CELGs - Compact emission-line galaxies studied with S-PLUS and 4MOST

CELGs - Compact emission-line galaxies studied with S-PLUS and 4MOST We propose 4MOST/LRS observations of 516 compact emission-line galaxies (CELGs), local analogues of high-z star-forming systems that are systematically missed by spectroscopic surveys due to their star-like morphology. Our candidates are selected from S-PLUS imaging, using their strong [OIII] emission at z≈0.3 to overcome this selection bias. This program will build the first large, spectroscopically-confirmed catalogue of this unexplored population. Our primary goals are to: (1) secure definitive redshifts; (2) characterize ionization sources (star formation vs. AGN) using key diagnostic lines ; and (3) determine physical properties, including SFRs, gas-phase metallicities, and stellar masses, to probe the drivers of compact starbursts and their evolutionary role across cosmic time.