# CTQ 327

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Gravitationally-lensed quasar in constellation Hydra

CTQ 327 DSS image of CTQ 327. Observation data (J2000.0 epoch) Constellation Hydra Right ascension 13h 55m 43.43s Declination −22° 57′ 23.16″ Redshift 1.370000 Heliocentric radial velocity 410,716 km/s Distance 8.735 Gly Apparent magnitude (B) +18.2 Characteristics Type QSO Other designations 2MASSI J1355434-225723, 2CXO J135543.4-225723, CTS 0327, CTS M15.16

**CTQ 327** also known as **Q 1355-2257**, is a [gravitationally-lensed](/source/Gravitational_lens) [quasar](/source/Quasar) located in the [constellation](/source/Constellation) of [Hydra](/source/Hydra_(constellation)). It was discovered in 1992 from the Calan-Tololo Survey,[1] with its [redshift](/source/Redshift) of the object calculated as (z) 1.37 by N.D. Morgan during the [Hubble Space Telescope](/source/Hubble_Space_Telescope) Imaging Spectrograph snapshot survey in August 2003.[2]

## Description

CTQ 327 is a double imaged quasar.[3][4] 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](/source/G_band_(IEEE)) flux [ratio](/source/Ratio) roughly 5 to 1. The components are found to display continuum and [emission line](/source/Spectral_line) features in their [spectra](/source/Spectral_density), mainly doubly ionized [carbon](/source/Carbon) and [magnesium](/source/Magnesium), despite not similar to one another, with component A having much weaker emission lines compared to component B.[2][5][6]

The lensing galaxy of CTQ 327 is resolved and classified an early-type [elliptical galaxy](/source/Elliptical_galaxy) with a redshift of (z) 0.70, located from component B by 0.29 [milliarcseconds](/source/Minute_and_second_of_arc).[2][7] An absorption feature is found to be associated with it at (z) 0.48.[8] A [stellar mass](/source/Stellar_mass) of 11.56 M☉, and an [effective radius](/source/Equivalent_radius) of 1.24 ± 0.29 arcseconds has been found for the lens galaxy with the total [Einstein radius](/source/Einstein_radius) of 0.62 arcseconds.[9]

The quasar displays [time-delays](/source/Delay_differential_equation). Based on observations by P. Saha using a lens model, the predicted time-delay is −89+28−39 days long.[6] A more recent study in August 2020, estimated a new time-delay of −81.5+10.8−12.0 days based on a measurement pipeline.[10] It is shown the flux ratios of both components have temporal variations based on g-band Magellan observations of 0.14 [magnitude](/source/Magnitude_(astronomy)) 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](/source/Brightness_temperature) by 0.125 ± 0.001 magnitude while component B showed no observed changes.[2]

CTQ 327 has evidence of chromatic [microlensing](/source/Gravitational_microlensing) with wavelengths greater than λ > 6180Å. Astronomers also noted, the core of emission lines and continuum also displayed a [discrepancy](/source/Discrepancy_theory) in magnitude results of -0.06 and +0.08 respectively. They also noted the [accretion disk](/source/Accretion_disk) of CTQ 327 is larger with a size of 3.6+3.0−1.6 x 1.3 ± 0.6 M/M☉ and has a [temperature](/source/Temperature) profile of 2.0 ± 0.7. The [black hole](/source/Black_hole) mass is estimated as 1.1 × 109 M☉.[11]

## References

1. **[^](#cite_ref-1)** Maza, J.; Ruiz, M. T.; Gonzalez, L. E.; Wischnjewsky, M.; Antezana, R. (April 1993). ["Calan-Tololo Survey. V. Two hundred new southern quasars"](https://articles.adsabs.harvard.edu/pdf/1993RMxAA..25...51M). *Revista Mexicana de Astronomía y Astrofísica*. **25**: 51–57. [Bibcode](/source/Bibcode_(identifier)):[1993RMxAA..25...51M](https://ui.adsabs.harvard.edu/abs/1993RMxAA..25...51M). [ISSN](/source/ISSN_(identifier)) [0185-1101](https://search.worldcat.org/issn/0185-1101).

1. ^ [***a***](#cite_ref-:0_2-0) [***b***](#cite_ref-:0_2-1) [***c***](#cite_ref-:0_2-2) [***d***](#cite_ref-:0_2-3) Morgan, N. D.; Gregg, M. D.; Wisotzki, L.; Becker, R.; Maza, J.; Schechter, P. L.; White, R. L. (August 2003). ["CTQ 327: A New Gravitational Lens"](https://iopscience.iop.org/article/10.1086/376470/pdf). *The Astronomical Journal*. **126** (2): 696–705. [Bibcode](/source/Bibcode_(identifier)):[2003AJ....126..696M](https://ui.adsabs.harvard.edu/abs/2003AJ....126..696M). [doi](/source/Doi_(identifier)):[10.1086/376470](https://doi.org/10.1086%2F376470). [ISSN](/source/ISSN_(identifier)) [0004-6256](https://search.worldcat.org/issn/0004-6256).

1. **[^](#cite_ref-3)** Morgan, Nicholas D. (2002). ["New optical surveys for gravitationally lensed quasars"](https://ui.adsabs.harvard.edu/abs/2002PhDT........29M/abstract). *Ph.D. Thesis*: 1287. [Bibcode](/source/Bibcode_(identifier)):[2002PhDT........29M](https://ui.adsabs.harvard.edu/abs/2002PhDT........29M).

1. **[^](#cite_ref-4)** Eigenbrod, A.; Courbin, F.; Meylan, G. (2007-04-01). ["COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - VI. Redshift of the lensing galaxy in seven gravitationally lensed quasars"](https://www.aanda.org/articles/aa/pdf/2007/13/aa6939-06.pdf) (PDF). *Astronomy & Astrophysics*. **465** (1): 51–56. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0612419](https://arxiv.org/abs/astro-ph/0612419). [Bibcode](/source/Bibcode_(identifier)):[2007A&A...465...51E](https://ui.adsabs.harvard.edu/abs/2007A&A...465...51E). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20066939](https://doi.org/10.1051%2F0004-6361%3A20066939). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-5)** Fian, C.; Mediavilla, E.; Motta, V.; Jiménez-Vicente, J.; Muñoz, J. A.; Chelouche, D.; Hanslmeier, A. (2021-09-01). ["Microlensing of the broad emission lines in 27 gravitationally lensed quasars - Broad line region structure and kinematics"](https://www.aanda.org/articles/aa/pdf/2021/09/aa39829-20.pdf) (PDF). *Astronomy & Astrophysics*. **653**: A109. [arXiv](/source/ArXiv_(identifier)):[2107.06227](https://arxiv.org/abs/2107.06227). [Bibcode](/source/Bibcode_(identifier)):[2021A&A...653A.109F](https://ui.adsabs.harvard.edu/abs/2021A&A...653A.109F). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202039829](https://doi.org/10.1051%2F0004-6361%2F202039829). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. ^ [***a***](#cite_ref-:1_6-0) [***b***](#cite_ref-:1_6-1) Saha, P.; Courbin, F.; Sluse, D.; Dye, S.; Meylan, G. (2006-05-01). ["COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - IV. Models of prospective time-delay lenses"](https://www.aanda.org/articles/aa/pdf/2006/17/aa2929-05.pdf) (PDF). *Astronomy & Astrophysics*. **450** (2): 461–469. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0601370](https://arxiv.org/abs/astro-ph/0601370). [Bibcode](/source/Bibcode_(identifier)):[2006A&A...450..461S](https://ui.adsabs.harvard.edu/abs/2006A&A...450..461S). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20052929](https://doi.org/10.1051%2F0004-6361%3A20052929). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-7)** Eigenbrod, A.; Courbin, F.; Meylan, G.; Vuissoz, C.; Magain, P. (2006-06-01). ["COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses - III. Redshift of the lensing galaxy in eight gravitationally lensed quasars"](https://www.aanda.org/articles/aa/pdf/2006/21/aa4454-05.pdf) (PDF). *Astronomy & Astrophysics*. **451** (3): 759–766. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0511026](https://arxiv.org/abs/astro-ph/0511026). [Bibcode](/source/Bibcode_(identifier)):[2006A&A...451..759E](https://ui.adsabs.harvard.edu/abs/2006A&A...451..759E). [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20054454](https://doi.org/10.1051%2F0004-6361%3A20054454). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-8)** Ofek, Eran O.; Maoz, Dan; Rix, Hans-Walter; Kochanek, Christopher S.; Falco, Emilio E. (April 2006). "Spectroscopic Redshifts for Seven Lens Galaxies". *The Astrophysical Journal*. **641** (1): 70–77. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0510465](https://arxiv.org/abs/astro-ph/0510465). [Bibcode](/source/Bibcode_(identifier)):[2006ApJ...641...70O](https://ui.adsabs.harvard.edu/abs/2006ApJ...641...70O). [doi](/source/Doi_(identifier)):[10.1086/500403](https://doi.org/10.1086%2F500403). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X).

1. **[^](#cite_ref-9)** Oguri, Masamune; Rusu, Cristian E.; Falco, Emilio E. (April 2014). ["The stellar and dark matter distributions in elliptical galaxies from the ensemble of strong gravitational lenses"](https://doi.org/10.1093%2Fmnras%2Fstu106). *Monthly Notices of the Royal Astronomical Society*. **439** (3): 2494–2504. [arXiv](/source/ArXiv_(identifier)):[1309.5408](https://arxiv.org/abs/1309.5408). [doi](/source/Doi_(identifier)):[10.1093/mnras/stu106](https://doi.org/10.1093%2Fmnras%2Fstu106). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

1. **[^](#cite_ref-10)** Millon, M.; Courbin, F.; Bonvin, V.; Paic, E.; Meylan, G.; Tewes, M.; Sluse, D.; Magain, P.; Chan, J. H. H.; Galan, A.; Joseph, R.; Lemon, C.; Tihhonova, O.; Anderson, R. I.; Marmier, M. (2020-08-01). ["COSMOGRAIL - XIX. Time delays in 18 strongly lensed quasars from 15 years of optical monitoring"](https://www.aanda.org/articles/aa/abs/2020/08/aa37740-20/aa37740-20.html). *Astronomy & Astrophysics*. **640**: A105. [arXiv](/source/ArXiv_(identifier)):[2002.05736](https://arxiv.org/abs/2002.05736). [Bibcode](/source/Bibcode_(identifier)):[2020A&A...640A.105M](https://ui.adsabs.harvard.edu/abs/2020A&A...640A.105M). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202037740](https://doi.org/10.1051%2F0004-6361%2F202037740). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-11)** Rojas, K.; Motta, V.; Mediavilla, E.; Jiménez-Vicente, J.; Falco, E.; Fian, C. (2020-02-06). ["Microlensing Analysis for the Gravitational Lens Systems SDSS0924+0219, Q1355-2257, and SDSS1029+2623"](https://doi.org/10.3847%2F1538-4357%2Fab63cb). *The Astrophysical Journal*. **890** (1): 3. [arXiv](/source/ArXiv_(identifier)):[2002.02861](https://arxiv.org/abs/2002.02861). [Bibcode](/source/Bibcode_(identifier)):[2020ApJ...890....3R](https://ui.adsabs.harvard.edu/abs/2020ApJ...890....3R). [doi](/source/Doi_(identifier)):[10.3847/1538-4357/ab63cb](https://doi.org/10.3847%2F1538-4357%2Fab63cb). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X).

## External links

- [CTQ 327 on NASA/IPAC Database](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 SIMBAD](http://simbad.u-strasbg.fr/simbad/sim-id?Ident=QSO%20B1352-2242)

v t e Constellation of Hydra List of stars in Hydra Hydra in Chinese astronomy Stars Bayer α (Alphard) β γ (Naga) δ ε (Ashlesha) ζ η θ ι (Ukdah) κ λ μ ν ξ ο π ρ σ (Minchir) τ1 τ2 υ1 (Zhang) υ2 φ1 φ2 φ3 χ1 χ2 ψ ω b1 b3 C F Flamsteed 1 2 3 6 (a) 9 10 12 (D) 14 15 17 19 20 21 23 24 25 26 27 (P) 28 29 33 (A) 34 37 44 47 48 50 51 (k) 52 (l) 54 (m) 55 56 57 58 (Solitaire) 59 60 10 Crt 17 Crt 20 Crt 2 Sex Variable R U V W TW EX HS KU LQ V361 V419 V421 V478 V484 HR 3378 3538 3749 (G) 3750 3858 (I) 3862 3919 3923 (Felis) 4162 4328 4339 (β Ant) 4445 5265 HD 72659 74156 82943 86226 86264 90156 (γ Ant) Other 2MASS 1114−2618 ESO 439-26 Gliese 328 Gliese 357 Gliese 433 Gliese 453 GJ 3634 HAT-P-30 HE 1256−2738 HE 1327−2326 LHS 2065 LHS 3003 LTT 3780 SDSS J090745.0+024507 WASP-25 WASP-36 WASP-84 WASP-166 (Filetdor) WISE 0855−0714 WISEA J1141−3326 Exoplanets Gliese 357 d HD 72659 b HD 74156 b c HD 82943 b c HD 86226 b HD 86264 b TW Hydrae b (unconfirmed) WASP-193b Star clusters Messier 48 Messier 68 NGC 5694 Price-Whelan 1 Nebulae Abell 33 Abell 35 NGC 3242 Southern Owl Nebula Galaxies Messier 83 NGC 2617 2642 2697 2708 2758 2835 2848 2865 2890 2935 2936 2937 2960 2962 2986 2992 3030 3052 3054 3081 3109 3124 3200 3285 3285B 3290 3305 3307 3308 3309 3311 3312 3313 3314 3315 3316 3336 3369 3383 3393 3402 3463 3464 3585 3621 3673 3717 3904 3923 3936 4980 4993 5042 5061 5078 5085 5101 5135 5260 5264 5495 5626 Other 3C 196.1 AM 1316−241 Arp 7 CTQ 327 ESO 510-G13 GAMA202627 GLEAM J0917−0012 Hydra A IC 535 MRC 1138−262 Peekaboo Galaxy PKS 1151−348 RX J0911.4+0551 SDSS J0841+0101 TN J0924−2201 Tololo 1247−232 ZwCl 1693 BCG Galaxy clusters Abell 754 Abell 3411 Abell 3412 Bullet Group Hickson 40 Astronomical events GW170817 Category

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Adapted from the Wikipedia article [CTQ 327](https://en.wikipedia.org/wiki/CTQ_327) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/CTQ_327?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.