Discovery of extreme [O III]+Hβ emitting galaxies tracing an overdensity at z ∼ 3.5 in CDF-South

Using deep multi-wavelength photometry of galaxies from ZFOURGE, we group galaxies at 2.5 6. Many of the EELGs also exhibit Ly alpha emission. Additionally, we find that many of these sources are clustered in an overdensity in the Chandra Deep Field South, with five spectroscopically confirmed members at z=3.474 +/- 0.004. The spatial distribution and photometric redshifts of the ZFOURGE population further confirm the overdensity highlighted by the EELGs.