Editing Virgo Supercluster

{{Short description|Former supercluster}}{{Infobox galaxy cluster
| name = Local Supercluster
| image = Local supercluster-ly.jpg
| caption = Distances from the [[Local Group]] for selected groups and clusters within the Local Supercluster{{citation needed|date=March 2025}}
| credit = 
| epoch = [[Epoch (astronomy)#Julian years and J2000|J2000]]
| constellation = 
| ra = <!-- {{RA|00|00}} -->
| dec = <!-- {{DEC|±00|00}} -->
| brightest_member = 
| member_no = 
| parent = [[Laniakea Supercluster]]
| major_axis_mpc = <!-- {{convert|000|Mpc|Mly|0|abbr=on|lk=on}} {{hub|0.00}} -->
| minor_axis_mpc = <!-- {{convert|000|Mpc|Mly|0|abbr=on|lk=on}} {{hub|0.00}} -->
| redshift = [[Doppler shift]]
| distance = <!-- {{convert|000|Mpc|Mly|0|abbr=on|lk=on}} {{hub|0.00}} -->
| mass = ~1.48 × 10<sup>15</sup><ref name="ein07" />
| luminosity_specify = 3{{e|12}} {{solar luminosity|link=yes}}<ref name="ein07" /> (total)
| flux = 
| other_names = Virgo Supercluster (old), LSC, LS
}}

The '''Local Supercluster''' ('''LSC''' or '''LS'''), or '''Virgo Supercluster''' is a formerly defined supercluster containing the [[Virgo Cluster]] and [[Local Group]], which itself contains the [[Milky Way]] and [[Andromeda Galaxy|Andromeda]] galaxies, as well as others. At least 100 [[galaxy group]]s and [[Galaxy cluster|clusters]] are located within its diameter of 33 [[Parsec|megaparsecs]] (110 million [[light-years]]). The Virgo Supercluster is one of about 10 million [[supercluster]]s in the [[observable universe]], with the main body of the supercluster, the [[Virgo Strand]], connecting the [[Hydra-Centaurus]] and the [[Perseus–Pisces Supercluster|Perseus–Pisces Superclusters]].<ref name=":1" />  The Virgo Supercluster is part of the [[Pisces–Cetus Supercluster Complex]], a [[galaxy filament]].<ref>{{Cite journal |last=Tully |first=R. B. |date=April 1986 |title=Alignment of clusters and galaxies on scales up to 0.1 C |url=http://adsabs.harvard.edu/doi/10.1086/164049 |journal=The Astrophysical Journal |language=en |volume=303 |pages=25 |doi=10.1086/164049 |bibcode=1986ApJ...303...25T |issn=0004-637X}}</ref><ref>{{Cite journal |last=Tully |first=R. Brent |date=December 1987 |title=More about clustering on a scale of 0.1 C |url=http://adsabs.harvard.edu/doi/10.1086/165803 |journal=The Astrophysical Journal |language=en |volume=323 |pages=1 |doi=10.1086/165803 |bibcode=1987ApJ...323....1T |issn=0004-637X}}</ref>

A 2014 study indicates that the Local Supercluster is only a part of an even greater supercluster, [[Laniakea Supercluster|Laniakea]], a larger group centered on the [[Great Attractor]],<ref>{{cite journal |title= The Laniakea supercluster of galaxies |author= R. Brent Tully |author2= Hélène Courtois|author-link2=Hélène Courtois|author3= Yehuda Hoffman|author4= Daniel Pomarède |date= 2 September 2014 |publication-date= 4 September 2014 |journal= Nature |volume= 513 |number= 7516 |pages= 71–73 |bibcode= 2014Natur.513...71T |arxiv= 1409.0880 |doi= 10.1038/nature13674 |pmid=25186900|s2cid= 205240232 }}</ref> thus subsuming the former Virgo Supercluster under Laniakea.

==Background==
Beginning with the first large sample of [[nebula]]e published by [[William Herschel|William]] and [[John Herschel]] in 1863, it was known that there is a marked excess of nebular fields in the constellation [[Virgo (constellation)|Virgo]], near the north [[Galactic coordinate system|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<ref>
cfa.harvard.edu, [http://www.cfa.harvard.edu/~huchra/seminar/lsc/ The Geometry of the Local Supercluster], ''John P. Huchra'',
'''2007'''
(accessed 12-12-2008)
</ref>) in 1958. [[Harlow Shapley]], in his 1959 book ''Of Stars and Men'', suggested the term ''Metagalaxy''.<ref>[[Harlow Shapley|Shapley, Harlow]] ''[[Of Stars and Men]]'' (1959)</ref> 

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.<ref name="deV81">
{{cite journal
 | author = de Vaucouleurs, G.
 | title = The Local Supercluster of Galaxies
 | journal = Bulletin of the Astronomical Society of India
 | date = March 1981
 | volume = 9
 | page = 6 (see note)
 | bibcode = 1981BASI....9....1D
 }}</ref> 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.<ref name="klypin03">
{{cite journal
 | author = Klypin, Anatoly
 | display-authors = etal
 | title = Constrained Simulations of the Real Universe: The Local Supercluster
 | journal = The Astrophysical Journal
 | date = October 2003
 | volume = 596
 | issue = 1
 | pages = 19–33
 | bibcode = 2003ApJ...596...19K
 | doi = 10.1086/377574
 | arxiv = astro-ph/0107104
| s2cid = 1830859
 }}</ref>

==Structure==
In 1982, [[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 third.<ref name="hu06">
{{cite journal
 | author = Hu, F. X.
 | display-authors = etal
 | title = Orientation of Galaxies in the Local Supercluster: A Review
 | journal = Astrophysics and Space Science
 | date = April 2006
 | volume = 302
 | issue = 1–4
 | pages = 43–59
 | bibcode = 2006Ap&SS.302...43H
 | doi = 10.1007/s10509-005-9006-7
 | arxiv = astro-ph/0508669
| s2cid = 18837475
 }}</ref> The disk itself is a thin (~1 [[Parsec|Mpc]]) ellipsoid with a long axis / short axis ratio of at least 6 to 1, and possibly as high as 9 to 1.<ref name="tully82">
{{cite journal
 | author = Tully, R. B.
 | title = The Local Supercluster
 | journal = Astrophysical Journal
 | date = 15 Jun 1982
 | volume = 257
 | issue = 1
 | pages = 389–422
 | bibcode = 1982ApJ...257..389T
 | doi = 10.1086/159999
| doi-access = free
 }}</ref> Data released in June 2003 from the 5-year [[2dF Galaxy Redshift Survey|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.<ref name="ein07">
{{cite journal
 | author = Einasto, M.
 | display-authors = etal
 | title = The richest superclusters. I. Morphology
 | journal = Astronomy and Astrophysics
 | date = December 2007
 | volume = 476
 | issue = 2
 | pages = 697–711
 | bibcode = 2007A&A...476..697E
 | doi = 10.1051/0004-6361:20078037
|arxiv = 0706.1122 | s2cid = 15004251
 }}</ref> 

The [[Local Group]] is located on the outskirts of the LS in a small filament extending from the [[Fornax Cluster]] to the [[Virgo Cluster]].<ref name="klypin03" /> The Virgo Supercluster's volume is roughly 7,000 times that of the Local Group, or 100 billion times that of the Milky Way.

The main body of the Virgo Supercluster, the flattened disk of galaxies is simply part of a larger [[galaxy filament]] known as the [[Virgo Strand]] or [[Centaurus–Virgo–PP Filament]].<ref name=":0">{{Cite journal |last1=Courtois |first1=Hélène M. |last2=Pomarède |first2=Daniel |last3=Tully |first3=R. Brent |last4=Hoffman |first4=Yehuda |last5=Courtois |first5=Denis |date=September 2013 |title=Cosmography of the Local Universe |url=https://ui.adsabs.harvard.edu/abs/2013AJ....146...69C/abstract |journal=The Astronomical Journal |language=en |volume=146 |issue=3 |pages=69 |doi=10.1088/0004-6256/146/3/69 |arxiv=1306.0091 |bibcode=2013AJ....146...69C |issn=0004-6256}}</ref><ref name=":1">{{Cite journal |last1=Pomarède |first1=Daniel |last2=Hoffman |first2=Yehuda |last3=Courtois |first3=Hélène M. |last4=Tully |first4=R. Brent |date=August 2017 |title=The Cosmic V-Web |journal=The Astrophysical Journal |language=en |volume=845 |issue=1 |pages=55 |doi=10.3847/1538-4357/aa7f78 |doi-access=free |arxiv=1706.03413 |bibcode=2017ApJ...845...55P |issn=0004-637X}}</ref> This filament eminates from the [[Centaurus Cluster]] through the [[Virgo Cluster]] and continues through the [[Ursa Major Cluster]] all the way to the [[Perseus–Pisces Supercluster]].<ref name=":1" />  The [[Virgo Strand]] constits of two branches, an upper branch constisting of the main body of the supercluster though the [[Virgo Southern Extension]], the [[Virgo Cluster|Virgo]] and the [[Ursa Major Cluster]], and a lower branch consting of the [[Crater Cloud|Crater]] and [[Leo Cloud|Leo Clouds]].<ref name=":0" /> The rest of remaing third of the galaxies in Virgo Supercluster, including the Milky Way, lie outside the main body of the Supercluster which is the [[Virgo Strand]].<ref name="tully82" /><ref name=":0" />

==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 [[Galaxy cloud|clouds]] (groups of [[galaxy cluster]]s). Ninety-eight percent can be found in the following 11 clouds, given in decreasing order of number of luminous galaxies: [[M94 Group#Canes Venatici Cloud|Canes Venatici]], Virgo Cluster, [[Virgo II Groups|Virgo II]] (southern extension), [[Leo II Groups|Leo II]], [[Virgo III Groups|Virgo III]], Crater ([[NGC 3672]]), [[M96 Group|Leo I]], Leo Minor ([[NGC 2841]]), Draco ([[NGC 5907]]), Antlia ([[NGC 2997]]), and [[NGC 5643]].<ref name="tully82" />

Of the luminous galaxies located in the disk, one third are in the Virgo Cluster, with the other two thirds located outside of the cluster.<ref name="tully82" />

The luminous galaxies in the halo are 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."<ref name="tully82" /> 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 [[Parsec|Mpc]] in diameter) voids in space.<ref name="ma96">
{{cite book
 | author = Carroll, Bradley
 | author2 = Ostlie, Dale
 | title = An Introduction to Modern Astrophysics
 | publisher = [[Addison-Wesley]]
 | date = 1996
 | location = New York
 | page = 1136
 | isbn = 0-201-54730-9
}}</ref> Long filamentary structures seem to predominate. An example of this is the [[Hydra–Centaurus Supercluster]], the nearest supercluster to the Virgo Supercluster, which starts at a distance of roughly 30 Mpc and extends to 60 Mpc.<ref name="fairall89">
{{cite journal
 | last1 = Fairall | first1 = A. P.
 | last2 = Vettolani | first2 = G.
 | last3 = Chincarini | first3 = G.
 | title = A wide angle redshift survey of the Hydra-Centaurus region
 | journal = Astronomy and Astrophysics Supplement Series
 | date = May 1989
 | volume = 78
 | issue = 2
 | page = 270
 | bibcode = 1989A&AS...78..269F
 | issn=0365-0138
}}</ref>

==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 [[Parsec|Mpc]] is experiencing a bulk flow on the order of 600&nbsp;km/s in the direction of the [[Norma Cluster| Norma Cluster (Abell 3627)]].<ref name="plionis91">
{{cite journal
 | author = Plionis, Manolis
 | author2 = Valdarnini, Riccardo
 | title = Evidence for large-scale structure on scales about 300/h MPC
 | journal = Monthly Notices of the Royal Astronomical Society
 | date = March 1991
 | volume = 249
 | pages = 46–61
 | bibcode = 1991MNRAS.249...46P
 | doi =10.1093/mnras/249.1.46
 | doi-access = free
 }}</ref>
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 Supercluster|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]].<ref>{{Cite web|url=http://www.universetoday.com/113150/what-is-the-great-attractor/|title = What is the Great Attractor?|date = 14 July 2014}}</ref>

===Dark matter===
The LS has a total mass ''M'' ≈ 10<sup>15</sup> {{solar mass|link=yes}} and a total optical luminosity ''L'' ≈ 3{{e|12}} {{solar luminosity|link=yes}}.<ref name="ein07" /> This yields a [[mass-to-light ratio]] of about 300 times that of the solar ratio ({{solar mass}}/{{solar luminosity}} = 1), a figure that is consistent with results obtained for other superclusters.<ref name="todd98">
{{cite journal
 | author = Small, Todd A.
 | display-authors = etal
 | title = The Norris Survey of the Corona Borealis Supercluster. III. Structure and Mass of the Supercluster
 | journal = Astrophysical Journal
 | date = Jan 1998
 | volume = 492
 | issue = 1| pages = 45–56
 | bibcode = 1998ApJ...492...45S
 | doi = 10.1086/305037
 | arxiv = astro-ph/9708153
| s2cid = 119451873
 }}</ref><ref name="heymans08">
{{cite journal
 | author = Heymans, Catherine
 | display-authors = etal
 | title = The dark matter environment of the A901 abell A901/902 supercluster: a weak lensing analysis of the HST STAGES survey
 | journal = [[Monthly Notices of the Royal Astronomical Society]]
 | date = April 2008
 | volume = 385
 | issue = 3
 | pages = 1431–1442
 | bibcode = 2008MNRAS.385.1431H
 | doi = 10.1111/j.1365-2966.2008.12919.x
| doi-access = free
 |arxiv = 0801.1156 | s2cid = 59057342
 }}</ref>
By comparison, the [[mass-to-light ratio]] for the [[Milky Way]] is 63.8 assuming a solar [[absolute magnitude]] of 4.83,<ref name=nssdc>
{{cite web
 | last = Williams
 | first = D. R.
 | date = 2004
 | title = Sun Fact Sheet
 | url = http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html
 | publisher = [[NASA]]
 | access-date = 2012-03-17
}}</ref> a Milky Way absolute magnitude of −20.9,<ref>{{cite web
 | url = http://www.universetoday.com/guide-to-space/the-universe/absolute-magnitude/
 | title = Absolute Magnitude
 | author = Jerry Coffey
 | access-date = 2010-04-09
}}</ref>
and a Milky Way mass of {{Solar mass|1.25{{e|12}}}}.<ref name=McMillan2011>{{citation
 | last1 = McMillan
 | first1 = Paul J.
 | title = Mass models of the Milky Way
 | journal = Monthly Notices of the Royal Astronomical Society
 | volume = 414
 | issue = 3
 | pages = 2446–2457
 |date=July 2011
 | doi = 10.1111/j.1365-2966.2011.18564.x
 | doi-access = free
 | bibcode = 2011MNRAS.414.2446M |arxiv = 1102.4340 | s2cid = 119100616
 }}</ref> 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==
<imagemap>
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 [[Virgo Cluster]]
circle 339 230 16 [[Centaurus A/M83 Group]]
circle 349 252 15 [[M81 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|NGC 5033 group]]
rect 445 247 508 276 [[Ursa Major Cluster]]
circle 391 270 18 [[Leo Group|Leo I Group]]
circle 277 197 25 [[NGC 6744|NGC 6744 Group]]
circle 236 314 22 [[Dorado Group]]
circle 518 87 40 [[Virgo III Groups]]
circle 526 225 20 [[NGC 4697]]
circle 546 331 34 [[Leo II Groups]]
circle 165 194 27 [[NGC 7582]]
poly 180 356 178 325 252 345 242 378 [[Fornax Cluster]]
poly 176 357 239 379 214 413 162 381 [[Eridanus Cluster]]
rect 295 213 324 239 [[Local Group]]
rect 252 235 304 257 [[Sculptor Group]]
desc bottom-left
</imagemap>

<imagemap>
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 [[Milky Way]]
circle 385 294 14 [[Large Magellanic Cloud]]
circle 429 267 20 [[NGC 3109]]
circle 395 338 16 [[Messier 31]]
circle 365 335 15 [[Messier 33]]
circle 278 311 20 [[NGC 247]]
circle 388 119 28 [[Circinus Galaxy]]
circle 456 124 17 [[NGC 5128]]
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 [[Virgo Cluster]]
circle 433 65 22 [[ESO 274-01]]
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]]
circle 184 301 20 [[NGC 45]]
circle 217 311 17 [[NGC 253]]
circle 265 260 22 [[Sculptor Group]]
rect 368 268 412 284 [[Local Group]]
circle 409 379 25 [[NGC 1569]]
circle 296 280 17 [[NGC 300]]
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]]
circle 397 510 20 [[Maffei I]]
rect 353 456 413 478 [[Maffei II]]
rect 371 526 434 553 [[Dwingeloo 1]]
circle 444 481 22 [[NGC 1560]]
rect 510 417 537 434 [[Messier 81]]
rect 527 433 578 443 [[IC 2574]]
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]]
circle 513 479 19 [[NGC 6503]]
circle 583 410 13 [[NGC 5204]]
circle 559 389 16 [[NGC 3738]]
circle 512 401 14 [[NGC 4236]]
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]]
rect 591 280 640 304 [[Canes I Group]]
poly 528 393 542 392 558 411 525 414 [[M81 Group]]
desc bottom-left
</imagemap>

==Diagrams==
{{wide image|Location of Earth (9x1-English Annot-small).png|2000px|A diagram of our location in the [[observable universe]]. (''[[:File:Location of Earth (3x3-English Annot-small).png|Alternative image]].'')}}

==See also==
* [[Abell catalogue]]
* [[Observable universe#Large-scale structure|Large-scale structure of the universe]]
* [[List of Abell clusters]]
* [[Supercluster]]
* [[KBC Void]]

==References==
{{reflist|30em}}

==Further reading==
* {{cite journal | last1 = Tully | first1 = Brent | date = 1982 | title = The Local Supercluster | journal = Astrophys. J. | volume = 257 | pages = 389–422 | doi=10.1086/159999|bibcode = 1982ApJ...257..389T | doi-access = free }}
* {{cite journal | last1 = Lynden-Bell | first1 = D. | display-authors = etal   | date = 1988 | title = Spectroscopy and photometry of elliptical galaxies. V&nbsp;— Galaxy streaming toward the new supergalactic center | url = http://adsabs.harvard.edu/cgi-bin/bib_query?1988ApJ...326...19L | journal = Astrophysical Journal | volume = 326 | pages = 19–49 | doi=10.1086/166066|bibcode = 1988ApJ...326...19L }}

==External links==
* [http://www.atlasoftheuniverse.com/ 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}}
{{Earth's location}}
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[[Category:Virgo Supercluster| ]]
[[Category:Galaxy superclusters]]
[[Category:Laniakea Supercluster]]