Note that US state location for Gemini North is incorrect and seem to be impossible to correct as it appears correctly in the STScI directory. It should be HI not AZ. -1902268925 Assigned ID: 1353 ----- Attempting Submission 1 (Fri Mar 01 01:58:39 GMT 2013) ----- We propose to process in a consistent fashion all available HST/ACS and WFC3 imaging of seven rich clusters of galaxies at z=1.2-1.6. The clusters are part of our larger project aimed at constraining models for galaxy evolution in dense environments from observations of stellar populations in rich z=1.2-2 galaxy clusters. The main objective is to establish the star formation (SF) history and structural evolution over this epoch during which large changes in SF rates and galaxy structure are expected to take place in cluster galaxies. The observational data required to meet our main objective are deep HST imaging and high S/N spectroscopy of individual cluster members. The HST imaging already exists for the seven rich clusters at z=1.2-1.6 included in this archive proposal. However, the data have not been consistently processed to derive colors, magnitudes, sizes and morphological parameters for all potential cluster members bright enough to be suitable for spectroscopic observations with 8-m class telescopes. We propose to carry out this processing and make all derived parameters publicly available. We will use the parameters derived from the HST imaging to (1) study the structural evolution of the galaxies, (2) select clusters and galaxies for spectroscopic observations, and (3) use the photometry and spectroscopy together for a unified analysis aimed at the SF history and structural changes. The analysis will also utilize data from the Gemini/HST Cluster Galaxy Project, which covers rich clusters at z=0.2-1.0 and for which we have similar HST imaging and high S/N spectroscopy available. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 Small false false 0.0 0.0 false false false SUPPORTED