New Insights on Ly-alpha and Lyman Continuum Radiative Transfer in the Greenest Peas

Understand

As some of the only Lyman continuum (LyC) emitters at z~0, Green Pea (GP) galaxies are possible analogs of the sources that reionized the universe.

• We present HST COS spectra of 13 of the most highly ionized GPs, with [O III]/[O II]=6-35, and investigate correlations between Ly-alpha, galaxy properties, and low-ionization UV lines.
• Galaxies with high [O III]/[O II] have higher H-alpha equivalent widths (EWs), and high intrinsic Ly-alpha production may explain the prevalence of high Ly-alpha EWs among GPs.
• While Ly-alpha escape fraction is closely linked to low gas covering fractions, implying a clumpy gas geometry, narrow Ly-alpha velocity peak separation (delta_v,LyA) correlates with the ionization state, suggesting a density-bounded geometry.