Next Previous


This book is based on a lecture course given at Copenhagen University in the past few years to a mixed audience of advanced undergraduates, graduate students and some senior colleagues with backgrounds in either physics or astronomy. It is intended to cover a wide range of interconnected topics including thermonuclear reactions, cosmic abundances, primordial synthesis of elements in the Big Bang, stellar evolution and nucleosynthesis. There is also a (mainly analytical) treatment of factors governing the distribution of element abundances in stars, gas clouds and galaxies and related observational data are presented.

Some of the content of the course is a concise summary of fairly standard material concerning abundance determinations in stars, cold gas and ionized nebulae, cosmology, stellar evolution and nucleosynthesis that is available in much more detail elsewhere, notably in the books cited in the reading list or in review articles; here I have attempted to concentrate on giving up-to-date information, often in graphical form, and to give the simplest possible derivations of well-known results (e.g. exponential distribution of exposures in the main s-process). The section on Chemical Evolution of Galaxies deals with a rapidly growing subject in a more distinctive way, based on work in which I and some colleagues have been engaged over the years. The problem in this field is that uncertainties arising from problems in stellar and galactic evolution are compounded. Observational results are accumulating at a rapid rate and numerical models making a variety of often arbitrary assumptions are proliferating, leading to a jungle of more or less justifiable inferences that are often forgotten in the next instant paper. The analytical formalism on which I have been working on and off since my paper with the late B.E. Patchett in 1975, and to which very significant contributions have also been made by D.D. Clayton, M.G. Edmunds, EG.A. Hartwick, R.B. Larson, D. Lynden-Bell, W.L.W. Sargent, L. Searle, B.M. Tinsley and others, is designed not only to keep the computations simple but also to introduce some order into the subiect and provide the reader with an insight into what actually are the important factors in chemical evolution models, whether analytical or numerical, and which are the major uncertainties.

The book should be considered basically as a textbook suitable for beginning graduate students with a background in either physics or astronomy, but it is hoped that parts of it will also be useful to professional scientists. For this purpose, I have tried to keep the text as expository as possible with a minimum of references, but added notes at the ends of some chapters to provide a guide to the literature.

I should like to take this opportunity to thank Donald Lynden-Bell for arousing my interest in this subject and for his continued encouragement and stimulation over the years; and likewise Michael Edmunds, whose collaboration in both observational and theoretical projects has been a source of pleasure as well as (one hopes) insight. Thanks are due to them, and also to Sven Aberg, Chris Pethick and the late Roger Tayler, for helpful comments on successive versions. Finally, I warmly thank Elisabeth Grothe for her willing and expert work on the diagrams.

Bernard Pagel

Next Previous