NGC 1808

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NGC 1808
The Many Layers of NGC 1808 (iotw2320a).jpg
NGC 1808 imaged by the Cerro Tololo Inter-American Observatory
Observation data (J2000 epoch)
Constellation Columba [1]
Right ascension 05h 07m 42.331s [2]
Declination −37° 30′ 45.88″ [2]
Redshift 0.003339 [2]
Distance 41.7 ± 3.9  Mly (12.8 ± 1.2  Mpc) [3]
Group or cluster Dorado Group
Apparent magnitude  (V)9.94 [4]
Apparent magnitude  (B)10.83 [5]
Characteristics
Type (R)SAB(s)a [6]
Size~88,100  ly (27.01  kpc) (estimated) [2]
Apparent size  (V)7′.41 × 3′.39 [7]
Other designations
ESO 305- G 008, IRAS 05059-3734, MCG -06-12-005, PGC 16779 [2]

NGC 1808 is a barred spiral galaxy [3] located in the southern constellation of Columba, about two degrees to the south and east of Gamma Caeli. [1] It was discovered on 10 May 1826 by Scottish astronomer James Dunlop, who described it as a "faint nebula". [8] [9] The galaxy is a member of the NGC 1808 group, which is part of the larger Dorado Group. [8]

Contents

The morphological classification of this galaxy is (R)SAB(s)a, [6] which indicates a spiral galaxy with a weak-bar around the nucleus (SAB), no ring around the bar (s), an outer ring (R), and tightly-wound spiral arms (a). It is inclined by an angle of 57° to the line of sight from the Earth, with the long axis oriented at a position angle of 324°. [3] The disk of gas and stars shows a noticeable warp, and there is a pronounced asymmetry in the distribution of neutral hydrogen and H II regions. [10]

A Hubble Space Telescope image of the center of NGC 1808 (Credit: HST/NASA/ESA) NGC 1808HSTCenter.jpg
A Hubble Space Telescope image of the center of NGC 1808 (Credit: HST/NASA/ESA)

The core region contains a suspected weak active galactic nucleus plus a circumnuclear ring containing star clusters and supernova remnants at a distance of ~280 pc from the center. These form a ring of peculiar "hot spots". [11] It was formerly identified as a possible Seyfert galaxy, [3] but evidence now points to starburst activity in a ~500 pc radius around the center. [12] A probable outflow of gas is directed to the north-east from the nucleus, forming prominent dust lanes. [3] The high level of star formation in this galaxy and the nearby NGC 1792 may indicate a recent, distant tidal interaction between the two. [10]

One supernova has been observed in NGC 1808: SN 1993af (type Ia, mag. 17) was discovered by Marina Wischnjewsky on 15 November 1993 at 220″ east and 94″ north of the galactic nucleus. [13] [14] [15]

See also

References

  1. 1 2 Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 1. Sky Publishing Corporation and the European Space Agency. ISBN   0-933346-84-0.
  2. 1 2 3 4 5 "NASA/IPAC Extragalactic Database". Results for object NGC 1808. Retrieved 2007-04-05.
  3. 1 2 3 4 5 Busch, Gerold; et al. (February 2017). "Star formation and gas flows in the centre of the NUGA galaxy NGC 1808 observed with SINFONI". Astronomy & Astrophysics. 598: 19. arXiv: 1611.07868 . Bibcode:2017A&A...598A..55B. doi:10.1051/0004-6361/201629440. S2CID   118950569. A55.
  4. ↑ Armando, Gil de Paz; et al. (2007). "The GALEX Ultraviolet Atlas of Nearby Galaxies". Astrophysical Journal . 173 (2): 185–255. arXiv: astro-ph/0606440 . Bibcode:2007ApJS..173..185G. doi:10.1086/516636. S2CID   119085482.
  5. ↑ Tully, R. Brent; et al. (August 2016). "Cosmicflows-3". The Astronomical Journal. 152 (2): 21. arXiv: 1605.01765 . Bibcode:2016AJ....152...50T. doi: 10.3847/0004-6256/152/2/50 . S2CID   250737862. 50.
  6. 1 2 Erwin, Peter; Debattista, Victor P. (June 2013). "Peanuts at an angle: detecting and measuring the three-dimensional structure of bars in moderately inclined galaxies". Monthly Notices of the Royal Astronomical Society . 431 (4): 3060–3086. arXiv: 1301.0638 . Bibcode:2013MNRAS.431.3060E. doi: 10.1093/mnras/stt385 .
  7. ↑ Paturel, G.; et al. (December 2003). "HYPERLEDA. I. Identification and designation of galaxies". Astronomy and Astrophysics. 412: 45–55. Bibcode:2003A&A...412...45P. doi: 10.1051/0004-6361:20031411 .
  8. 1 2 O'Meara, Stephen James (2013), Deep-Sky Companions: Southern Gems, Cambridge University Press, p. 116, Bibcode:2013dcsg.book.....O, ISBN   978-1107015012
  9. ↑ Seligman, Courtney. "New General Catalogue Objects: NGC 1808". Celestial Atlas. Retrieved 7 December 2024.
  10. 1 2 Dahlem, M.; et al. (July 2001). "A search for intergalactic H I gas in the NGC 1808 group of galaxies". Astronomy and Astrophysics. 373 (2): 485–493. arXiv: astro-ph/0106050 . Bibcode:2001A&A...373..485D. doi:10.1051/0004-6361:20010614. S2CID   15512721.
  11. ↑ Salak, Dragan; et al. (May 2016). "Gas Dynamics and Outflow in the Barred Starburst Galaxy NGC 1808 Revealed with ALMA". The Astrophysical Journal. 823 (1): 28. arXiv: 1603.05881 . Bibcode:2016ApJ...823...68S. doi: 10.3847/0004-637X/823/1/68 . S2CID   118634377. 68.
  12. ↑ Salak, Dragan; et al. (November 2017). "Evolution of Molecular Clouds in the Superwind Galaxy NGC 1808 Probed by ALMA Observations". The Astrophysical Journal. 849 (2): 20. arXiv: 1710.01829 . Bibcode:2017ApJ...849...90S. doi: 10.3847/1538-4357/aa91cb . S2CID   119456694. 90.
  13. ↑ Hamuy, M.; et al. (November 1993). Green, D. W. E. (ed.). "Supernovae 1993af, 1993ag, 1993ah". IAU Circular (5895): 1. Bibcode:1993IAUC.5895....1H.
  14. ↑ Hamuy, M.; et al. (December 1996). "BVRI Light Curves for 29 Type IA Supernovae". Astronomical Journal. 112: 2408. arXiv: astro-ph/9609064 . Bibcode:1996AJ....112.2408H. doi:10.1086/118192. S2CID   119520520.
  15. ↑ "SN 1993af". Transient Name Server. IAU . Retrieved 7 December 2024.
  16. ↑ "HubbleSite - NewsCenter - Hubble Captures the Heart of Star Birth" . Retrieved 2007-04-05.
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