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3C 99
3C 99 captured by SDSS
Observation data (J2000.0 epoch)
ConstellationTaurus
Right ascension04h 01m 07.59s[1]
Declination+00° 36′ 32.39″[1]
Redshift0.426000[1]
Heliocentric radial velocity127,712 km/s ± 0[1]
Distance4.625 Gly
Apparent magnitude (V)19.01
Apparent magnitude (B)20.20
Characteristics
TypeN galaxy; HEG Sy2[1]
Size~74,000 ly (22.68 kpc) (estimated)[1]
Other designations
0358+004, LEDA 2817528, 4C +00.14, DA 121, G4Jy 0406, NRAO 0153, NVSS J040107+003633, PAPER J060.29+00.52, OE +097, 2MASS J04010760+0036324, 87GB 035832.9+002802[1]

3C 99 is a Seyfert type 2 galaxy located in the constellation of Taurus. Its redshift is (z) 0.426[1][2] and it was first discovered as an astronomical radio source in 1959 by astronomers.[3] This object has also been designated as PKS 0358+00 in the Parkes Survey[4] and categorized as a high-excitation radio galaxy (HEG)[5] or an N galaxy in literature.[6][7]

Description

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3C 99 is classified as a strong doubled-lobed source and low frequency variable object.[8] It has a radio spectrum that appears as steep. When observed with MERLIN at 408 MHz, it was shown to have two components that are connected via a radio emission bridge.[6] It's active galactic nucleus (AGN) is as radio-loud.[9]

Imaging with Very Long Baseline Interferometry (VLBI), has found both central and eastern components with a total angular resolution of around 11 x 3 milliarcseconds2. There are also emission blob features present inside the central component, with two of them being misaligned with the source's axis. A bright radio component is found, suggesting the central component has a nucleus.[6] The jet region is polarized to a slight degree.[10]

Further studies have confirmed 3C 99 is a compact steep spectrum (CSS) source.[11] When observed on arcsecond scales, the source is found to contain a triple radio structure with further components of asymmetrical positions and of different surface brightness.[12] There is a one-sided radio jet described as straight and collimated, connecting both the core region and hotspot feature on the northeast side. The jet also has a bent appearance and it increases slightly before reaching the hotspot region.[13] The estimated dynamical age of the source is around 4 x 105 years.[11] In the galaxy's optical spectrum, there are narrow permitted lines. An extended emission-line region (EELR) was discovered in 3C 99.[14]

References

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  1. ^ a b c d e f g h "NED Search results for 3C 99". NASA/IPAC Extragalactic Database. Retrieved 2025-12-20.
  2. ^ Massaro, F.; Harris, D. E.; Liuzzo, E.; Orienti, M.; Paladino, R.; Paggi, A.; Tremblay, G. R.; Wilkes, B. J.; Kuraszkiewicz, J.; Baum, S. A.; O'Dea, C. P. (September 2015). "The Chandra Survey of Extragalactic Sources in the 3CR Catalog: X-ray Emission from Nuclei, Jets, and Hotspots in the Chandra Archival Observations". The Astrophysical Journal Supplement Series. 220 (1): 5. arXiv:1609.07145. Bibcode:2015ApJS..220....5M. doi:10.1088/0067-0049/220/1/5. ISSN 0067-0049.
  3. ^ Edge, D. O.; Shakeshaft, J. R.; McAdam, W. B.; Baldwin, J. E.; Archer, S. (1959). "A survey of radio sources at a frequency of 159 Mc/s". Memoirs of the Royal Astronomical Society. 68: 37–60. Bibcode:1959MmRAS..68...37E.
  4. ^ Day, G. A.; Shimmins, A. J.; Ekers, R. D.; Cole, D. J. (February 1966). "The Parkes catalogue of radio sources, declination zone 0° to +20°". Australian Journal of Physics. 19: 35. Bibcode:1966AuJPh..19...35D. doi:10.1071/PH660035 (inactive 20 December 2025). ISSN 0004-9506.{{cite journal}}: CS1 maint: DOI inactive as of December 2025 (link)
  5. ^ Varano, S.; Chiaberge, M.; Macchetto, F. D.; Capetti, A. (December 2004). "The nuclear radio-optical properties of intermediate-redshift FR II radio galaxies and quasars". Astronomy and Astrophysics. 428 (2): 401–408. arXiv:astro-ph/0407307. Bibcode:2004A&A...428..401V. doi:10.1051/0004-6361:20040303. ISSN 0004-6361.
  6. ^ a b c Mantovani, F.; Saikia, D. J.; Browne, I. W. A.; Fanti, R.; Muxlow, T. W. B.; Padrielli, L. (August 1990). "The steep-spectrum low-frequency variable source 3C 99: radio and optical observations". Monthly Notices of the Royal Astronomical Society. 245 (3): 427–433. doi:10.1093/mnras/245.3.427. ISSN 0035-8711.
  7. ^ Smith, H. E.; Spinrad, H.; Hunstead, R. (June 1976). "Spectrophotometric observations of N galaxies at large redshift: PKS 0353+027, 3C 99, 3C 467". The Astrophysical Journal. 206: 345–354. Bibcode:1976ApJ...206..345S. doi:10.1086/154388. ISSN 0004-637X.
  8. ^ Mantovani, F.; Junor, W.; Fanti, R.; Padrielli, L.; Browne, I. W. A.; Muxlow, T. W. B. (July 1992). "Obervations at arcsecond resolution of steep-spectrum sources which vary at low frequencies". Monthly Notices of the Royal Astronomical Society. 257 (2): 353–367. doi:10.1093/mnras/257.2.353. ISSN 0035-8711.
  9. ^ Barvainis, Richard; Lonsdale, Colin (March 1998). "Search for Free-Free Absorption Cutoffs from Tori in Three Type 2 Active Galactic Nuclei". The Astronomical Journal. 115 (3): 885–889. arXiv:astro-ph/9711247. Bibcode:1998AJ....115..885B. doi:10.1086/300262. ISSN 0004-6256.
  10. ^ Mantovani, F.; Junor, W.; Fanti, R.; Padrielli, L.; Saikia, D. J. (November 1997). "VLA polarimetry of compact steep spectrum sources" (PDF). Astronomy and Astrophysics Supplement Series. 125 (3): 573–580. Bibcode:1997A&AS..125..573M. doi:10.1051/aas:1997244. ISSN 0365-0138.
  11. ^ a b Ferrari, C.; Fanti, R.; Mantovani, F. (2001). "Structure and physical characteristics of 3C 99". Memorie della Societa Astronomica Italiana. 72: 95–96. Bibcode:2001MmSAI..72...95F. ISSN 0037-8720.
  12. ^ Mantovani, F.; Junor, W.; Bondi, M.; Cotton, W.; Fanti, R.; Padrielli, L.; Nicolson, G.; Salerno, E. (1997-12-05), Large bent jets in the inner region of CSSs, arXiv:astro-ph/9712084, arXiv:astro-ph/9712084
  13. ^ Mantovani, F.; Fanti, R.; Ferrari, C.; Cotton, W.; Muxlow, T. W. B. (2003-02-01). "Radio asymmetry in 3C 99" (PDF). Astronomy & Astrophysics. 399 (2): 449–456. arXiv:astro-ph/0211318. Bibcode:2003A&A...399..449M. doi:10.1051/0004-6361:20021682. ISSN 0004-6361.
  14. ^ Hes, R.; Barthel, P. D.; Fosbury, R. a. E. (September 1996). "Emission line imaging of 3CR quasars and radio galaxies". Astronomy and Astrophysics. 313: 423–438. Bibcode:1996A&A...313..423H. ISSN 0004-6361.
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