NGC 2293

NGC 2293 is a lenticular galaxy located in the constellation Canis Major. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2293 is about 160,000 light years across. It was discovered by John Herschel on January 20, 1835.[3] NGC 2293 forms a pair with NGC 2292 and has an HI ring that surrounds both galaxies.

NGC 2293
NGC 2292 (right) and NGC 2293 (left) by the Hubble Space Telescope
Credit: NASA, ESA, and W. Keel
Observation data (J2000 epoch)
ConstellationCanis Major
Right ascension06h 47m 42.9s[1]
Declination−26° 45′ 16″[1]
Redshift0.006795 ± 0.000020 [1]
Helio radial velocity2037 ± 6 km/s[1]
Distance107 ± 49 Mly (32.9 ± 15.0 Mpc)[1]
Apparent magnitude (V)11.2[2]
Characteristics
TypeSAB(s)0+ pec [1]
Apparent size (V)4′.2 × 3′.3[1]
Notable featuresInteracts with NGC 2292
Other designations
ESO 490-IG 049, VV 178a, MCG -04-16-023, PGC 19619[1]

Characteristics

NGC 2293 is a lenticular galaxy with hints of a spiral structure. The old stars that make it give the galaxy an orange color.[4] Located 0.8 arcminutes away from NGC 2292 lies NGC 2293. Both galaxies appear to share a common envelope and a complete ring of neutral hydrogen gas (HI) has been found to encircle both galaxies. The ring apparently has a color change to the southwestern view, that has been attributed to the presence of star formation. On the other hand, there is a marked absence of HI near the centre of the two galaxies.[5] The total HI mass is 0.75×109 M☉.[5][6]

It is possible that the ring is the result of an ongoing merger between the two galaxies, that would result in a giant elliptical galaxy.[5] Various models have been suggested for the formation of the ring. The most likely models is the collision between one of the two galaxies and one more galaxy that sweept gas away, with the star formation region on the ring been created by a density wave or it is a population that was stripted by the intruder galaxy.[5] It hasn't been ruled out that the positioning is an projection effect of two galaxies separated by a few million light years.[5]

Based on far infrared observations there is an extensive amount of cold dust at the pair, with temperature 13 K, which is lower that dust temperature found in spiral and interacting galaxies. The temperature indicates however that it isn't of primodial origin.[6]

Nearby galaxies

NGC 2292/2293 pair belongs to a galaxy group known as LGG 138. Other members of the group are the spiral galaxy NGC 2280, NGC 2295, ESO 490−G010 and ESO 490−G045. Because of its large angular diameter, about one degree, the group was identified when redshift information were available, by Garcia et al. in 1993.[7]

References
  1. "NASA/IPAC Extragalactic Database". Results for NGC 2293. Retrieved 2016-01-18.
  2. "Revised NGC Data for NGC 2293". spider.seds.org. Retrieved 25 November 2018.
  3. Seligman, Courtney. "NGC 2293 (= PGC 19531)". Celestial Atlas. Retrieved 19 November 2018.
  4. "Hubble finds "Greater Pupkin" galaxy pair". HubbleSite.org. 29 October 2020. Retrieved 3 November 2020.
  5. Barnes, David G. (1999). "A New H I Ring: LGG 138". Publications of the Astronomical Society of Australia. 16 (1): 77–83. doi:10.1071/AS99077.
  6. Stickel, M.; Barnes, D.; Krause, O. (November 2005). "Extended very cold dust in the interacting HI ring galaxy pair NGC 2293 / 2292". Astronomy & Astrophysics. 443 (2): 373–381. doi:10.1051/0004-6361:20053227.
  7. Barnes, D. G.; Webster, R. L. (July 2001). "A study of neutral hydrogen in five small galaxy groups". Monthly Notices of the Royal Astronomical Society. 324 (4): 859–876. Bibcode:2001MNRAS.324..859B. doi:10.1046/j.1365-8711.2001.04273.x.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.