Journal article

Low-mass galaxy formation and the ionizing photon budget during reionization

Alan R Duffy, J Stuart B Wyithe, Simon J Mutch, Gregory B Poole



We use high-resolution simulations of cosmological volumes to model galaxy formation at high redshift, with the goal of studying the photon budget for reionization. We demonstrate that galaxy formation models that include a strong, thermally coupled supernovae scheme reproduce current observations of star formation rates and specific star formation rates, both during and after the reionization era. These models produce enough UV photons to sustain reionization at z ≲ 8 (z ≲ 6) through a significant population of faint, unobserved, galaxies for an assumed escape fraction of 20 per cent (5 per cent). This predicted population is consistent with extrapolation of the faint end of observed UV lum..

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University of Melbourne Researchers


Funding Acknowledgements

ARD would like to thank Dan Stark, Pascal Oesch and Brant Robertson for helpfully providing their results and discussions, Claudio Dalla Vecchia for his SNe feedback models; Chris Power and Doug Potter for their efforts with initial conditions, Steven Finkelstein, Katie Mack, Kasper Schmidt and Mike Shull for stimulating discussions and comments and a general thanks to OWLS teammates for their efforts in creating a wonderful simulation series package. JSBW acknowledges the support of an Australian Research Council Laureate Fellowship. This work was supported by the Flagship Allocation Scheme of the NCI National Facility at the ANU, generous allocations of time through the iVEC Partner Share and Australian Supercomputer Time Allocation Committee. We would like to thank the PYTHON developers of MATPLOTLIB (Hunter 2007), COSMOLOPY ( and PYNBODY (Pontzen et al. 2013) hosted at for easing the visualization and analysis efforts in this work.