Green Pea Galaxies Reveal Secrets of Ly$\alpha$ Escape

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We analyze archival Ly$\alpha$ spectra of 12 "Green Pea" galaxies observed with the Hubble Space Telescope, model their Ly$\alpha$ profiles with radiative transfer models, and explore the dependence of Ly$\alpha$ escape fraction on various properties.

• Green Pea galaxies are nearby compact starburst galaxies with [OIII]$\lambda$5007 equivalent widths of hundreds of \AA.
• All 12 Green Pea galaxies in our sample show Ly$\alpha$ lines in emission, with a Ly$\alpha$ equivalent width distribution similar to high redshift Ly$\alpha$ emitters.
• Combining the optical and UV spectra of Green Pea galaxies, we estimate their Ly$\alpha$ escape fractions and find correlations between Ly$\alpha$ escape fraction and kinematic features of Ly$\alpha$ profiles.