NGC 2997

NGC 2997 is a face-on unbarred spiral galaxy about 40[3] million light-years away in the faint southern constellation of Antlia.[3] It was discovered March 4, 1793 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "a remarkable object, very faint, very large, very gradually then very suddenly bright middle and 4 arcsec nucleus.[7] This is the brightest galaxy of the NGC 2997 group of galaxies, and was featured on the cover of the first edition of Galactic Dynamics by James Binney and Scott Tremaine.[8]

NGC 2997
NGC 2997
Observation data (J2000 epoch)
ConstellationAntlia
Right ascension09h 45m 38.75379s[1]
Declination−31° 11′ 27.3570″[1]
Helio radial velocity1,088±2 km/s[2]
Distance39.8 megalight-years (12.2 Mpc)[3]
Group or clusterNGC 2997 group
Apparent magnitude (V)10.1[2]
Characteristics
TypeSAB(rs)c[4] or Sc(s)I.3[5]
Apparent size (V)8′.9 × 6′.8[2]
Other designations
ESO 434-35, NGC 2997,[6] PGC 27978[2]

This is a grand-design galaxy with a symmetrical, two-armed form.[5] The morphological classification of NGC 2997 is SAB(rs)c,[4] indicating a weakly-barred spiral galaxy (SAB) with an incomplete ring around the bar (rs) and loosely-wound spiral arms (c). It is inclined at an angle of 40° to the line of sight from the Earth, with the major axis aligned along a position angle of 110°.[9] The arms host a series of dusty knots that are star-forming regions being generated through gas compression from density waves.[5] At the core, the arms converge to form a circumnuclear ring with symmetrically-placed hot spots containing super star clusters.[4]

A pair of supernova events have been detected in the proximity of this galaxy. CCD images taken October 24, 2003 revealed supernova SN 2003jg, positioned 11″ east and 6″ north of the galactic nucleus.[10] This was determined to be a Type Ib/c supernova.[11] Supernova SN 2008eh was reported on July 21, 2008, reaching magnitude 15.0. It was positioned 123″ east and 34″ north of the galactic core.[12]

See also

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. "NASA/IPAC Extragalactic Database". Results for NGC 2997. Retrieved 2006-11-25.
  3. Hess, K. M.; et al. (2009). "Anomalous HI in NGC 2997". The Astrophysical Journal. 699 (1): 76–88. arXiv:0904.3494v1. Bibcode:2009ApJ...699...76H. doi:10.1088/0004-637X/699/1/76.
  4. Elmegreen, Debra Meloy; et al. (August 1999). "Near-Infrared Observations of Hot Spots in the Circumnuclear Rings of NGC 2997 and NGC 6951". The Astronomical Journal. 118 (2): 777–784. Bibcode:1999AJ....118..777E. doi:10.1086/300970.
  5. Grosbøl, P.; Dottori, H. (June 2009). "Pattern speed of main spiral arms in NGC 2997. Estimate based on very young stellar complexes". Astronomy and Astrophysics. 499 (3): L21–L24. Bibcode:2009A&A...499L..21G. doi:10.1051/0004-6361/200911805.
  6. "NGC 2997". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-09-15.
  7. Seligman, Courtney. "NGC Objects: NGC 2950 - 2999". Celestial Atlas. Retrieved 2016-03-01.
  8. Binney, J.; Tremaine, S. "Galactic Dynamics". Princeton University Press. Archived from the original on 2007-04-20. Retrieved 2007-04-09.
  9. Ho, I. -Ting; et al. (October 2018). "Azimuthal variations of gas-phase oxygen abundance in NGC 2997". Astronomy & Astrophysics. 618: 13. arXiv:1807.02043. Bibcode:2018A&A...618A..64H. doi:10.1051/0004-6361/201833262. A64.
  10. Martin, R.; Biggs, J. (October 2003). Green, D. W. E. (ed.). "Supernova 2003jg in NGC 2997". IAU Circulars. 8235: 1. Bibcode:2003IAUC.8235....1M.
  11. Kuncarayakti, H.; et al. (May 2018). "Constraints on core-collapse supernova progenitors from explosion site integral field spectroscopy". Astronomy & Astrophysics. 613: 18. arXiv:1711.05765. Bibcode:2018A&A...613A..35K. doi:10.1051/0004-6361/201731923. A35.
  12. Monard, L. A. G. (July 2008). Green, D. W. E. (ed.). "Supernova 2008eh in NGC 2997". Central Bureau Electronic Telegrams. 1445: 1. Bibcode:2008CBET.1445....1M.

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