The gravitational million-body problem is a model for understanding the dynamics of rich star clusters. This text describes the theory astronomers need for studying globular star clusters. After introducing the million-body problem from various view-points, the book systematically develops the tools needed for studying the million-body problems in nature, and introduces the most important theoretical models. Written for graduate students and researchers in astrophysics and astronomy, this text also has important applications in the fields of theoretical physics, computational science and mathematics.

The previous Saas-Fee Advanced Course dedicated to the interstellar medium took place in 1972. The tremendous scientific advances that have occurred in this field since then, in particular owing to the availabihty of receivers working at completely unexplored wavelength bands, fuUy justified a new set of lectures. As a consequence, the members of the Swiss Society for Astrophysics and As tronomy voted that "The Galactic Interstellar Medium" should be the subject of the 1991 course. The 21st Saas Fee Advanced Course took place in Les Diablerets from 18 to 23 March 1991, gathering together about 80 participants from all over the world, but mostly from Europe. According to a rule that has proved to lead to success, but also to chal lenge the lecturers' energy, the format of a Saas-Fee Advanced Course consists traditionally of 28 lectures of 45 minutes which take place in the morning and late afternoon, leaving ample time for discussions, self-study, hiking or skiing. Despite the inordinate work load imposed, this year's lecturers felt that the subject was sufficiently dense to increase the lecture time by 1/3! This proved judicious and left more time for questions and discussions during the lectures.

It is the stars, The stars above us, govern our conditions. William Shakespeare, King Lear A Few Words about What, Why and How The structure of the stars in general, and the Sun in particular, has been the subject of extensivescienti?cresearchanddebateforoveracentury.Thediscoveryofquantum theoryduringthe?rsthalfofthenineteenthcenturyprovidedmuchofthetheoretical background needed to understand the making of the stars and how they live off their energysource. Progress in the theoryof stellar structurewasmade through extensive discussions and controversies between the giants of the ?elds, as well as brilliant discoveries by astronomers. In this book, we shall carefully expose the building of the theory of stellar structure and evolution, and explain how our understanding of the stars has emerged from this background of incessant debate. About hundred years were required for astrophysics to answer the crucial ques tions: What is the energy source of the stars? How are the stars made? How do they evolve and eventually die? The answers to these questions have profound im plications for astrophysics, physics, and biology, and the question of how we our selves come to be here. While we already possess many of the answers, the theory of stellar structure is far from being complete, and there are many open questions, for example, concerning the mechanisms which trigger giant supernova explosions. Many internal hydrodynamic processes remain a mystery. Yet some global pictures can indeed be outlined, and this is what we shall attempt to do here.

Based on a number of new discoveries resulting from 10 years of Chandra and XMM-Newton observations and corresponding theoretical works, this is the first book to address significant progress in the research of the Hot Interstellar Matter in Elliptical Galaxies. A fundamental understanding of the physical properties of the hot ISM in elliptical galaxies is critical, because they are directly related to the formation and evolution of elliptical galaxies via star formation episodes, environmental effects such as stripping, infall, and mergers, and the growth of super-massive black holes. Thanks to the outstanding spatial resolution of Chandra and the large collecting area of XMM-Newton, various fine structures of the hot gas have been imaged in detail and key physical quantities have been accurately measured, allowing theoretical interpretations/predictions to be compared and tested against observational results. This book will bring all readers up-to-date on this essential field of research.

Binary systems of stars are as common as single stars. This original text provides a pedagogical and comprehensive introduction to binary stars. The author combines theory and observations at all wavelengths to develop a unified understanding of binaries of all categories. Chapters review methods for calculating orbits, the Roche model, ideas about mass exchange and loss, methods for analyzing light curves, the masses and dimensions of different binary systems, and imaging the surfaces of stars and accretion structures. This volume offers advanced undergraduate and graduate students a thorough introduction to binary stars that will aid their learning of stellar astrophysics, stellar structure and evolution, and observational astrophysics.

In 1965 Fritz Zwicky proposed a class of supernovae that he called "Type V", described as "excessively faint at maximum". There were only two members, SN1961v and Eta Carinae. We now know that Eta Carinae was not a true supernova, but if it were observed today in a distant galaxy we would call it a "supernova impostor". 170 years ago it experienced a "great eruption" lasting 20 years, expelling 10 solar masses or more, and survived. Eta Carinae is now acknowledged as the most massive, most luminous star in our region of the Galaxy, and it may be our only example of a very massive star in a pre-supernova state. In this book the editors and contributing authors review its remarkable history, physical state of the star and its ejecta, and its continuing instability. Chapters also include its relation to other massive, unstable stars, the massive star progenitors of supernovae, and the "first" stars in the Universe.

7 Hydrodynamic Instabilities in Close Binary Systems (Frederic A. Rasio) 121 7. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . 121 7. 1. 1 The stability of self-gravitating fluid equilibria 121 7. 1. 2 Astrophysical motivation . 123 7. 1. 3 Common envelope systems 125 7. 2 Dynamical instabilities. . . . . . . 126 7. 2. 1 Physical mechanism . . . . 126 7. 2. 2 Application to coalescing neutron star binaries 127 7. 3 Secular instabilities. . . . . . . . . . . 130 7. 3. 1 Physical mechanism . . . . . . 130 7. 3. 2 Application to contact binaries 133 8 Common Envelope Evolution in Binary Systems (Mario Livio) 141 8. 1 Introduction. . . . . . . . . . . . . . . . . . . . 141 8. 2 The entrance into the common envelope phase . . . . . 142 8. 3 The outcome of the CE phase. . . . . . . . . . . . . . . 145 8. 4 How close can we get to observing the common envelope Phase? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 8. 4. 1 How can PNe with binary nuclei be used to constrain CE physics . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 8. 4. 2 How can nova systems be used to constrain CE physics 148 8. 4. 3 Other tests of common envelope evolution 150 8. 5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . 151 9 Structure and Evolution of Massive Close Binaries (Dany Vanbeveren) 155 9. 1 Introduction. . . . . . . . . . . . . . . . . . 155 9. 2 Definitions. . . . . . . . . . . . . . . . . . . 156 9. 3 Intermediate mass and massive single stars 156 9. 3. 1 Observations . . . . . . . . . . . . . 156 9. 3. 2 Stellar structure equations for non-rotating IMS's and MS's 160 9. 3. 3 Evolutionary computations of non-rotating IMS's and MS's 162 9. 3. 4 Overall comparison with observations '" 163 9. 3. 5 The role of rotation in single star evolution . . .

This thesis combines a theoretical model of galaxy formation with a treatment of the radiative transfer in the titular dusty star-forming galaxies. Embedding this within the well-established CDM (Lambda cold dark matter) cosmology, the author was able to simulate galaxy populations from which realistic observational images were synthesised. Based on further analysis, he shows that there is a good correspondence with observations from new instruments such as the SCUBA2 bolometric camera and the Atacama Large Millimeter Array (ALMA) interferometer, and reveals some novel aspects of this exciting galaxy population. In particular, he shows that blending of these galaxies in the imaging produces an artificial enhancement in their clustering, which he dubs "blending bias". This implies that the host dark matter halo masses for these galaxies have previously been significantly overestimated. He also presents amongst the first predictions from a galaxy formation model for observations of these galaxies that will be made by the James Webb Space Telescope (the successor to the Hubble Space Telescope).

The first Asia-Pacific Conference on Few-Body Problems in Physics took place from August 23 to August 28, 1999, at the Noda campus of the Sci ence University of Tokyo in Noda-city and Sawayaka Chiba Kenmin Plaza in Kashiwa-city, a suburb of Tokyo close to the Narita-Tokyo International Air port, with the Frontier Research Center for Computation Sciences (FRCCS) of the Science University of Tokyo as the host institute. The High Energy Accel erator Research Organization (KEK), the Institute of Physical and Chemical Research (RIKEN), the Research Center for Nuclear Physics (RCNP)-Osaka University, the Physical Society of Japan, and the Association of Asia Pacific Physical Societies (AAPPS) supported this conference. The conference was initiated in the Asia Pacific area as a counterpart to the successful European Conference on Few-Body Problems in Physics (APFB99), in addition to the International Few-Body Conference Series and the Few Body Gordon Conference series in North America. The Physics of Few-Body Problems covers, as is well known, systems with finite numbers of particles in contrast to many-body systems with very large numbers of particles. Therefore, it covers such wide fields as mesoscopic, atom-molecular, exotic atom, nucleon, hyperon, and quark-gluon physics, plus their applications."

X-ray binaries are stellar systems that combine one normal star (like our sun) and a smaller star, such as a white dwarf, a neutron star, or a black hole. This timely text provides a comprehensive overview of the unique and varied behavior of these combinations. Fifteen specially-written chapters by a team of the world's foremost researchers in the field explore all aspects of the X-ray binaries, including the X-ray, ultraviolet, optical, and radio properties of these violent systems, and address key issues such as how these systems formed and what their fate might be. They also discuss X-ray bursts and quasi-periodic oscillations, the connections between millisecond radio pulsars and low-mass X-ray binaries, and how the magnetic field of a neutron star decays. This long-awaited review provides graduate students and researchers with the standard reference on X-ray binaries for many years to come.

Proceedings of IAU Symposium No. 53 held in Boulder, Colorado, 21-26 August 1972

Supernovae are among the most exciting things occurring in the universe. Much recent research has concentrated on phenomena related to supernovae. For example, the origin of the cosmic rays and the origin of the bulk of the heavy elements seem to be closely associated with the phenomenon of supernovae. With the discovery of the pulsar in the Crab, it seemed clear that supernovae were also intimately as sociated with the formation of neutron stars and perhaps even black holes. The purpose of the conference, of which this volume contains the proceedings, was to bring together the leaders of supernova re search, each of whom has concentrated on different aspects of the problem, to try to form a coherent picture both observationally and theoretically of our current understanding of supernovae. In so doing, key invited talks were presented on the light curves of super novae, both observationally and theoretically; on the possible uses of supernovae, for example in determination of the Hubble Constant; on the formation and evolution of supernova remnants, again both ob servationally and theoretically. The possibility that supernovae might explain quasars was also presented. A review of the current status of statistics of supernovae was presented, giving the rate at which they go off and the implications with regard to what mass stars are the progenitors for supernovae. Again, this was presented both from the observational point of view and from the theoretical stellar evolution point of view."

'It is strongly biased towards the author's speciality of galaxy morphology, and particularly to bars and rings. To be fair, these are often given fairly short shrift in other textbooks, so this is a useful source of detail on such topics from an expert. In addition, references to original technical papers are given throughout which makes the book a handy introduction to the literature (which students may well find useful).'The Observatory MagazineThe main goal of the book is to introduce the reader to the world of spiral galaxies, how spirals were discovered, what they represent from a physical point of view, and what people have learned about the universe and the nature of galaxies in general from the study of spirals. Topics include early discoveries of nebulae, the island universe concept, the structure of spirals as seen both visually with telescopes and in images obtained with different filters, the role of spirals in the discovery of interstellar dust and dark matter, the different kinds of spiral galaxies and the importance of bars and rings, how different non-spiral galaxy types such as elliptical galaxies and S0 galaxies connect to spirals, and how spirals have contributed to our understanding of star formation and evolution, galaxy formation and evolution, the cosmological distance scale, and the universal expansion. The Milky Way as a spiral galaxy is also discussed.The book is profusely illustrated and not only a discourse on the spirals, but is also a personal reminiscence based on the author's studies of spiral galaxies over the past 45 years.

The 50th anniversary of the discovery of quasars in 1963 presents an interesting opportunity to ask questions about the current state of quasar research. Formatted as a series of interviews with noted researchers in the field, each of them asked to address a specific set of questions covering topics selected by the editors, this book deals with the historical development of quasar research and discusses how advances in instrumentation and computational capabilities have benefitted quasar astronomy and have changed our basic understanding of quasars. In the last part of the book the interviews address the current topic of the role of quasars in galaxy evolution. They summarise open issues in understanding active galactic nuclei and quasars and present an outlook regarding what future observational facilities both on the ground and in space might reveal.

Its interview format, the fascinating topic of quasars and black holes, and the lively recollections and at times controversial views of the contributors make this book both rewarding and a pleasure to read

'It is strongly biased towards the author's speciality of galaxy morphology, and particularly to bars and rings. To be fair, these are often given fairly short shrift in other textbooks, so this is a useful source of detail on such topics from an expert. In addition, references to original technical papers are given throughout which makes the book a handy introduction to the literature (which students may well find useful).'The Observatory MagazineThe main goal of the book is to introduce the reader to the world of spiral galaxies, how spirals were discovered, what they represent from a physical point of view, and what people have learned about the universe and the nature of galaxies in general from the study of spirals. Topics include early discoveries of nebulae, the island universe concept, the structure of spirals as seen both visually with telescopes and in images obtained with different filters, the role of spirals in the discovery of interstellar dust and dark matter, the different kinds of spiral galaxies and the importance of bars and rings, how different non-spiral galaxy types such as elliptical galaxies and S0 galaxies connect to spirals, and how spirals have contributed to our understanding of star formation and evolution, galaxy formation and evolution, the cosmological distance scale, and the universal expansion. The Milky Way as a spiral galaxy is also discussed.The book is profusely illustrated and not only a discourse on the spirals, but is also a personal reminiscence based on the author's studies of spiral galaxies over the past 45 years.

The book begins with a historical introduction, "Star Formation: The Early History", that presents new material of interest for students and historians of science. This is followed by two long articles on "Pre-Main-Sequence Evolution of Stars and Young Clusters" and "Observations of Young Stellar Objects". These articles on the fascinating problem of star formation from interstellar matter give a thorough overview of present-day theories and observations. The articles contain material so far unpublished in the astronomical literature. The book addresses graduate students and can be used as a textbook for advanced courses in stellar astrophysics.

More than two-thirds of stars belong to multiple stellar systems. Binary stars are considered now as one of the best constraints on stellar formation models. Not only do binaries keep memory of their birth conditions but their orbit will also be subjected to changes by tidal effects, wind accretion and encounters in clusters. Certainly the correlation between orbital eccentricity and period is a clue to our understanding of double star history. These proceedings aim to disentangle evidence of stellar formation from later physical evolution. Each article in this 1992 volume is a paper that was read at a meeting organized to honour Dr Roger Griffin of the University of Cambridge for his pioneer work in galactic astronomy, dynamics of clusters and study on binary stars due to his cross-correlation technique to determine stellar radial velocities.

This long-awaited "second edition" of the classical textbook on "Stellar Structure and Evolution" by Kippenhahn and Weigert is a thoroughly revised version of the original text. Taking into account modern observational constraints as well as additional physical effects such as mass loss and diffusion, Achim Weiss and Rudolf Kippenhahn have succeeded in bringing the book up to the state-of-the-art with respect to both the presentation of stellar physics and the presentation and interpretation of current sophisticated stellar models. The well-received and proven pedagogical approach of the first edition has been retained.
The book provides a comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The models developed to explain the stability, dynamics and evolution of the stars are presented and great care is taken to detail the various stages in a star's life. Just as the first edition, which remained a standard work for more than 20 years after its first publication, the second edition will be of lasting value not only for students but also for active researchers in astronomy and astrophysics.

On March 28 and 29, 1969, at the occasion of the dedication of the European Southern Observatory, some 90 astronomers from all over the world gathered at the ESO headquarters at Santiago de Chile for discussing problems of the Magellanic Clouds. They came from Argentina, Australia, Chile, Mexico, South Mrica and the United States as well as from Europe; these latter, naturally, mostly from the member states ofESO. The choice of the subject was an obvious one. When erecting the European Southern Observatory as a joint effort in European astronomy, it was agreed from the beginning that the field of research should be the southern sky, so far hardly explored with large telescopes. Among the objects to be investigated, the Magellanic Clouds rank highest, together with the galactic centre region and the southern spiral structure. Being located ten times closer than the nearest large stellar systems accessible to northern observers, and containing a stellar population ranging in age from the oldest down of star formation, the Clouds provide an ideal laboratory for research on to the stage current problems in astrophysics. Yet, most of the northern observational astronomers were hardly acquainted with the Magellanic Clouds; naturally, they are used to think in terms of research projects that can be conducted at their observatories. A survey of the status of knowledge and research on the Clouds therefore appeared in order now that the first- medium size- telescopes of ESO came into operation.

It is well known that stellar winds are variable, and the fluctuations are often cyclical in nature. This property seems to be shared by the winds of cool and hot stars, even though their outflows are driven by fundamentally different physical mechanisms. Since very similar models have been proposed to explain the cyclical wind variations observed in a wide variety of stars, the time was ripe for astrophysicists from many different sub-disciplines to present the state of the art in a concise form. The proceedings will provide a useful, up-to-date overview of the observations, interpretation, and modelling of the time-dependent mass outflows from all sorts of stars.