NGC 7237

NGC 7237
NGC 7237 by PanSTARRS
Observation data (J2000 epoch)
ConstellationPegasus
Right ascension22h 14m 46.9s[1]
Declination+13° 50′ 27″[1]
Redshift0.026213 ± 0.000007 [1]
Heliocentric radial velocity7,858 ± 2 km/s[1]
Distance371 ± 99 Mly (114 ± 30.5 Mpc)[1]
Apparent magnitude (V)13.9[2]
Characteristics
TypeSA0- [1]
Apparent size (V)1.81′ × 0.72′[1]
Notable featuresInteracting galaxy, radio galaxy
Other designations
UGC 11958, Arp 169, II Zw 172, CGCG 428-058, MCG +02-56-024, 3C 442A, PGC 68383[1]

NGC 7237 is an interacting lenticular galaxy located in the constellation Pegasus. It is located at a distance of about 350 million light years from Earth, which, given its apparent dimensions, means that NGC 7237 is about 240,000 light years across.[1] NGC 7237 forms a pair with NGC 7236 and is a radio galaxy. It was discovered by Albert Marth on August 25, 1864.[3]

NGC 7237 forms a pair with lenticular galaxy NGC 7236,[4] which lies 35 arcseconds to the northwest. The two galaxies are undergoing a merger and are surrounded by hot gas (corona) with temperature of around 1 keV. The total mass of that gas is estimated to be 3×1010 M☉.[5] A smaller elliptical galaxy, NGC 7237C, lies 38 arcseconds southeast of NGC 7237. It is included in the Atlas of Peculiar Galaxies, in the category diffuse counter-tails. A tail is also visible in X-rays.[6] The isophotes in the central region of NGC 7237 are irregular.[7]

The galaxy pair is a source of radiowaves. The radio emission has a double lobe structure, with filaments, but no jets, while a weak core is identified as the nucleus of NGC 7237.[8] The filaments could be created by the interaction of hot gas with the preexisting radio emitting plasma. Some bright radio sources are visible within the lobes but they could be background active galaxies.[6] The core has been found to be variable source of X-rays.[6]

References

  1. ^ a b c d e f g h i "NASA/IPAC Extragalactic Database". Results for NGC 7237. Retrieved 2023-07-07.
  2. ^ "Revised NGC Data for NGC 7237". spider.seds.org. Retrieved 25 November 2018.
  3. ^ Seligman, Courtney. "NGC 7237 (with NGC 7236 = Arp 169)". Celestial Atlas. Retrieved 19 November 2018.
  4. ^ Borne, Kirk D.; Hoessel, John G. (July 1988). "Interacting binary galaxies. III - Observations of NGC 1587/1588 and NGC 7236/7237". The Astrophysical Journal. 330: 51. doi:10.1086/166454.
  5. ^ Worrall, D. M.; Birkinshaw, M.; Kraft, R. P.; Hardcastle, M. J. (1 April 2007). "The Effect of a Chandra -measured Merger-related Gas Component on the Lobes of a Dead Radio Galaxy". The Astrophysical Journal. 658 (2): L79–L82. doi:10.1086/513869. S2CID 15963632.
  6. ^ a b c Hardcastle, M. J.; Kraft, R. P.; Worrall, D. M.; Croston, J. H.; Evans, D. A.; Birkinshaw, M.; Murray, S. S. (10 June 2007). "The Interaction between Radio Lobes and Hot Gas in the Nearby Radio Galaxies 3C 285 and 3C 442A". The Astrophysical Journal. 662 (1): 166–181. arXiv:astro-ph/0703080. doi:10.1086/517997. S2CID 18803836.
  7. ^ Martel, André R.; Baum, Stefi A.; Sparks, William B.; Wyckoff, Eric; Biretta, John A.; Golombek, Daniel; Macchetto, Ferdinando D.; de Koff, Sigrid; McCarthy, Patrick J.; Miley, George K. (May 1999). "Hubble Space Telescope Snapshot Survey of 3CR Radio Source Counterparts. III. Radio Galaxies with [FORMULA][F]z". The Astrophysical Journal Supplement Series. 122 (1): 81–108. doi:10.1086/313205. S2CID 249153931.
  8. ^ Comins, Neil F.; Owen, Frazer N. (November 1991). "The extraordinary radio source 3C 442". The Astrophysical Journal. 382: 108. doi:10.1086/170698.
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