# OQ 172

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Quasar in the constellation Boötes

OQ 172 The quasar OQ 172. Observation data (J2000.0 epoch) Constellation Boötes Right ascension 14h 45m 16.465s Declination +09° 58′ 36.073″ Redshift 3.540681 Distance 11.543 Gly Apparent magnitude (V) 17.78 Apparent magnitude (B) 18.58 Characteristics Type GPS, FSRQ Other designations LEDA 2828124, PKS 1442+101, NVSS J144516+095836, QSO B1442+101, TXS 1442+101, CoNFIG 200, IERS B1442+101

**OQ 172** (**OHIO Q 172**) is a [quasar](/source/Quasar)[1] located in the [constellation](/source/Constellation) of [Boötes](/source/Bo%C3%B6tes). It has a [redshift](/source/Redshift) of (z) 3.544,[2] making it one of the [most distant quasars](/source/List_of_quasars) at the time of its discovery by [astronomers](/source/Astronomer) in 1973.[3] This object was the record holder for almost a decade, before being surpassed by [PKS 2000-330](/source/PKS_2000-330) in 1982 located at the redshift of (z) 3.78.[4]

## Description

The source of OQ 172 has a [radio spectrum](/source/Radio_spectrum) characterized by its [spectral](/source/Spectral_density) peak in the [gigahertz](/source/Hertz) domain, making it a [gigahertz](/source/Hertz)-peaked spectrum quasar (GPS)[5][6] or a compact steep spectrum source (CSS).[7]

OQ 172 contains a core-jet structure with the radio core itself located in the northern region of the radio emission.[8] This core is found to show a flat [spectrum](/source/Spectrum) up to > 30 GHz in the rest frame with a steep spectrum above 30 GHz which continues steepening until 1000 GHz, thus confirming there is no buried flat spectrum core within the emission source.[9]

The [jet](/source/Astrophysical_jet) of OQ 172 is found to turn almost at an 180° [angle](/source/Angle) with jet emission in the west-southwest direction extending right from the core, eventually bending almost southwards. When reaching 20 mas south of the core, the jet immediately bends once again, this time at 90° and extends towards the east.[10] A further study also shows the jet has three components, one of which is the fastest at a [proper motion](/source/Proper_motion) of 0.13 ± 0.01 mas yr−1. With a mean TB of 15.5 ± 6.4 × 1010 K, this suggests OQ 172 has a highly [beamed jet](/source/Relativistic_beaming).[11]

[Very long baseline interferometry](/source/Very-long-baseline_interferometry) radio observations revealed OQ 172 has [magnetic fields](/source/Magnetic_field) on parsec scales which rotate the polarization plane of the radio emission originating from both its core and inner jet.[10] Based on the derived rest-frame rotational measurement of RM 40,000 rad m−2, it is found OQ 172 has the highest value amongst other known RM sources.[12] When at 10 mas from the core, the jet's absolute value of RM decreases to <100 rad m−2.[10] Additionally, linear [polarized](/source/Polarization_(waves)) emission has been detected in both components in all five [frequencies](/source/Frequency). The core has low fractional polarization, while the jet components have a higher polarization. A rotational measurement was obtained at 4.8 and 8.3 GHz respectively, showing a high value of 2000 rad m−2 in the innermost region of OQ 172. Towards the outer jet regions, this value drops to 700 rad m−2, quickly decreasing to lower values.[12][8]

## References

1. **[^](#cite_ref-1)** Fomenko, A. F.; Levshakov, S. A.; Varshalovich, D. A.; Nebelitskii, V. B. (1984-02-01). ["Spectra of the quasar OQ 172"](https://ui.adsabs.harvard.edu/abs/1984PAZh...10...83F/abstract). *Pis'ma v Astronomicheskii Zhurnal*. **10**: 83–89. [Bibcode](/source/Bibcode_(identifier)):[1984PAZh...10...83F](https://ui.adsabs.harvard.edu/abs/1984PAZh...10...83F). [ISSN](/source/ISSN_(identifier)) [0320-0108](https://search.worldcat.org/issn/0320-0108).

1. **[^](#cite_ref-2)** Morton, D. C.; Peterson, B. A.; Chen, J.-S.; Wright, A. E.; Jauncey, D. L. (1989-12-01). ["The spectrum of the QSO 1442 + 101 (OQ172) at intermediate dispersion"](https://doi.org/10.1093%2Fmnras%2F241.3.595). *Monthly Notices of the Royal Astronomical Society*. **241** (3): 595–612. [doi](/source/Doi_(identifier)):[10.1093/mnras/241.3.595](https://doi.org/10.1093%2Fmnras%2F241.3.595). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

1. **[^](#cite_ref-3)** Gurvits, L.I.; Schilizzi, R.T.; Barthel, P.D.; Kardashev, N.S.; Kellermann, K.L.; Lobanov, A.P. (1994). ["Milliarcsecond structures of extremely distant quasars: 0336-017, 0636+680, 1442+101, and 2048+312"](https://articles.adsabs.harvard.edu/full/1994A%26A...291..737G/0000738.000.html). *Astronomy & Astrophysics*. **291** (3): 737–742. [Bibcode](/source/Bibcode_(identifier)):[1994A&A...291..737G](https://ui.adsabs.harvard.edu/abs/1994A&A...291..737G). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-4)** Shaver, Peter (December 1987). ["Ever more distant quasars?"](https://www.nature.com/articles/330426a0.pdf) (PDF). *Nature*. **330** (6147): 426. [Bibcode](/source/Bibcode_(identifier)):[1987Natur.330..426S](https://ui.adsabs.harvard.edu/abs/1987Natur.330..426S). [doi](/source/Doi_(identifier)):[10.1038/330426a0](https://doi.org/10.1038%2F330426a0). [ISSN](/source/ISSN_(identifier)) [0028-0836](https://search.worldcat.org/issn/0028-0836).

1. **[^](#cite_ref-5)** Liu, Y.; Jiang, D. R.; Gu, M.; Gurvits, L. I. (2016-02-01). ["The compact radio structure of the high-redshift quasar OQ172"](https://ui.adsabs.harvard.edu/abs/2016AN....337..101L/abstract). *Astronomische Nachrichten*. **337** (1–2): 101. [Bibcode](/source/Bibcode_(identifier)):[2016AN....337..101L](https://ui.adsabs.harvard.edu/abs/2016AN....337..101L). [doi](/source/Doi_(identifier)):[10.1002/asna.201512273](https://doi.org/10.1002%2Fasna.201512273). [ISSN](/source/ISSN_(identifier)) [0004-6337](https://search.worldcat.org/issn/0004-6337).

1. **[^](#cite_ref-6)** Barthel, Peter D.; Vestergaard, Marianne; Lonsdale, Colin J. (2000-02-01). ["Radio imaging of core-dominated high redshift quasars"](https://articles.adsabs.harvard.edu/pdf/2000A%26A...354....7B). *Astronomy and Astrophysics*. **354**: 7–16. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9911474](https://arxiv.org/abs/astro-ph/9911474). [Bibcode](/source/Bibcode_(identifier)):[2000A&A...354....7B](https://ui.adsabs.harvard.edu/abs/2000A&A...354....7B). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-7)** Mantovani, F.; Rossetti, A.; Junor, W.; Saikia, D. J.; Salter, C. J. (2013-06-18). ["Radio polarimetry of compact steep spectrum sources at sub-arcsecond resolution"](https://www.aanda.org/articles/aa/pdf/2013/07/aa20769-12.pdf) (PDF). *Astronomy & Astrophysics*. **555**: A4. [arXiv](/source/ArXiv_(identifier)):[1305.1644](https://arxiv.org/abs/1305.1644). [Bibcode](/source/Bibcode_(identifier)):[2013A&A...555A...4M](https://ui.adsabs.harvard.edu/abs/2013A&A...555A...4M). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201220769](https://doi.org/10.1051%2F0004-6361%2F201220769). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. ^ [***a***](#cite_ref-:0_8-0) [***b***](#cite_ref-:0_8-1) Mantovani, F.; Junor, W.; Bondi, M.; Cotton, W.; Fanti, R.; Padrielli, L. (1998). ["Large bent jets in the inner region of CSSs"](https://articles.adsabs.harvard.edu/pdf/1998A%26A...332...10M). *Astronomy & Astrophysics*. **332**: 10–18. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9712084](https://arxiv.org/abs/astro-ph/9712084). [Bibcode](/source/Bibcode_(identifier)):[1998A&A...332...10M](https://ui.adsabs.harvard.edu/abs/1998A&A...332...10M).

1. **[^](#cite_ref-9)** Punsly, Brian; Marziani, Paola; Kharb, Preeti; O’Dea, Christopher P.; Vestergaard, Marianne (2015-10-09). ["The Extreme Ultraviolet Deficit: Jet Connection In the Quasar 1442+101"](https://dx.doi.org/10.1088/0004-637x/812/1/79). *The Astrophysical Journal*. **812** (1): 79. [arXiv](/source/ArXiv_(identifier)):[1509.02619](https://arxiv.org/abs/1509.02619). [Bibcode](/source/Bibcode_(identifier)):[2015ApJ...812...79P](https://ui.adsabs.harvard.edu/abs/2015ApJ...812...79P). [doi](/source/Doi_(identifier)):[10.1088/0004-637x/812/1/79](https://doi.org/10.1088%2F0004-637x%2F812%2F1%2F79). [ISSN](/source/ISSN_(identifier)) [1538-4357](https://search.worldcat.org/issn/1538-4357).

1. ^ [***a***](#cite_ref-:1_10-0) [***b***](#cite_ref-:1_10-1) [***c***](#cite_ref-:1_10-2) Udomprasert, P. S.; Taylor, G. B.; Pearson, T. J.; Roberts, D. H. (1997-07-01). ["Evidence for Ordered Magnetic Fields in the Quasar Environment"](https://iopscience.iop.org/article/10.1086/310725/fulltext/). *The Astrophysical Journal*. **483** (1): L9–L12. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9704112](https://arxiv.org/abs/astro-ph/9704112). [Bibcode](/source/Bibcode_(identifier)):[1997ApJ...483L...9U](https://ui.adsabs.harvard.edu/abs/1997ApJ...483L...9U). [doi](/source/Doi_(identifier)):[10.1086/310725](https://doi.org/10.1086%2F310725). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X).

1. **[^](#cite_ref-11)** Zhang, Yingkang; An, Tao; Frey, Sándor; Gabányi, Krisztina Éva; Sotnikova, Yulia (September 2022). ["Radio Jet Proper-motion Analysis of Nine Distant Quasars above Redshift 3.5"](https://doi.org/10.3847%2F1538-4357%2Fac87f8). *The Astrophysical Journal*. **937** (1): 19. [arXiv](/source/ArXiv_(identifier)):[2209.10760](https://arxiv.org/abs/2209.10760). [Bibcode](/source/Bibcode_(identifier)):[2022ApJ...937...19Z](https://ui.adsabs.harvard.edu/abs/2022ApJ...937...19Z). [doi](/source/Doi_(identifier)):[10.3847/1538-4357/ac87f8](https://doi.org/10.3847%2F1538-4357%2Fac87f8). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X).

1. ^ [***a***](#cite_ref-:2_12-0) [***b***](#cite_ref-:2_12-1) Liu, Yi; Jiang, D. R.; Gu, Minfeng; Gurvits, L. I. (2017-03-15). ["Multifrequency VLBA polarimetry of the high-redshift GPS quasar OQ172"](https://doi.org/10.1093%2Fmnras%2Fstx617). *Monthly Notices of the Royal Astronomical Society*. **468** (3): 2699–2712. [arXiv](/source/ArXiv_(identifier)):[1703.04066](https://arxiv.org/abs/1703.04066). [doi](/source/Doi_(identifier)):[10.1093/mnras/stx617](https://doi.org/10.1093%2Fmnras%2Fstx617). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

## External links

- [OQ 172 on SIMBAD](http://simbad.u-strasbg.fr/simbad/sim-id?Ident=QSO%20B1445%2B101)

- [OQ 172 on NASA/IPAC Database](http://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Obj_id&objid=63686&objname=2&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1)

v t e Constellation of Boötes Boötes in Chinese astronomy Boötes Void List of stars in Boötes Stars Bayer α (Arcturus) β (Nekkar) γ (Seginus) δ (Qigong) ε (Izar, Pulcherrima) ζ η (Muphrid) θ ι κ λ (Xuange) μ1 (Alkalurops) μ2 ν1 ν2 ξ ο π ρ (Kalasungsang) σ (Genghe) τ (Tepiamenit) υ φ χ ψ ω Flamsteed 1 2 3 6 (e) 7 9 10 11 12 (d) 13 14 15 18 20 22 (f) 24 (g) 26 31 32 33 34 (Alrumh) 38 (Merga) 39 40 44 (Quadrans) 45 (c) 46 (b) 47 (k) 50 Variable R S T RX ZZ AB BL BP BX BY CE CH CI CN CP CR CX CY (101 Vir) DE EK HN HP HD 118508 118889 122563 125040 125351 (A) 125658 126128 126129 126141 126200 126271 127304 127334 127726 128093 128198 129132 129357 130084 130603 130917 131040 131473 131496 (Arcalís) 132029 132406 132563 134064 134335 135438 135530 135944 141399 Other 2MASS J15031961+2525196 CFBDSIR 1458+10 Gliese 526 HAT-P-4 LHS 2924 PSR J1544+4937 SDSS J1416+1348 SDSS J1433+1011 TVLM 513-46546 WASP-14 WD 1425+540 ZTF J153932.16+502738.8 Exoplanets HAT-P-4b HD 128311 b c HD 132406 b HD 136418 b (Awasis) τ Boötis b TOI-1853 b WASP-14b Star clusters NGC 5466 Galaxies NGC 5008 5248 5251 5416 5490 5500 5504 5508 5514 5523 5529 5532 5533 5535 5539 5541 5544 5545 5548 5557 5559 5562 5579 5582 5591 5601 5603 5609 5613 5614 5615 5624 5629 5630 5641 5642 5653 5665 5676 5681 5682 5683 5698 5714 5722 5752 5753 5754 5755 5772 5778 5784 5790 5820 5821 5829 5837 5857 5875 5876 5886 5888 5896 5929 5930 5966 Numbered I II III Other 3C 295 3C 299 3C 300 3C 303 3C 315 4C 19.44 4C +26.42 7C 1354+2552 Abell 2009 BCG Arp 302 B2 1420+32 B2 1441+26 CEERS-2112 CEERS-93316 CEERS2-588 CLASS B1359+154 Cloverleaf quasar DDO 190 EGS-zs8-1 EGS-z11-R0 EGSY8p7 H1426+428 IC 4397 IC 4461 IC 4462 IC 4481 IC 4516 IRAS 13349+2438 IRAS 14394+5332 IRAS 15206+3342 LEDA 2108986 MACS 1423-z7p64 MACS J1447.4+0827 BCG Maisie's Galaxy Markarian 463 Markarian 471 Markarian 478 MS 1455.0+2232 BCG MS 1512-cB58 NVSS J141343+433945 OQ 172 OQ 530 PG 1411+442 PG 1543+489 PGC 93125 PGC 1470080 PKS 1345+125 PKS 1413+135 QSO B1422+202 RBS 1467 RGZ J145001.5+144747 RGZ J145039.8+441829 SBS 1415+437 SDSS J135646.10+102609.0 SDSS J1430+2303 Teacup galaxy UGC 8669 UGC 9128 UGC 9425 UGC 9684 UGC 9796 ULAS J1342+0928 VV 191 Galaxy clusters Abell 1795 Abell 1991 BoRG-58 IDCS J1426.5+3508 Astronomical events GRB 990123 GRB 080319B SCP 06F6 SN 2003fg SN 2005bc SN 2020tlf Category

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Adapted from the Wikipedia article [OQ 172](https://en.wikipedia.org/wiki/OQ_172) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/OQ_172?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.