Early Results from GLASS-JWST. XXII. Rest-frame UV-Optical Spectral Properties of Lyα Emitting Galaxies at 3 < z < 6

Ly alpha emission is possibly the best indirect diagnostic of Lyman continuum (LyC) escape since the conditions that favor the escape of Ly alpha photons are often the same that allow for the escape of LyC photons. In this work, we present the rest-frame UV-optical spectral characteristics of 11 Ly alpha emitting galaxies at 3 < z < 6-the redshift range that optimizes between intergalactic medium attenuation effects and temporal proximity to the epoch of reionization. From a combined analysis of JWST/NIRSpec and MUSE data, we present the Ly alpha escape fraction and study its correlation with other physical properties of galaxies that might facilitate Ly alpha escape. We find that our galaxies have low masses (80% of the sample with log(10) M-star 9.5 M-circle dot), compact sizes (median R-e similar to 0.7 kpc), low dust content, moderate [O III]/[O II] flux ratios (mean similar to 6.8 +/- 1.2), and moderate Ly alpha escape fractions (mean f(esc)(Ly alpha) similar to 0.11). Our sample shows characteristics that are broadly consistent with low-redshift galaxies with Ly alpha emission, which are termed as "analogs" of the high-redshift population. We predict the LyC escape fraction in our sample to be low (0.03-0.07), although larger samples in the postreionization epoch are needed to confirm these trends.