MOND PREDICTION FOR THE VELOCITY DISPERSION OF THE "FEEBLE GIANT" CRATER II

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) approximate to 34 km(2) s(-2) kpc(-1) << a(0) = 3700 km(2) s(-2) kpc(-1)). Despite its great distance (approximate to 120 kpc) from the Milky Way, the external field of the host (g(ex) approximate to 282 km(2) 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: sigma(efe) 2.1(-0.6)(+0.9)km s(-1).