3C 99

3C 99
3C 99 captured by SDSS
Observation data (J2000.0 epoch)
ConstellationTaurus
Right ascension04h 01m 07.59s
Declination+00° 36′ 32.39″
Redshift0.426000
Heliocentric radial velocity127,712 km/s ± 0
Distance4.625 Gly
Apparent magnitude (V)19.01
Apparent magnitude (B)20.20
Characteristics
TypeN galaxy; HEG Sy2
Size~74,000 ly (22.68 kpc) (estimated)
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

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

Description

3C 99 is classified as a strong doubled-lobed source and low frequency variable object. 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. It's active galactic nucleus (AGN) is as radio-loud.

Imaging with Very Long Baseline Interferometry (VLBI), has found both central and eastern components with a total angular resolution of around 11 × 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. The jet region is polarized to a slight degree.

Further studies have confirmed 3C 99 is a compact steep spectrum (CSS) source. 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. 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. The estimated dynamical age of the source is around 4 × 105 years. In the galaxy's optical spectrum, there are narrow permitted lines. An extended emission-line region (EELR) was discovered in 3C 99.

References

  1. 1 2 3 4 5 6 7 8 "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. 1 2 3 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). "Observations 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. 1 2 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
  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.