Lyman Continuum Emission Escaping from Luminous Green Pea Galaxies at z=0.5

Understand

Compact starburst galaxies are thought to include many or most of the galaxies from which substantial Lyman continuum emission can escape into the intergalactic medium.

• Li and Malkan (2018) used SDSS photometry to find a population of such starburst galaxies at z~0.5.
• They were discovered by their extremely strong [OIII]4959+5007 emission lines, which produce a clearly detectable excess brightness in the i bandpass, compared with surrounding filters.
• We therefore used the HST/COS spectrograph to observe two of the newly discovered i-band excess galaxies around their Lyman limits.