NGC 3169

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] It is a member of the NGC 3166 Group of galaxies, which is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster.^[8]

NGC 3169
NGC 3169 by Hubble Space Telescope
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]
Heliocentric radial velocity	+1,232[3] km/s
Distance	57 Mly (17.43 Mpc)[3]
Apparent magnitude (V)	10.3
Characteristics
Type	SA(s)a pec[4]
Apparent size (V)	4.2′ × 2.9′
Other designations
UGC 5525, PGC 29855[4]

This is a LINER 2 galaxy that displays an extended emission of X-rays in the region of the nucleus.^[9] A hard X-ray source at the center most likely indicates an active galactic nucleus.^[10] 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]

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.^[11] 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]

Supernovae

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.^[12] A second supernova was discovered in 2003: SN 2003 cg (type Ia, mag. 14.4).^[13][14]

References

1. Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331.
2. De Vaucouleurs, G.; De Vaucouleurs, A.; Corwin, H. G. Jr.; Buta, R. J.; Paturel, G.; Fouque, P. (1991), Third Reference Catalogue of Bright Galaxies, 3.9.
3. Crook, Aidan C.; et al. (February 2007), "Groups of Galaxies in the Two Micron All Sky Redshift Survey", The Astrophysical Journal, 655 (2): 790–813, arXiv:astro-ph/0610732, Bibcode:2007ApJ...655..790C, doi:10.1086/510201, S2CID 11672751.
4. "NED results for object NGC 3169", NASA/IPAC Extragalactic Database, NASA, retrieved 2013-05-30.
5. 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): 534–544, Bibcode:2006AstL...32..534S, CiteSeerX 10.1.1.515.4412, doi:10.1134/S1063773706080044, S2CID 53956086.
6. Buta, Ronald J.; et al. (2007), Atlas of Galaxies, Cambridge University Press, pp. 13–17, ISBN 978-0521820486.
7. Haynes, M. P. (August 1981), "Neutral hydrogen streams in groups of galaxies. I - Observations", Astronomical Journal, 86: 1126–1154, Bibcode:1981AJ.....86.1126H, doi:10.1086/112993.
8. "The Leo III Groups". Atlas of the Universe. Archived from the original on July 22, 2012. Retrieved 2010-11-27.
9. 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, S2CID 16047866.
10. Mathur, Smita; et al. (October 2008), "AIP Conference Proceedings", American Institute of Physics Conference Series, 1053: 43–49, arXiv:0807.0422, Bibcode:2008AIPC.1053...43M, doi:10.1063/1.3009521, S2CID 118424765.
11. Drory, Niv; Fisher, David B. (August 2007), "A Connection between Bulge Properties and the Bimodality of Galaxies", The Astrophysical Journal, 662 (2): 640–649, arXiv:0705.0973, Bibcode:2007ApJ...664..640D, doi:10.1086/519441, S2CID 17999271.
12. 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: 112–115, Bibcode:1987PASP...99..112H, doi:10.1086/131962.
13. 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): 1880–1900, arXiv:astro-ph/0603316, Bibcode:2006MNRAS.369.1880E, doi:10.1111/j.1365-2966.2006.10430.x, S2CID 15108977.
14. Transient Name Server entry for SN 2003cg. Retrieved 29 March 2023.

External links

• APOD: NGC 3169 and NGC 3166 (02/28/2004) Archived 2015-05-11 at the Wayback Machine
• ADS: Supernova 2003cg in NGC 3169
• SEDS: NGC3169
• NGC 3169 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images