NGC 4178 is theNew General Catalogue identifier for abarred spiral galaxy in the equatorialconstellation ofVirgo. It was discovered April 11, 1825 by English astronomerJohn Herschel.[7] Located some 43.8 millionlight years away,[4] this galaxy spans2.3 × 0.4[1]arc minutes and is seen at a low angle, being inclined by 77° to theline of sight from the Earth.[5] Themorphological classification of NGC 4178 is SB(rs)dm, indicating that it has a bar feature at the core, and, per the '(rs)', has traces of a ring-like structure surrounding the bar. The 'dm' suffix indicates the spiral arms are diffuse, broken, and irregular in appearance with no bulge at the nucleus.[2] This galaxy is a member of theVirgo Cluster, which is the richest nearby group of galaxies outside theLocal Group and forms the core of theVirgo Supercluster.[5]
The radio continuum emission along the galaxy's major axis is asymmetrical, being brighter in the southwestern part than in the northeast. But the overall radio surface brightness is on the low side.[8] In the mid-infrared range, the spectrum shows indications of high ionization levels usually associated with anactive galactic nucleus.[9] However, optical observations show no signs of an active nucleus, which may just mean it is heavily obscured. Indeed, the amount of ionized matter appears to increase near the core.[10] Although this galaxy lacks a bulge that could supply mass to asupermassive black hole, a large black hole was detected at the core by theChandra X-ray Observatory in 2012. It is inferred to have a mass of around 104 to 105 times themass of the Sun.[10] This makes it one of the lowest mass nuclear black holes known.[9]
Onesupernova has been observed in NGC 4178. SN 1963I was discovered by G. V. Zaytsheva on 14 May 1963 at the Konkoly Observatory in Budapest.[11][12] It was suspected of being aType Ia supernova eruption, but this remains unconfirmed.[13]
^abcdSkrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006)."The Two Micron All Sky Survey (2MASS)".The Astronomical Journal.131 (2):1163–1183.Bibcode:2006AJ....131.1163S.doi:10.1086/498708.ISSN0004-6256.S2CID18913331.
^abcTully, R. B.; Fisher, J. R. (February 1977), "A new method of determining distances to galaxies",Astronomy and Astrophysics,54 (3):661–673,Bibcode:1977A&A....54..661T.
^Thernoe, K. A. (21 May 1963)."Circular No. 1830".Central Bureau for Astronomical Telegrams. Smithsonian Astrophysical Observatory. Retrieved1 December 2024.
^Kukarkin, B. V. (May 1963), "Supernova in NGC 4178",Information Bulletin on Variable Stars,28: 1,Bibcode:1963IBVS...28....1K.
^Lanoix, P. (March 1998), "HIPPARCOS calibration of the peak brightness of four SNe IA and the value of H_0",Astronomy and Astrophysics,331:421–427,arXiv:astro-ph/9712137,Bibcode:1998A&A...331..421L.
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