0 Assigned ID: 102 ----- Attempting Submission 1 (Tue Apr 04 16:42:09 GMT 2017) ----- HST Phase I Proposal 102 (narayanan_dust_cycle25.submitted.pdf.apt) successfully submitted. Receipt: # 102-1 ----- Attempting Submission 2 (Tue Apr 04 16:49:02 GMT 2017) ----- HST Phase I Proposal 102 (narayanan_dust_cycle25.submitted.pdf.apt) successfully submitted. Receipt: # 102-2 ----- Attempting Submission 3 (Thu Apr 06 15:19:40 GMT 2017) ----- HST Phase I Proposal 102 (narayanan_dust_cycle25.submitted.pdf.apt) successfully submitted. Receipt: # 102-3 ----- Attempting Submission 4 (Fri Apr 07 13:41:55 GMT 2017) ----- The attenuation of star light in galaxies by dust imposes a major uncertainty in the derivation of galaxy physical properties. As we show in this proposal, for example, incorrect assumptions about attenuation laws in SED fitting can result in errors of ~0.3 dex in the derived M* and SFR from galaxies. While HST observations have revealed variations in inferred dust attenuation laws, we currently lack a comprehensive theory for how and why attenuation curves vary within and between galaxies. Complicating the issue are both the necessity for 3D radiative transfer modeling (to capture absorption and scattering), as well as a model for the geometry of luminous sources and dust in galaxies. To address this, we propose to conduct a large series of high-resolution cosmological zoom galaxy formation simulations in which we super-resolve giant clouds in the interstellar medium. These simulations will be coupled with a novel 3D dust radiative transfer package in order to derive theoretical dust attenuation curves. Our main scientific goals are twofold: (1) to derive the first ever connection between global properties of galaxies and their dust attenuation laws; and (2) to build better SED fitting techniques in order to improve the accuracy of physical properties inferred from galaxy SED fitting. All of our simulation results, population synthesis codes, and SED fitting codes will be made publicly available. Galaxies and the IGM 0 Regular false false true SUPPORTED