Lyman break galaxies and LAEs HST photometry

The stellar population fit to MD5b indicates an age of <~50 Myr, which is in the youngest 10% of the HST sample and the youngest third of typical z~3 Lyman break galaxies, and may be a contributing factor to its LyC detection. We obtain a revised, contamination-free estimate for the comoving specific ionizing emissivity at z=2.85, indicating (with large uncertainties) that star-forming galaxies provide roughly the same contribution as QSOs to the ionizing background at this redshift.

Our results show that foreground contamination prevents ground-based LyC studies from obtaining a full understanding of LyC emission from z~3 star-forming galaxies. Future progress in direct LyC searches is contingent upon the elimination of foreground contaminants through high spatial-resolution observations, and upon acquisition of sufficiently deep LyC imaging to probe ionizing radiation in high-redshift galaxies.