NGC 3995 is aMagellanic spiral galaxy in the constellationUrsa Major. The galaxy lies about 100 millionlight years away from Earth based on theTully–Fisher relation, which means, given its apparent dimensions, that NGC 3995 is approximately 80,000 light years across, while based on redshift it lies 170 million light years away.[1] It was discovered byHeinrich d'Arrest on February 5, 1864.[3]
NGC 3995 forms a triplet of galaxies withNGC 3994, which lies 1.9 arcminutes, andNGC 3991, which lies 3.7 arcminutes away. The triplet has been included inHalton Arp'sAtlas of Peculiar Galaxies as Arp 313. Both NGC 3995 and NGC 3991 have disturbed appearances while NGC 3994 does not.[4] The triplet is part of the NGC 3966 Group or LGG 259. Other members includeNGC 3966,NGC 3935,NGC 3986, IC 2973, UGC 6892, IC 2978, and IC 2979.[5][6]
Thestar formation rate of NGC 3995 is estimated to be4.2±0.9 M☉ per year, with higher rates observed near the centre of the galaxy.[7] The nucleus of the galaxy has emission that resembles anHII region.[8] The spectrum of the galaxy hasWolf-Rayet features, indicative of recent star formation.[9]Hubble Space Telescope detected 46 star formation knots in the galaxy, most of them having ages less than 20 million years.[10]
^Logroño-García, R.; Vilella-Rojo, G.; López-Sanjuan, C.; Varela, J.; Viironen, K.; Muniesa, D. J.; Cenarro, A. J.; Cristóbal-Hornillos, D.; Ederoclite, A.; Marín-Franch, A.; Moles, M.; Vázquez Ramió, H.; Bonoli, S.; Díaz-García, L. A.; Orsi, A.; San Roman, I.; Akras, S.; Chies-Santos, A. L.; Coelho, P. R. T.; Daflon, S.; Costa-Duarte, M. V.; Dupke, R.; Galbany, L.; González Delgado, R. M.; Hernandez-Jimenez, J. A.; Lopes de Oliveira, R.; Mendes de Oliveira, C.; Oteo, I.; Gonçalves, D. R.; Sánchez-Portal, M.; Schmidtobreick, L.; Sodré, L. (February 2019). "J-PLUS: Measuring H α emission line fluxes in the nearby universe".Astronomy & Astrophysics.622: A180.arXiv:1804.04039.Bibcode:2019A&A...622A.180L.doi:10.1051/0004-6361/201732487.
^Kewley, Lisa J.; Rupke, David; Jabran Zahid, H.; Geller, Margaret J.; Barton, Elizabeth J. (20 September 2010). "Metallicity Gradients and Gas Flows in Galaxy Pairs".The Astrophysical Journal.721 (1):L48 –L52.arXiv:1008.2204.Bibcode:2010ApJ...721L..48K.doi:10.1088/2041-8205/721/1/L48.
^Eggers, D.; Weistrop, D.; Stone, A.; Nelson, C. H.; Hancock, M. (January 2005). "Hubble Space Telescope Observations of Star-forming Regions in NGC 3994/3995".The Astronomical Journal.129 (1):136–147.Bibcode:2005AJ....129..136E.doi:10.1086/426358.
^Richmond, M.; Filippenko, A. V.; Shields, J. C. (1989). "Supernova 1988ac in NGC 3995".International Astronomical Union Circular (4903): 2.Bibcode:1989IAUC.4903....2R.
^"SN1988ac".Transient Name Server.IAU. Retrieved6 December 2024.
^Hurst, G. M.; Armstrong, M.; Schwartz, M.; Garnavich, P.; Boles, T. (2000). "Supernova 2000ez in NGC 3995".International Astronomical Union Circular (7533): 1.Bibcode:2000IAUC.7533....1H.
^"SN2000ez".Transient Name Server.IAU. Retrieved6 December 2024.
