NGC 1744 is a barred spiral galaxy in the constellation Lepus. The galaxy lies about 30 million light years away from Earth based on redshift independent methods, which means, given its apparent dimensions, that NGC 1744 is approximately 75,000 light years across.[1] It was discovered by John Herschel on November 20, 1835.[3]

Characteristics

NGC 1744 has a narrow bright bar with many knots measuring 1.3 by 0.3 arcminutes across. The spiral arm pattern is asymmetric.[4] The arms have many star forming regions visible in H-alpha. The north and west arms host many HII regions, while the short southeastern arm has a single giant one. Star forming regions are visible along the faint and diffuse arm running from north of the bar southwards.[5] The galaxy is seen with an inclination of 70°.[6]

The appearance of the galaxy in ultraviolet is similar, with open arms and star forming regions.[7] Hydrogen line emission is diffuse, with no discernible spiral pattern although there are some clumps at the locations of large star forming regions, and appears undisturbed.[8] The total hydrogen mass of the galaxy is estimated to be (7.6±0.2)×109 M☉, with no hydrogen emission outside the plane of the disk.[6]

The galaxy has a steep metallicity gradient, probably caused by the presence of the bar, and enhanced star formation there.[9] The total star formation rate is estimated to be 0.15 M☉ per year.[10]

In the nucleus lies a nuclear star cluster which is 3.3 arcseconds across.[11]

Nearby galaxies

NGC 1744 forms a non interacting pair with ESO 486-G021, which lies 58 arcminutes away, which at the distance of NGC 1744 corresponds to a projected distance about 200 kpc (650,000 light years).[6] NGC 1744 has been considered a member of the LGG 127 Group, which also includes NGC 1792 and NGC 1808.[7]

References

  1. ^ a b c d e f g h i j "NASA/IPAC Extragalactic Database". Results for NGC 1744. Retrieved 6 February 2025.
  2. ^ "Revised NGC Data for NGC 1744". spider.seds.org. Retrieved 30 March 2024.
  3. ^ Seligman, Courtney. "NGC 1744 (= PGC 16517)". Celestial Atlas. Retrieved 19 November 2018.
  4. ^ de Vaucouleurs, Gerard Henri; de Vaucouleurs, Antoinette; Shapley, Harlow (1964). Reference catalogue of bright galaxies. Austin: University of Texas Press. Bibcode:1964rcbg.book.....D.
  5. ^ Ryder, Stuart D.; Dopita, Michael A. (October 1993). "An H-alpha atlas of nearby southern spiral galaxies". The Astrophysical Journal Supplement Series. 88: 415. Bibcode:1993ApJS...88..415R. doi:10.1086/191827.
  6. ^ a b c Sardone, Amy; Pisano, D. J.; Pingel, N. M.; Sorgho, A.; Carignan, Claude; de Blok, W. J. G. (1 March 2021). "A Census of the Extended Neutral Hydrogen around 18 MHONGOOSE Galaxies". The Astrophysical Journal. 910 (1): 69. arXiv:2101.07822. Bibcode:2021ApJ...910...69S. doi:10.3847/1538-4357/abde45.
  7. ^ a b Marino, A.; Bianchi, L.; Rampazzo, R.; Buson, L. M.; Bettoni, D. (February 2010). "Galaxy evolution in Local Group analogs: I. A GALEX study of nearby groups dominated by late-type galaxies". Astronomy and Astrophysics. 511: A29. arXiv:0912.4266. Bibcode:2010A&A...511A..29M. doi:10.1051/0004-6361/200913216.
  8. ^ Pisano, D. J.; Wilcots, Eric M.; Elmegreen, Bruce G. (March 1998). "The H [CSC]i[/CSC] Distribution and Dynamics in Two Late-Type Barred Spiral Galaxies: NGC 925 and NGC 1744". The Astronomical Journal. 115 (3): 975–999. doi:10.1086/300239.
  9. ^ Chen(陈千惠), Qian-Hui; Grasha, Kathryn; Battisti, Andrew J; Kewley, Lisa J; Madore, Barry F; Seibert, Mark; Rich, Jeff A; Beaton, Rachael L (17 January 2023). "Metallicity gradient of barred galaxies with TYPHOON". Monthly Notices of the Royal Astronomical Society. 519 (4): 4801–4817. arXiv:2212.10751. doi:10.1093/mnras/stac3790.
  10. ^ Parkash, Vaishali; Brown, Michael J. I.; Jarrett, T. H.; Bonne, Nicolas J. (1 September 2018). "Relationships between Hi Gas Mass, Stellar Mass, and the Star Formation Rate of HICAT+WISE (H i-WISE) Galaxies". The Astrophysical Journal. 864 (1): 40. arXiv:1807.06246. Bibcode:2018ApJ...864...40P. doi:10.3847/1538-4357/aad3b9.
  11. ^ Georgiev, Iskren Y.; Böker, Torsten; Leigh, Nathan; Lützgendorf, Nora; Neumayer, Nadine (1 April 2016). "Masses and scaling relations for nuclear star clusters, and their co-existence with central black holes". Monthly Notices of the Royal Astronomical Society. 457 (2): 2122–2138. arXiv:1601.02613. doi:10.1093/mnras/stw093.
Allikas: https://en.wikipedia.org/wiki/NGC_1744
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