Physical and Morphological Parameters of [O II] Emitting Galaxies in the HETDEX Pilot Survey

The Hobby-Eberly Dark Energy Experiment (HETDEX) pilot survey found 284 [O II] λ3727 emitting galaxies in a 169 arcmin₂ field of sky in the redshift range 0 < z < 0.57. This sample provides a bridge between studies in the local universe and higher-redshift [O II] surveys. We present an analysis of the star formation rates (SFRs) of these galaxies as a function of stellar mass as determined via spectral energy distribution fitting. The [O II] emitters fall on the "main sequence" of star-forming galaxies with SFR decreasing at lower masses and redshifts. The mass specific SFR increases for lower mass objects, supporting the idea that more massive galaxies formed more quickly and efficiently than their lower mass counterparts. Examination of the morphologies of the [O II] emitters reveals that their star formation is not a result of mergers. The equivalent widths of the [O II] emission lines trend larger with larger mass galaxies. The half-light radii of the galaxies indicate that they have non-evolving physical sizes.