Void galaxy

A void galaxy is a galaxy located in a cosmological void.^[1] Few galaxies exist in voids; most are located in sheets, walls and filaments that surround voids and supervoids.^[2][3] Many void galaxies are connected through void filaments^[4] or tendrils,^[5] less massive versions of the regular galaxy filaments that surround voids. These filaments are often straighter than their non-void counterparts due to the lack of influence by surrounding filaments.^[4] These filaments can even be rich enough to form poor galaxy clusters.^[6] The void galaxies themselves are thought to represent pristine examples of galactic evolution, having few neighbours, and likely to have formed from pure intergalactic gas.^[7]

Formation

It is theorised by many astrophysicists that void galaxies are the result of large galactic filaments being pulled by the gravity of a major super cluster out of the less densely populated areas, causing voids such as the Boötes Void to grow. Galaxies such as MCG+01-02-015 are sometimes left behind from such events.^[8]

List of void galaxies

Galaxy	Void	Filament	Notes	Comments
PC 1357+4641	Boötes Void		[9]	Emission-line galaxy
IRAS 14288+5255	Boötes Void		[9]	AGN X-ray source
G 1432+5302	Boötes Void		[10]	Starburst galaxy
G 1458+4944	Boötes Void		[10]	LINER galaxy
G 1507+4554	Boötes Void		[10]	Starburst galaxy
G 1510+4727A & G 1510+4727B	Boötes Void		[10]	Interacting galaxy pair
BHI 1514+3819	Boötes Void		[9]
FSS 1515+3823	Boötes Void		[9]
G 1517+3949	Boötes Void		[10]	Starburst galaxy
G 1517+3956A & G 1517+3956B	Boötes Void		[10]	Interacting galaxy pair
IRAS 15195+5050	Boötes Void		[9]	AGN X-ray source
Markarian 845	Boötes Void		[9]	Seyfert 1 (X-ray source)
CG 547	Boötes Void		[9]	Emission-line Galaxy
CG 637	Boötes Void		[9]	Emission-line Galaxy
CG 922	Boötes Void		[9]	Emission-line Galaxy
MCG+01-02-015			[11][12][13][14]	LEDA 1852 (Pisces)
Pisces A	Local Void		[15]
Pisces B	Local Void		[15]
NGC 7077	Local Void		[16]

See also

• Field galaxy

References

1. Rien van de Weygaert; Platen, Erwin; Tigrak, Esra; Hidding, Johan; Thijs van der Hulst; Aragon-Calvo, Miguel A.; Stanonik, Kathryn; Jacqueline van Gorkom (17 December 2009). "The Cosmically Depressed: Life, Sociology and Identity of Voids". Galaxies in Isolation: Exploring Nature Versus Nurture. 421: 99. arXiv:0912.3473v1. Bibcode:2010ASPC..421...99V.
2. SchmidtFirst1=K.-H.; Bohm, P.; Elsasser, H. (February 1997). "On the emptiness of voids". Astronomische Nachrichten. 318 (2): 81. Bibcode:1997AN....318...81S. doi:10.1002/asna.2113180204.
3. Astronomy and Astrophysics, "Results of a search for faint galaxies in voids", Kuhn, B.; Hopp, U.; Elsaesser, H.;, 'v.318', 02/1997, Bibcode:1997A&A...318..405K
4. Park, Daeseong; Lee, Jounghun (December 2009). "The Bridge Effect of Void Filaments". Monthly Notices of the Royal Astronomical Society. 400 (2): 1105–1108. arXiv:0905.4277v2. Bibcode:2009MNRAS.400.1105P. doi:10.1111/j.1365-2966.2009.15524.x. S2CID 16612240.
5. Alpaslan, Mehmet; Robotham, Aaron S. G.; Obreschkow, Danail; Penny, Samantha; Driver, Simon; Norberg, Peder; Brough, Sarah; Brown, Michael; Cluver, Michelle; Holwerda, Benne; Hopkins, Andrew M.; van Kampen, Eelco; Kelvin, Lee S.; Lara-Lopez, Maritza A.; Liske, Jochen; Loveday, Jon; Mahajan, Smriti; Pimbblet, Kevin (1 May 2014). "Galaxy and Mass Assembly (GAMA): fine filaments of galaxies detected within voids". Monthly Notices of the Royal Astronomical Society: Letters. 440 (1): L106–L110. arXiv:1401.7331. Bibcode:2014MNRAS.440L.106A. doi:10.1093/mnrasl/slu019.
6. "Studies of Selected Voids. Faint Galaxies in the Direction of the Void 0049+05", G.T. Petrov, L. Slavcheva-Mihova, V. Kopchev, 2007' '
7. arXiv, "Cosmic Voids: structure, dynamics and galaxies", Rien van de Weygaert, Erwin Platen, 16 Dec 2009, arXiv:0912.2997, Bibcode:2009arXiv0912.2997V
8. Dvorsky, George (6 July 2012). "Behold the Boötes void, the spookiest place in the cosmos". io9. Retrieved 25 August 2019.
9. The Astrophysical Journal Letters, "Detection of X-Ray Emission from Galaxies inside the Bootes Void", Chulhee Kim, Th. Boller, Kajal K. Ghosh, Douglas A. Swartz, Brian D. Ramsey, 'Volume 546, Number 2', 10 January 2001, doi:10.1086/318868
10. The Astronomical Journal, "Spectroscopy of Galaxies in the Bootes Void", Shawn Cruzen 1, Tara Wehr, Donna Weistrop, Ronald J. Angione, Charles Hoopes, 'Volume 123, Number 1', 2002 January, doi:10.1086/324739
11. "The loneliest of galaxies". Hubble Space Telescope. 9 November 2015. Retrieved 10 November 2015.
12. SIMBAD, MCG+01-02-015
13. Sci-News, "NASA’s Hubble Space Telescope Focuses on Lonely Galaxy", 9 November 2015
14. SpaceDaily, "Hubble Views a Lonely Galaxy", 18 November 2015
15. "Hubble Sees Two Dwarf Galaxies in Pisces". Sci-News. 15 August 2016.
16. Tully, Brent. "The Local Void" (PDF).

External links

• Panjkov, Sonja (22 April 2023). "Is One Really the Loneliest Number? Void Galaxies Compared to Their More Popular Counterparts in the Field". Astrobites.