{{Short description|Gravitationally-lensed quasar in constellation Hydra}} {{Infobox galaxy|name=CTQ 327|epoch=[[J2000.0]]|constellation name=[[Hydra (constellation)|Hydra]]|image=File:Image of quasar CTQ 327.png|caption=[[Digitized Sky Survey|DSS]] image of CTQ 327.|ra={{RA|13|55|43.43}}|dec={{DEC|-22|57|23.16}}|z=1.370000|h_radial_v=410,716 [[kilometer per second|km/s]]|dist_ly=8.735 [[light year|Gly]]|appmag_b=+18.2|type=QSO|names=[[2MASSI]] J1355434-225723, [[Chandra X-ray Observatory|2CXO]] J135543.4-225723, CTS 0327, CTS M15.16}}
'''CTQ 327''' also known as '''Q 1355-2257''', is a [[Gravitational lens|gravitationally-lensed]] [[quasar]] located in the [[constellation]] of [[Hydra (constellation)|Hydra]]. It was discovered in 1992 from the Calan-Tololo Survey,<ref>{{Cite journal |last1=Maza |first1=J. |last2=Ruiz |first2=M. T. |last3=Gonzalez |first3=L. E. |last4=Wischnjewsky |first4=M. |last5=Antezana |first5=R. |date=April 1993 |title=Calan-Tololo Survey. V. Two hundred new southern quasars. |url=https://articles.adsabs.harvard.edu/pdf/1993RMxAA..25...51M |journal=Revista Mexicana de Astronomía y Astrofísica |language=en |volume=25 |pages=51–57 |bibcode=1993RMxAA..25...51M |issn=0185-1101}}</ref> with its [[redshift]] of the object calculated as (z) 1.37 by N.D. Morgan during the [[Hubble Space Telescope]] Imaging Spectrograph snapshot survey in August 2003.<ref name=":0">{{Cite journal |last1=Morgan |first1=N. D. |last2=Gregg |first2=M. D. |last3=Wisotzki |first3=L. |last4=Becker |first4=R. |last5=Maza |first5=J. |last6=Schechter |first6=P. L. |last7=White |first7=R. L. |date=August 2003 |title=CTQ 327: A New Gravitational Lens |url=https://iopscience.iop.org/article/10.1086/376470/pdf |journal=The Astronomical Journal |language=en |volume=126 |issue=2 |pages=696–705 |doi=10.1086/376470 |bibcode=2003AJ....126..696M |issn=0004-6256}}</ref>
== Description == CTQ 327 is a double imaged quasar.<ref>{{Cite journal |last=Morgan |first=Nicholas D. |date=2002 |title=New optical surveys for gravitationally lensed quasars |url=https://ui.adsabs.harvard.edu/abs/2002PhDT........29M/abstract |journal=Ph.D. Thesis |language=en |pages=1287 |bibcode=2002PhDT........29M }}</ref><ref>{{Cite journal |last1=Eigenbrod |first1=A. |last2=Courbin |first2=F. |last3=Meylan |first3=G. |date=2007-04-01 |title=COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - VI. Redshift of the lensing galaxy in seven gravitationally lensed quasars |url=https://www.aanda.org/articles/aa/pdf/2007/13/aa6939-06.pdf |journal=Astronomy & Astrophysics |language=en |volume=465 |issue=1 |pages=51–56 |doi=10.1051/0004-6361:20066939 |arxiv=astro-ph/0612419 |bibcode=2007A&A...465...51E |issn=0004-6361}}</ref> When imaged by Morgan, the object is found to separate into two bright images or components, with an estimated separation gap of 1.22 arcseconds and a [[G band (IEEE)|g-band]] flux [[ratio]] roughly 5 to 1. The components are found to display continuum and [[Spectral line|emission line]] features in their [[Spectral density|spectra]], mainly doubly ionized [[carbon]] and [[magnesium]], despite not similar to one another, with component A having much weaker emission lines compared to component B.<ref name=":0" /><ref>{{Cite journal |last1=Fian |first1=C. |last2=Mediavilla |first2=E. |last3=Motta |first3=V. |last4=Jiménez-Vicente |first4=J. |last5=Muñoz |first5=J. A. |last6=Chelouche |first6=D. |last7=Hanslmeier |first7=A. |date=2021-09-01 |title=Microlensing of the broad emission lines in 27 gravitationally lensed quasars - Broad line region structure and kinematics |url=https://www.aanda.org/articles/aa/pdf/2021/09/aa39829-20.pdf |journal=Astronomy & Astrophysics |language=en |volume=653 |pages=A109 |doi=10.1051/0004-6361/202039829 |arxiv=2107.06227 |bibcode=2021A&A...653A.109F |issn=0004-6361}}</ref><ref name=":1">{{Cite journal |last1=Saha |first1=P. |last2=Courbin |first2=F. |last3=Sluse |first3=D. |last4=Dye |first4=S. |last5=Meylan |first5=G. |date=2006-05-01 |title=COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - IV. Models of prospective time-delay lenses |url=https://www.aanda.org/articles/aa/pdf/2006/17/aa2929-05.pdf |journal=Astronomy & Astrophysics |language=en |volume=450 |issue=2 |pages=461–469 |doi=10.1051/0004-6361:20052929 |arxiv=astro-ph/0601370 |bibcode=2006A&A...450..461S |issn=0004-6361}}</ref>
The lensing galaxy of CTQ 327 is resolved and classified an early-type [[elliptical galaxy]] with a redshift of (z) 0.70, located from component B by 0.29 [[Minute and second of arc|milliarcseconds]].<ref name=":0" /><ref>{{Cite journal |last1=Eigenbrod |first1=A. |last2=Courbin |first2=F. |last3=Meylan |first3=G. |last4=Vuissoz |first4=C. |last5=Magain |first5=P. |date=2006-06-01 |title=COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - III. Redshift of the lensing galaxy in eight gravitationally lensed quasars |url=https://www.aanda.org/articles/aa/pdf/2006/21/aa4454-05.pdf |journal=Astronomy & Astrophysics |language=en |volume=451 |issue=3 |pages=759–766 |doi=10.1051/0004-6361:20054454 |arxiv=astro-ph/0511026 |bibcode=2006A&A...451..759E |issn=0004-6361}}</ref> An absorption feature is found to be associated with it at (z) 0.48.<ref>{{Cite journal |last1=Ofek |first1=Eran O. |last2=Maoz |first2=Dan |last3=Rix |first3=Hans-Walter |last4=Kochanek |first4=Christopher S. |last5=Falco |first5=Emilio E. |date=April 2006 |title=Spectroscopic Redshifts for Seven Lens Galaxies |journal=The Astrophysical Journal |language=en |volume=641 |issue=1 |pages=70–77 |doi=10.1086/500403 |arxiv=astro-ph/0510465 |bibcode=2006ApJ...641...70O |issn=0004-637X}}</ref> A [[stellar mass]] of 11.56 M<sub>☉</sub>, and an [[Equivalent radius|effective radius]] of 1.24 ± 0.29 arcseconds has been found for the lens galaxy with the total [[Einstein radius]] of 0.62 arcseconds.<ref>{{Cite journal |last1=Oguri |first1=Masamune |last2=Rusu |first2=Cristian E. |last3=Falco |first3=Emilio E. |date=April 2014 |title=The stellar and dark matter distributions in elliptical galaxies from the ensemble of strong gravitational lenses |journal=Monthly Notices of the Royal Astronomical Society |language=en |volume=439 |issue=3 |pages=2494–2504 |doi=10.1093/mnras/stu106 |arxiv=1309.5408 |doi-access=free |issn=0035-8711}}</ref>
The quasar displays [[Delay differential equation|time-delays]]. Based on observations by P. Saha using a lens model, the predicted time-delay is −89<sup>+28</sup><sub>−39</sub> days long.<ref name=":1" /> A more recent study in August 2020, estimated a new time-delay of −81.5<sup>+10.8</sup><sub>−12.0</sub> days based on a measurement pipeline.<ref>{{Cite journal |last1=Millon |first1=M. |last2=Courbin |first2=F. |last3=Bonvin |first3=V. |last4=Paic |first4=E. |last5=Meylan |first5=G. |last6=Tewes |first6=M. |last7=Sluse |first7=D. |last8=Magain |first8=P. |last9=Chan |first9=J. H. H. |last10=Galan |first10=A. |last11=Joseph |first11=R. |last12=Lemon |first12=C. |last13=Tihhonova |first13=O. |last14=Anderson |first14=R. I. |last15=Marmier |first15=M. |date=2020-08-01 |title=COSMOGRAIL - XIX. Time delays in 18 strongly lensed quasars from 15 years of optical monitoring |url=https://www.aanda.org/articles/aa/abs/2020/08/aa37740-20/aa37740-20.html |journal=Astronomy & Astrophysics |language=en |volume=640 |pages=A105 |doi=10.1051/0004-6361/202037740 |arxiv=2002.05736 |bibcode=2020A&A...640A.105M |issn=0004-6361}}</ref> It is shown the flux ratios of both components have temporal variations based on g-band Magellan observations of 0.14 [[Magnitude (astronomy)|magnitude]] during a period of over three months. Comparison of second-epoch data obtained in March and June, have also found component A of CTQ 327 underwent a significant decrease in [[Brightness temperature|brightness]] by 0.125 ± 0.001 magnitude while component B showed no observed changes.<ref name=":0" />
CTQ 327 has evidence of chromatic [[Gravitational microlensing|microlensing]] with wavelengths greater than λ > 6180Å. Astronomers also noted, the core of emission lines and continuum also displayed a [[Discrepancy theory|discrepancy]] in magnitude results of -0.06 and +0.08 respectively. They also noted the [[accretion disk]] of CTQ 327 is larger with a size of 3.6<sup>+3.0</sup><sub>−1.6</sub> x 1.3 ± 0.6 M/M<sub>☉</sub> and has a [[temperature]] profile of 2.0 ± 0.7. The [[black hole]] mass is estimated as 1.1 × 10<sup>9</sup> M<sub>☉</sub>.<ref>{{Cite journal |last1=Rojas |first1=K. |last2=Motta |first2=V. |last3=Mediavilla |first3=E. |last4=Jiménez-Vicente |first4=J. |last5=Falco |first5=E. |last6=Fian |first6=C. |date=2020-02-06 |title=Microlensing Analysis for the Gravitational Lens Systems SDSS0924+0219, Q1355-2257, and SDSS1029+2623 |journal=The Astrophysical Journal |volume=890 |issue=1 |pages=3 |doi=10.3847/1538-4357/ab63cb |arxiv=2002.02861 |bibcode=2020ApJ...890....3R |doi-access=free |issn=0004-637X}}</ref>
== References == <references />
== External links == *[https://ned.ipac.caltech.edu/byname?objname=CTQ+327&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1 CTQ 327 on NASA/IPAC Database] *[http://simbad.u-strasbg.fr/simbad/sim-id?Ident=QSO%20B1352-2242 CTQ 327 on SIMBAD]
[[Category:Quasars]] [[Category:Hydra (constellation)]] [[Category:Gravitationally lensed quasars]] [[Category:Astronomical objects discovered in 2003]]
{{Hydra (constellation)}}