Abstract
Investigating the impact of galaxy properties on emergent Lyman-alpha emission is a crucial aspect of reionization studies, given the sensitivity of Lyman-alpha to neutral hydrogen. This study presents an analysis of the physical characteristics of 155 star-forming galaxies, 29 w/ Lyman-alpha detected, and 126 w/ Lyman-alpha not detected w/ EW < 20 Angstroms, at z = 1.9 -- 3.5, drawn from the MOSFIRE Deep Evolution Field (MOSDEF) survey that have overlapping observations from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) survey. To unravel the interstellar medium (ISM) conditions in our sample, we developed a custom nebular line diagnostic algorithm based on the MAPPINGS V photoionization model grid and the emcee framework. Combining nebular-based ISM properties with photometry-based global properties, constrained via Bagpipes, we explore distinctions in the stellar and gas properties between Lyman-alpha detected and Lyman-alpha non-detected galaxies. Our analysis reveals statistically significant differences between the two samples in terms of stellar mass and dust attenuation at > 2 sigma significance, as determined via a Kolmogorov-Smirnov (KS) test. Moreover, there are weaker (< 1 sigma significance) indications that the ionization parameter and metallicity exhibit differences between the two samples. Our results also demonstrate that the escape fraction of Lyman-alpha is inversely correlated with stellar mass, SFR, and dust attenuation, while positively correlated with the ionization parameter, with significance levels exceeding 2 sigma. Our findings suggest that the interstellar environment of the Lyman-alpha detected galaxies, characterized by low mass, low dust, low gas-phase metallicity, and high ionization parameters, play a pivotal role in promoting the escape of Lyman-alpha radiation.
