Assigned ID: 852 ----- Attempting Submission 1 (Sat Feb 27 00:06:35 GMT 2010) ----- The reionization of cosmic hydrogen is a critical process in the evolution of the intergalactic medium. Absorption spectra of high-redshift quasars indicate that reionization was largely completed by redshift z=6, but the duration of this process and its sources remain uncertain. The newest ultra-deep HST ACS and WFC3 observations revealed high-redshift galaxies that are contributing to reionization. Do they indicate that galaxies produce enough ionizing photons for reionization? We propose to model the uncertainty in the constraints on the epoch of reionization resulting from the current HST surveys. We will use several complementary approaches to estimate the number of ionizing photons per atom. We will build a theoretical model for the evolution of the UV luminosity function at z=6-10, based on globular clusters as tracers of most active star formation. We will use this model to predict the comoving number density of z>8 Lyman break dropouts. We will provide an easy-to-use public code to connect the observational UV LF and SFR data to the theoretical quantities such as the number of ionizing photons per atom. This code will assist on-going HST campaigns for the highest-redshift galaxies and will serve as a guide for planning future JWST observations.

UNRESOLVED STELLAR POPULATIONS AND GALAXY STRUCTURE 12 34200 false 0.0 0.0 false false false true false false SUPPORTED