Document Type
Article
Publication Date
11-14-2016
Abstract
Crater II is an unusual object among the dwarf satellite galaxies of the Local Group in that it has a very large size for its small luminosity. This provides a strong test of MOND, as Crater II should be in the deep MOND regime (g in ≈ 34 km2 s-2 kpc-1 ≪ a 0 = 3700 km2 s-2 kpc-1). Despite its great distance (≈120 kpc) from the Milky Way, the external field of the host (g ex ≈ 282 km2 s-2 kpc-1) comfortably exceeds the internal field. Consequently, Crater II should be subject to the external field effect, a feature unique to MOND. This leads to the prediction of a very low velocity dispersion: δefe = 2.1+0.9-0.6.
Keywords
dark matter, galaxies: dwarf, galaxies: kinematics and dynamics
Publication Title
Astrophysical Journal Letters
Rights
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Recommended Citation
Mond Prediction for the Velocity Dispersion of the "Feeble Giant" Crater II. Stacy S. McGaugh 2016 ApJL 832 L8. 10.3847/2041-8205/832/1/L8
Manuscript Version
Final Publisher Version