In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of galactic superclusters. These massive, thread-like formations can commonly reach 50 to 80 megaparsecs (160 to 260 megalight-years)—with the largest found to date being Quipu (400 megaparsecs),[1][2] and possibly the still unconfirmed Hercules-Corona Borealis Great Wall at around 3 gigaparsecs (9.8 Gly) in length—and form the boundaries between voids.[3] Due to the accelerating expansion of the universe, the individual clusters of gravitationally bound galaxies that make up galaxy filaments are moving away from each other at an accelerated rate; in the far future they will dissolve.[4]
Galaxy filaments form the cosmic web and define the overall structure of the observable universe.[5][6][7]
Discovery of structures larger than superclusters began in the late 1980s. In 1987, astronomer R. Brent Tully of the University of Hawaii's Institute of Astronomy identified what he called the Pisces–Cetus Supercluster Complex. The CfA2 Great Wall was discovered in 1989,[8] followed by the Sloan Great Wall in 2003.[9]
z=2.38 filament around protocluster ClG J2143-4423
2004
z=2.38
110 Mpc
A filament the length of the Great Wall was discovered in 2004. As of 2008, it was still the largest structure beyond redshift 2.[18][19][20][21]
A short filament was proposed by Adi Zitrin and Noah Brosch—detected by identifying an alignment of star-forming galaxies—in the neighborhood of the Milky Way and the Local Group.[22] The proposal of this filament, and of a similar but shorter filament, were the result of a study by McQuinn et al. (2014) based on distance measurements using the TRGB method.[23]
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
Wall
Date
Mean distance
Dimension
Notes
CfA2 Great Wall (Coma Wall, Great Wall, Northern Great Wall, Great Northern Wall, CfA Great Wall)
This was the first super-large large-scale structure or pseudo-structure in the universe to be discovered. The CfA Homunculus lies at the heart of the Great Wall, and the Coma Supercluster forms most of the homunculus structure. The Coma Cluster lies at the core.[24][25]
3 Gpc long,[12] 150 000 km/s deep[12] (in redshift space)
The largest known structure in the universe.[11][12][13] This is also the first time since 1991 that a galaxy filament/great wall held the record as the largest known structure in the universe.
A "Centaurus Great Wall" (or "Fornax Great Wall" or "Virgo Great Wall") has been proposed, which would include the Fornax Wall as a portion of it (visually created by the Zone of Avoidance) along with the Centaurus Supercluster and the Virgo Supercluster, also known as the Local Supercluster, within which the Milky Way galaxy is located (implying this to be the Local Great Wall).[26][27]
A wall was proposed to be the physical embodiment of the Great Attractor, with the Norma Cluster as part of it. It is sometimes referred to as the Great Attractor Wall or Norma Wall.[28] This suggestion was superseded by the proposal of a supercluster, Laniakea, that would encompass the Great Attractor, Virgo Supercluster, Hydra–Centaurus Superclusters.[29]
A wall was proposed in 2000 to lie at z=1.47 in the vicinity of radio galaxy B3 0003+387.[30]
A wall was proposed in 2000 to lie at z=0.559 in the northern Hubble Deep Field (HDF North).[31][32]
Map of nearest galaxy walls
The Universe within 500 million light years, showing the nearest galaxy walls
Large quasar groups
Large quasar groups (LQGs) are some of the largest structures known.[33] They are theorized to be protohyperclusters/proto-supercluster-complexes/galaxy filament precursors.[34]
↑Bharadwaj, Somnath; Bhavsar, Suketu; Sheth, Jatush V (2004). "The Size of the Longest Filaments in the Universe". Astrophys J606 (1): 25–31. doi:10.1086/382140. Bibcode: 2004ApJ...606...25B.
↑ 12.012.112.212.312.412.5Horvath, I.; Hakkila, J.; Bagoly, Z. (2013). "The largest structure of the Universe, defined by Gamma-Ray Bursts". 7th Huntsville Gamma-Ray Burst Symposium, GRB 2013: Paper 33 in EConf Proceedings C13041431311: 1104. Bibcode: 2013arXiv1311.1104H.
↑Fontanelli, P. (1983). "Clustering in the Universe: A filament of galaxies in the Coma/A1367 supercluster". Astronomy and Astrophysics138: 85–92. ISSN0004-6361. Bibcode: 1984A&A...138...85F.
↑Gavazzi, Giuseppe; Catinella, Barbara; Carrasco, Luis et al. (May 1998). "The Star Formation Properties of Disk Galaxies: Hα Imaging of Galaxies in the Coma Supercluster". The Astronomical Journal115 (5): 1745–1777. doi:10.1086/300314. Bibcode: 1998AJ....115.1745G.
↑Batuski, D. J.; Burns, J. O. (December 1985). "A possible 300 megaparsec filament of clusters of galaxies in Perseus-Pegasus" (in en). The Astrophysical Journal299: 5. doi:10.1086/163677. ISSN0004-637X. Bibcode: 1985ApJ...299....5B.
↑ 17.017.1Takeuchi, Tsutomu T.; Tomita, Akihiko; Nakanishi, Kouichiro; Ishii, Takako T.; Iwata, Ikuru; Saitō, Mamoru (April 1999). "Photometric Properties of Kiso Ultraviolet-Excess Galaxies in the Lynx–Ursa Major Region" (in en). The Astrophysical Journal Supplement Series121 (2): 445–472. doi:10.1086/313203. ISSN0067-0049. Bibcode: 1999ApJS..121..445T.
↑Palunas, Povilas; Teplitz, Harry I.; Francis, Paul J.; Williger, Gerard M.; Woodgate, Bruce E. (2004). "The Distribution of Lyα-Emitting Galaxies at z = 2.38". The Astrophysical Journal602 (2): 545–554. doi:10.1086/381145. Bibcode: 2004ApJ...602..545P.
↑Francis, Paul J.; Palunas, Povilas; Teplitz, Harry I.; Williger, Gerard M.; Woodgate, Bruce E. (2004). "The Distribution of Lyα-emitting Galaxies at z =2.38. II. Spectroscopy". The Astrophysical Journal614 (1): 75–83. doi:10.1086/423417. Bibcode: 2004ApJ...614...75F.
↑Williger, G.M.; Colbert, J.; Teplitz, H.I. et al. (2008). Aschenbach, B.. ed. "Ultraviolet-Bright, High-Redshift ULIRGS" (in en). Relativistic Astrophysics Legacy and Cosmology - Einstein's Legacy (Berlin, Heidelberg: Springer Berlin Heidelberg): 358–362. doi:10.1007/978-3-540-74713-0_83. ISBN978-3-540-74712-3. Bibcode: 2007ralc.conf..358W.
↑Zitrin, A.; Brosch, N. (2008). "The NGC 672 and 784 galaxy groups: evidence for galaxy formation and growth along a nearby dark matter filament". Monthly Notices of the Royal Astronomical Society390 (1): 408–420. doi:10.1111/j.1365-2966.2008.13786.x. Bibcode: 2008MNRAS.390..408Z.
↑ 26.026.126.2Fairall, A. P.; Paverd, W. R.; Ashley, R. P. (1994). "Unveiling large-scale structures behind the Milky Way: Visualization of Nearby Large-Scale Structures". Astronomical Society of the Pacific Conference Series67: 21. Bibcode: 1994ASPC...67...21F.
↑Vanden Berk, Daniel E.; Stoughton, Chris; Crotts, Arlin P. S.; Tytler, David; Kirkman, David (2000). "QSO[CLC]s[/CLC] and Absorption-Line Systems surrounding the Hubble Deep Field". The Astronomical Journal119 (6): 2571–2582. doi:10.1086/301404. Bibcode: 2000AJ....119.2571V.
↑ 34.034.1Clowes, Roger G.; Harris, Kathryn A.; Raghunathan, Srinivasan; Campusano, Luis E.; Söchting, Ilona K.; Graham, Matthew J. (March 2013). "A structure in the early Universe at z ∼ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology" (in en). Monthly Notices of the Royal Astronomical Society429 (4): 2910–2916. doi:10.1093/mnras/sts497. ISSN1365-2966.
↑Yusef-Zadeh, F.; Arendt, R. G.; Wardle, M.; Heywood, I. (1 June 2023). "The Population of the Galactic Center Filaments: Position Angle Distribution Reveals a Degree-scale Collimated Outflow from Sgr A* along the Galactic Plane". The Astrophysical Journal Letters949 (2): L31. doi:10.3847/2041-8213/acd54b. ISSN2041-8205. Bibcode: 2023ApJ...949L..31Y.
Further reading
Pimbblet, Kevin A. (2005). "Pulling Out Threads from the Cosmic Tapestry: Defining Filaments of Galaxies" (in en). Publications of the Astronomical Society of Australia22 (2): 136–143. doi:10.1071/AS05006. ISSN1323-3580. Bibcode: 2005PASA...22..136P.