Program: GN-2008B-Q-68

The tidal disruption of satellite galaxies is a natural prediction of hierarchical galaxy formation scenarios currently proposed to explain the formation and evolution of L_star galaxies like M31. Our group has identified a candidate stellar stream in the halo of M31 which emanating from NGC205, the bright dwarf elliptical companion to M31. Here, we propose to obtain 4 GMOS fields across this feature. These observations will unambiguously confirm whether this feature is a stream from NGC205, and will measure its velocity, velocity dispersion and metallicity as a function of position. These dynamical data are of fundamental importance to allow a complete model of the orbit of NGC205 to track its destruction as it orbits inside the M31 potential, providing detailed insight into both the potential of the host and, for the first time, the orbital evolution of its satellite companion. Pre-imaging was obtained for two of these fields in 2007B.