UGC 6944,
Arp 313, VV 249a,
MCG +06-26-061,
PGC 37624, HOLM 309A
NGC 3995 is a
Magellanic spiral galaxy in the constellation
Ursa Major. The galaxy lies about 100 million
light years away from Earth based on the
Tully–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 by
Heinrich d'Arrest on February 5, 1864.[3]
NGC 3995 forms a triplet of galaxies with
NGC 3994, which lies 1.9 arcminutes, and
NGC 3991, which lies 3.7 arcminutes away. The triplet has been included in
Halton Arp's Atlas 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 include
NGC 3966,
NGC 3935,
NGC 3986, IC 2973, UGC 6892, IC 2978, and IC 2979.[5][6]
The
star formation rate of NGC 3995 is estimated to be 4.2±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 an
HII region.[8] The spectrum of the galaxy has
Wolf-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.
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.
doi:
10.1088/2041-8205/721/1/L48.
^Schaerer, D.; Contini, T.; Pindao, M. (April 1999). "New catalogue of Wolf-Rayet galaxies and high-excitation extra-galactic Hii regions". Astronomy and Astrophysics Supplement Series. 136 (1): 35–52.
doi:
10.1051/aas:1999197.
^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.
doi:
10.1086/426358.