3C 309.1 is a quasar[1] located in the constellation of Ursa Minor. It has a redshift (z) of 0.90[2] and was first identified as an astronomical radio source from the Third Cambridge Catalogue of Radio Sources by in 1966.[3] This object contains a compact steep spectrum (CSS) source,[4] and classified as one of the most brightest and largest of its kind.[2][5]

3C 309.1
The quasar 3C 309.1.
Observation data (J2000.0 epoch)
ConstellationUrsa Minor
Right ascension14h 59m 07.583s
Declination+71° 40′ 19.867″
Redshift0.901113
Heliocentric radial velocity270,147 km/s
Distance7.665 Gly
Apparent magnitude (V)16.78
Apparent magnitude (B)17.24
Characteristics
TypeCSS
Other designations
LEDA 2821824, 4C 71.15, WMAP 071, QSO B1458+718, 2E 3367, NRAO 464, 1Jy 1458+718

Description

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3C 309.1 has a triple radio structure. It has a radio core found self-absorbed with an extended position angle of 162° ± 2°. On both sides of the core, there are two relatively extended outer radio lobes having a defined positional angle of 90°.[6]

In sub-arcsecond resolutions, the structure is made up of several components. Three of them are aligned east–west while the others are located along the path of extended emission in south direction, clearly detected by two X-ray images. In two of the brightest components, there are presence of polarized emission.[7] However, when viewed in at a 5 GHz milliarcsecond resolution, a bright core is found instead straddled by two other weaker components with a separation of 8.7 kiloparsecs.[8] Sub-milliarcsecond imaging shows the core to be compact with a more extended component located 20 mas to the south.[9]

The jet of 3C 309.1 is one-sided. It is found to be flaring away from the nucleus with a sharp change in brightness, likely caused through various Kelvin-Helmholtz instabilities in confined fluid flow and pressure being exerted in confined medium.[10] In Very Long Baseline Interferometry radio imaging, the jet is shown to extend from core southwards with a distance of 260 parsecs (60 mas). At eastwards, it bends at 90° before fading rapidly.[8] Furthermore, the jet is found extremely polarized.[11][12]

The host galaxy of 3C 309.1 is a flat elliptical galaxy according to Hubble Space Telescope imaging. It has a major axis orientated along the position angle of 130°.[13] Extensive emission-line gas is also seen surrounding the object at high pressure, with a massive cooling rate exceeding 1000 Mʘ yr−1 implying its host galaxy might have been formed within a Hubble time.[14]

References

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  1. ^ Simon, R. S. (1983-09-01). "High Resolution Maps of the Quasars 3C48, 3C147, 3C309.1, 3C380, and 3C454.3 Using 90cm VLBI". Bulletin of the American Astronomical Society. 15: 976.
  2. ^ a b Aaron, Scott E.; Wardle, John F.C.; Roberts, David H. (1998). "A Multi-Frequency VLBI Polarization Study of the CSS Quasar 3C 309.1". International Astronomical Union Colloquium. 164: 105–106. doi:10.1017/s0252921100044729. ISSN 0252-9211.
  3. ^ Véron, P. (June 1966). "Optical Positions for Radio Sources in the 3c Revised Catalogue". The Astrophysical Journal. 144: 861. doi:10.1086/148682. ISSN 0004-637X.
  4. ^ Gawronski, Marcin; Kus, Andrzej J. (2007-11-22). "Multi-frequency VSOP and VLBI observations of the quasar 3C309.1" (PDF). Proceedings of 8th European VLBI Network Symposium — PoS(8thEVN). Trieste, Italy: Sissa Medialab: 020. doi:10.22323/1.036.0020.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  5. ^ "3C 309.1 | Image Gallery | Brandeis Radio Astronomy Group | Brandeis University". www.brandeis.edu. Retrieved 2024-11-17.
  6. ^ Kus, A. J.; Wilkinson, P. N.; Booth, R. S. (1981-03-01). "The radio structure of 3C 309.1 determined by multi-baseline interferometry". Monthly Notices of the Royal Astronomical Society. 194 (3): 527–535. doi:10.1093/mnras/194.3.527. ISSN 0035-8711.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  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" (PDF). Astronomy & Astrophysics. 555: A4. doi:10.1051/0004-6361/201220769. ISSN 0004-6361.
  8. ^ a b 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. doi:10.1086/166274. ISSN 0004-637X.
  9. ^ 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. doi:10.1086/341585. ISSN 0004-6256.
  10. ^ Wilkinson, P.N.; Kus, A.J.; Pearson, T.J.; Readhead, A.C.S.; Cornwell, T.J. (1986). "The Nuclear Jets in 3c 309.1 and 3c 380". International Astronomical Union.
  11. ^ Akujor, C.E.; Garrington, S.T. (1995). "Compact steep-spectrum sources - polarisation observations at 1.6, 4.9, 8.4 and 15 GHz". Astronomy and Astrophysics Supplement. 112: 235–255.
  12. ^ 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. doi:10.1046/j.1365-8711.1998.01843.x. ISSN 0035-8711.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  13. ^ Lehnert, Matthew D.; Miley, George K.; Sparks, William B.; Baum, Stefi A.; Biretta, John; Golombek, Daniel; de Koff, Sigrid; Macchetto, Ferdinando D.; McCarthy, Patrick J. (August 1999). "Hubble Space Telescope – Snapshot Survey of 3CR Quasars: The Data". The Astrophysical Journal Supplement Series. 123 (2): 351–376. doi:10.1086/313239. ISSN 0067-0049.
  14. ^ Forbes, D. A.; Crawford, C. S.; Fabian, A. C.; Johnstone, R. M. (1990-06-01). "Extended emission-line gas around the quasars 3C 254 and 3C 309.1 . Very massive cooling flows". Monthly Notices of the Royal Astronomical Society. 244: 680. ISSN 0035-8711.
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