I present the results of two independent searches for analogs to the first generation of galaxies. In the first, I use a compilation of spectroscopic data on the GOODS fields to select candidate Lyman continuum (LyC) leakers at z > 2.35 in the HDUV survey footprint. After removing foreground-contaminated candidates, I find 5 galaxies that remain moderately bright in F275W, which, at these redshifts, probes the rest-frame LyC. These 5 galaxies dominate the combined F275W flux output of all 129 galaxies in the parent sample, suggesting a dichotomy in LyC escape. Given that at least 1 of our 5 candidates does not show Lyman-alpha in emission, meaning it would be missed in most targeted followup programs, this work demonstrates the usefulness of direct photometric searches for LyC emitters.
In the second project, I turn my attention to intermediate redshift emission-line galaxies (ELGs), with an emphasis on finding candidate extremely-metal-poor ELGs. Using 45 deg2 of deep broad- and narrowband (NB) imaging from Subaru/Hyper SuprimeCam (HSC), I select photometric ELG candidates with a NB flux excess in the greater North Ecliptic Pole (NEP) field, which includes regions that were (or will be) covered by AKARI, Euclid, and JWST. I spectroscopically confirm ~a few hundred using Hydra on the WIYN 3.5m, allowing me to “back-calibrate” the photometric sample and derive line luminosity functions at discrete redshifts. Many of our galaxies have large rest-frame Hβ equivalent widths (~30 A or greater), which has been shown to correlate with significant emission in the [OIII] 4363 auroral line and hence extremely low metallicity.