Virgo Supercluster: Difference between revisions
imported>Arjayay m Sp + English |
imported>Ugha mNo edit summary |
||
| Line 1: | Line 1: | ||
{{Short description| | {{Short description|Galaxy supercluster home to the Milky Way}} | ||
| name = Local Supercluster | {{Redirect|Local supercluster|the larger proposed supercluster sometimes called by the same name|Laniakea Supercluster}} | ||
| image = Local supercluster-ly.jpg | {{Infobox galaxy cluster | ||
| caption = Distances from the [[Local Group]] for selected groups and clusters within the Local Supercluster{{citation needed|date=March 2025}} | | name = Local Supercluster | ||
| credit = | | image = Local supercluster-ly.jpg | ||
| epoch = [[Epoch (astronomy)#Julian years and J2000|J2000]] | | caption = Distances from the [[Local Group]] for selected groups and clusters within the Local Supercluster{{citation needed|date=March 2025}} | ||
| constellation = | | credit = | ||
| ra = | | epoch = [[Epoch (astronomy)#Julian years and J2000|J2000]] | ||
| dec = | | constellation = [[Virgo (constellation)|Virgo]] & [[Coma Berenices]] (''[[Virgo Cluster]]'') | ||
| brightest_member = | | ra = {{RA|12|31}}<ref name="SIMBAD">{{cite simbad|title=Virgo Supercluster|access-date=2025-11-10}}</ref> | ||
| member_no = | | dec = {{DEC|+12|24}}<ref name="SIMBAD"/> | ||
| parent = [[Laniakea Supercluster]] | | brightest_member = | ||
| major_axis_mpc = | | member_no = 47,000+ | ||
| minor_axis_mpc = | | parent = [[Laniakea Supercluster]] | ||
| redshift = [[Doppler shift]] | | major_axis_mpc = {{cvt|45|Mpc|Mly|sigfig=3|abbr=unit|lk=on|order=flip}}<ref name="klypin03"/> | ||
| distance = | | minor_axis_mpc = ≈{{cvt|8|Mpc|Mly|sigfig=3|abbr=unit|lk=on|order=flip}}<ref name=nedrood>{{cite web|url=https://ned.ipac.caltech.edu/level5/Sept01/Rood/Rood2_2.html}}</ref> | ||
| mass = ~1.48 | | redshift = [[Doppler shift]]{{cn|date=November 2025}} | ||
| luminosity_specify = | | distance = {{cvt|17.053|+/-|2.574|Mpc|Mly|sigfig=4|abbr=unit|lk=on|order=flip}} (''[[Virgo Cluster]]'')<ref name="ned">{{NED link|id=Virgo+Cluster|name=Virgo Cluster}}</ref> | ||
| flux = | | mass = ~{{val|1.48|e=15}}<ref name="ein07" /> | ||
| other_names = Virgo Supercluster | | luminosity_specify = {{val|3|e=12|ul=solar luminosity}}<ref name="ein07" /> (total) | ||
| flux = | |||
| other_names = {{odlist |name=Local Supercluster|name2=Virgo Supercluster| name3=LSC |name4=LS }}<ref name="SIMBAD"/> | |||
}} | }} | ||
The '''Local Supercluster''' ('''LSC''' or '''LS''') | The '''Local Supercluster''' ('''LSC''' or '''LS''') is a [[supercluster]] of [[galaxy|galaxies]] containing the [[Virgo Cluster]] and [[Local Group]]. The latter contains the [[Milky Way]] and [[Andromeda Galaxy|Andromeda]] galaxies, among others. Sometimes referred to as '''Virgo Supercluster''', the Local Supercluster is roughly centered on the Virgo Cluster, with the Local Group located near one edge and revolving around its center.<ref name=nasa>{{cite web|title=Imagine the Universe! |url=https://imagine.gsfc.nasa.gov/features/cosmic/local_supercluster_info.html}}</ref> | ||
A 2014 study | At least 100 [[galaxy group]]s and [[Galaxy cluster|clusters]]<ref>{{Cite web|url=https://theplanets.org/superclusters/the-virgo-supercluster/|title = The Virgo Supercluster|date = 18 November 2025}}</ref> are located within the supercluster diameter of {{convert|45|Mpc|e6ly km|lk=on|abbr=off|sigfig=3}}.<ref name="klypin03"/> The Local Supercluster is one of about 10 million superclusters in the [[observable universe]], with the main body of the supercluster, the Virgo Strand, connecting the [[Hydra-Centaurus]] and the [[Perseus–Pisces Supercluster]]s.<ref name=":1" /> It is part of the [[Pisces–Cetus Supercluster Complex]], a [[List of largest cosmic structures|very large]] [[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 indicated that the Local Supercluster is only a part of an even greater supercluster centered on the [[Great Attractor]], [[Laniakea Supercluster]].<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> This thus would subsume the former as a component under Laniakea as the newly defined local supercluster based on the definition for a supercluster as basins of attraction rather than large high-density regions as traditionally accepted. Basins of attraction such as Laniakea were later proposed to be called [[supercluster cocoon]]s to distinguish them from smaller and traditional superclusters, such as Virgo, as high-density regions of the [[cosmic web]].<ref name=einasto2019/> | |||
==Background== | ==Background== | ||
| Line 58: | Line 62: | ||
==Structure== | ==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"> | [[File:Universe Reference Map (Location) 001.jpeg|thumb|alt=|upright=2.1|An old diagram showing the location of the [[Local Group]], including the [[Solar System]], within the Local Supercluster, revealing its location at the supercluster's outskirts with the [[Virgo Cluster]] forming its heart.<ref name="klypin03"/> The [[Fornax Cluster]] shown at the left was later revealed to be a separated part of the [[Southern Supercluster]]. Both superclusters are part of the greater [[Laniakea Supercluster|Laniakea Supercluster cocoon]] ([[Virgo Supercluster#Diagrams|see below]]),.]] | ||
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 | {{cite journal | ||
| author = Hu, F. X. | | author = Hu, F. X. | ||
| Line 72: | Line 77: | ||
| arxiv = astro-ph/0508669 | | arxiv = astro-ph/0508669 | ||
| s2cid = 18837475 | | s2cid = 18837475 | ||
}}</ref> The disk itself is a thin (~ | }}</ref> The disk itself is a thin ({{val|1|p=~|ul=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 | {{cite journal | ||
| author = Tully, R. B. | | author = Tully, R. B. | ||
| Line 106: | Line 111: | ||
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" /> | 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" /> | 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"> | 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"> | ||
| Line 132: | Line 137: | ||
| issn=0365-0138 | | issn=0365-0138 | ||
}}</ref> | }}</ref> | ||
Below is a table of known supercluster members. | |||
{| class="wikitable sortable" | |||
|+Known Supercluster members | |||
!Cluster name | |||
!Brightest member | |||
|- | |||
|[[Local Group]] | |||
| - | |||
|- | |||
|[[Virgo Cluster]] | |||
|[[Messier 49]] | |||
|- | |||
|[[Sculptor Group]] | |||
|[[Sculptor Galaxy|NGC 253]] | |||
|- | |||
|[[IC 342/Maffei Group]] | |||
|[[IC 342]]/[[Dwingeloo 1]] | |||
|- | |||
|[[M81 Group|M 81 Group]] | |||
|[[M 81]] | |||
|- | |||
|[[Canes I Group]] | |||
|[[Messier 94|M 94]] | |||
|- | |||
|[[Canes II Group]] | |||
|[[Messier 106|M 106]] | |||
|- | |||
|[[NGC 5128 Group]] | |||
|[[Centaurus A]]<ref>{{Cite journal |last=Karachentsev |first=I. D. |date=January 2005 |title=The Local Group and Other Neighboring Galaxy Groups |url=https://ui.adsabs.harvard.edu/abs/2005AJ....129..178K/abstract |journal=The Astronomical Journal |language=en |volume=129 |issue=1 |pages=178–188 |doi=10.1086/426368 |issn=0004-6256|arxiv=astro-ph/0410065 |bibcode=2005AJ....129..178K }}</ref> | |||
|- | |||
|[[Leo I Group]] | |||
|[[Messier 96|M 96]] | |||
|- | |||
|[[Leo II Groups]] | |||
| - | |||
|} | |||
==Cosmology== | ==Cosmology== | ||
===Large-scale dynamics=== | ===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 km/s in the direction of the [[Norma Cluster| Norma Cluster (Abell 3627)]].<ref name="plionis91"> | 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 km/s in the direction of the [[Norma Cluster|Norma Cluster (Abell 3627)]].<ref name="plionis91"> | ||
{{cite journal | {{cite journal | ||
| author = Plionis, Manolis | | author = Plionis, Manolis | ||
| Line 149: | Line 191: | ||
| doi-access = free | | doi-access = free | ||
}}</ref> | }}</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 | 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 and basin of attraction (BoA), dubbed "[[Laniakea Supercluster|Laniakea]]", which includes the Virgo Supercluster (including the Local Group) as well as the Hydra-Centaurus, Pavo-Indus, and Southern Superclusters. Laniakea has therefore been proposed to be called a [[supercluster cocoon]] instead to distinguish the structure from smaller embedded superclusters traditionally defined as high-density regions.<ref name=einasto2019>{{cite journal|last1=Einasto |first1=J. |last2=Suhhonenko |first2=I. |last3=Liivamägi |first3=L. J. |last4=Einasto |first4=M. |title=Evolution of superclusters in the cosmic web |journal=Astronomy & Astrophysics |date=2019 |volume=623 |pages=A97 |doi=10.1051/0004-6361/201834450 |arxiv=1901.09378 |bibcode=2019A&A...623A..97E }}</ref> | ||
The Great Attractor, together with the entire | The Great Attractor, together with the entire Laniakea, 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> and may be itself potentially part of this even greater concentration.<ref name=dupuy>{{cite journal|last1=Dupuy |first1=A. |last2=Courtois |first2=H. M. |title=Dynamic cosmography of the local Universe: Laniakea and five more watershed superclusters |journal=Astronomy & Astrophysics |date=2023 |volume=678 |pages=A176 |doi=10.1051/0004-6361/202346802 |arxiv=2305.02339 |bibcode=2023A&A...678A.176D }}</ref><ref name=valade>{{cite journal|last1=Valade |first1=A. |last2=Libeskind |first2=N. I. |last3=Pomarède |first3=D. |last4=Tully |first4=R. B. |last5=Hoffman |first5=Y. |last6=Pfeifer |first6=S. |last7=Kourkchi |first7=E. |title=Identification of basins of attraction in the local Universe |journal=Nature Astronomy |date=2024 |volume=8 |issue=12 |pages=1610–1616 |doi=10.1038/s41550-024-02370-0 |arxiv=2409.17261 |bibcode=2024NatAs...8.1610V }}</ref> | ||
===Dark matter=== | ===Dark matter=== | ||
The LS has a total mass ''M'' ≈ | The LS has a total mass ''M'' ≈ {{val|e=15|ul=solar mass}} and a total optical luminosity ''L'' ≈ {{val|3|e=12|ul=solar luminosity}}.<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 | {{cite journal | ||
| author = Small, Todd A. | | author = Small, Todd A. | ||
| Line 197: | Line 239: | ||
| access-date = 2010-04-09 | | access-date = 2010-04-09 | ||
}}</ref> | }}</ref> | ||
and a Milky Way mass of {{ | and a Milky Way mass of {{val|1.25|e=12|u=solar mass}}.<ref name=McMillan2011>{{citation | ||
| last1 = McMillan | | last1 = McMillan | ||
| first1 = Paul J. | | first1 = Paul J. | ||
| Line 299: | Line 341: | ||
==Diagrams== | ==Diagrams== | ||
{{wide image|Location of Earth (9x1-English Annot-small).png|2000px|A diagram of | {{wide image|Location of Earth (9x1-English Annot-small).png|2000px|A diagram of Earth's location in the [[observable universe]]. (''[[:File:Location of Earth (3x3-English Annot-small).png|Alternative image]].'')}} | ||
==See also== | ==See also== | ||
| Line 305: | Line 347: | ||
* [[Observable universe#Large-scale structure|Large-scale structure of the universe]] | * [[Observable universe#Large-scale structure|Large-scale structure of the universe]] | ||
* [[List of Abell clusters]] | * [[List of Abell clusters]] | ||
* [[ | * [[Local Hole]] | ||
==References== | ==References== | ||
| Line 314: | Line 355: | ||
* {{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 = 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 — 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 }} | * {{cite journal | last1 = Lynden-Bell | first1 = D. | display-authors = etal | date = 1988 | title = Spectroscopy and photometry of elliptical galaxies. V — 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 }} | ||
* {{cite journal| last1 = Einasto| first1 = Maret| title = Galaxy Superclusters and Their Complexes in the Cosmic Web| journal = Universe| date = 2025| volume = 11| issue = 6| page = 167| doi = 10.3390/universe11060167| doi-access = free| arxiv = 2505.22082| bibcode = 2025Univ...11..167E}} | |||
==External links== | ==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). | * [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). | ||
* {{cite web|title=The Local Supercluster |url=https://lweb.cfa.harvard.edu/~dfabricant/huchra/seminar/lsc/}} | |||
{{Virgo Supercluster}} | {{Virgo Supercluster}} | ||
Latest revision as of 11:26, 18 November 2025
Template:Short description Script error: No such module "redirect hatnote". Script error: No such module "Infobox".Template:Template otherScript error: No such module "Check for unknown parameters".
The Local Supercluster (LSC or LS) is a supercluster of galaxies containing the Virgo Cluster and Local Group. The latter contains the Milky Way and Andromeda galaxies, among others. Sometimes referred to as Virgo Supercluster, the Local Supercluster is roughly centered on the Virgo Cluster, with the Local Group located near one edge and revolving around its center.[1]
At least 100 galaxy groups and clusters[2] are located within the supercluster diameter of Template:Convert.[3] The Local Supercluster is one of about 10 million superclusters in the observable universe, with the main body of the supercluster, the Virgo Strand, connecting the Hydra-Centaurus and the Perseus–Pisces Superclusters.[4] It is part of the Pisces–Cetus Supercluster Complex, a very large galaxy filament.[5][6]
A 2014 study indicated that the Local Supercluster is only a part of an even greater supercluster centered on the Great Attractor, Laniakea Supercluster.[7] This thus would subsume the former as a component under Laniakea as the newly defined local supercluster based on the definition for a supercluster as basins of attraction rather than large high-density regions as traditionally accepted. Basins of attraction such as Laniakea were later proposed to be called supercluster cocoons to distinguish them from smaller and traditional superclusters, such as Virgo, as high-density regions of the cosmic web.[8]
Background
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[9]) in 1958. Harlow Shapley, in his 1959 book Of Stars and Men, suggested the term Metagalaxy.[10]
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.[11] 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.[3]
Structure
_001.jpeg){kind=link}
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.[12] The disk itself is a thin (Template:Val) ellipsoid with a long axis / short axis ratio of at least 6 to 1, and possibly as high as 9 to 1.[13] 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.[14]
The Local Group is located on the outskirts of the LS in a small filament extending from the Fornax Cluster to the Virgo Cluster.[3] 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.[15][4] This filament emanates from the Centaurus Cluster through the Virgo Cluster and continues through the Ursa Major Cluster all the way to the Perseus–Pisces Supercluster.[4] The Virgo Strand consists of two branches, an upper branch consisting of the main body of the supercluster though the Virgo Southern Extension, the Virgo and the Ursa Major Cluster, and a lower branch consisting of the Crater and Leo Clouds.[15] The rest of remaining third of the galaxies in Virgo Supercluster, including the Milky Way, lie outside the main body of the Supercluster which is the Virgo Strand.[13][15]
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.[13]
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.[13]
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."[13] 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.[16] 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.[17]
Below is a table of known supercluster members.
| Cluster name | Brightest member |
|---|---|
| Local Group | - |
| Virgo Cluster | Messier 49 |
| Sculptor Group | NGC 253 |
| IC 342/Maffei Group | IC 342/Dwingeloo 1 |
| M 81 Group | M 81 |
| Canes I Group | M 94 |
| Canes II Group | M 106 |
| NGC 5128 Group | Centaurus A[18] |
| Leo I Group | M 96 |
| Leo II Groups | - |
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).[19] 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 and basin of attraction (BoA), dubbed "Laniakea", which includes the Virgo Supercluster (including the Local Group) as well as the Hydra-Centaurus, Pavo-Indus, and Southern Superclusters. Laniakea has therefore been proposed to be called a supercluster cocoon instead to distinguish the structure from smaller embedded superclusters traditionally defined as high-density regions.[8]
The Great Attractor, together with the entire Laniakea, is found to be moving toward Shapley Supercluster, with center of Shapley Attractor,[20] and may be itself potentially part of this even greater concentration.[21][22]
Dark matter
The LS has a total mass M ≈ Template:Val and a total optical luminosity L ≈ Template:Val.[14] This yields a mass-to-light ratio of about 300 times that of the solar ratio (Template:Solar mass/Template:Solar luminosity = 1), a figure that is consistent with results obtained for other superclusters.[23][24] By comparison, the mass-to-light ratio for the Milky Way is 63.8 assuming a solar absolute magnitude of 4.83,[25] a Milky Way absolute magnitude of −20.9,[26] and a Milky Way mass of Template:Val.[27] 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
Error: Image is invalid or non-existent.
Error: Image is invalid or non-existent.
Diagrams
See also
References
Further reading
- Script error: No such module "Citation/CS1".
- Script error: No such module "Citation/CS1".
- Script error: No such module "Citation/CS1".
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).
- Script error: No such module "citation/CS1".
Template:Virgo Supercluster Template:Earth's location Template:Portal bar
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ a b c d Script error: No such module "Citation/CS1".
- ↑ a b c Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ cfa.harvard.edu, The Geometry of the Local Supercluster, John P. Huchra, 2007 (accessed 12-12-2008)
- ↑ Shapley, Harlow Of Stars and Men (1959)
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ a b c d e Script error: No such module "Citation/CS1".
- ↑ a b Script error: No such module "Citation/CS1".
- ↑ a b c Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".