HETDEX [OIII] emitters. I. Low-z galaxies

Star-forming galaxies that occupy the lowest-mass and lowest-metallicity end of the mass-metallicity relation tend to be undersampled in continuum-based surveys as their spectra are typically dominated by emission from newly forming stars.

We search for galaxies with high [OIII]{lambda}5007/[OII]{lambda}3727, implying highly ionized nebular emission often indicative of low-metallicity systems. With the Second Generation Low Resolution Spectrograph on the Hobby-Eberly Telescope we acquired follow-up spectra, with higher resolution and broader wavelength coverage, of each low-metallicity candidate in order to confirm the redshift, measure the H{alpha} and [NII] line strengths, and, in many cases, obtain deeper spectra of the blue lines.