The stellar structure and kinematics of dwarf spheroidal galaxies formed
  by tidal stirring
  Using high-resolution N-body simulations we study the stellar properties of
dwarf spheroidal galaxies resulting from the tidally induced morphological
transformation of disky dwarfs on a cosmologically motivated eccentric orbit
around the Milky Way. Dwarf galaxy models initially consist of an exponential
stellar disk embedded in an extended spherical dark matter halo. Depending on
the initial orientation of the disk with respect to the orbital plane,
different final configurations are obtained. The least evolved dwarf is
triaxial and retains a significant amount of rotation. The more evolved dwarfs
are prolate spheroids with little rotation. We show that the final density
distribution of stars can be approximated by a simple modification of the
Plummer law. The kinematics of the dwarfs is significantly different depending
on the line of sight which has important implications for mapping the observed
stellar velocity dispersions of dwarfs to subhalo circular velocities. When the
dwarfs are observed along the long axis, the measured velocity dispersion is
higher and decreases faster with radius. In the case where rotation is
significant, when viewed perpendicular to the long axis, the effect of minor
axis rotation is detected, as expected for triaxial systems. We model the
velocity dispersion profiles and rotation curves of the dwarfs by solving the
Jeans equations for spherical and axisymmetric systems and adjusting different
sets of free parameters. We find that the mass is typically overestimated when
the dwarf is seen along the long axis and underestimated when the observation
is along the short or intermediate axis. The effect of non-sphericity cannot
however bias the inferred mass by more than 60 percent in either direction,
even for the most strongly stripped dwarf which is close to disruption.
