0 Assigned ID: 953 ----- Attempting Submission 1 (Fri Apr 10 22:30:07 GMT 2015) ----- HST Phase I Proposal 953 (hff_submitted_v1.apt) successfully submitted. Receipt: # 953-1 ----- Attempting Submission 2 (Fri Apr 10 23:44:49 GMT 2015) ----- HST Phase I Proposal 953 (hff_submitted_v1.apt) successfully submitted. Receipt: # 953-2 ----- Attempting Submission 3 (Fri Apr 10 23:56:47 GMT 2015) ----- We request funding to support the study of the complete data from the Hubble Frontier Fields (HFF) program. We have developed a method for detecting the faintest lensed galaxies in the cluster fields using wavelet decomposition, and propose to use these data to study several key science areas: 1) The faint end of the rest-frame ultraviolet (UV) luminosity function at z=7-8: We will improve the estimates of the faint-end slope, which remains poorly constrained. The lensing fields will probe luminosities <<0.1L*, while the blank fields will increase the number of <0.5L* galaxies by a factor of 3x. By the completion of the HFF survey, we expect to be able to measure the faint-end slope to within 10%, honing in on the contribution of galaxies to reionization. 2) The colors of faint galaxies: The HFF will probe low-metallicity stars at high-z. The cluster fields will yield galaxies with intrinsic absolute magnitudes fainter than -17, where we expect to see low-metallicity star formation, and the blank fields will increase the numbers of m=28-29 galaxies by 3x, strongly reducing the uncertainty on their mean color. 3) The abundance of galaxies at z=9: The inclusion of the F140W filter in all HFF observations will allow the robust two-band detection of z=9 galaxies. Using a larger sample over a wider dynamic range in luminosity, we will investigate the apparent discrepancy between previous studies at z=9 based on the HUDF. With funding to carry out this work on the complete dataset, we will be able to place the most robust constraints yet on these high-z galaxies, maximizing the output from the HFF program in advance of JWST. COSMOLOGY 0 Regular false false false false false SUPPORTED