Dwarf spheroidal galaxies and non-Newtonian gravity

Abstract

view Abstract Citations (54) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Dwarf Spheroidal Galaxies and Non-Newtonian Gravity Gerhard, Ortwin E. ; Spergel, David N. Abstract We derive a virial theorem and an analog for King's formula in modified Newtonian dynamics (MOND; Milgrom 1983) and use these to estimate the mass-to-light ratios (M/Ls) in MOND of the dwarf spheroidal galaxies in the Local Group. We find that the low-velocity dispersion observed in the Fornax dwarf galaxy implies low values for its M/L in MOND: 0.3-1. In particular the derived value in the core of Fornax (0.3) is much lower than expected for a normal old stellar population. Conversely, the velocity-dispersion measurements in Draco and Ursa Minor appear to still require dark matter in MOND. We show that M/L must vary between the dwarf spheroidals around the Galaxy by a factor of order at least 20, even in MOND. Publication: The Astrophysical Journal Pub Date: September 1992 DOI: 10.1086/171763 Bibcode: 1992ApJ...397...38G Keywords: Dark Matter; Dwarf Galaxies; Elliptical Galaxies; Galactic Clusters; Mass To Light Ratios; Galactic Evolution; Gravitation Theory; Kinematics; Metallicity; Astrophysics; COSMOLOGY: DARK MATTER; GALAXIES: ELLIPTICAL AND LENTICULAR; CD; GALAXIES: KINEMATICS AND DYNAMICS; GRAVITATION full text sources ADS | data products SIMBAD (5) NED (5)