Assigned ID: 564 ----- Attempting Submission 1 (Fri Feb 24 18:45:23 GMT 2012) ----- HST Phase I Proposal 564 (phase1-AR.pdf.apt) successfully submitted. ----- Attempting Submission 2 (Fri Feb 24 21:39:11 GMT 2012) ----- HST Phase I Proposal 564 (phase1-AR.pdf.apt) successfully submitted. ----- Attempting Submission 3 (Fri Feb 24 23:47:47 GMT 2012) ----- We propose to run ten very high resolution simulations of the Local Group in order to better understand the dynamics and formation histories of nearby galaxies. This is a field to which the HST has made unique and essential contributions, from proper motion measurements of dwarf galaxies in and around the Milky Way to star formation histories of a volume-limited sample of dwarf galaxies within 4 Mpc from the Galaxy. Our simulations will be chosen to match observations of the Local Group, including the mass, present separation, and radial velocity of the Milky Way-M31 system and the overdensity of nearby galaxies on 4 and 8 Mpc scales. We will use the simulations to focus on three main areas: (1) are observed dynamics of galaxies in and around the Local Group typical of those from LCDM simulations of apparently similar systems? (2) what is the role of environment in establishing the morphologies and controlling the star formation histories of nearby dwarf galaxies? and (3) how many faint galaxies remain to be discovered (to specific luminosity limits) within 4 Mpc of the Local Group? These questions all address issues for which HST data has been and continues to be indispensable. Halo catalogs and merger trees from our simulations will be made publicly available; this will constitute an order of magnitude increase to the number of high resolution simulations of Milky Way-mass dark matter halos with public data products. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 Medium false 0.0 0.0 false false true false SUPPORTED