  Self-consistent simulations of the dynamical evolution of low-mass satellite
galaxies without dark matter on different orbits interacting with an extended
Galactic dark halo are described. The calculations proceed for many orbital
periods until well after the satellite dissolves. In all cases the dynamical
evolution converges to a remnant that contains roughly 1% of the initial
satellite mass. The stable remnant results from severe tidal shaping of the
initial satellite. To an observer from Earth these remnants look strikingly
similar to the Galactic dwarf spheroidal satellite galaxies. Their apparent
mass-to-light ratios are very large despite the fact that they contain no dark
matter.
  These computations show that a remnant without dark matter displays larger
line-of-sight velocity dispersions for more eccentric orbits, which is a result
of projection onto the observational plane. Assuming they are not dark matter
dominated, it follows that the Galactic dSph satellites with sigma>6km/s should
have orbital eccentricities of e>0.5. Some remnants have sub-structure along
the line-of-sight that may be apparent in the morphology of the horizontal
branch.

Astrophysics