) in 1958. (

Harlow Shapley Harlow Shapley (November 2, 1885 – October 20, 1972) was an American scientist, head of the Harvard College Observatory (1921–1952), and political activist during the latter New Deal and Fair Deal. Shapley used Cepheid variable stars to estim ...

, in his 1959 book ''Of Stars and Men'', suggested the term ''Metagalaxy''.) 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. 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.

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. 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. 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. The Local Group is located on the outskirts of the LS in a small filament extending from the

Fornax Cluster The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of solar masses, making it the second richest galaxy cluster within 100 million light-years, after the consider ...

to the

. 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 The number density (symbol: ''n'' or ''ρ''N) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volumetric num ...

of galaxies in the LS falls off with the square of the distance from its center near the

, suggesting that this cluster is not randomly located. Overall, the vast majority of the luminous galaxies (less than

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it ...

−13) are concentrated in a small number of

clouds In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid drop (liquid), droplets, ice crystals, frozen crystals, or other particulates, particles suspended in the atmosphere of a planetary body or similar space. ...

(groups of

galaxy cluster A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-lar ...

s). 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 NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * Nati ...

Leo I The LEO I (Lyons Electronic Office I) was the first computer used for commercial business applications. The prototype LEO I was modelled closely on the Cambridge EDSAC. Its construction was overseen by Oliver Standingford, Raymond Thompson and ...

, Leo Minor ( NGC 2841), Draco (

NGC 5907 NGC 5907 (also known as Knife Edge Galaxy or Splinter Galaxy) is a spiral galaxy located approximately 50 million light years from Earth. It has an anomalously low metallicity and few detectable giant stars, being apparently composed almost entir ...

), Antlia ( NGC 2997), and

NGC 5643 NGC 5643 is an intermediate spiral galaxy in the constellation Lupus (constellation), Lupus. Based on the tip of the red-giant branch distance indicator, it is located at a distance of about 40 million light-years (12.5 megaparsecs). NGC 5643 has ...

. 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." A helpful analogy that matches the observed distribution is that of soap bubbles. Flattish clusters and

superclusters A supercluster is a large group of smaller galaxy clusters or galaxy groups; they are among the largest known structures in the universe. The Milky Way is part of the Local Group galaxy group (which contains more than 54 galaxies), which in tu ...

are found at the intersection of bubbles, which are large, roughly spherical (on the order of 20–60 Mpc in diameter) voids in space. Long filamentary structures seem to predominate. An example of this is the

Hydra–Centaurus Supercluster The Hydra-Centaurus Supercluster (SCl 128), or the Hydra and Centaurus Superclusters, is a supercluster in two parts, the closest neighbour of Virgo Supercluster. Hydra-Centaurus The cluster includes four large galaxy clusters in the Centaurus p ...

, the nearest supercluster to the LS, which starts at a distance of roughly 30 Mpc and extends to 60 Mpc.

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). 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 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 a ...

, with center of Shapley Attractor.

Dark matter

The LS has a total mass ''M'' ≈ 10¹⁵ and a total optical luminosity ''L'' ≈ 3 . This yields a mass-to-light ratio of about 300 times that of the solar ratio (/ = 1), a figure that is consistent with results obtained for other superclusters. By comparison, the mass-to-light ratio for the

is 63.8 assuming a solar

of 4.83, a Milky Way absolute magnitude of −20.9, and a Milky Way mass of . These ratios are one of the main arguments in favor of the presence of large amounts of

dark matter Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not ...

in the universe; if dark matter did not exist, much smaller mass-to-light ratios would be expected.

Maps

File:Virgosupercluster atlasoftheuniverse.gif, frame, center, 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) circle 473 220 33

circle 339 230 16

Centaurus A/M83 Group The Centaurus A/M83 Group is a complex group of galaxies in the constellations Hydra, Centaurus, and Virgo. The group may be roughly divided into two subgroups. The Cen A Subgroup, at a distance of 11.9 Mly (3.66 Mpc), is centered on Centa ...

circle 349 252 15

M81 group The M81 Group is a galaxy group in the constellations Ursa Major and Camelopardalis that includes the galaxies Messier 81 and Messier 82, as well as several other galaxies with high apparent brightnesses. The approximate center of the group ...

circle 326 264 15 Maffei Group circle 289 292 20 NGC 1023 Group circle 370 236 13 M101 group circle 347 299 20 NGC 2997 Group circle 405 238 20 Canes Venatici I Group circle 426 203 19 NGC 5033 group rect 445 247 508 276

Ursa Major Cluster The Ursa Major Cluster (Ursa Major I Cluster, UMa I ClG) is a spiral-rich galaxy cluster of the Virgo Supercluster. Some of its largest members are NGC 3631, NGC 3953, M109 on North (M109 Group) and NGC 3726, NGC 3938, NGC 4051 on South. ...

circle 391 270 18 Leo I Group circle 277 197 25 NGC 6744 Group circle 236 314 22 Dorado Group circle 518 87 40

Virgo III Groups The Virgo III Groups, or Virgo III Cloud, are a series of at least 75 galactic clusters and individual galaxies stretching approximately off the eastern edge of the Virgo Supercluster. Parts of it are in the constellations Virgo, Libra, and Se ...

circle 526 225 20

NGC 4697 NGC 4697 (also known as Caldwell 52) is an elliptical galaxy some 40 to 50 million light-years away in the constellation Virgo. It is a member of the NGC 4697 Group, a group of galaxies also containing NGC 4731 and several generally much sm ...

circle 546 331 34

Leo II Groups The Leo II Groups, or Leo II Cloud, are a series of at least 110 galactic clusters and individual galaxies stretching approximately 30 Mly (9.2 Mpc) off the right edge of the Virgo Supercluster. It is located approximately 65 Mly (20 Mpc) to 95 M ...

circle 165 194 27

NGC 7582 NGC 7582 is a spiral galaxy of the Hubble type SB(s)ab in the constellation Grus. It has an angular size of 5.0' × 2.1' and an apparent magnitude of 11.37. It is about 70 million light years away from Earth and has a diameter of about 100,000 ...

poly 180 356 178 325 252 345 242 378

poly 176 357 239 379 214 413 162 381

Eridanus Cluster The Eridanus Cluster is a galaxy cluster roughly from Earth, containing about 73 main galaxies and about 200 total galaxies. About 30% have Hubble classifications of elliptical or S0 and the remaining 70% are spiral or irregular. These galax ...

rect 295 213 324 239 Local Group rect 252 235 304 257

Sculptor Group The Sculptor Group is a loose group of galaxies visible near the south galactic pole. The group is one of the closest groups of galaxies to the Local Group; the distance to the center of the group from the Milky Way is approximately . The Sculp ...

desc bottom-left File:Nearest Groups of Galaxies atlasoftheuniverse.gif, frame, center, The nearest galaxy groups projected onto the supergalactic plane (click on feature names for more information) circle 333 283 20 NGC 55 rect 399 299 419 325

circle 385 294 14

Large Magellanic Cloud The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the ...

circle 429 267 20

NGC 3109 NGC 3109 is a small barred Magellanic type spiral or irregular galaxy around 4.34 Mly away in the direction of the constellation of Hydra. NGC 3109 is believed to be tidally interacting with the dwarf elliptical galaxy Antlia Dwarf. It was d ...

circle 395 338 16 Messier 31 circle 365 335 15

Messier 33 Messier may refer to: People with the surname *Charles Messier, French astronomer * Éric Messier, former NHL defenseman * George Messier, French inventor *Jean-Marie Messier, former CEO of Vivendi Universal * Marc Messier, Canadian actor from Queb ...

circle 278 311 20 NGC 247 circle 388 119 28 Circinus Galaxy circle 456 124 17

NGC 5128 Centaurus A (also known as NGC 5128 or Caldwell 77) is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable d ...

circle 494 161 20 NGC 5253 poly 475 149 500 133 483 113 463 137 NGC 5102 circle 440 165 28 NGC 5128 Group circle 368 206 27 IC 4662 circle 520 105 20 Messier 83 rect 699 183 774 265

circle 433 65 22

ESO 274-01 The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 mem ...

circle 266 177 22 NGC 1313 circle 214 255 20 NGC 625 circle 235 282 16 NGC 7793 rect 435 80 472 107

NGC 4945 NGC 4945 (also known as Caldwell 83) is a barred spiral galaxy in the constellation Centaurus, visible near the star Xi Centauri. The galaxy was discovered by James Dunlop in 1826 and is thought to be similar to the Milky Way Galaxy, althoug ...

circle 184 301 20

NGC 45 NGC 45 is a low surface brightness spiral galaxy in the equatorial constellation of Cetus. It was discovered on 11 November 1835 by the English astronomer John Herschel. The galaxy is located at a distance of 22 million light years and i ...

circle 217 311 17 NGC 253 circle 265 260 22

rect 368 268 412 284 Local Group circle 409 379 25 NGC 1569 circle 296 280 17

NGC 300 NGC 300 (also known as Caldwell 70) is a spiral galaxy in the constellation Sculptor. It is one of the closest galaxies to the Local Group, and probably lies between the latter and the Sculptor Group. It is the brightest of the five main spir ...

circle 424 418 20 IC 342 rect 383 429 415 451 Maffei Group circle 325 442 20 NGC 404 circle 272 508 20

NGC 784 NGC 784 is a barred spiral galaxy about 16.0 Mly away in the constellation Triangulum. NGC 784 is located within the Virgo Supercluster The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of gal ...

circle 397 510 20 Maffei I rect 353 456 413 478

Maffei II Maffei 2 is an intermediate spiral galaxy about 1 E23 m, 10 million light-years away in the constellation Cassiopeia (constellation), Cassiopeia. Maffei 2 and Maffei 1 were both discovered by Paolo Maffei in 1968 from their infrared emission. M ...

rect 371 526 434 553 Dwingeloo 1 circle 444 481 22 NGC 1560 rect 510 417 537 434

Messier 81 Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of . Because of its relative proximity to the Milky W ...

rect 527 433 578 443

IC 2574 IC 2574, also known as Coddington's Nebula, is a dwarf spiral galaxy discovered by American astronomer Edwin Foster Coddington in 1898. Located in Ursa Major, a constellation in the northern sky, it is an outlying member of the M81 Group The ...

rect 500 434 515 450 Messier 82 poly 516 434 521 456 554 456 552 447 533 445 523 435 NGC 3077 circle 549 476 18 NGC 2976 circle 604 440 22

NGC 4605 NGC 4605 is a dwarf barred spiral galaxy in the constellation Ursa Major, located at a distance of from the Milky Way. Physically it is similar in size and in UBV photometric system, B-band absolute magnitude to the Large Magellanic Cloud. It is ...

circle 513 479 19 NGC 6503 circle 583 410 13 NGC 5204 circle 559 389 16 NGC 3738 circle 512 401 14

NGC 4236 NGC 4236 (also known as Caldwell 3) is a barred spiral galaxy located in the constellation Draco. The galaxy is a member of the M81 Group, a group of galaxies located at a distance of approximately 11.7 Mly (3.6 Mpc) from Earth. The group a ...

rect 452 442 485 461 NGC 2366 rect 451 420 484 440 NGC 2403 rect 485 433 502 465 NGC 4305 circle 659 382 20 NGC 5023 rect 634 344 658 364 Messier 94 circle 618 355 15 NGC 4244 circle 594 337 13 NGC 4214 circle 577 361 19 NGC 4449 circle 615 319 17

NGC 4395 NGC commonly refers to: * New General Catalogue of Nebulae and Clusters of Stars, a catalogue of deep sky objects in astronomy NGC may also refer to: Companies * NGC Corporation, name of US electric company Dynegy, Inc. from 1995 to 1998 * Nati ...

rect 591 280 640 304

Canes I Group The M94 Group (Canes I Group or Canes Venatici I Group) is a loose, extended group of galaxies located about 13 million light-years away in the constellations Canes Venatici and Coma Berenices. The group is one of many groups that lies within th ...

poly 528 393 542 392 558 411 525 414

M81 Group The M81 Group is a galaxy group in the constellations Ursa Major and Camelopardalis that includes the galaxies Messier 81 and Messier 82, as well as several other galaxies with high apparent brightnesses. The approximate center of the group ...

desc bottom-left

Diagrams

References

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). {{Portal bar, Stars, Spaceflight, Solar System, Science Galaxy superclusters