NGC 4504 is aspiral galaxy in the constellationVirgo. The galaxy lies about 55 millionlight years away from Earth, which means, given its apparent dimensions, that NGC 4504 is approximately 70,000 light years across.[1] It was discovered byWilliam Herschel on March 20, 1789.[3]
NGC 4504 has a point source nucleus embedded in a highly ellipticalbulge. It is possible there is a smallbar in the bulge. The galaxy has very low surface brightness arms emerging from the bulge.[4]HII regions are visible in the disk, the largest of which are more than 3 arcseconds across.[5] The star formation rate is estimated to be 0.45M☉ per year based on theH-alpha emission.[6] The galaxy has a small bar 0.36 arcminutes long and a ring with a diameter 0.93 arcminutes.[7] In the nucleus of the galaxy lies anuclear star cluster which has a radius of 4 arcseconds.[8]
NGC 4504 forms a pair withNGC 4487, which lies 35 arcminutes away.[5] NGC 4504 is a member of the Messier 104 Group, which also includes theSombrero Galaxy (M104), NGC 4487, UGCA 287, and UGCA 289.[9] A. M. Garcia considers the galaxy part of the LGG 293 Group, in which are included the galaxies NGC 4487, NGC 4504, andNGC 4597.[10] It is part of aVirgo II Groups, a chain of groups extending from theVirgo Cluster.[11]
^Eskridge, Paul B.; Frogel, Jay A.; Pogge, Richard W.; Quillen, Alice C.; Berlind, Andreas A.; Davies, Roger L.; DePoy, D. L.; Gilbert, Karoline M.; Houdashelt, Mark L.; Kuchinski, Leslie E.; Ramirez, Solange V.; Sellgren, K.; Stutz, Amelia; Terndrup, Donald M.; Tiede, Glenn P. (November 2002). "Near-Infrared and Optical Morphology of Spiral Galaxies".The Astrophysical Journal Supplement Series.143 (1):73–111.arXiv:astro-ph/0206320.Bibcode:2002ApJS..143...73E.doi:10.1086/342340.
^abSandage, A., Bedke, J. (1994),The Carnegie Atlas of Galaxies. Volume I, Carnegie Institution of Washington
^Comerón, S.; Salo, H.; Laurikainen, E.; Knapen, J. H.; Buta, R. J.; Herrera-Endoqui, M.; Laine, J.; Holwerda, B. W.; Sheth, K.; Regan, M. W.; Hinz, J. L.; Muñoz-Mateos, J. C.; Gil de Paz, A.; Menéndez-Delmestre, K.; Seibert, M.; Mizusawa, T.; Kim, T.; Erroz-Ferrer, S.; Gadotti, D. A.; Athanassoula, E.; Bosma, A.; Ho, L. C. (February 2014)."ARRAKIS: atlas of resonance rings as known in the S 4 G"(PDF).Astronomy & Astrophysics.562: A121.arXiv:1312.0866.Bibcode:2014A&A...562A.121C.doi:10.1051/0004-6361/201321633.
