The Magellanic Stream in Modified Newtonian Dynamics

The dynamics of the Magellanic Stream (MS) as a series of clouds extendingfrom the Magellanic Clouds (MCs) to the south Galactic pole is affected by thedistribution and the amount of matter in the Milky Way. We calculate thegravitational effect of the Galactic disk on the MS in the framework ofmodified Newtonian dynamics(MOND) and compare with observations of the Stream'sradial velocity. We consider the tidal force of the Galaxy, which stripsmaterial from the MCs to form the MS, and, using a no-halo model of the Galaxy,we ignore the effect of the drag of the Galactic halo on the MS. We alsocompare the MONDian dynamics with that in logarithmic and power-law dark halomodels and show that the MOND theory seems plausible for describing thedynamics of satellite galaxies such as the MCs. Finally, we perform a maximumlikelihood analysis to obtain the best MOND parameters for the Galactic disk.Comment: 11 pages, 6 figure