Program: GS-2013B-Q-58

We propose to obtain deep, high-resolution GeMS/GSAOI images of a galaxy group at z ~ 0.7. The unique performance and Field of View (FoV) provided by GeMS/GSAOI will be used to derive an accurate and unprecedented morphological analysis of the group's galaxies. At these redshifts the GeMS/GSAOI Near Infra-Red (NIR) images are critical to determine the morphologies as they probe the old, underlying stellar populations that trace the bulk of the galaxy mass and avoid bias due to young stellar formation. In fact, this opens the way to unambiguously identify a galaxy morphology, and for instance disentangle star forming clumps, from potential minor or major mergers. This unique morphological information will then be combined with resolved internal kinematics and metallicity derived from 3D spectroscopy. Two galaxies of the field already benefit from VLT/SINFONI observations, and seven more will soon be observed with the MUSE instrument, a new generation 3D spectrograph for the VLT. The combination of high-angular images with the galaxy kinematics has proven to be a powerful tool to accurately describe the internal dynamics, and bring strong constraints on the process at work in each individual galaxy studied. By combining high resolution morphology, kinematics and metallicity information, we will establish for the first time a complete description and understanding of the mass assembly mechanisms at work in a galaxy group.