Astronomy:Local Sheet

From HandWiki
Local Sheet
File:300px
Observation data (Epoch )
Brightest memberLocal Group
Major axis17 Mly (5 Mpc) [1]
Minor axis1.5 Mly (0.5 Mpc) [1]
Redshift0.00
Distance
(co-moving)		0 Mly (0 Mpc)
See also: Galaxy group, Galaxy cluster, List of galaxy groups and clusters

The Local Sheet in astronomy is a nearby extragalactic region of space where the Milky Way, the members of the Local Group and other galaxies share a similar peculiar velocity.[2] This region lies within a radius of about 7 Mpc (23 Mly),[3] 0.46 Mpc (1.5 Mly) thick,[1] and galaxies beyond that distance show markedly different velocities.[3] The Local Group has only a relatively small peculiar velocity of 66 km⋅s−1 with respect to the Local Sheet. Typical velocity dispersion of galaxies is only 40 km⋅s−1 in the radial direction.[2] Nearly all nearby bright galaxies belong to the Local Sheet.[1] The Local Sheet is part of the Local Volume and is in the Virgo Supercluster (Local Supercluster).[4] The Local Sheet forms a wall of galaxies delineating one boundary of the Local Void.[5]

A significant component of the mean velocity of the galaxies in the Local Sheet appears as the result of the gravitational attraction of the Virgo Cluster of galaxies, resulting in a peculiar motion ~185 km⋅s−1 toward the cluster.[2] A second component is directed away from the center of the Local Void; an expanding region of space spanning an estimated 45 Mpc (150 Mly) that is only sparsely populated with galaxies.[3] This component has a velocity of 259 km⋅s−1.[2] The Local Sheet is inclined 8° from the Local Supercluster (Virgo Supercluster).[4]

The so-called Council of Giants is a ring of twelve large galaxies surrounding the Local Group in the Local Sheet, with a radius of 3.75 Mpc (12.2 Mly).[4] Ten of these are spirals, while the remaining two are ellipticals. The two ellipticals (Maffei 1 and Centaurus A) lie on opposite sides of the Local Group.

Local Sheet (top view)
Galaxies in the "Council of Giants"[4]
Catalog ID Name Constellation Distance (Mly) Stellar mass *
NGC 253 Sculptor Galaxy Sculptor 11 10.805
PGC 9892 Maffei 1 Cassiopeia 11 10.928
PGC 10217 Maffei 2 Cassiopeia 11 10.493
IC 342   Camelopardalis 11 10.302
NGC 3031 M 81 Ursa Major 12 10.905
NGC 3034 M 82 Ursa Major 11 10.573
NGC 4736 M 94 Canes Venatici 15 10.458
NGC 4826 M 64 Coma Berenices 16 10.496
NGC 5236 M 83 Hydra 16 10.642
NGC 5128 Centaurus A Centaurus 11 11.169
NGC 4945   Centaurus 12 10.528
ESO 97-G13 Circinus Galaxy Circinus 14 10.559

* The mass is given as the logarithm (base unspecified) of the mass in solar masses.

Location

The Local Sheet is the co-moving part of the Coma-Sculptor Cloud,[6] which was identified and described in 1987 by astronomer Brent Tully with colleague Richard Fisher in his book The Nearby Galaxies Atlas as Cloud 14.[7] It is a huge 10 Mpc (33 Mly) prolate,[8] filament[9][10][2][8] and is mostly host to late-type galaxies, in contrast to the Virgo Cluster, in which more than half of the giant galaxies are early-type galaxies.[11]

Tully maintains that the Coma-Sculptor Cloud and the Local Sheet do not quite overlap,[2] as the Local-Sheet comprises only the co-moving part of the Coma-Sculptor Cloud.[6] McCall considers the two terms synonymous, referring to one and the same region.[4]

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 "Milky Way amidst a 'Council of Giants'". Science Daily. 11 March 2014. https://www.sciencedaily.com/releases/2014/03/140311100606.htm. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Tully, R. Brent; Shaya, Edward J.; Karachentsev, Igor D.; Courtois, Hélène M.; Kocevski, Dale D.; Rizzi, Luca; Peel, Alan (March 2008). "Our Peculiar Motion Away from the Local Void". The Astrophysical Journal 676 (1): 184–205. doi:10.1086/527428. Bibcode: 2008ApJ...676..184T. 
  3. ↑ 3.0 3.1 3.2 Tully, R. Brent (May 2008), "The Local Void is Really Empty", Dark Galaxies and Lost Baryons, Proceedings of the International Astronomical Union, IAU Symposium, 244, pp. 146–151, doi:10.1017/S1743921307013932, Bibcode: 2008IAUS..244..146T 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 McCall, Marshall L. (29 April 2013). "A Council of Giants". Monthly Notices of the Royal Astronomical Society 440 (1): 405–426. 10 March 2014. doi:10.1093/mnras/stu199. Bibcode: 2014MNRAS.440..405M. 
  5. ↑ Shaya, Ed J.; Tully, R. Brent (December 2013). "The Formation of the Local Group Planes of Galaxies". Royal Astronomical Society (Oxford University Press) 436 (3): 2096–2119. doi:10.1093/mnras/stt1714. Bibcode: 2013MNRAS.436.2096S. 
  6. ↑ 6.0 6.1 Tully, R. Brent (2008). "The Local Velocity Anomaly" (in en). Galaxies in the Local Volume. Astrophysics and Space Science Proceedings. 5. pp. 3–12. doi:10.1007/978-1-4020-6933-8_1. ISBN 978-1-4020-6932-1. Bibcode: 2008ASSP....5....3T. https://ui.adsabs.harvard.edu/abs/2008ASSP....5....3T/abstract. 
  7. ↑ Tully, R. Brent; Fisher, J. Richard (1987) (in en). Atlas of Nearby Galaxies. Bibcode: 1987ang..book.....T. https://ui.adsabs.harvard.edu/abs/1987ang..book.....T/abstract. 
  8. ↑ 8.0 8.1 Müller, Oliver; Scalera, Roberto; Binggeli, Bruno; Jerjen, Helmut (June 2017). "The M 101 group complex: new dwarf galaxy candidates and spatial structure". Astronomy & Astrophysics 602: A119. doi:10.1051/0004-6361/201730434. ISSN 0004-6361. Bibcode: 2017A&A...602A.119M. http://www.aanda.org/10.1051/0004-6361/201730434. 
  9. ↑ Tully, R. Brent; Verheijen, Marc A. W.; Pierce, Michael J.; Huang, Jia-Sheng; Wainscoat, Richard J. (December 1996). "The Ursa Major Cluster of Galaxies.I.Cluster Definition and Photometric Data" (in en). The Astronomical Journal 112: 2471. doi:10.1086/118196. ISSN 0004-6256. Bibcode: 1996AJ....112.2471T. https://ui.adsabs.harvard.edu/abs/1996AJ....112.2471T/abstract. 
  10. ↑ Hartwick, F. D. A. (May 2000). "The Structure of the Outer Halo of the Galaxy and its Relationship to Nearby Large-Scale Structure". The Astronomical Journal 119 (5): 2248–2253. doi:10.1086/301332. Bibcode: 2000AJ....119.2248H. https://iopscience.iop.org/article/10.1086/301332. 
  11. ↑ Burstein, D. (2000). "Elliptical galaxies dynamics: the issues pertaining to galaxy formation" (in en). Building Galaxies; from the Primordial Universe to the Present: 85. doi:10.48550/arXiv.astro-ph/9908355. Bibcode: 2000bgfp.conf...85B. https://ui.adsabs.harvard.edu/abs/2000bgfp.conf...85B/abstract. 



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Local_Sheet&oldid=3942855"