1995A&A...300..117D

We use space motions of globular clusters as a new constraint to determine the mass distribution of our Galaxy. Among the 26 globular clusters with known radial velocity and proper motions (Dauphole et al. 1994), eight of them are now observed at distances smaller than or nearly 20kpc from the Galactic centre with a velocity that throws them at a distance greater than 40kpc, with the usual galactic potentials. Moreover, the time spent at large distances from the Galactic centre corresponds to a large part of the orbital period. Statistically, we must normally find a lot of globular clusters at these distances. But the distribution of the globular clusters shows a gap beyond 40kpc. We use this contradiction between observations and theory as a new constraint to build a potential model of our Galaxy, that is globular clusters with known space velocities must not have apocentric distances greater than 40 kpc or in other words the potential must be strong enough to prevent galactic globular clusters to go beyond this limit. The derived model is simple, completely analytical and works quite nicely with this large scale constraint. Total mass of the model is 7.9x10¹¹M_☉. A large part of this mass must be distributed between 15 and 40kpc and must be in fact dark matter.