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  • 21 Aug, 2019

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NGC 3945

NGC 3945 is a barred lenticular galaxy in the constellation Ursa Major. It was discovered on March 19, 1790, by the astronomer William Herschel.

NGC 3945 has a complex structure, with two concentric bars and a pseudobulge. Unlike classical bulges which are like miniature elliptical galaxies, pseudobulges have features similar to disk galaxies, including a flattened structure and significant rotation. It is classified as a LINER galaxy. The formation history of NGC 3945 is likely quite complex, with the pseudo-bulge being formed gradually from disk material, while bulges (spheroidal components) would have formed from violent merger events.

Unlike galaxies with similar velocity dispersions and luminosities, the central black hole of NGC 3945 has an unusually low mass, estimated to be around 9×10 M. However, it is also possible that NGC 3945 has no central black hole at all.

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. ^ "NGC 3945". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-05-18.
  3. ^ Dullo, Bililign T.; Martínez-Lombilla, Cristina; Knapen, Johan H. (2016). "Complex central structures suggest complex evolutionary paths for barred S0 galaxies". Monthly Notices of the Royal Astronomical Society. 462 (4): 3800–3811. arXiv:1608.03539. doi:10.1093/mnras/stw1868.
  4. ^ "Search specification: NGC 3945". HyperLeda. Université Claude Bernard Lyon 1. Retrieved 2021-05-18.
  5. ^ Seligman, Courtney. "New General Catalogue objects: NGC 3900 - 3949". cseligman.com. Retrieved 2021-05-18.
  6. ^ Fisher, David B.; Drory, Niv (2008). "The Structure of Classical Bulges and Pseudobulges: The Link Between Pseudobulges and Sérsic Index". The Astronomical Journal. 136 (2): 773–839. arXiv:0805.4206. Bibcode:2008AJ....136..773F. doi:10.1088/0004-6256/136/2/773. S2CID 16126374.
  7. ^ Gültekin, Kayhan; Richstone, Douglas O.; Gebhardt, Karl; Lauer, Tod R.; Pinkney, Jason; Aller, M. C.; Bender, Ralf; Dressler, Alan; Faber, S. M.; Filippenko, Alexei V.; Green, Richard; Ho, Luis C.; Kormendy, John; Siopis, Christos (2009). "A Quintet of Black Hole Mass Determinations". The Astrophysical Journal. 695 (2): 1577–1590. arXiv:0901.4162. Bibcode:2009ApJ...695.1577G. doi:10.1088/0004-637X/695/2/1577. S2CID 14365610.

Media related to NGC 3945 at Wikimedia Commons