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3C 395

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3C 395
The quasar 3C 395.
Observation data (J2000.0 epoch)
ConstellationLyra
Right ascension19h 02m 55.9389s
Declination+31° 59′ 41.702″
Redshift0.635000
Heliocentric radial velocity190,368 km/s
Distance5.746 Gly
Apparent magnitude (V)17.5
Characteristics
TypeSy 1.5, FSRQ
Other designations
4C 31.52, NRAO 592, LEDA 2817714, QSO B1901+319, WMAP 34, 2MASS J19025610+3159439, 2MASSI J1902561+315943, DA 470

3C 395 is a quasar located in the constellation of Lyra. The redshift of the object is (z) 0.635[1] and it was first documented in a Fourth Cambridge Survey in 1966, designated as 4C 31.52.[2] This is a known quasar with a complex radio structure, classified as a superluminal source.[3][4][5]

Description

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The structure of the source in 3C 395 is asymmetrical. When imaged on milliarcseconds (mas), it is shown to be resolved into two individual components, each having an equal intensity of 0.8 Jansky but separated by 15.9 mas. Further evidence also pointed one of the components is found have a steep spectrum index, making its symmetry reversed.[3] A newer observation conducted by Very Long Baseline Interferometry (VLBI) in 1994, showed the component is very variable, exhibiting a flux density at 5 GHz between 1978 and 1986.[6] MERLIN observations at 6 centimeters found an extended radio core with a jet-like structure extending both north and north-west.[7]

Centi-arcseconds observations, found there is a presence of an extended structure located at a 102° position angle. There is radio emission present in the structure at the distance of 84 mas.[8] It is also suggested 3C 395 is implied to be a radio galaxy with a double radio source and two superimposed radio lobes.[9]

The jet of 3C 395 as a whole, is straight and extended by 15 mas eastwards.[10] When probed deeply, it has an inner jet component found displaying a sharp bend from the core region, connecting with its compact structure by the emission.[11] This inner jet, described as being one-sided, is also found to be polarized by 1.5% with its average Faraday rotation measure gradient of 300 rad m−2.[12][10]

A tertiary weak component was discovered between the two components, separated by 1.2 ± 0.3 mas from the core at the position angle of 118°.[13][14] The component is found to have superluminal motion, moving away at a proper motion of 0.64 ± 0.1 mas yr−1.[15] When observed by VLBI, the superluminal component is heading towards the direction of a stationary knot.[16][17]

3C 395 is classified as a blazar. Its long-term optical behavior is shown to increase from 17 to 18.4 magnitude between 1980 and around 1985–1986. However, during the first 6 months in 1985, its magnitude declined by 0.9.[18] In February 2021, gamma-ray emission was shown to be emitted from the object, detected by Large Area Telescope.[19]

References

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  1. ^ Phillips, R. B.; Shaffer, D. B. (August 1983). "VLBI maps of 3C 147, 3C 286, 3C 380, NRAO 150, CTD 93, and 3C 395 at 2.3 GHz". The Astrophysical Journal. 271: 32. Bibcode:1983ApJ...271...32P. doi:10.1086/161173. ISSN 0004-637X.
  2. ^ Long, R. F.; Smith, M. A.; Stewart, P.; Williams, P. J. S. (1966-01-01). "The radio spectra of sources in the fourth Cambridge catalogue". Monthly Notices of the Royal Astronomical Society. 134 (4): 371–388. Bibcode:1966MNRAS.134..371L. doi:10.1093/mnras/134.4.371. ISSN 0035-8711.
  3. ^ a b Johnston, K. J.; Spencer, J. H.; Witzel, A.; Fomalont, E. B. (February 1983). "3C 395 - A quasar with asymmetrical radio structure". The Astrophysical Journal. 265: L43. Bibcode:1983ApJ...265L..43J. doi:10.1086/183955. ISSN 0004-637X.
  4. ^ Simon, R. S.; Hall, J.; Johnston, K. J.; Spencer, J. H.; Waak, J. A. (1986-09-01). "Superluminal Motion in the Quasar 3C 395". Bulletin of the American Astronomical Society. 18: 993.
  5. ^ von Montigny, C.; Bertsch, D. L.; Chiang, J.; Dingus, B. L.; Esposito, J. A.; Fichtel, C. E.; Fierro, J. M.; Hartman, R. C.; Hunter, S. D.; Kanbach, G.; Kniffen, D. A.; Lin, Y. C.; Mayer-Hasselwander, H. A.; Michelson, P. F.; Nolan, P. L. (1995-07-01). "Studies of some superluminal blazars and strong flat-spectrum radio quasars, that are not seen in high energy gamma-rays by EGRET". Astronomy and Astrophysics. 299: 680. Bibcode:1995A&A...299..680V. ISSN 0004-6361.
  6. ^ Lara, L.; Alberdi, A.; Marcaide, J. M.; Muxlow, T. W. B. (1994-05-01). "The quasar 3C395 revisited: new VLBI observations and numerical simulations". Astronomy and Astrophysics. 285: 393–403. Bibcode:1994A&A...285..393L. ISSN 0004-6361.
  7. ^ Saikia, D. J.; Muxlow, T. W. B.; Junor, W. (1990-07-01). "MERLIN observations of the unusual superluminal quasar 3C 395". Monthly Notices of the Royal Astronomical Society. 245: 503. Bibcode:1990MNRAS.245..503S. ISSN 0035-8711.
  8. ^ Altschuler, D. R.; Gurvits, L. I.; Alef, W.; Dennison, B.; Graham, D.; Trotter, A. S.; Carson, J. E. (1995-12-01). "The centi-arcsecond structure of 16 low-frequency variable sources at 92 cm". Astronomy and Astrophysics Supplement Series. 114: 197. Bibcode:1995A&AS..114..197A. ISSN 0365-0138.
  9. ^ Lara, L.; Muxlow, T. W. B.; Alberdi, A.; Marcaide, J. M.; Junor, W.; Saikia, D. J. (1997-03-01). "Radio observations of the quasar 3C 395 from parsec to kiloparsec scales". Astronomy and Astrophysics. 319: 405–412. Bibcode:1997A&A...319..405L. ISSN 0004-6361.
  10. ^ a b Taylor, Gregory B. (2000-04-10). "Magnetic Fields in Quasar Cores. II". The Astrophysical Journal. 533 (1): 95–105. arXiv:astro-ph/9911414. Bibcode:2000ApJ...533...95T. doi:10.1086/308666. ISSN 0004-637X.
  11. ^ Lara, L.; Alberdi, A.; Marcaide, J. M.; Muxlow, T. W. B. (1999-12-01). "Space-VLBI observations of the twisted jet in 3C 395". Astronomy and Astrophysics. 352: 443–446. arXiv:astro-ph/9911084. Bibcode:1999A&A...352..443L. ISSN 0004-6361.
  12. ^ Lara, L.; Alberdi, A.; Marcaide, J. M. (2001-03-01). "Variability and polarization in the inner jet of 3C 395" (PDF). Astronomy & Astrophysics. 368 (3): 817–823. arXiv:astro-ph/0101325. Bibcode:2001A&A...368..817L. doi:10.1051/0004-6361:20010059. ISSN 0004-6361.
  13. ^ Lara, L.; Marcaide, J. M.; Alberdi, A.; Guirado, J. C. (1996-10-01). "VLBI differential astrometry at large angular separation: 3C 395 - 3C 382". Astronomy and Astrophysics. 314: 672–678. Bibcode:1996A&A...314..672L. ISSN 0004-6361.
  14. ^ Waak, J. A.; Spencer, J. H.; Johnston, K. J.; Simon, R. S. (October 1985). "Superluminal resupply of a stationary hot SPOT in 3C 395?". The Astronomical Journal. 90: 1989. Bibcode:1985AJ.....90.1989W. doi:10.1086/113902. ISSN 0004-6256.
  15. ^ Simon, R. S.; Johnston, K. J.; Spencer, J. H. (1988-01-01). "Recent Observations and Superluminal Monitoring of the Quasar 3c 395". The Impact of VLBI on Astrophysics and Geophysics; Proceedings of the 129th IAU Symposium, Cambridge, MA, May 10–15, 1987. 129: 21. Bibcode:1988IAUS..129...21S.
  16. ^ Simon, R. S.; Hall, J.; Johnston, K. J.; Spencer, J. H.; Waak, J. A.; Mutel, R. L. (March 1988). "Superluminal motion toward a stationary knot in the radio core of the quasar 3C 395". The Astrophysical Journal. 326: L5. Bibcode:1988ApJ...326L...5S. doi:10.1086/185111. ISSN 0004-637X.
  17. ^ Spencer, J. H.; Waak, J. A.; Johnston, K. J.; Simon, R. S. (1984-09-01). "Superluminal Resupply of a Radio Lobe in 3C395". Bulletin of the American Astronomical Society. 16: 956. Bibcode:1984BAAS...16..956S.
  18. ^ Pica, Andrew J.; Smith, Alex G.; Webb, James R.; Leacock, Robert J.; Clements, Sandra; Gombola, Paul P. (1988-10-01). "Long-Term Optical Behavior of 144 Compact Extragalactic Objects: 1969-1988". The Astronomical Journal. 96: 1215. Bibcode:1988AJ.....96.1215P. doi:10.1086/114875. ISSN 0004-6256.
  19. ^ Giroletti, M.; Angioni, R.; Cheung, C. C. (2021-02-01). "Fermi-LAT detection of a new gamma-ray source associated with the quasar 3C 395". The Astronomer's Telegram. 14383: 1. Bibcode:2021ATel14383....1G.
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