On the universality of luminosity-metallicity and mass-metallicity relations for compact star-forming galaxies at redshifts 0 < z < 3

We study relations between global characteristics of low-redshift (0 < z < 1) compact star-forming galaxies, including absolute optical magnitudes, H beta emission-line luminosities (or equivalently star formation rates), stellar masses, and oxygen abundances. The sample consists of 5182 galaxies with high-excitation H II regions selected from the SDSS DR7 and SDSS/BOSS DR10 surveys adopting a criterion [O III] lambda 4959/H beta >= 1. These data were combined with the corresponding data for high-redshift (2 less than or similar to z less than or similar to 3) star-forming galaxies. We find that in all diagrams low-z and high-z star-forming galaxies are closely related indicating a very weak dependence of metallicity on stellar mass, redshift, and star formation rate. This finding argues in favour of the universal character of the global relations for compact star-forming galaxies with high-excitation H II regions over redshifts 0 < z < 3.