Alarge quasar group (LQG) is a collection ofquasars (a form ofsupermassive black holeactive galactic nuclei) that form what are thought to constitute the largest astronomical structures in theobservable universe. LQGs are thought to be precursors to thesheets, walls and filaments of galaxies found in the relatively nearby universe.[1]
Prominent LQGs
editOn January 11, 2013, the discovery of theHuge-LQG was announced by theUniversity of Central Lancashire, as the largest known structure in the universe by that time. It is composed of 74quasars and has a minimum diameter of 1.4 billionlight-years, but over 4 billion light-years at its widest point.[2] 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.[3][4]
List of LQGs
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Redshift, 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.
| LQG | Date | Mean Distance | Dimension | # of quasars | Notes |
|---|---|---|---|---|---|
| Webster LQG (LQG 1) | 1982 | z=0.37 | 100 Mpc | 5 | First LQG discovered. At the time of its discovery, it was the largest structure known.[1][4][5] |
| Crampton–Cowley–Hartwick LQG (LQG 2,CCH LQG,Komberg-Kravtsov-Lukash LQG 10) | 1987 | z=1.11 | 60 Mpc | 28 | Second LQG discovered[1][4][6] |
| Clowes–Campusano LQG (U1.28,CCLQG,LQG 3) | 1991 | z=1.28 |
| 34 | Third LQG discovered[4][7] |
| U1.90 | 1995 | z=1.9 | 120Mpc/h | 10 | Discovered by Graham, Clowes, Campusano.[1][6][8] |
| 7Sf Group (U0.19) | 1995 | z=0.19 | 60 Mpc/h | 7 | Discovered by Graham, Clowes, Campusano; this is a grouping of 7Seyfert galaxies.[1][6][8] |
| Komberg–Kravtsov–Lukash LQG 1 | 1996 | z=0.6 | R=96 Mpc/h | 12 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 2 | 1996 | z=0.6 | R=111 Mpc/h | 12 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 3 | 1996 | z=1.3 | R=123 Mpc/h | 14 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 4 | 1996 | z=1.9 | R=104 Mpc/h | 14 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 5 | 1996 | z=1.7 | R=146 Mpc/h | 13 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 6 | 1996 | z=1.5 | R=94 Mpc/h | 10 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 7 | 1996 | z=1.9 | R=92 Mpc/h | 10 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 8 | 1996 | z=2.1 | R=104 Mpc/h | 12 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 9 | 1996 | z=1.9 | R=66 Mpc/h | 18 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 11 | 1996 | z=0.7 | R=157 Mpc/h | 11 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Komberg–Kravtsov–Lukash LQG 12 | 1996 | z=1.2 | R=155 Mpc/h | 14 | Discovered by Komberg, Kravtsov, Lukash.[1][6] |
| Newman LQG (U1.54) | 1998 | z=1.54 | 150 Mpc/h | 21 | Discovered by P.R. Newman[9] 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 latervoid bubbles andwalls of galaxies.,[1][7] |
| Tesch–Engels LQG | 2000 | z=0.27 | 140 Mpc/h | 7 | The first X-ray selected LQG.[1] |
| U1.11 | 2011 | z=1.11 |
| 38 | [4][7] |
| Huge-LQG (U1.27) | 2013 | z=1.27 |
| 73 | The largest structure known in theobservable universe[4][10] until it was eclipsed by theHercules–Corona Borealis Great Wall found one year later.[11][12][13] |
See also
editReferences
edit- ^abcdefghijklmnopqrR.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;ISBN 1-58381-065-X ;Bibcode:2001ASPC..232..108C
- ^Wall, Mike (2013-01-11)."Largest structure in universe discovered".Fox News.
- ^Wall, Mike (2013-01-11)."Largest Structure In Universe, Large Quasar Group, Challenges Cosmological Principle".The Huffington Post.
- ^abcdefClowes, R. G.; Harris, K. A.; Raghunathan, S.; Campusano, L. E.; Sochting, I. K.; Graham, M. J. (January 11, 2013)."A structure in the early Universe at z ~ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology".Monthly Notices of the Royal Astronomical Society.429 (4):2910–2916.arXiv:1211.6256.Bibcode:2013MNRAS.429.2910C.doi:10.1093/mnras/sts497.
- ^Webster, Adrian (May 1982)."The clustering of quasars from an objective-prism survey".Monthly Notices of the Royal Astronomical Society.199 (3):683–705.Bibcode:1982MNRAS.199..683W.doi:10.1093/mnras/199.3.683.
- ^abcdefghijklmnKomberg, Boris V.; Kravtsov, Andrey V.; Lukash, Vladimir N. (October 1996)."The search and investigation of the Large Groups of Quasars".Monthly Notices of the Royal Astronomical Society.282 (3):713–722.arXiv:astro-ph/9602090.doi:10.1093/mnras/282.3.713.
- ^abcClowes, Roger; Luis E. Campusano, Matthew J. Graham and Ilona K. S¨ochting (2001-09-01)."Two close Large Quasar Groups of size ~ 350 Mpc at z ~ 1.2".Monthly Notices of the Royal Astronomical Society.419 (1):556–565.arXiv:1108.6221.Bibcode:2012MNRAS.419..556C.doi:10.1111/j.1365-2966.2011.19719.x.S2CID 31553670.
- ^abGraham, M. J.; Clowes, R. G.; Campusano, L. E. (1995)."Finding Quasar Superstructures".Monthly Notices of the Royal Astronomical Society.275 (3): 790.Bibcode:1995MNRAS.275..790G.doi:10.1093/mnras/275.3.790.
- ^Newman, Peter R (1999).Large groups of quasars in an ultraviolet-excess survey (Thesis). University of Central Lancashire.Bibcode:1999PhDT..........N.doi:10.17030/uclan.thesis.00020658.
- ^ScienceDaily,"Biggest Structure in Universe: Large Quasar Group Is 4 Billion Light Years Across", Royal Astronomical Society, 11 January 2013 (accessed 13 January 2013)
- ^Horváth, István; Hakkila, Jon; Bagoly, Zsolt (2014). "Possible structure in the GRB sky distribution at redshift two".Astronomy & Astrophysics.561: L12.arXiv:1401.0533.Bibcode:2014A&A...561L..12H.doi:10.1051/0004-6361/201323020.S2CID 24224684.
- ^Horvath, I.; Hakkila, J.; Bagoly, Z. (2013). "The largest structure of the Universe, defined by Gamma-Ray Bursts".arXiv:1311.1104 [astro-ph.CO].
- ^Klotz, Irene (2013-11-19)."Universe's Largest Structure is a Cosmic Conundrum". Discovery. Retrieved2013-11-22.
Further reading
edit- 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;ISBN 1-58381-065-X ;Bibcode:2001ASPC..232..108C