3C 380

3C 380
The quasar 3C 380.
Observation data (J2000.0 epoch)
Constellation	Draco
Right ascension	18^h 29^m 31.7809^s
Declination	+48° 44′ 46.161″
Redshift	0.6920000
Heliocentric radial velocity	207,456 km/s
Distance	6.074 Gly
Apparent magnitude (V)	16.81
Apparent magnitude (B)	17.05
Characteristics
Type	Opt. var, Sy 1.5, LPQ
Other designations
CTA 79, NRAO 565, LEDA 2817708, QSO B1828+4842, 4C +48.46, S4 1828+487, WK 396, WMAP 46,

3C 380 is a radio-loud quasar located in the constellation of Draco.[1][2] First discovered in 1965 and identified with a starlike object,[3][4] it is one of the luminous and powerful radio sources in Third Cambridge Catalogue, with a redshift of (z) 0.692 and a compact steep spectrum (CSS) source.[5][6][7]

Description

3C 380 contains a complex radio structure. Radio images produced by the very long baseline interferometry (VLBI) at 5 GHz, showed the source is mainly extended, containing several components including a compact radio core and a ridge of extended radio emission.[8][9] In additional, the quasar also has a diffused halo with a spectral index of 1.0 ± 0.2 which represents a common feature of the radio lobes in Fanaroff-Riley class II quasars.[6] An extended radio lobe was also discovered in 3C 380, having a low spectral index when compared to those at decimeter wavelengths.[10] There are also two hotpots located in northwest direction.[11]

The radio jet of 3C 380 on parsec-scales is known to be bent. Based on VLBI observations, it is shown to be resolved when travelling in a transverse direction, however it also shows signs of rapid brightness variations unlike other nuclear jets indicating phase effects play a role in causing these changes. Apart from that, the jet shows superluminal motion[12] and a Faraday rotation gradient measuring 70-200 parsecs in width across it.[13] Radio imaging Very Long Baseline Array (VLBA) also finds the jet is extending in a northwest direction.[14]

According to Hubble Space Telescope (HST) and VLBA, the jet has two knots. These knots are respectively named as knot 1, located 0.73 arcseconds from the core and knot 2 which is located 0.4 arcseconds away from the former. Together, these knots are found laid over lobelike emission which in turn, is stretched out in both east and northeast directions.[15]

Multifrequency polarization have also been found in 3C 380. Based on observations, both the core and jet contains polarization by 6 percent, while the other component has 16 percent polarization.[16] Enhanced flux density at 24 GHz from the object was also detected in September 2020.[17]

References

1. Gulati, Sanna; Bhattacharya, Debbijoy; Sreekumar, P. (November 2024). "Constraining the Location of the γ-Ray Emission Region in Radio-loud AGN 3C 380". The Astrophysical Journal. 977 (1): 9. Bibcode:2024ApJ...977....9G. doi:10.3847/1538-4357/ad891e. ISSN 0004-637X.
2. Koyama, Shoko; Kino, Motoki; Nagai, Hiroshi; Hada, Kazuhiro; Kameno, Seiji; Kobayashi, Hideyuki (2013-04-25). "VLBI Imagings of a Kilo-Parsec Knot in 3C 380". Publications of the Astronomical Society of Japan. 65 (2): 29. arXiv:1211.6124. doi:10.1093/pasj/65.2.29. ISSN 0004-6264.
3. Sandage, Allan; Wyndham, John D. (January 1965). "On the Optical Identification of Eleven New Quasi-Stellar Radio Sources". The Astrophysical Journal. 141: 328. Bibcode:1965ApJ...141..328S. doi:10.1086/148125. ISSN 0004-637X.
4. Burbidge, E. Margaret (1965-11-01). "Redshifts of the Quasi-Stellar Radio Sources 3c 334, 3c 345, 3c 380, and a Discussion of the Possible Redshift of 3c 446". The Astrophysical Journal. 142: 1674. Bibcode:1965ApJ...142.1674B. doi:10.1086/148459. ISSN 0004-637X.
5. Taylor, Gregory B. (1998-10-20). "Magnetic Fields in Quasar Cores". The Astrophysical Journal. 506 (2): 637–646. Bibcode:1998ApJ...506..637T. doi:10.1086/306286. ISSN 0004-637X.
6. Wilkinson, P. N.; Akujor, Chidi E.; Cornwell, T. J.; Saikia, D. J. (1991-01-01). "3C 380 : a powerful radio source seen end-on ?". Monthly Notices of the Royal Astronomical Society. 248: 86–90. doi:10.1093/mnras/248.1.86. ISSN 0035-8711.
7. Kameno, Seiji; Inoue, Makoto; Fujisawa, Kenta; Shen, Zhi-Qiang; Wajima, Kiyoaki (2000-12-01). "First-Epoch VSOP Observation of 3C 380: Kinematics of the Parsec-Scale Jet". Publications of the Astronomical Society of Japan. 52 (6): 1045–L1053. doi:10.1093/pasj/52.6.1045. ISSN 0004-6264.
8. Pearson, T. J.; Readhead, A. C. S. (May 1988). "The milliarcsecond structure of a complete sample of radio sources. II - First-epoch maps at 5 GHz". The Astrophysical Journal. 328: 114. Bibcode:1988ApJ...328..114P. doi:10.1086/166274. ISSN 0004-637X.
9. Pearson, T. J.; Readhead, A. C. S.; Perley, R. A. (May 1985). "Compact radio sources in the 3C catalog". The Astronomical Journal. 90: 738. Bibcode:1985AJ.....90..738P. doi:10.1086/113782. ISSN 0004-6256.
10. Megn, A. V.; Rashkovskiĭ, S. L.; Shepelev, V. A.; Inyutin, G. A.; Brazhenko, A. I.; Bulatsen, V. G.; Vashchishin, R. V.; Koshevoĭ, V. V.; Lozinskiĭ, A. B.; Kassim, N. E. (2006-09-01). "Extended component in the quasar 3C 380". Astronomy Reports. 50 (9): 692–698. Bibcode:2006ARep...50..692M. doi:10.1134/S1063772906090022. ISSN 1063-7729.
11. de Vries, W. H.; O'Dea, C. P.; Baum, S. A.; Sparks, W. B.; Biretta, J.; de Koff, S.; Golombek, D.; Lehnert, M. D.; Macchetto, F.; McCarthy, P.; Miley, G. K. (June 1997). "Hubble Space Telescope Imaging of Compact Steep Spectrum Radio Sources". The Astrophysical Journal Supplement Series. 110 (2): 191–211. Bibcode:1997ApJS..110..191D. doi:10.1086/313001. ISSN 0067-0049.
12. Polatidis, A. G.; Wilkinson, P. N. (1998-02-21). "Superluminal motion in the parsec-scale jet in 3C 380". Monthly Notices of the Royal Astronomical Society. 294 (2): 327–337. doi:10.1111/j.1365-8711.1998.01246.x. ISSN 0035-8711.
13. Gabuzda, D. C.; Cantwell, T. M.; Cawthorne, T. V. (2014-02-01). "Magnetic field structure of the extended 3C 380 jet". Monthly Notices of the Royal Astronomical Society. 438 (1): L1 – L5. Bibcode:2014MNRAS.438L...1G. doi:10.1093/mnrasl/slt129. hdl:10468/4956. ISSN 0035-8711.
14. Zensus, J. A.; Ros, E.; Kellermann, K. I.; Cohen, M. H.; Vermeulen, R. C.; Kadler, M. (August 2002). "Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei. II. Additional Sources". The Astronomical Journal. 124 (2): 662–674. arXiv:astro-ph/0205076. Bibcode:2002AJ....124..662Z. doi:10.1086/341585. ISSN 0004-6256.
15. O'Dea, Christopher P.; de Vries, Willem; Biretta, John A.; Baum, Stefi A. (March 1999). "Hubble Space Telescope and VLA Observations of Two Optical Continuum Knots in the Jet of 3C 380". The Astronomical Journal. 117 (3): 1143–1150. Bibcode:1999AJ....117.1143O. doi:10.1086/300758. ISSN 0004-6256.
16. Ludke, E.; Garrington, S. T.; Spencer, R. E.; Akujor, C. E.; Muxlow, T. W. B.; Sanghera, H. S.; Fanti, C. (1998-09-01). "MERLIN polarization observations of compact steep-spectrum sources at 5 GHz". Monthly Notices of the Royal Astronomical Society. 299 (2): 467–478. Bibcode:1998MNRAS.299..467L. doi:10.1046/j.1365-8711.1998.01843.x. ISSN 0035-8711.
17. Marchili, N.; Righini, S.; Giroletti, M.; Egron, E.; Perrodin, D.; Grandi, P.; Torresi, E. (2020-09-01). "Enhanced 24 GHz flux density from 3C 380". The Astronomer's Telegram. 14012: 1. Bibcode:2020ATel14012....1M.

External links

• 3C 380 on SIMBAD
• 3C 380 on NASA/IPAC Database