Abstract
We study the evolution of the Sagittarius dwarf galaxy by means of N-body numerical simulations. We find the initial conditions of the orbit of the satellite, such that after a time shorter than 10 Gyr, this astrophysical object has the position and galactocentric radial velocity currently observed (16 kpc and 171 km s^{-1}, respectively). Subsequently, these results are used to simulate the evolution of the progenitor of Sagittarius both with only barionic matter and with different contents of dark matter. These simulations were made by using a modification of the code Gadget-2. The satellite is represented by a plummer sphere and the dark halo by a NFW distribution. The number of particles for each object is 10^6. The Milky Way is modeled as a rigid potential of three components. In this paper we present some of the most significant results obtained in our simulations.