For other uses, see Quasar (disambiguation)."Quasi-stellar object" redirects here. Not to be confused with Quasi-star or 50000 Quaoar.
Active galactic nucleus containing a supermassive black hole
Nature timeline
This box:
view
talk
edit
−13 —
–
−12 —
–
−11 —
–
−10 —
–
−9 —
–
−8 —
–
−7 —
–
−6 —
–
−5 —
–
−4 —
–
−3 —
–
−2 —
–
−1 —
–
0 —
Dark Ages
Reionization
Matter-dominated era
Accelerated expansion
Water on Earth
Single-celled life
Photosynthesis
Multicellular life
Vertebrates
←
Earliest Universe
←
Earliest stars
←
Earliest galaxy
←
Earliest quasar / black hole
←
Omega Centauri
←
Andromeda Galaxy
←
Milky Way spirals
←
NGC 188 star cluster
←
Alpha Centauri
←
Earth / Solar System
←
Earliest known life
←
Earliest oxygen
←
Atmospheric oxygen
←
Sexual reproduction
←
Earliest fungi
←
Earliest animals / plants
←
Cambrian explosion
←
Earliest mammals
←
Earliest apes / humans
L i f e
(billion years ago)
A quasar (/ˈkweɪzɑːr/KWAY-zar) is an extremely luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO. The emission from an AGN is powered by a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosities thousands of times greater than that of a galaxy such as the Milky Way.[2][3] Quasars are usually categorized as a subclass of the more general category of AGN. The redshifts of quasars are of cosmological origin.[4]
The term quasar originated as a contraction of "quasi-stellar [star-like] radio source"—because they were first identified during the 1950s as sources of radio-wave emission of unknown physical origin—and when identified in photographic images at visible wavelengths, they resembled faint, star-like points of light. High-resolution images of quasars, particularly from the Hubble Space Telescope, have shown that quasars occur in the centers of galaxies, and that some host galaxies are strongly interacting or merging galaxies.[5] As with other categories of AGN, the observed properties of a quasar depend on many factors, including the mass of the black hole, the rate of gas accretion, the orientation of the accretion disc relative to the observer, the presence or absence of a jet, and the degree of obscuration by gas and dust within the host galaxy.
About a million quasars have been identified with reliable spectroscopic redshifts,[6] and between 2-3 million identified in photometric catalogs.[7][8] The nearest known quasar is about 600 million light-years from Earth. The record for the most distant known quasar continues to change. In 2017, quasar ULAS J1342+0928 was detected at redshift z = 7.54. Light observed from this 800-million-solar-mass quasar was emitted when the universe was only 690 million years old.[9][10][11] In 2020, quasar Pōniuāʻena was detected from a time only 700 million years after the Big Bang, and with an estimated mass of 1.5 billion times the mass of the Sun.[12][13] In early 2021, the quasar QSO J0313–1806, with a 1.6-billion-solar-mass black hole, was reported at z = 7.64, 670 million years after the Big Bang.[14]
Quasar discovery surveys have shown that quasar activity was more common in the distant past; the peak epoch was approximately 10 billion years ago.[15] Concentrations of multiple quasars are known as large quasar groups and may constitute some of the largest known structures in the universe if the observed groups are good tracers of mass distribution.
^Wu, Xue-Bing; et al. (2015). "An ultraluminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30". Nature. 518 (7540): 512–515. arXiv:1502.07418. Bibcode:2015Natur.518..512W. doi:10.1038/nature14241. PMID 25719667. S2CID 4455954.
^Frank, Juhan; King, Andrew; Raine, Derek J. (February 2002). Accretion Power in Astrophysics (Third ed.). Cambridge, UK: Cambridge University Press. Bibcode:2002apa..book.....F. ISBN 0521620538.
^"Quasars and Active Galactic Nuclei". ned.ipac.caltech.edu. Retrieved 2020-08-31.
^Bahcall, J. N.; et al. (1997). "Hubble Space Telescope Images of a Sample of 20 Nearby Luminous Quasars". The Astrophysical Journal. 479 (2): 642–658. arXiv:astro-ph/9611163. Bibcode:1997ApJ...479..642B. doi:10.1086/303926. S2CID 15318893.
^"Million Quasars Catalog, Version 8 (2 August 2023)". MILLIQUAS. 2023-08-02. Retrieved 2023-11-20.
^Shu, Yiping; Koposov, Sergey E; Evans, N Wyn; Belokurov, Vasily; McMahon, Richard G; Auger, Matthew W; Lemon, Cameron A (2019-09-05). "Catalogues of active galactic nuclei from Gaia and unWISE data". Monthly Notices of the Royal Astronomical Society. 489 (4). Oxford University Press (OUP): 4741–4759. arXiv:1909.02010. doi:10.1093/mnras/stz2487. ISSN 0035-8711.
^Storey-Fisher, Kate; Hogg, David W.; Rix, Hans-Walter; Eilers, Anna-Christina; Fabbian, Giulio; Blanton, Michael; Alonso, David (2024). "Quaia, the Gaia-unWISE Quasar Catalog: An All-Sky Spectroscopic Quasar Sample". AAS Journals. 964 (1): 69. arXiv:2306.17749. Bibcode:2024ApJ...964...69S. doi:10.3847/1538-4357/ad1328.
^Bañados, Eduardo; et al. (6 March 2018). "An 800-million-solar-mass black hole in a significantly neutral Universe at a redshift of 7.5". Nature. 553 (7689): 473–476. arXiv:1712.01860. Bibcode:2018Natur.553..473B. doi:10.1038/nature25180. PMID 29211709. S2CID 205263326.
^Choi, Charles Q. (6 December 2017). "Oldest Monster Black Hole Ever Found Is 800 Million Times More Massive Than the Sun". Space.com. Retrieved 6 December 2017.
^Landau, Elizabeth; Bañados, Eduardo (6 December 2017). "Found: Most Distant Black Hole". NASA. Retrieved 6 December 2017.
^"Monster Black Hole Found in the Early Universe". Gemini Observatory. 2020-06-24. Retrieved 2020-08-31.
^Yang, Jinyi; Wang, Feige; Fan, Xiaohui; Hennawi, Joseph F.; Davies, Frederick B.; Yue, Minghao; Banados, Eduardo; Wu, Xue-Bing; Venemans, Bram; Barth, Aaron J.; Bian, Fuyan (2020-07-01). "Poniua'ena: A Luminous z = 7.5 Quasar Hosting a 1.5 Billion Solar Mass Black Hole". The Astrophysical Journal Letters. 897 (1): L14. arXiv:2006.13452. Bibcode:2020ApJ...897L..14Y. doi:10.3847/2041-8213/ab9c26. S2CID 220042206.
^Maria Temming (January 18, 2021), "The most ancient supermassive black hole is bafflingly big", Science News.
^Schmidt, Maarten; Schneider, Donald; Gunn, James (1995). "Spectroscopic CCD Surveys for Quasars at Large Redshift. IV. Evolution of the Luminosity Function from Quasars Detected by Their Lyman-Alpha Emission". The Astronomical Journal. 110: 68. Bibcode:1995AJ....110...68S. doi:10.1086/117497.
A quasar (/ˈkweɪzɑːr/ KWAY-zar) is an extremely luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO...
Quasar was the name of the first concept car produced by Peugeot. It was assembled in 1984 at the Peugeot plant in La Garenne, and first displayed at the...
3C 273 is a quasar located at the center of a giant elliptical galaxy in the constellation of Virgo. It was the first quasar ever to be identified and...
The Quasar Framework (commonly referred to as Quasar; pronounced /ˈkweɪ.zɑːr/) is an open-source Vue.js based framework for building apps with a single...
of quasars. More than a million quasars have been observed, so any list on Wikipedia is necessarily a selection of them. Proper naming of quasars are...
The Twin Quasar (also known as Twin QSO, Double Quasar, SBS 0957+561, TXS 0957+561, Q0957+561 or QSO 0957+561 A/B), was discovered in 1979 and was the...
Daniel Quasar is an American artist and graphic designer, known for their design of the Progress Pride flag, a variation of the rainbow pride flag that...
Tonantzintla 618) is a hyperluminous, broad-absorption-line, radio-loud quasar and Lyman-alpha blob located near the border of the constellations Canes...
An optically violent variable quasar (often abbreviated as OVV quasar) is a type of highly variable quasar. It is a subtype of blazar that consists of...
A large quasar group (LQG) is a collection of quasars (a form of supermassive black hole active galactic nuclei) that form what are thought to constitute...
and luminous than present-day stars. Another scenario is that it may be a quasar hosting a supermassive black hole; such a scenario would put constraints...
gravitationally lensed quasar that sits directly behind the centre of the galaxy ZW 2237+030, called Huchra's Lens. Four images of the same distant quasar (plus one...
The Cloverleaf quasar (H1413+117, QSO J1415+1129) is a bright, gravitationally lensed quasar. Molecular gas (notably CO) detected in the host galaxy associated...
created by Davis and series co-creator Keith Alcorn under the name of Johnny Quasar, and was developed in a 13-minute long short film pitched to SIGGRAPH sometime...
Khanh (1934 in Hanoi – June 30, 2016 in Ho Chi Minh City), also known as Quasar Khanh, was a French and Vietnamese engineer, an inventor, and a designer...