Large quasar group

A large quasar group ( LQG) is a collection of (a form of supermassive black hole active galactic nuclei) that form what are thought to constitute the largest astronomical structures in the observable universe. LQGs are thought to be precursors to the galaxy filament found in the relatively nearby universe.

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Prominent LQGs On January 11, 2013, the discovery of the Huge-LQG was announced by the University of Central Lancashire, as the largest known structure in the universe by that time. It is composed of 74 and has a minimum diameter of 1.4 billion , but over 4 billion light-years at its widest point. According to researcher and author, Roger Clowes, the existence of structures with the size of LQGs was believed theoretically impossible. Cosmological structures had been believed to have a size limit of approximately 1.2 billion light-years.

Other scientists have expressed doubt whether these structure really exist.

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List of LQGs , represented by "z," is a fundamental concept in astrophysics. It measures how much the light from celestial objects shift as they move away from Earth. A higher redshift value means the object is farther away in the universe.

+ Large Quasar Groups
Webster LQG (LQG 1)	1982	z=0.37	Mpc	5	First LQG discovered. At the time of its discovery, it was the largest structure known.R.G.Clowes; "Large Quasar Groups - A Short Review"; 'The New Era of Wide Field Astronomy', ASP Conference Series, Vol. 232.; 2001; Astronomical Society of the Pacific; ;
Crampton–Cowley–Hartwick LQG (LQG 2, CCH LQG, Komberg-Kravtsov-Lukash LQG 10)	1987	z=1.11	Mpc	28	Second LQG discovered
Clowes–Campusano LQG (U1.28, CCLQG, LQG 3)	1991	z=1.28		34	Third LQG discovered
U1.90	1995	z=1.9	Mpc/h	10	Discovered by Graham, Clowes, Campusano.
7Sf Group (U0.19)	1995	z=0.19	Mpc/h	7	Discovered by Graham, Clowes, Campusano; this is a grouping of 7 Seyfert galaxies.
Komberg–Kravtsov–Lukash LQG 1	1996	z=0.6	R=96 Mpc/h	12	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 2	1996	z=0.6	R=111 Mpc/h	12	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 3	1996	z=1.3	R=123 Mpc/h	14	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 4	1996	z=1.9	R=104 Mpc/h	14	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 5	1996	z=1.7	R=146 Mpc/h	13	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 6	1996	z=1.5	R=94 Mpc/h	10	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 7	1996	z=1.9	R=92 Mpc/h	10	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 8	1996	z=2.1	R=104 Mpc/h	12	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 9	1996	z=1.9	R=66 Mpc/h	18	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 11	1996	z=0.7	R=157 Mpc/h	11	Discovered by Komberg, Kravtsov, Lukash.
Komberg–Kravtsov–Lukash LQG 12	1996	z=1.2	R=155 Mpc/h	14	Discovered by Komberg, Kravtsov, Lukash.
Newman LQG (U1.54)	1998	z=1.54	Mpc/h	21	Discovered by P.R. Newman et al. This structure is parallel to the CCLQG, with its discovery, suggesting that the cellular structure of sheets and voids already existed in this era, as found in later supervoid bubbles and galaxy filament.,
Tesch–Engels LQG	2000	z=0.27	Mpc/h	7	The first X-ray selected LQG.
U1.11	2011	z=1.11		38
Huge-LQG (U1.27)	2013	z=1.27		73	The largest structure known in the observable universe ScienceDaily, "Biggest Structure in Universe: Large Quasar Group Is 4 Billion Light Years Across", Royal Astronomical Society, 11 January 2013 (accessed 13 January 2013) until it was eclipsed by the Hercules–Corona Borealis Great Wall found one year later.

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See also

• List of largest cosmic structures
• Large-scale structure of the cosmos

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Further reading

• R. G. Clowes; "Large Quasar Groups - A Short Review"; 'The New Era of Wide Field Astronomy', ASP Conference Series, Vol. 232.; 2001; Astronomical Society of the Pacific; ;

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