ON THE OXYGEN AND NITROGEN CHEMICAL ABUNDANCES AND THE EVOLUTION OF THE “GREEN PEA” GALAXIES

摘要: We have investigated the oxygen and nitrogen chemical abundances in extremely compact star-forming galaxies (SFGs) with redshifts between {approx}0.11 0.35, popularly referred to as 'green peas'. Direct strong-line methods sensitive N/O ratio applied their Sloan Digital Sky Survey (SDSS) spectra reveal that these systems are genuine metal-poor galaxies, mean {approx}20% solar. At a given metallicity display systematically large ratios compared normal which can explain strong difference our metallicities measurements previous ones. While follow relation stellar mass of local SFGs SDSS, we find mass-metallicity peas' is offset {approx_gt}0.3 dex lower metallicities. argue recent interaction-induced inflow gas, possibly coupled selective metal-rich gas loss, driven by supernova winds, may findings known galaxy properties, namely high specific star formation rates, extreme compactness, disturbed optical morphologies. The pea' properties seem be uncommon nearby universe, suggesting short stage evolution. Therefore, allow us study great detail many processes, such starburst activitymore » enrichment, under physical conditions approaching those at higher redshifts.« less