Sunday, November 6, 2011

Galactic Filaments

Mirror, mirror, on the Wall, what is the biggest frigging thing and the second most beautiful after women in the Universe of them all?

WATSON: "Tell me, Holmes, if we could step back from it all, wot ... would the Universe look like?"

SHERLOCK HOLMES: "It's filamentary, my dear Watson."

From Wikipedia:

In physical cosmologygalaxy filaments, also called supercluster complexes or great walls, are, so far, the largest known cosmic structures in the universe. They are massive, thread-like structures with a typical length of 50 to 80 megaparsecs h-1 that form the boundaries between large voids in the universe.[1] Filaments consist of gravitationally-bound galaxies; parts where a large number of galaxies are very close to each other are called superclusters.
Discoveries of superclusters started in the 1980s. In 1987 astronomer R. Brent Tully of the University of Hawaii’s Institute of Astronomy identified what he called thePisces-Cetus Supercluster Complex. In 1989 the CfA2 Great Wall was discovered,[2] followed by the Sloan Great Wall in 2003.[3]
In 2006, scientists announced the discovery of three filaments aligned to form the largest structure known to humanity[citation needed], composed of densely-packed galaxies and enormous blobs of gas known as Lyman alpha blobs.[4]
In 2011 further study was conducted by undergraduate students at Monash University in Australia that amounted to several hypotheses for the nature of filaments. One student, Amelia Fraser-McKelvie, confirmed through X-ray analysis that filaments contain an amount of mass large enough to contend with the theory of dark matter.[5]Supervising Monash astrophysicist Dr. Kevin Pimbblet's earlier work had suggested the filaments as a possible location for the "missing" matter, thought to be low in density but high in temperature.[6]



[edit]Galaxy filaments

Filament subtype of filaments have roughly similar major and minor axes in cross-section, along the lengthwise axis.
Filaments of Galaxies
FilamentDateMean DistanceDimensionNotes
Coma FilamentThe Coma Supercluster lies within the Coma Filament.[7] It forms part of the CfA2 Great Wall.[8]
Perseus-Pegasus Filament1985Connected to the Pisces-Cetus Supercluster, with the Perseus-Pisces Supercluster being a member of the filament.[9]
Ursa Major FilamentConnected to the CfA Homunculus, a portion of the filament forms a portion of the "leg" of the Homunculus.[10]
Lynx-Ursa Major Filament (LUM Filament)1999from 2000 km/s to 8000 km/s inredshift spaceConnected to and separate from the Lynx-Ursa Major Supercluster.[10]
z=2.38 filament around protocluster ClG J2143-44232004z=2.38110MpcA filament the length of the Great Wall was discovered in 2004. As of 2008, it was still the largest structure beyond redshift 2.[11][12][13][14]

[edit]Galaxy walls

The Galaxy wall subtype of filaments have a significantly greater major axis than minor axis in cross-section, along the lengthwise axis.
Walls of Galaxies
WallDateMean DistanceDimensionNotes
CfA2 Great Wall (Coma Wall, Great Wall, Northern Great Wall, Great Northern Wall, CfA Great Wall)1989z=0.03058251Mpc long
750 Mly long 250 Mly wide 20 Mly thick
This was the first super-large large-scale structure or pseudo-structure in the universe to be discovered. It is also the second largest. The CfA Homunculus lies at the heart of the Great Wall, and the Coma Supercluster forms most of the homunculus structure. TheComa Cluster lies at the core.[15][16]
Sloan Great Wall (SDSS Great Wall)2005z=0.07804433Mpc longThis is the largest known structure or pseudo-structure in the universe discovered so far.[15]
Sculptor Wall (Southern Great Wall, Great Southern Wall, Southern Wall)8000 km/s long
5000 km/s wide
1000 km/s deep
(in redshift spacedimensions)
The Sculptor Wall is "parallel" to the Fornax Wall and "perpendicular" to the Grus Wall.[17][18]
Grus WallThe Grus Wall is "perpendicular" to the Fornax and Sculptor Walls.[18]
Fornax WallThe Fornax Cluster is part of this wall. The wall is "parallel" to the Sculptor Wall and "perpendicular" to the Grus Wall.[17][18]
  • A wall has been proposed, in 2000, to lie at z=1.47 in the vicinity of radio galaxy B3 0003+387.[20]

[edit]Map of nearest galaxy walls

The Universe within 500 million Light Years, showing the nearest galaxy walls

[edit]Maps of large scale distribution

[edit]See also


  1. ^ Bharadwaj, Somnath; Bhavsar, Suketu; Sheth, Jatush V. The Size of the Longest Filaments in the Universe. Astrophys.J. 606 (2004) 25-31
  2. ^ M. J. Geller & J. P. Huchra, Science 246, 897 (1989).
  3. ^ Sky and Telescope, "Refining the Cosmic Recipe", 14 November 2003
  4. ^ Than, Ker (2006-07-28). "Scientists: Cosmic blob biggest thing in universe". Retrieved 2007-03-11.
  5. ^ Monash student helps solve cosmic mystery of massive dimensions Sarah-Jane Collins, May 27, 2011
  6. ^
  7. ^ 'Astronomy and Astrophysics' (ISSN 0004-6361), vol. 138, no. 1, Sept. 1984, p. 85-92. Research supported by Cornell University"The Coma/A 1367 filament of galaxies" 09/1984Bibcode1984A&A...138...85F
  9. ^ 'Astrophysical Journal', Part 1 (ISSN 0004-637X), vol. 299, Dec. 1, 1985, p. 5-14. "A possible 300 megaparsec filament of clusters of galaxies in Perseus-Pegasus" 12/1985Bibcode1985ApJ...299....5B
  10. a b 'The Astrophysical Journal Supplement Series', Volume 121, Issue 2, pp. 445-472. "Photometric Properties of Kiso Ultraviolet-Excess Galaxies in the Lynx-Ursa Major Region" 04/1999Bibcode1999ApJS..121..445T
  12. ^ 'The Astrophysical Journal', Volume 602, Issue 2, pp. 545-554.The Distribution of Lyα-Emitting Galaxies at z=2.38 02/2004Bibcode2004ApJ...602..545P doi:10.1086/381145
  13. ^ 'The Astrophysical Journal', Volume 614, Issue 1, pp. 75-83. The Distribution of Lyα-emitting Galaxies at z=2.38. II. Spectroscopy10/2004 Bibcode2004ApJ...614...75F doi:10.1086/423417
  14. ^ 'Relativistic Astrophysics Legacy and Cosmology - Einstein's, ESO Astrophysics Symposia', Volume . ISBN 978-3-540-74712-3. Springer-Verlag Berlin Heidelberg, 2008, p. 358 Ultraviolet-Bright, High-Redshift ULIRGS 00/2008 Bibcode2008ralc.conf..358W
  15. a b Chin. J. Astron. Astrophys. Vol. 6 (2006), No. 1, 35–42 Super-Large-Scale Structures in the Sloan Digital Sky SurveyPDF
  16. ^ 'Scientific American', Vol. 280, No. 6, p. 30 - 37 Mapping the UniversePDF (1.43 MB) 06/1999 Bibcode1999SciAm.280f..30L
  17. a b c Unveiling large-scale structures behind the Milky Way. Astronomical Society of the Pacific Conference Series, Vol. 67; Proceedings of a workshop at the Observatoire de Paris-Meudon; 18–21 January 1994; San Francisco: Astronomical Society of the Pacific (ASP); c1994; edited by Chantal Balkowski and R. C. Kraan-Korteweg, p.21 ; Visualization of Nearby Large-Scale Structures ; Fairall, A. P., Paverd, W. R., & Ashley, R. P. ; 1994ASPC...67...21F
  18. a b c d 'Astrophysics and Space Science', Volume 230, Issue 1-2, pp. 225-235 Large-Scale Structures in the Distribution of Galaxies 08/1995 Bibcode1995Ap&SS.230..225F
  19. ^ World Science, Wall of galaxies tugs on ours, astronomers findApril 19, 2006
  20. ^ 'The Astronomical Journal', Volume 120, Issue 5, pp. 2331-2337.B3 0003+387: AGN-Marked Large-Scale Structure at Redshift 1.47? 11/2000 Bibcode2000AJ....120.2331Tdoi:10.1086/316827
  21. ^ FermiLab, Astronomers Find Wall of Galaxies Traversing the Hubble Deep FieldDARPAMonday, January 24, 2000
  22. ^ 'The Astronomical Journal', Volume 119, Issue 6, pp. 2571-2582 ;QSOS and Absorption-Line Systems surrounding the Hubble Deep Field ; 06/2000 ; doi:10.1086/301404 ;Bibcode2000AJ....119.2571V ;

[edit]Further reading

[edit]External links


Phil Warnell said...

Hi Steve,

For me what’s most amazing is as galactic groupings are drawn together under the effect of gravity the larger structure is becoming more widely separated with the accelerated expansion of space-time. This has it necessary to discard our rubber sheet for something displaying not one but two dynamics which as of now stretches the imagination beyond comprehension.

“Look, it cannot be seen — it is beyond form.
Listen, it cannot be heard — it is beyond sound.
Grasp, it cannot be held — it is intangible.
These three are indefinable;
Therefore they are joined in one…

Stand before it and there is no beginning.
Follow it and there is no end.
Stay with the ancient Tao,
Move with the present.”

-Dao de Jing, Chapter Fourteen



webspider said...

hello friends,
San Francisco Astrological Society It can also be shown that the set of all fractions are also countably infinite, although this is a little harder to show and is not really the purpose of this discussion. To see a proof of this see the pdf given above. It has a very nice proof of this fact.