Astronomy:NGC 7496

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Short description: Galaxy in the constellation Grus
NGC 7496
Hubble Goes Galactic Birdwatching (potw2222a).jpg
NGC 7496 by the Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationGrus
Right ascension 23h 09m 47.3s[1]
Declination−43° 25′ 40.6″[1]
Redshift0.005500 ± 0.000018 [1]
Helio radial velocity1,649 ± 5 km/s[1]
Distance61 Mly (18.7 Mpc)[2]
Apparent magnitude (V)11.1
Characteristics
Type(R':)SB(rs)bc [1]
Apparent size (V)3.3 × 3.0[1]
Notable featuresSeyfert galaxy, starburst galaxy
Other designations
ESO 291- G001, VV 771, MCG -07-47-020, PGC 70588[1]

NGC 7496 is a barred spiral galaxy located in the constellation Grus. It is located at a distance of about 60 million light-years from Earth, which, given its apparent dimensions, means that it is 75,000 light years across. It was discovered by John Herschel on September 5, 1834.[3] It is a type 2 Seyfert galaxy with high star formation rate around the nucleus.[4]

Characteristics

The nucleus of the galaxy has been found to be active and it has been categorised as a type 2 Seyfert galaxy. The nucleus has fairly strong emission lines in the optical wavelengths and an intense source of ultraviolet radiation. The spectrum also revealed the presence of an HII region in the nucleus, indicating the presence of young hot stars. The nucleus is also a source of radio waves.[5] The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole.

NGC 7496 was one of the first galaxies to be examined by the James Webb Space Telescope, in June 2022, as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS)–JWST survey, whose goal was to study star formation and the interstellar medium in nearby galaxies.[6] The mid infrared images revealed filaments and cavities created by the stellar wind of young stars. Imaging of 3.3 μm polycyclic aromatic hydrocarbons (PAH) emission, which is caused the ultraviolet radiation being reprossesed by dust, revealed the presence of 67 candidate star clusters embedded in dust. The age of these clusters was estimated to be less than 2 million years while their mass was estimated to be 104–105 M. Their location was also correlated with H-alpha and CO(2–1) emission.[2]

Clumpy ultraviolet emission has been observed from the spiral arms of the galaxy. Massive stellar complexes are present in the north arm and regions with young stellar complexes are present in the end of both arms. The age of the stars in these complexes is estimated to be less than 200 million years. Photometry in various wavelengths indicates that there is very cold dust in the galaxy.[7]

Nearby galaxies

NGC 7496 is a member of the NGC 7582 galaxy group.[8] Other members of the group include NGC 7552, NGC 7582, NGC 7590, and NGC 7599, which are also known as the Grus Quartet,[9] NGC 7531, NGC 7632, and IC 5325.[8] This group, along with the group centred around IC 1459 form the Grus cloud, a region of elevated galaxy density. The Grus cloud, along with the nearby Pavo-Indus cloud, lies between the Local Supercluster and Pavo–Indus Supercluster.[10]

Gallery

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 "NASA/IPAC Extragalactic Database". Results for NGC 7496. http://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC+7496. 
  2. 2.0 2.1 Rodríguez, M. Jimena; Lee, Janice C.; Whitmore, B. C.; Thilker, David A.; Maschmann, Daniel; Chandar, Rupali; Deger, Sinan; Boquien, Médéric et al. (1 February 2023). "PHANGS–JWST First Results: Dust-embedded Star Clusters in NGC 7496 Selected via 3.3 μm PAH Emission". The Astrophysical Journal Letters 944 (2): L26. doi:10.3847/2041-8213/aca653. 
  3. Seligman, Courtney. "NGC 7496 (= PGC 68165)". https://cseligman.com/text/atlas/ngc74a.htm#7496. 
  4. Schmitt, H. R.; Calzetti, D.; Armus, L.; Giavalisco, M.; Heckman, T. M.; Kennicutt, Jr., R. C.; Leitherer, C.; Meurer, G. R. (May 2006). "Multiwavelength Star Formation Indicators: Observations". The Astrophysical Journal Supplement Series 164 (1): 52–80. doi:10.1086/501529. 
  5. Kinney, A. L.; Bohlin, R. C.; Calzetti, D.; Panagia, N.; Wyse, Rosemary F. G. (May 1993). "An atlas of ultraviolet spectra of star-forming galaxies". The Astrophysical Journal Supplement Series 86: 5. doi:10.1086/191771. 
  6. Lee, Janice C.; Sandstrom, Karin M.; Leroy, Adam K.; Thilker, David A.; Schinnerer, Eva; Rosolowsky, Erik; Larson, Kirsten L.; Egorov, Oleg V. et al. (1 February 2023). "The PHANGS–JWST Treasury Survey: Star Formation, Feedback, and Dust Physics at High Angular Resolution in Nearby GalaxieS". The Astrophysical Journal Letters 944 (2): L17. doi:10.3847/2041-8213/acaaae. 
  7. Singh, Swapnil; Ashby, M L N; Vig, Sarita; Ghosh, S K; Jarrett, T; Crawford, T M; Malkan, Matthew A; Archipley, M et al. (12 May 2021). "The cold dust content of the nearby galaxies IC 5325, NGC 7496, NGC 7590, and NGC 7599". Monthly Notices of the Royal Astronomical Society 504 (3): 4143–4159. doi:10.1093/mnras/stab1048. 
  8. 8.0 8.1 Makarov, Dmitry; Karachentsev, Igor (21 April 2011). "Galaxy groups and clouds in the local (z~ 0.01) Universe". Monthly Notices of the Royal Astronomical Society 412 (4): 2498–2520. doi:10.1111/j.1365-2966.2010.18071.x. Bibcode2011MNRAS.412.2498M. http://www.sao.ru/hq/dim/groups/galaxies.dat. Retrieved 20 January 2019. 
  9. Bakich, Michael E. (2010). 1,001 Celestial Wonders to See Before You Die. New York, New York: Springer Science+Business Media, LLC. p. 334. ISBN 978-1-4419-1777-5. Bibcode2010ocws.book.....B. 
  10. Fouque, P.; Proust, D.; Quintana, H.; Ramirez, A.; Proust, D.; Quintana, H.; Ramirez, A. (1993). "Dynamics of the Pavo-Indus and Grus Clouds of Galaxies". Astronomy and Astrophysics Supplement Series 100 (3): 493–500. Bibcode1993A&AS..100..493F. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1993A%26AS..100..493F&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf. 
  11. "NGC 7496 (MIRI Image)" (in en). 16 February 2023. https://esawebb.org/images/weic2306c/. 

External links