Submission 3 -- just in case 373190390 Assigned ID: 383 ----- Attempting Submission 1 (Fri Apr 07 03:28:02 GMT 2017) ----- HST Phase I Proposal 383 (near-far.apt) successfully submitted. Receipt: # 383-1 ----- Attempting Submission 2 (Fri Apr 07 14:25:36 GMT 2017) ----- HST Phase I Proposal 383 (near-far.apt) successfully submitted. Receipt: # 383-2 ----- Attempting Submission 3 (Fri Apr 07 15:25:58 GMT 2017) ----- We propose to use cosmological hydrodynamical simulations - both zoom-in and large-volume - to study the connections between the faintest observable galaxies in the high-redshift Universe and dwarf galaxies locally. Studies of the likely descendants of very faint HUDF / Frontier Field galaxies will provide a powerful complement to direct observations at z~8 for investigating the physical processes in the high-redshift Universe and, in connection with properties of low-mass galaxies in the nearby Universe, will produce strong constraints on reionization scenarios and dark matter models. Understanding the relationship between high-redshift and local galaxy populations through simulations requires an accurate knowledge of the links between galaxy populations at cosmic dawn and those locally. All existing results on this topic either suffer from poor statistics or are unable to resolve the hosts of Frontier Field galaxies, however. Our program will address this shortcoming by combining a series of zoom-in hydrodynamical simulations with the next generation of large-volume hydrodynamical simulations of the galaxy population from the Illustris project. HST has made unique and invaluable contributions to surveys of galaxies at high redshifts and to detailed, resolved-star studies of individual galaxies in the very nearby Universe. Our study will help cement links between these two HST legacies. We will quantify the relationships between faint populations at low and high redshifts, characterize the merger histories of dwarf galaxies (both forward and backward in time), and test the validity of various popular models such as abundance matching based on UV luminosity functions. Galaxies and the IGM Cosmology 0 Regular false false true SUPPORTED