Assigned ID: 325 ----- Attempting Submission 1 (Fri Feb 24 07:45:17 GMT 2012) ----- HST Phase I Proposal 325 (HST_APT_FP_proposal_2012.apt) successfully submitted. ----- Attempting Submission 2 (Fri Feb 24 23:51:41 GMT 2012) ----- HST Phase I Proposal 325 (HST_APT_FP_proposal_2012.apt) successfully submitted. ----- Attempting Submission 3 (Sat Feb 25 00:31:20 GMT 2012) ----- We propose for archival funding to create the first large homogenous sample of sizes, structural parameters, velocity dispersions, and stellar masses of ~730 field early-type galaxies complete to R=24.1 (AB) over 0.2<z<1.0 in the AEGIS/DEEP and GOODS-N fields. We will use scaling relations created from this dataset to constrain our theoretical models (Porter, Somerville et al. 2012; Oser, Naab et al. 2012). It has recently been discovered that the population of early-types has grown significantly since z=1: galaxies at this epoch constitute only ~20-35% of the population today (e.g., Bundy et al. 2005, Abraham et al. 2007). A fundamental unknown in our picture of galaxy formation and evolution is the physics behind this transformation. There are a variety of phenomena likely at work: mergers of late-types, mergers of early-types, minor mergers, the role of dark matter, and mass loss from AGN/star-formation. Only now are theoretical models mature enough to make predictions for how early-types evolve, but they are unfortunately poorly constrained over 0.1<z<1.2. The most robust constraints on our models come from velocity dispersions, but only when coupled with size and stellar mass measurements. Hubble images are essential to (1) measure sizes, (2) measure structural parameters, and (3) remove red interacting and late-type galaxies from the sample. We already have in hand velocity dispersions measured from high-resolution Keck spectra for all galaxies, and stellar masses for 75% of the sample. Preliminary results for ~1/3 of the final sample indicate the need for winds/supernovae feedback and more minor merging than previously expected. UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 Medium false 0.0 0.0 false false false false SUPPORTED