NGC 4203
| NGC 4203 | |
|---|---|
| Observation data (J2000 epoch) | |
| Constellation | Coma Berenices |
| Right ascension | 12h 15m 05.0s[1] |
| Declination | +33° 11′ 50″[1] |
| Redshift | 0.003620[2] |
| Heliocentric radial velocity | 1,083[3] km/s |
| Galactocentric velocity | 1,093[3] km/s |
| Distance | 49.84 ± 0.46 Mly (15.28 ± 0.14 Mpc)[3] |
| Apparent magnitude (V) | 11.99[4] |
| Apparent magnitude (B) | 12.98[4] |
| Characteristics | |
| Type | SAB0−[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] | |
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 asymptotic giant branch star that is losing mass to the black hole along a contrail.[12]
References
- ^ a b Myers, S. T.; et al. (May 2003), "The Cosmic Lens All-Sky Survey - I. Source selection and observations", Monthly Notices of the Royal Astronomical Society, 341 (1): 1−12, arXiv:astro-ph/0211073, Bibcode:2003MNRAS.341....1M, doi:10.1046/j.1365-8711.2003.06256.x.
{{citation}}: CS1 maint: unflagged free DOI (link) - ^ Kochanek, C. S.; et al. (October 2001), "The K-Band Galaxy Luminosity Function", The Astrophysical Journal, 560 (2): 566−579, arXiv:astro-ph/0011456, Bibcode:2001ApJ...560..566K, doi:10.1086/322488.
- ^ a b c Tully, R. Brent; et al. (October 2013), "Cosmicflows-2: The Data", The Astronomical Journal, 146 (4): 25, arXiv:1307.7213, Bibcode:2013AJ....146...86T, doi:10.1088/0004-6256/146/4/86, 86.
- ^ a b Véron-Cetty, M.-P.; Véron, P. (July 2010), "A catalogue of quasars and active nuclei", Astronomy and Astrophysics, 518 (13th ed.): A10, Bibcode:2010A&A...518A..10V, doi:10.1051/0004-6361/201014188.
- ^ a b Erwin, Peter; Debattista, Victor P. (June 2013), "Peanuts at an angle: detecting and measuring the three-dimensional structure of bars in moderately inclined galaxies", Monthly Notices of the Royal Astronomical Society, 431 (4): 3060−3086, arXiv:1301.0638, Bibcode:2013MNRAS.431.3060E, doi:10.1093/mnras/stt385.
{{citation}}: CS1 maint: unflagged free DOI (link) - ^ Skrutskie, M. F.; et al. (February 2006), "The Two Micron All Sky Survey (2MASS)", Astrophysical Journal, 131 (2): 1163–1183, Bibcode:2006AJ....131.1163S, doi:10.1086/498708.
- ^ "NGC 4203 -- LINER-type Active Galaxy Nucleus", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-01-03.
- ^ Seligman, Courtney (November 23, 2012), "NGC Objects: NGC 4200 - 4249", Celestial Atlas, retrieved 2015-01-04.
- ^ O'Meara, Steve (2007), Herschel 400 Observing Guide, Cambridge University Press, p. 190, ISBN 0521858933.
- ^ de Vaucouleurs, G.; et al. (1991), Third reference catalogue of bright galaxies, version 9, New York: Springer-Verlag, Bibcode:1994AJ....108.2128C, doi:10.1086/117225, retrieved 2015-11-25.
{{citation}}: CS1 maint: multiple names: authors list (link) - ^ Yıldız, Mustafa K.; et al. (July 2015), "Star formation in the outer regions of the early-type galaxy NGC 4203", Monthly Notices of the Royal Astronomical Society, 451 (1): 103–113, arXiv:1505.02981, Bibcode:2015MNRAS.451..103Y, doi:10.1093/mnras/stv992.
{{citation}}: CS1 maint: unflagged free DOI (link) - ^ Devereux, Nick (December 2011), "Time Variable Broad-line Emission in NGC 4203: Evidence for Stellar Contrails", The Astrophysical Journal, 743 (1): 10, arXiv:1106.4790, Bibcode:2011ApJ...743...83D, doi:10.1088/0004-637X/743/1/83, 83.