A Dynamical Model of the Local Group
  This dynamical model for the 28 galaxies with distances less than 1.5 Mpc,
and not apparently tight satellites, is constrained by the initial condition
that peculiar velocities at high redshift are small and growing in accordance
with the standard cosmology. The solution is a satisfactory fit to most of the
measured redshifts, distances, and proper motions, with some interesting
exceptions that call for further investigation. The model predicts Milky Way
rotation speed 256 km/s, consistent with Reid et al. (2009a). Ten Local Group
galaxies emanate from low supergalactic latitude and supergalactic longitude ~
70 degrees, perhaps as remnants from failed assembly of a larger galaxy. NGC
6822 passes close to the Milky Way at redshift ~0.27, in an orbit similar to
the Magellanic Clouds. Leo I has heliocentric angular velocity 0.33 mas/yr,
perhaps measurable by the mean stellar motion, and 15 galaxies have proper
motions greater than 0.05 mas/yr, measurable for any with masers.
