Abstract

Aims. The purpose of this work is to make available new gas-phase oxygen abundance measurements for a serendipitous sample of 27 galaxies with redshifts 0.35 = z = 0.52. Methods. We measured the equivalent widths of the [OII]lambda 3727, H beta, and [OIII]lambda lambda 4959, 5007 emission lines observed in the galaxy spectra obtained with the Visible Multi-Object Spectrograph mounted at the Very Large Telescope. For each galaxy, we derived the metallicity-sensitive emission-line ratio R-23, ionization-sensitive emission-line ratio O-32, and gas-phase oxygen abundance 12 + log(O/H). Results. The values of the gas-phase oxygen abundance 12 + log(O/H) that we obtained for all the sample galaxies are consistent with previous findings for galaxies at intermediate redshift.