Large quasar group
A large quasar group is a collection of quasars that form what are thought to constitute the largest astronomical structures in the known universe. LQGs are thought to be precursors to the sheets, walls and filaments of galaxies found in the relatively nearby universe.
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 comprises 74 quasars and has a minimum diameter of 1.4 billion light-years, 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.List of LQGs
| LQG | Date | Mean Distance | Dimension | # of quasars | Notes |
| Webster LQG | 1982 | z=0.37 | 100 Mpc | 5 | First LQG discovered. At the time of its discovery, it was the largest structure known. |
| Crampton–Cowley–Hartwick LQG | 1987 | z=1.11 | 60 Mpc | 28 | Second LQG discovered |
| Clowes–Campusano LQG | 1991 | z=1.28 | 34 | Third LQG discovered | |
| U1.90 | 1995 | z=1.9 | 120 Mpc/h | 10 | Discovered by Graham, Clowes, Campusano. |
| 7Sf Group | 1995 | z=0.19 | 60 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 | 1998 | z=1.54 | 150 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 void bubbles and walls of galaxies., |
| Tesch–Engels LQG | 2000 | z=0.27 | 140 Mpc/h | 7 | The first X-ray selected LQG. |
| U1.11 | 2011 | z=1.11 | 38 | ||
| Huge-LQG | 2013 | z=1.27 | 73 | The largest structure known in the observable universe until it was eclipsed by the Hercules–Corona Borealis Great Wall found one year later. |