NGC 4203

NGC 4203
NGC 4203 (SDSS)
Observation data (J2000 epoch)
ConstellationComa Berenices
Right ascension12h 15m 05.0s[1]
Declination+33° 11′ 50″[1]
Redshift0.003620[2]
Heliocentric radial velocity1,083[3] km/s
Galactocentric velocity1,093[3] km/s
Distance49.84 ± 0.46 Mly (15.28 ± 0.14 Mpc)[3]
Group or clusterComa I
Apparent magnitude (V)11.99[4]
Apparent magnitude (B)12.98[4]
Characteristics
TypeSAB0−[5]
Apparent size (V)2.467′ × 2.319′[6]
Other designations
2MASX J12150502+3311500, LEDA 39158, UGC 7256, UZC J121505.0+331152, Z 187-29 .[7]
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NGC 4203 is the New General Catalogue identifier for a lenticular galaxy in the northern constellation of Coma Berenices. It was discovered on March 20, 1787 by English astronomer William Herschel,[8] and is situated 5.5° to the northwest of the 4th magnitude star Gamma Comae Berenices and can be viewed with a small telescope.[9] The morphological classification of NGC 4203 is SAB0−,[5] indicating that it has a lenticular form with tightly wound spiral arms and a weak bar structure at the nucleus.[10]

This galaxy has a fairly large reservoir of neutral hydrogen containing on the order of a billion solar masses (M☉), but it is only undergoing a low rate of new star formation. Hence, the inner star formation of the galaxy is fairly old; roughly ten billion years on average. The neutral hydrogen is arranged in two ring-like structures, with the outer ring having nine times the mass of the inner. In the central region there is around 2.5×107 M☉ of molecular hydrogen, plus dust structures within 980 ly (300 pc) of the nucleus. The gas in the outer disk may have been accreted from the inter-galactic medium, or captured during a close encounter with a dwarf galaxy.[11]

The nucleus of the galaxy contains a low-ionization nuclear emission-line region of type 1.9. This is being generated by a supermassive black hole of an estimated (6±1)×107 M☉. An influx of gas of around 2×10−2 M☉/yr is sufficient to explain the measured X-ray luminosity. The time-varying emissions from the region are perhaps best explained by an infalling red supergiant star that is losing mass to the black hole along a contrail.[12]

NGC 4203 is a member of the Coma I Group[13][14][15] which is part of the Virgo Supercluster.[16]

  1. ^ a b Cite error: The named reference mnras341_1_1 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference apj560_2_566 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference aj146_86 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Cetty2010 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference mnras431_4_3060 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference ApJ131_1163 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Seligman was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference omeara2007 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference vaucoulerus1991 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference mnras451_1_103 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference apj743_1_83 was invoked but never defined (see the help page).
  13. ^ R. B. Tully (1988). Nearby Galaxies Catalog. Cambridge: Cambridge University Press. ISBN 978-0-521-35299-4.
  14. ^ A. Garcia (1993). "General study of group membership. II - Determination of nearby groups". Astronomy and Astrophysics Supplement. 100: 47–90. Bibcode:1993A&AS..100...47G.
  15. ^ Giuricin, Giuliano; Marinoni, Christian; Ceriani, Lorenzo; Pisani, Armando (2000). "Nearby Optical Galaxies: Selection of the Sample and Identification of Groups". The Astrophysical Journal. 543 (1): 178. arXiv:astro-ph/0001140. Bibcode:2000ApJ...543..178G. doi:10.1086/317070. ISSN 0004-637X. S2CID 9618325.
  16. ^ Gregory, Stephen A.; Thompson, Laird A. (April 15, 1977). "The Coma i Galaxy Cloud". The Astrophysical Journal. 213: 345–350. Bibcode:1977ApJ...213..345G. doi:10.1086/155160. ISSN 0004-637X.