NGC 7421
| NGC 7421 | |
|---|---|
 Legacy Surveys DR10 image of NGC 7421 | |
| Observation data (J2000epoch) | |
| Constellation | Grus |
| Right ascension | 22h56m54.353s[1] |
| Declination | −37° 20′ 50.44″[1] |
| Distance | 81.6Mly(25.01Mpc)[2] |
| Apparent magnitude(V) | 12.0[3] |
| Characteristics | |
| Type | SB(rs)bc[4] |
| Mass | 20.9×109[5]M☉ |
| Apparent size(V) | 2.2′[3] |
| Other designations | |
| NGC7421,LEDA70083,MCG-06-50-015[6] | |
NGC 7421is abarred spiral galaxyin the southernconstellationofGrus.It was discovered by English astronomerJohn Herschelon August 30, 1834.[7]In Danish astronomerJ. L. E. Dreyer'sNew General Catalogueof Nebulae and Clusters of Starsit was described as: considerably bright, large, very little extended, gradually pretty much brighter middle, and partially resolved.[3]NGC 7421 is located at an estimated distance of 81.6 millionlight-years(25.01Mpc) from the Sun.[2]It is a member of theIC 1459galaxy group.[5]
In theThird Reference Catalogue of Bright Galaxies,NGC 7421 was assigned amorphological classificationof SB(rs)bc, which indicates abarred spiral galaxy(SB) with a transitional ring structure (rs) and moderately woundspiral arms(bc).[4]Thegalactic planeis inclined at an angle of 36.2° to theplane of the sky,with the major axis aligned along aposition angleof 80.6°. It displays an asymmetric morphology, which shows up in a lopsided optical appearance and in the distribution ofCOandneutral hydrogenatoms. New stars are forming at a rate of0.274±0.041M☉·yr−1.The gas fraction and star formation rate is significantly lower than normal, suggesting an interaction with the external environment.[5]
The western boundary of this galaxy resembles abow shockthat suggests an interaction with the intracluster medium. Radio mapping of neutral hydrogen by theATCAdisplays an extended wake to the north and south of the galaxy, supporting this hypothesis.[8]A pasttidal interactionmay be needed to explain the asymmetry of this galaxy. A candidate galaxy isNGC 7418,which is located at anangular separationof~20′.However, there are notidal tailsvisible from such an encounter.[9]The total mass of the neutral hydrogen in this galaxy is1.5×109M☉.[8]
Thetype II supernovaSN 2023abdgwas observed in association with this galaxy. It was discovered on December 12, 2023, byATLAS.[10]
See also
[edit]References
[edit]- ^abBrown, A. G. A.;et al. (Gaia collaboration) (2021)."GaiaEarly Data Release 3: Summary of the contents and survey properties ".Astronomy & Astrophysics.649:A1.arXiv:2012.01533.Bibcode:2021A&A...649A...1G.doi:10.1051/0004-6361/202039657.S2CID227254300.(Erratum:doi:10.1051/0004-6361/202039657e).Gaia EDR3 record for this sourceatVizieR.
- ^abCrook, 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,S2CID11672751.
- ^abcFrommert, Hartmut,"NGC 7421",Students for the Exploration and Development of Space,retrieved2024-02-05.
- ^abDe Vaucouleurs, Gerard; et al. (1991),Third Reference Catalogue of Bright Galaxies,3.9,Bibcode:1991rc3..book.....D.
- ^abcLee, Bumhyun; et al. (September 2022), "ALMA/ACA CO Survey of the IC 1459 and NGC 4636 Groups: Environmental Effects on the Molecular Gas of Group Galaxies",The Astrophysical Journal Supplement Series,262(1), id. 31,arXiv:2204.06022,Bibcode:2022ApJS..262...31L,doi:10.3847/1538-4365/ac7eba.
- ^"NGC 7421".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2024-02-01.
- ^Seligman, Courtney,"NGC Objects: NGC 7400 - 7449",Celestial Atlas,retrieved2024-02-05.
- ^abRyder, Stuart D.; et al. (April 1997), "NGC 7421: Surfing the Intracluster Medium?",Publications of the Astronomical Society of Australia,14(1): 81–84,Bibcode:1997PASA...14...81R,doi:10.1071/AS97081.
- ^abRyder, S. D.; et al. (2000), Combes, Francoise; et al. (eds.), "The Interaction of NGC 7421 with the Intracluster Medium",Dynamics of Galaxies: from the Early Universe to the Present, 15th IAP meeting held in Paris, France, July 9–13, 1999,ASP Conference Series, vol. 197, pp. 405–406,Bibcode:2000ASPC..197..405R.
- ^"SN 2023abdg",Transient Name Server,retrieved2024-02-04.
