Among 'empirical' methods of estimating oxygen abundances in extragalactic H ii regions, the use of the ratio of nebular lines of [O iii] and [N ii], first introduced by Alloin et al. in 1979, is reappraised with modern calibration data and shown to have certain advantages over R 23 ≡ ([O ii] + [O iii])/Hβ and N 2 ≡ [N ii] λ6583/Hα, particularly when applied to star-forming galaxies at high redshifts.

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The distribution of elements in the cosmos is the result of many processes, and it provides a powerful tool to study the Big Bang, the density of baryonic matter, nucleosynthesis and the formation and evolution of stars and galaxies. Covering many exciting topics in astrophysics and cosmology, this textbook, by a pioneer of the field, provides a lucid and wide-ranging introduction to the interdisciplinary subject of galactic chemical evolution for advanced undergraduates and graduate students. It is also an authoritative overview for researchers and professional scientists. This new edition includes results from recent space missions and new material on abundances from stellar populations, nebular analysis, and meteoric isotopic anomalies, and abundance analysis of X-ray gas. Simple derivations for key results are provided, together with problems and helpful solution hints, enabling the student to develop an understanding of results from numerical models and real observations.

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