New light on the search for low-metallicity galaxies

摘要

In many cases the oxygen abundance can only be estimated using empirical methods such as R_(23) (Pagel et al 1979), S_(23) (vilchez & Esteban 1996) or S_(234) (Oey & Shields 2000). But in face of the weak points and limitations of each R_(23) and S_(23(4)) methods, we understand that a more precise calibrationwith another method involving easily measurable lines, for a larger redshift range and with a monotonic low-dispersion relation, would be highly desirable.