Virgo Cluster

Coordinates: Sky map 12h 27m 00s, 12° 43′ 00″
Source: Wikipedia, the free encyclopedia.
Virgo Cluster
J2000)
Constellation(s)Virgo & Coma Berenices
Right ascension12h 27m [1]
Declination+12° 43′[1]
Brightest memberMessier 49
Number of galaxies~1,500[1]
Parent structureVirgo Supercluster
Bautz–Morgan classificationIII[1]
Binding mass1015 M☉
See also: Galaxy group, Galaxy cluster, List of galaxy groups and clusters

The Virgo Cluster is a large

Mly (16.5 ± 0.1 Mpc)[2] away in the constellation Virgo. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies,[3] the cluster forms the heart of the larger Virgo Supercluster, of which the Local Group (containing our Milky Way galaxy) is a member. The Local Group actually experiences the mass of the Virgo Supercluster as the Virgocentric flow. It is estimated that the Virgo Cluster's mass is 1.2×1015 M☉ out to 8 degrees of the cluster's center or a radius of about 2.2 Mpc.[4]

Many of the brighter galaxies in this cluster, including the giant elliptical galaxy Messier 87, were discovered in the late 1770s and early 1780s and subsequently included in Charles Messier's catalogue of non-cometary fuzzy objects. Described by Messier as nebulae without stars, their true nature was not recognized until the 1920s.[A]

The cluster subtends a maximum arc of approximately 8 degrees centered in the constellation Virgo. Although some of the cluster's most prominent members can be seen with smaller instruments, a 6-inch telescope will reveal about 160 of the cluster's galaxies on a clear night. Its brightest member is the elliptical galaxy Messier 49; however its most famous member is the elliptical galaxy Messier 87, which is located in the center of the cluster.[6]

Characteristics

The cluster is a fairly

prolate filament, approximately four times as long as it is wide, stretching along the line of sight from the Milky Way.[8] The elliptical galaxies are more centrally concentrated than the spiral galaxies.[9]

The cluster is an aggregate of at least three separate

M60 as well as a LVC (Low Velocity Cloud) subclump, centered on the large spiral galaxy NGC 4216.[10] Notably, the giant elliptical galaxy M87 contains a supermassive black hole, whose event horizon was observed by the Event Horizon Telescope Collaboration in 2019.[11][12]

Of all of the subclumps, Virgo A, formed by a mixture of elliptical, lenticular, and (usually) gas-poor spiral galaxies,[13] is the dominant one, with a mass of approximately 1014 M☉, which is approximately an order of magnitude larger than the other two subclumps.[14]

Turbulence may prevent galaxy clusters from cooling (Chandra X-ray).

The three subgroups are in the process of merging to form a larger single cluster

galaxy clouds, mostly composed of spiral galaxies, known as N Cloud, S Cloud, and Virgo E that are in the process of infalling to merge with them,[15] plus other farther isolated galaxies and galaxy groups (like the galaxy cloud Coma I) that are also attracted by the gravity of Virgo to merge with it in the future.[16] This strongly suggests the Virgo cluster is a dynamically young cluster that is still forming.[15]

Other two nearby aggregations known as M Cloud, W Cloud, and W' Cloud[10] seem to be background systems independent of the main cluster.[15]

The large mass of the cluster is indicated by the high peculiar velocities of many of its galaxies, sometimes as high as 1,600 km/s with respect to the cluster's center.

The Virgo cluster lies within the Virgo Supercluster, and its gravitational effect slows down the nearby galaxies. The large mass of the cluster has the effect of slowing down the recession of the Local Group from the cluster by approximately ten percent.

Molecular gasses in Virgo Cluster has been swept away by a huge cosmic broom that is preventing nearby galaxies from birthing new stars. The actual cause of it has been a long standing mystery in astrophysics. According to scientists, it occurs because of the extreme environment of the Virgo Cluster.[17]

Intracluster medium

As with many other rich galaxy clusters, Virgo's

X-Rays.[18] Within the intracluster medium (ICM) are found a large number of intergalactic stars[19][20] (up to 10% of the stars in the cluster),[21] including some planetary nebulae.[22] It is theorized that these were expelled from their home galaxies by interactions with other galaxies.[21] The ICM also contains some globular clusters,[23][24][25] possibly stripped off dwarf galaxies,[25] and even at least one star formation region.[26]

Galaxies

Mpc
). The Virgo Cluster is visible in the center right of the image, at about 50 Mly from the Local Group.
Photograph of the Virgo Cluster with labelled galaxies

Below is a table of bright or notable objects in the cluster and their subunit (subcluster). Note that in some cases a galaxy may be considered in a different subunit by other researchers (sources:[10][15][27][28])

Column 1: The name of the galaxy.
Column 2: The right ascension for epoch 2000.
Column 3: The declination for epoch 2000.
Column 4: The blue apparent magnitude of the galaxy.
Column 5: The galaxy type: E=Elliptical, S0=Lenticular, Sa,Sb,Sc,Sd=Spiral, SBa,SBb,SBc,SBd=Barred spiral, Sm,SBm,Irr=Irregular.
Column 6: The angular diameter of the galaxy (arcminutes).
Column 7: The diameter of the galaxy (thousands of light years).
Column 8: The recessional velocity (km/s) of the galaxy relative to the cosmic microwave background.
Column 9: Subcluster where the galaxy is located.
Cluster members
Designation Coordinates (Epoch 2000) Apparent
magnitude
(blue) 		Type
Angular size
 Diameter
(kly) 		RV
(km/s) 		Subcluster
RA
 Dec
Messier 98 12 13.8 14 54 10.9 SBb 9.8′ 150 184 Virgo A or N Cloud
NGC 4216 12 15.9 13 09 10.9 SBb 7.9′ 120 459 Virgo A, N Cloud, or LVC.
Messier 99 12 18.8 14 25 10.4 Sc 5.4′ 80 2735 Virgo A or N Cloud
NGC 4262 12 19.5 14 53 12.4 S0 1.9′ 30 1683 Virgo A
NGC 4388 12 25.5 12 39 11.8 SAb 6.2′ 85 2845 Virgo A
Messier 61 12 21.9 04 28 10.2 SBbc 6.2′ 100 1911 S Cloud
Messier 100 12 22.9 15 49 10.1 SBbc 7.6′ 115 1899 Virgo A
Messier 84 12 25.1 12 53 10.1 E1 6.0′ 90 1239 Virgo A
Markarian's Chain
Messier 85 12 25.4 18 11 10.0 S0 7.1′ 105 1056 Virgo A
Messier 86 12 26.2 12 57 9.9 E3 10.2′ 155 37 Virgo A or own subgroup.
Markarian's Chain
NGC 4435 12 27.7 13 05 11.7 S0 3.0′ 45 1111 Virgo A
NGC 4438 12 27.8 13 01 11.0 Sa 8.7′ 130 404 Virgo A
NGC 4450 12 28.5 17 05 10.9 Sab 5.1′ 80 2273 Virgo A
Messier 49 12 29.8 08 00 9.3 E2 9.8′ 150 1204 Virgo B
Messier 87 12 30.8 12 23 9.6 E0–1 9.8′ 980 1204 Virgo A
Messier 88 12 32.0 14 25 10.3 Sb 6.8′ 100 2599 Virgo A
NGC 4526 12 32.0 07 42 10.6 S0 7.1′ 105 931 Virgo B
NGC 4527 12 34.1 02 39 12.4 Sb 4.6′ 69 1730 S Cloud
NGC 4536 12 34.4 02 11 11.1 SBbc 7.2′ 115 2140 S Cloud
Messier 91 12 35.4 14 30 11.0 SBb 5.2′ 80 803 Virgo A
NGC 4546 12 35.5 -03 48 11.3 S0 2.3' 30 1054 S Cloud
NGC 4550 12 35.5 12 13 12.5 S0 3.2′ 50 704 Virgo A
Messier 89 12 35.7 12 33 10.7 E0 5.0′ 75 628 Virgo A
NGC 4567 12 36.5 11 15 12.1 Sbc 2.8′ 40 2588 Virgo A
NGC 4568 12 36.6 11 14 11.7 Sbc 4.4′ 65 2578 Virgo A
Messier 90 12 36.8 13 10 10.2 SBab 10.5′ 160 87 Virgo A
NGC 4571 12 36.9 14 13 11.9 Sc 3.7′ 55 659 Virgo A
Messier 58 12 37.7 11 49 10.6 SBb 5.6′ 85 1839 Virgo A
Messier 59 12 42.9 11 39 10.8 E5 5.0′ 75 751 Virgo A or Virgo E
Messier 60 12 43.7 11 33 9.8 E2 7.2′ 110 1452 Virgo A, Virgo E, or Virgo C
NGC 4651 12 43.7 16 24 11.4 Sc 4.0′ 60 1113
NGC 4654 12 43.9 13 08 11.1 SBc 5.0′ 75 1349 Virgo A

Fainter galaxies within the cluster are usually known by their numbers in the Virgo Cluster Catalog, particularly members of the numerous dwarf galaxy population.[29]

See also

Notes

  1. ^ Following the entry for M91 in the Connoissance des Temps for 1784, Messier added the following note:
    The constellation of Virgo, & especially the northern Wing is one of the constellations which encloses the most Nebulae: this Catalog contains thirteen which have been determined: viz. Nos. 49, 58, 59, 60, 61, 84, 85, 86, 87, 88, 89, 90, & 91. All these nebulae appear to be without stars: one can see them only in a very good sky, & near their meridian passage. Most of these nebulae have been pointed to me by Mr. Méchain.[5]

References

  1. ^ a b c d "NASA/IPAC Extragalactic Database". Results for Virgo Cluster. Retrieved 2006-10-19.
  2. S2CID 16483538
    .
  3. ^ "Virgo Cluster". Cosmos. Swinburne University of Technology.
  4. S2CID 10468717
    .
  5. SEDS
    .
  6. ^ "Virgo Cluster | Messier Objects". www.messier-objects.com. 9 August 2017. Retrieved 2018-06-24.
  7. S2CID 18021414
    .
  8. doi:10.1086/186928
    .
  9. ^ "Virgo Cluster". ned.ipac.caltech.edu. Retrieved 2018-06-24.
  10. ^
    S2CID 119244700
    . A69.
  11. doi:10.3847/2041-8213/ab0ec7
    .
  12. ^ "Publications | Event Horizon Telescope". eventhorizontelescope.org. Retrieved 2020-09-10.
  13. ^ Chamaraux, P.; Balkowski, C.; Gerard, E. (1980). "The H I deficiency of the Virgo cluster spirals". Astronomy & Astrophysics. 83 (1–2): 38–51.
    Bibcode:1980A&A....83...38C
    .
  14. ^ a b The Virgo Super Cluster: home of M87 (with frames)
  15. ^
    S2CID 41700753
    .
  16. doi:10.1086/162073
    .
  17. S2CID 240354399
    .
  18. S2CID 120960432
    .
  19. Bibcode:1997hst..prop.7411F
    .
  20. S2CID 4390832
    .
  21. ^
    S2CID 4390832
    .
  22. S2CID 9761241
    .
  23. ISBN 978-3-540-76960-6. {{cite book}}: |journal= ignored (help
    )
  24. Bibcode:2010AAS...21547814D
    .
  25. ^
    S2CID 20743125
    .
  26. S2CID 8686119
    .
  27. ^ "Galaxy On Line Database Milano Network". GOLDMine. Retrieved 2012-08-06.
  28. ^ "The Virgo Cluster". Retrieved 2013-04-06.
  29. doi:10.1086/113874
    .

External links


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