NGC 3169

NGC 3169

NGC 3169 by HST; 2.85′ × 1.68′ view
Observation data (J2000 epoch)
Constellation Sextans
Right ascension 10h 14m 15.099s[1]
Declination +03° 27′ 58.03″[1]
Redshift +0.004113 ± 0.000017[2]
Helio radial velocity +1,232[3] km/s
Distance 400.000 Mly (17.43 Mpc)[3]
Type SA(s)a pec[4]
Apparent dimensions (V) 4.2′ × 2.9′
Apparent magnitude (V) 10.3
Other designations
UGC 5525, PGC 29855[4]
This image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile captures the pair of galaxies NGC 3169 (left) and NGC 3166 (right).

NGC 3169 is a spiral galaxy about 75 million light years[3] away in the constellation Sextans. It has the morphological classification SA(s)a pec,[5] which indicates this is a pure, unbarred spiral galaxy with tightly-wound arms and peculiar features.[6] There is an asymmetrical spiral arm and an extended halo around the galaxy.[7]

This is a LINER 2 galaxy that displays an extended emission of X-rays in the region of the nucleus.[8] A hard X-ray source at the center most likely indicates an active galactic nucleus.[9] The stellar population in the nucleus, and a ring at an angular radius of 6″, shows an age of only one billion years and is generally younger than the surrounding stellar population. This suggests that a burst of star formation took place in the nucleus roughly one billion years ago.[5]

In 1984, a Type II-L supernova was discovered in this galaxy. Designated 1984E, the spectrum of this event at maximum light showed prominent balmer lines that indicated the explosion occurred inside a dense shell of hydrogen surrounding the star. This shell was likely created by a strong stellar wind from the progenitor star.[10] A second supernova was discovered in 2003; this time of type 1a. It was designated SN 2003 cg and reached peak magnitude 15.94.[11]

NGC 3169 is located in close physical proximity to NGC 3166, and the two have an estimated separation of around 160 kly (50 kpc). Their interaction is creating a gravitational distortion that has left the disk of NGC 3166 warped.[12] Combined with NGC 3156, the three galaxies form a small group within the larger Leo 1 group. The three are embedded within an extended ring of neutral hydrogen that is centered on NGC 3169.[5]

References

  1. 1 2 Skrutskie, M. F.; et al. (February 2006), "The Two Micron All Sky Survey (2MASS)", The Astronomical Journal 131 (2): 1163–1183, Bibcode:2006AJ....131.1163S, doi:10.1086/498708.
  2. ↑ De Vaucouleurs, G.; De Vaucouleurs, A.; Corwin, Jr., H. G.; Buta, R. J.; Paturel, G.; Fouque, P. (1991), Third Reference Catalogue of Bright Galaxies, 3.9.
  3. 1 2 3 Crook, Aidan C.; et al. (February 2007), "Groups of Galaxies in the Two Micron All Sky Redshift Survey", The Astrophysical Journal 655: 790–813, arXiv:astro-ph/0610732, Bibcode:2007ApJ...655..790C, doi:10.1086/510201.
  4. 1 2 "NED results for object NGC 3169", NASA/IPAC Extragalactic Database (NASA), retrieved 2013-05-30.
  5. 1 2 3 Sil'chenko, O. K.; Afanasiev, V. L. (August 2006), "Central regions of the early-type galaxies in the NGC 3169 group", Astronomy Letters 32 (8), pp. 534–544, Bibcode:2006AstL...32..534S, doi:10.1134/S1063773706080044.
  6. ↑ Buta, Ronald J.; et al. (2007), Atlas of Galaxies, Cambridge University Press, pp. 13–17, ISBN 0521820480.
  7. ↑ Haynes, M. P. (August 1981), "Neutral hydrogen streams in groups of galaxies. I - Observations", Astronomical Journal 86, pp. 1126–1154, Bibcode:1981AJ.....86.1126H, doi:10.1086/112993.
  8. ↑ Terashima, Yuichi; Wilson, Andrew S. (January 2003), "Chandra Snapshot Observations of Low-Luminosity Active Galactic Nuclei with a Compact Radio Source", The Astrophysical Journal 583 (1): 145–158, arXiv:astro-ph/0209607, Bibcode:2003ApJ...583..145T, doi:10.1086/345339.
  9. ↑ Mathur, Smita; et al. (October 2008), "Finding Local Low-mass Supermassive Black Holes", AIP Conference Proceedings 1053, pp. 43–49, arXiv:0807.0422, Bibcode:2008AIPC.1053...43M, doi:10.1063/1.3009521.
  10. ↑ Henry, Richard B. C.; Branch, David (February 1987), "The spectrum of the type II-L supernova 1984E in NGC 3169 Further evidence for a superwind?", Publications of the Astronomical Society of the Pacific 99, pp. 112–115, Bibcode:1987PASP...99..112H, doi:10.1086/131962.
  11. ↑ Elias-Rosa, N.; et al. (July 2006), "Anomalous extinction behaviour towards the Type Ia SN 2003cg", Monthly Notices of the Royal Astronomical Society 369 (4), pp. 1880–1900, arXiv:astro-ph/0603316, Bibcode:2006MNRAS.369.1880E, doi:10.1111/j.1365-2966.2006.10430.x.
  12. ↑ Drory, Niv; Fisher, David B. (August 2007), "A Connection between Bulge Properties and the Bimodality of Galaxies", The Astrophysical Journal 662 (2), pp. 640–649, arXiv:0705.0973, Bibcode:2007ApJ...664..640D, doi:10.1086/519441.

External links

Coordinates: 10h 14m 14.7s, +03° 28′ 01″

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