{{Short description|Rare example of a quadruply-lensed quasar}} {{Quasar | name = Cloverleaf, H1413+117, QSO 1415+1129 | image =File:Cloverleaf-quasar.jpg | caption=[[European Southern Observatory|ESO]] image of the Cloverleaf quasar | epoch = [[J2000]] | ra = {{RA| 14 | 15 | 46.27 }} | dec = {{DEC| +11 | 29 | 43.4 }} | constellation name = | z = 2.56 | type = | dist_ly = 11 [[light-year|Gly]] | appmag_v = 17 | size_v = | notes = Four-image lens, bright CO emission | names = QSO J1415+1129, QSO B1413+1143, H 1413+117, Clover Leaf Quasar }} The '''Cloverleaf quasar''' ('''H1413+117''', '''QSO J1415+1129''') is a bright, [[gravitational lensing|gravitationally lensed]] [[quasar]] discovered by [[Cyril Hazard| Hazard]], Morton, Terlevich and McMahon in 1984.<ref name="Hazard"> {{cite journal |author1=C. Hazard |author2=D. C. Morton |author3=R. Terlevich |author4=R. G. McMahon | title = Nine new quasi-stellar objects with broad absorption lines. | date = 1984 | journal = [[Astrophysical Journal]] | volume = 282 | pages = 33-52 | bibcode = 1984ApJ...282...33H | doi = 10.1086/162174}} </ref> It receives its name because of [[Gravitational lens|gravitational lensing]] splitting the single quasar into four images.<ref>{{Cite web |last=information@eso.org |title=The Cloverleaf quasar |url=https://www.eso.org/public/images/cloverleaf-quasar/ |access-date=2024-08-28 |website=www.eso.org |language=en}}</ref> Gravitational lensing of the quasar H1413+1011 was discovered in Magain et al. <ref name="Hazard"/> in 1988, which found that the quasar's light was split by gravitational lensing by a foreground galaxy into four images gave it the name "Cloverleaf quasar".
== Quasar == 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 [[gravitational lens|lens]], the Cloverleaf is the brightest known source of CO emission at high redshift<ref> {{cite journal |author1=S. Venturini |author2=P. M. Solomon | title = The Molecular Disk in the Cloverleaf Quasar | date = 2003 | journal = [[Astrophysical Journal]] | volume = 590 |issue=2 | pages = 740–745 | bibcode = 2003ApJ...590..740V | doi = 10.1086/375050 |arxiv = astro-ph/0210529 |s2cid=761080 }}</ref> and was also the first source at a [[redshift]] {{nowrap|''z'' {{=}} 2.56}} to be detected with HCN<ref name=":0"> {{cite journal |author1=P. Solomon |author2=P. Vanden Bout |author3=C. Carilli |author4=M. Guelin | date = 2003 | title = The Essential Signature of a Massive Starburst in a Distant Quasar | journal = [[Nature (journal)|Nature]] | volume = 426 | issue = 6967 | pages = 636–638 | bibcode = 2003Natur.426..636S | doi = 10.1038/nature02149 | pmid = 14668856 |arxiv = astro-ph/0312436 |s2cid=4414417 }}</ref> or HCO<sup>+</sup> emission.<ref> {{cite journal | author = D. A. Riechers | date = 2006 | title = First Detection of HCO<sup>+</sup> Emission at High Redshift | journal = [[Astrophysical Journal Letters]] | volume = 645 | issue = 1 | pages = L13–L16 | bibcode = 2006ApJ...645L..13R | doi = 10.1086/505908 |arxiv = astro-ph/0605437 | s2cid = 17504751 |display-authors=etal}}</ref> This suggests the quasar is currently undergoing an intense wave of [[Star formation|star formations]] thus increasing its [[luminosity]].<ref name=":0" /> A [[Astrophysical jet|radio jet]] has also been found on the side of quasar according to a study published in 2023.<ref>{{Cite journal |last1=Zhang |first1=Lei |last2=Zhang |first2=Zhi-Yu |last3=Nightingale |first3=James W. |last4=Zou |first4=Ze-Cheng |last5=Cao |first5=Xiaoyue |last6=Tsai |first6=Chao-Wei |last7=Yang |first7=Chentao |last8=Shi |first8=Yong |last9=Wang |first9=Junzhi |last10=Xu |first10=Dandan |last11=Lin |first11=Ling-Rui |last12=Zhou |first12=Jing |last13=Li |first13=Ran |date=2023-09-01 |title=Discovery of a radio jet in the Cloverleaf quasar at z = 2.56 |journal=Monthly Notices of the Royal Astronomical Society |volume=524 |issue=3 |pages=3671–3682 |doi=10.1093/mnras/stad2069 |doi-access=free |arxiv=2212.07027 |bibcode=2023MNRAS.524.3671Z |issn=0035-8711}}</ref> [[File:The "cloverleaf" quasar H 1413+117 (eso8806a).jpg|thumb|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.<ref name=":1">{{Cite web |title=Chandra :: Photo Album :: Cloverleaf Quasar (a.k.a. H1413+117) :: More Images of the Cloverleaf Quasar |url=https://chandra.harvard.edu/photo/2004/h1413/more.html |access-date=2024-08-28 |website=chandra.harvard.edu}}</ref>
===Black hole=== 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.<ref name=":1" /> Additionally, inner regions of the quasar's [[accretion disk]] around the black hole has been detected suggesting outflow wind.<ref>{{Cite journal |last1=Chartas |first1=G. |last2=Eracleous |first2=M. |last3=Dai |first3=X. |last4=Agol |first4=E. |last5=Gallagher |first5=S. |date=2007-06-01 |title=Discovery of Probable Relativistic Fe Emission and Absorption in the Cloverleaf Quasar H 1413+117 |url=https://ui.adsabs.harvard.edu/abs/2007ApJ...661..678C/abstract |journal=The Astrophysical Journal |volume=661 |issue=2 |pages=678–692 |doi=10.1086/516816 |arxiv=astro-ph/0702742 |bibcode=2007ApJ...661..678C |issn=0004-637X}}</ref>
=== Lensing galaxy and partial Einstein ring === Data from [[Near Infrared Camera and Multi-Object Spectrometer|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.<ref>{{Cite journal|last1=Chantry|first1=Virginie|last2=Magain|first2=Pierre|date=August 2007|title=Deconvolution of HST images of the Cloverleaf gravitational lens : detection of the lensing galaxy and a partial Einstein ring|journal=Astronomy & Astrophysics|volume=470|issue=2|pages=467–473|doi=10.1051/0004-6361:20066839|arxiv=astro-ph/0612094|bibcode=2007A&A...470..467C|issn=0004-6361|doi-access=free}}</ref>
== History == 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.<ref name=":1" />
== Gallery == <gallery> File:Coverleaf Quasar HST ACS+HRC.png|Quadruple image of the quasar taken with [[Hubble Space Telescope]]. File:Gravitational Lensing Graphic - PIA23641.tiff|Graphic illustration of four images of the quasar caused by gravitational lensing. </gallery>
== See also == * [[List of quasars]]
==References== {{reflist}}
== Further reading == *{{cite journal |author1=R. Barvainis |author2=L. Tacconi |author3=R. Antonucci |author4=D. Alloin |author5=P. Coleman |date=2002 |title=Extremely strong carbon monoxide emission from the Cloverleaf quasar at a redshift of 2.5 |journal=[[Nature (journal)|Nature]] |volume=371 |pages=586–588 |doi=10.1038/371586a0 |bibcode = 1994Natur.371..586B |issue=6498|s2cid=4246365 }} *{{cite journal |author=C. M. Bradford |date=2009 |title=The Warm Molecular Gas Around the Cloverleaf Quasar |journal=[[Astrophysical Journal]] |volume=705 |issue=1 |page=112 |doi=10.1088/0004-637X/705/1/112 |bibcode=2009ApJ...705..112B |arxiv = 0908.1818 |s2cid=13889803 |display-authors=etal}}
==External links== * Chandra at Havard CfA, [http://chandra.harvard.edu/photo/2004/h1413/ "Cloverleaf Quasar: Chandra Looks Over a Cosmic Four-Leaf Clover"], 20 February 2009
{{Boötes|state=collapsed}}
{{DEFAULTSORT:Cloverleaf Quasar}} [[Category:Gravitationally lensed quasars]] [[Category:Boötes]]