The Cloverleaf quasar (H1413 117, QSO J1415 1129) is a bright, gravitationally lensed quasar. It receives its name because of gravitational lensing spitting the single quasar into four images.[1]

Cloverleaf, H1413 117, QSO 1415 1129
ESO image of the Cloverleaf quasar
Observation data (Epoch J2000)
Right ascension14 h 15 m 46.27 s
Declination 11°  29 ′  43.4 ″
Redshift2.56
Distance11 Gly
Apparent magnitude (V)17
Notable featuresFour-image lens, bright CO emission
Other designations
QSO J1415 1129, QSO B1413 1143, H 1413 117, Clover Leaf Quasar
See also: Quasar, List of quasars

Quasar

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Molecular gas (notably CO) detected in the host galaxy associated with the quasar is the oldest molecular material known and provides evidence of large-scale star formation in the early universe. Thanks to the strong magnification provided by the foreground lens, the Cloverleaf is the brightest known source of CO emission at high redshift[2] and was also the first source at a redshift z = 2.56 to be detected with HCN[3] or HCO emission.[4] This suggests the quasar is currently undergoing an intense wave of star formations thus increasing its luminosity.[3] A radio jet has also been found on the side of quasar according to a study published in 2023.[5]

 
CCD image of the Cloverleaf quasar taken in March 1988 by the ESO/MPI 2.2m telescope. The four separated images are part of the quasar.

The 4 quasar images were originally discovered in 1984; in 1988, they were determined to be a single quasar split into four images, instead of 4 separate quasars. The X-rays from iron atoms were also enhanced relative to X-rays at lower energies. Since the amount of brightening due to gravitational lensing doesn't vary with the wavelength, this means that an additional object has magnified the X-rays. The increased magnification of the X-ray light can be explained by gravitational microlensing, an effect which has been used to search for compact stars and planets in our galaxy. Microlensing occurs when a star or a multiple star system passes in front of light from a background object. If a single star or a multiple star system in one of the foreground galaxies passed in front of the light path for the brightest image, then that image would be selectively magnified.[6]

Black hole

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The X-rays would be magnified much more than the visible light if they came from a region around the central supermassive black hole of the lensing galaxy that was smaller than the origin region of the visible light. The enhancement of the X-rays from iron ions would be due to this same effect. The analysis indicates that the X-rays are coming from a very small region, about the size of the Solar System, around the central black hole. The visible light is coming from a region ten or more times larger. The angular size of these regions at a distance of 11 billion light years is tens of thousands times smaller than the smallest region that can be resolved by the Hubble Space Telescope. This provides a way to test models for the flow of gas around a supermassive black hole.[6] Additionally, inner regions of the quasar's accretion disk around the black hole has been detected suggesting outflow wind.[7]

Lensing galaxy and partial Einstein ring

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Data from NICMOS and a special algorithm resolved the lensing galaxy and a partial Einstein ring. The Einstein ring represents the host galaxy of the lensed quasar.[8]

History

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The Cloverleaf quasar was discovered in 1988. Data on the Cloverleaf collected by the Chandra X-ray Observatory in 2004 were compared with that gathered by optical telescopes. One of the X-ray components (A) in the Cloverleaf is brighter than the others in both optical and X-ray light but was found to be relatively brighter in X-ray than in optical light. The X-rays from iron atoms were also enhanced relative to X-rays at lower energies.[6]

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See also

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References

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  1. ^ [email protected]. "The Cloverleaf quasar". www.eso.org. Retrieved 2024-08-28.
  2. ^ S. Venturini; P. M. Solomon (2003). "The Molecular Disk in the Cloverleaf Quasar". Astrophysical Journal. 590 (2): 740–745. arXiv:astro-ph/0210529. Bibcode:2003ApJ...590..740V. doi:10.1086/375050. S2CID 761080.
  3. ^ a b P. Solomon; P. Vanden Bout; C. Carilli; M. Guelin (2003). "The Essential Signature of a Massive Starburst in a Distant Quasar". Nature. 426 (6967): 636–638. arXiv:astro-ph/0312436. Bibcode:2003Natur.426..636S. doi:10.1038/nature02149. PMID 14668856. S2CID 4414417.
  4. ^ D. A. Riechers; et al. (2006). "First Detection of HCO Emission at High Redshift". Astrophysical Journal Letters. 645 (1): L13–L16. arXiv:astro-ph/0605437. Bibcode:2006ApJ...645L..13R. doi:10.1086/505908. S2CID 17504751.
  5. ^ Zhang, Lei; Zhang, Zhi-Yu; Nightingale, James W.; Zou, Ze-Cheng; Cao, Xiaoyue; Tsai, Chao-Wei; Yang, Chentao; Shi, Yong; Wang, Junzhi; Xu, Dandan; Lin, Ling-Rui; Zhou, Jing; Li, Ran (2023-09-01). "Discovery of a radio jet in the Cloverleaf quasar at z = 2.56". Monthly Notices of the Royal Astronomical Society. 524 (3): 3671–3682. arXiv:2212.07027. Bibcode:2023MNRAS.524.3671Z. doi:10.1093/mnras/stad2069. ISSN 0035-8711.
  6. ^ a b c "Chandra :: Photo Album :: Cloverleaf Quasar (a.k.a. H1413 117) :: More Images of the Cloverleaf Quasar". chandra.harvard.edu. Retrieved 2024-08-28.
  7. ^ Chartas, G.; Eracleous, M.; Dai, X.; Agol, E.; Gallagher, S. (2007-06-01). "Discovery of Probable Relativistic Fe Emission and Absorption in the Cloverleaf Quasar H 1413 117". The Astrophysical Journal. 661 (2): 678–692. arXiv:astro-ph/0702742. Bibcode:2007ApJ...661..678C. doi:10.1086/516816. ISSN 0004-637X.
  8. ^ Chantry, Virginie; Magain, Pierre (August 2007). "Deconvolution of HST images of the Cloverleaf gravitational lens : detection of the lensing galaxy and a partial Einstein ring". Astronomy & Astrophysics. 470 (2): 467–473. arXiv:astro-ph/0612094. Bibcode:2007A&A...470..467C. doi:10.1051/0004-6361:20066839. ISSN 0004-6361.

Further reading

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