These proceedings offer professional astronomers an overview of the rapidly advancing subject of galaxy interactions at low and high redshifts. The symposium gave participants an exciting glimpse of a developing synthesis highlighting galactic encounters and their role in the history of the Universe.

IAU Transactions are published as a volume corresponding to each General Assembly. Volume A is produced prior to the Assembly and contains Reports on Astronomy, prepared by each Commission President. The intention is to summarize the astronomical results that have affected the work of the Commission since the production of the previous Reports up to a time which is about one year prior to the General Assembly. Volume B is produced after the Assembly and contains accounts of Commission Meetings which were held, together with other material. The reports included in the present volume range from outline summaries to lengthy compilations and references. Most reports are in English.

This volume presents lectures of the XI Canary Islands Winter School of Astrophysics written by experts in the field.

Progress towards an understanding of the dynamics and interactions of galaxies has been spurred on more than ever by a wealth of new observations and numerical experiments. The Heidelberg Conference 1989, the papers of which are collected in this volume, was extremely successful in presenting a synoptic view of the field in all its aspects: galaxy interactions in the early universe and in recent times, interactions of our galaxy and its neighbours, dynamical problems of elliptical and disk galaxies, groups and clusters, starburst and nuclear activity triggered by interactions, merger scenarios, and numerical experiments. Researchers and graduate students, specialists or not, will find here a complete overview of a rapidly growing field of astronomy.

Contests the 'establishment' view of quasars as the most distant objects in the universe.

Starbursts are regions of unusually rapid star formation, often located in the central parts of galaxies. They differ from more normal regions of star formation in terms of the throughput of mass and the rapidity with which the gas is consumed. In the last twenty years, extensive observational data at most wavelengths have become available on starbursts, but many important issues remain to be addressed, observationally as well as theoretically. How are strong episodes of star formation triggered? What is the quantity of gas converted into stars during bursts? What is the initial mass function of stars in these events? How does the feedback from stars influence the interstellar medium and self-regulate star formation? What is the subsequent chemical and photometric evolution? How do starbursts rule the formation and evolution of galaxies? In recent years, many observational data at different wavelengths (optical, radio, infrared, X-ray) have become available. However, these observations are still fragmentary in the sense that different classes of objects have been observed in different ways, and the coverage is not consistently deep or complete. As a consequence, an overall observational picture of starburst galaxies is missing, and theoretical understanding and modelling have remained highly tentative. The purpose of the school Starbursts: Triggers, Nature, and Evolution was to gather theorists and observers with complementary approaches to the starburst phenomenon, in order to summarize the state-of-the-art of the observations and models, emphasizing the consistency of the various viewpoints.

This volume contains the written versions of the lectures given at the 26th course of the renowned Saas-Fee series. The book represents a comprehensive and up-to-date review of the field of galaxy interaction. Nowadays, galaxies are no longer seen as immutable objects: they evolve, interact, merge, blaze, and reshape. Dynamic forces can induce powerful stellar activity able to transform the matter composition and morphology of galaxies. The lectures included in this book aim at a better understanding of these remarkable and fascinating phenomena. Though the book is intended for graduate students and young post-docs in astrophysics, it contains more advanced and original material, as well as historical perspectives, which will be of great interest to experts and astronomy teachers also.