Using Mg ii Doublet to Predict the Lyman Continuum Escape Fraction from 14 HETDEX Galaxies

Abstract

Abstract Indirect diagnostics of Lyman continuum (LyC) escape are needed to constrain which sources reionized the universe. We used Mg ii to predict the LyC escape fraction ( f esc LyC ) in 14 galaxies selected from the Hobby-Eberly Telescope Dark Energy Experiment solely based upon their Mg ii properties. Using the Low Resolution Spectrograph on HET, we identified 7 and 5 possible LyC leakers depending on the method, with f esc LyC ranging from 3% to 80%. Interestingly, our targets display diverse [O iii]/[O ii] ratios (O32), with strong inferred LyC candidates showing lower O32 values than previous confirmed LyC leaker samples. Additionally, a correlation between dust and f esc LyC was identified. Upcoming Hubble Space Telescope/Cosmic Origins Spectrograph LyC observations of our sample will test if Mg ii and dust are predictors of f esc LyC , providing insights for future JWST studies of high-redshift galaxies.