Characterizing extreme em. line gal. II. COS & LBT

Extreme emission line galaxies (EELGs) in the nearby universe are likely analogs to galaxies during the Epoch of Reionization and provide nearby laboratories to understand the physical processes important to the early universe. We use Hubble Space Telescope/Cosmic Origins Spectrograph and Large Binocular Telescope/Multi-Object Double Spectrographs spectra to study two nearby EELGs, J104457 and J141851.

The far-UV spectra indicate that these two galaxies contain stellar populations with ages <~10Myr and metallicities <=0.15Z_{sun}_. We use photoionization modeling to compare emission lines from models of single-age bursts of star formation to observed emission lines and find that the single-age bursts do not reproduce high-ionization lines including [OIII] or very-high-ionization lines like HeII or OIV]. Photoionization modeling using the stellar populations fit from the UV continuum similarly is not capable of reproducing the very-high-energy emission lines.