Assigned ID: 500 ----- Attempting Submission 1 (Fri Feb 25 18:46:12 GMT 2011) ----- HST Phase I Proposal 500 (fesc_apt) successfully submitted. ----- Attempting Submission 2 (Fri Feb 25 19:06:05 GMT 2011) ----- The emission from star forming galaxies appears to be responsible for reionization of the universe at z > 6. In order to reionize the intergalactic medium (IGM) by z = 6, large fractions of ionizing photons must escape from the galaxies which we are now just beginning to detect at 6 < z < 10. Due to the increasing opacity of the IGM, it is difficult to directly measure escaping, photoionizing emission from the Lyman continuum (LyC) at z > 3. Thus, a comparison of observations and models of the escape fraction at z < 3 offers the best test of our understanding of how ionizing radiation escapes from galaxies. At z = 3, roughly 10-25% of galaxies are detected with escaping LyC emission, a rate that might be explained if escaping radiation is anisotropic. However, no such detections have been found in galaxies at lower redshifts. Here we propose to use high resolution N-Body+SPH simulations that resolve the clumpy nature of the ISM all the way to z = 0 to tie the observations together across time. These will be the first simulations to study the escape fraction at z < 2.5. We will quantify the anisotropic escape distribution, it's dependence on viewing angle, and it's duty cycle, for application to understanding a statistical sample of observed galaxies. We will explore the escape fraction as a function of SFR and redshift, to explain the current observations at z < 3. Finally, we will tie the escape fraction of galaxies to other observables that can be traced at z > 6 to make testable predictions for high z observations.

UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 Medium false 0.0 0.0 false false true false SUPPORTED