As part of an ongoing large-scale project, here we present a detailed spectrophotometric study of a small sample of extreme emission-line galaxies at redshift 0.15-0.35, using OSIRIS (GTC) long-slit spectroscopy and broad-band imaging. These galaxies, popularly referred to as "Green Peas" (GP), are luminous, very compact objects with vigorously high specific star formation rates. Their properties seem to be uncommon in the nearby Universe, suggesting a short and extreme stage of their evolution. Our high quality GTC data allow us to (a) derive physical properties and chemical abundances of the ionized gas with high accuracy and, (b) to place constraints on the star formation history of the sample using the combined approach of evolutionary and population spectral synthesis models.
Thus, our results provide important additional clues about the nature and evolutionary state of these galaxies.