Dwarf spheroidal galaxies ( dSphs ) appear to be some of the most dark matter dominated objects in the Universe .
Their dynamical masses are commonly derived using the kinematics of stars under the assumption of equilibrium .
However , these objects are satellites of massive galaxies ( e.g .
the Milky Way ) and thus can be influenced by their tidal fields .
We investigate the implication of the assumption of equilibrium focusing on the Sculptor dSph by means of ad-hoc N -body simulations tuned to reproduce the observed properties of Sculptor following the evolution along some observationally motivated orbits in the Milky Way gravitational field .
For this purpose , we used state-of-the-art spectroscopic and photometric samples of Sculptor ’ s stars .
We found that the stellar component of the simulated object is not directly influenced by the tidal field , while \approx 30 \% - 60 \% the mass of the more diffuse DM halo is stripped .
We conclude that , considering the most recent estimate of the Sculptor proper motion , the system is not affected by the tides and the stellar kinematics represents a robust tracer of the internal dynamics .
In the simulations that match the observed properties of Sculptor , the present-day dark-to-luminous mass ratio is \approx 6 within the stellar half-light radius ( \approx 0.3 kpc ) and > 50 within the maximum radius of the analysed dataset ( \approx 1.5 ^ { \circ } \approx 2 kpc ) .