Recent advances in observational and theoretical efforts in understanding the nature of cataclysmic variables had reached such maturity that there existed a strong, shared feeling among the workers in this field that an international colloquium sponsored by the International Astronomical Union would be timely. To be more specific, this was due primarily to the accumulation of the new data from satellite observatories, such as the International Ultraviolet Observatory (IUE) and EXOSAT, as well as ground-based optical and radio telescopes, and the advances in modeling the putative accretion disks and the thermo-nuclear run-away phenomena in the vinicity of the white dwarf stars in cataclysmic variables. A series of workshops on this subject held in North America over the past several years and that held in Europe in 1985 had all contributed to the advances in our knowledge that led to IAU Colloguium No. 93, held in Bamberg from the 16th to 19th of June 1986. In all, 157 astronomers from 27 countries participated in this conference. Judging from the papers presented, both invited and contributed, and from the enthusiasm seen in discussions, the meeting was indeed a success.

The articles collected in this volume cover topics ranging from Planck-scale physics to galaxy clustering. They deal with various new ideas from cosmology, astrophysics and particle physics that might lead to a better understanding of our physical universe. Among the topics covered are inflationary models, nucleosynthesis, dark matter, large-scale clustering, cosmic microwave background radiations and more. The book addresses researchers but it also gives a good overview of the subject for graduate students in astrophysics and particle physics.

In this volume seven leading theoreticians and experimenters review the origin of the asymmetry of matter and antimatter in the Big Bang, solar neutrinos, the physics of enormous densities and temperatures in stars and of immense magnetic fields around collapsed stars, strong electric fields in heavy ion collisions, and the extreme conditions in quark-gluon plasmas. The articles address nuclear and particle physicists, especially graduate students, but also astrophysicists and cosmologists, since they have to deal with events under the extreme physical conditions discussed here.

Le ciel est, par-dessus le toit, The sky is, up above the roof, Si bleu, si calme So blue, so calm Un arbre, par-dessus Je toit, A tree there, up above the roof, Berce sa palme. Waves leaves of palm. La cloche, dans le ciel qu'on voit, A church bell, in the sky I see, Doucement tinte. Softly tolls. Un oiseau, sur l'arbre qu'on voit, A bird, upon the tree I see, Chante sa plainte. Sadly calls. PAUL VERLAINE Like Verlaine, we are in prison. The prison is our Earth, "which is so pretty"; our atmosphere and its clouds, its "marvellous clouds." (You would think that Verlaine, Prevert and Baudelaire had been comparing notes ) The sky is up above the roof... A tree there, up above the roof... Stars in the sky, like birds ... their rays, like bells (and here we are with Apollinaire ) What we see opens the way to what we guess at; what we observe Ieads us towards the unobservable. A poem releases images, and the invisible grows big with reality. Astronomcrs are a little like poets (indirectly from the Greek 7tostco, make): they make the universe by interpreting messages, extrapolating spectra, and inventing 'models' of the cosmos or of stars - fictional constructions whose observable part constitutes only a small fraction of the whole, and which only the inductive logic of the theoretician allows us to consider as representing unique physical reality.

The present volume colleets the review and contributed papers presented at the Europhysics Study Conferenee "Acere- tion Disks and Magnetie Fields in Astrophysies" held in Noto, Sicily, Italy, from 16 to 21 June 1988, under the High Patronage of the President of the Italian Republie and the 10ea1 patronage of the Cent ro di Studi Superiori e di Rieer- ehe (Center for Advaneed Study and Research), a seientific institution supported by the City of Nota and the Oniversity of Catania. The attendanee to the Conferenee was limited to about fifty seleeted partieipants from Canada, China, Denmark, Franee, Germany F.R., Italy, Japan, the Netherlands, Spain, Sl~itzerland. Onited Kingdom and Onited States, in order to give the meeting the character and appearance of areal lolorkshop, whose main aim was to highl ight a varied but same wh at uni fied picture of the interact ion, in di fferent astrophysical systems, of rotation, turbulenee and magnetism, with speeifie referenee to aeeretion disks.

The universe is the largest system of all. It consists of elementary particles bound together by gravitational, electromagnetic and nuclear forces. Its structural hierar chy in space (from atomic nuclei to supergalaxies) and its evolutionary sequence (from the fireball to the diversity of present forms) is governed by the properties of elementary particles and their interactions. This book is an attempt to interpret the structure and evolution of the universe in terms of elementary particles and of their interactions. This book is intended to present a background for students in astronomy and related sciences, such as geophysics, meteorology, plasma physics, chemistry, nuc lear physics, space sciences and some others. The universe forms a general framework fo: all the phenomena studied by these sciences. It was possible to squeeze an extensive range of topics from various disciplines into one book of acceptable size only under some severe limitations: (a) no references are given; (b) arguments are shortcut; (c) quantities are often expressed in the order of magnitude; and (d) formulae have been limited to a minimum. Often more hypo theses or theories exist for a phenomenon. We have chosen only one. The preference for a theory or hypothesis may be personal and the theory itself may later prove incorrect. But, many theories about a particular phenomenon would cover many pages and might lead to confusing effects."

The articles in this book deal with energetic hadron processes near astrophysical compact objects, including compact binary systems and active galactic nuclei. A variety of observational results suggest that relativistic hadrons can be produced in the vicinity of these objects. Amongthe topics treated in detail are the question whether a large fraction of the energy produced by active galactic nuclei is channeled into a population of relativistic protons and the problem of the origin of very high and ultra-high energy gamma rays from galactic compact sources.

This collection of papers presents a rather complete review of current knowledge of hot spots in some strong extragalactic radio sources. An overview of known results along with new data on radio observations and optical observations is given in the first and second parts of the book. Recent computational techniques which allow modelling and simulations of hot spots and jet behaviour are presented in the third part. The fourth part discusses particle acceleration and shock front phenomena. The articles will help the reader to appreciate the role hot spots play as laboratories for studying the interaction of jets with the surrounding medium and for testing our understanding of the overall source dynamics. The book is a valuable complement to the existing literature and an excellent introduction to this fairly new field of research.

The observational evidence for the existence of black holes has grown significantly over recent decades. Stellar-mass black holes are detected as X-ray sources in binary systems, while supermassive black holes, with masses more than a million times the mass of the Sun, lurk in the nuclei of galaxies. These proceedings provide a useful and up-to-date overview of the observations of black holes in binaries, in the center of the Milky Way, and in the nuclei of galaxies, presented by leading expert astronomers. Special attention is given to the formation (including the recent evidence from gamma-ray bursts), physical properties, and demographics of black holes.

This outstanding collection of surveys addresses graduate and predoctoral students. It reports on theoretical research and observational data on active galactic nuclei: The enigma of the nuclei of galaxies with their central "monster" driving the vast range of activity observed in quasars, radio galaxies, Seyferts, starburst galaxies and even our own Galaxy are explored in this volume. Topics covered include: the impact of recent measurements in the infrared and radio region on our knowledge of thenucleus of our Galaxy; the spectra and classification of active galactic nuclei, the properties of their host galaxies, their cosmological distribution and evolution, the role of stars and thehydrodynamics of the interstellar medium in the nuclei; the description of the inner parsec of a standard active galactic nucleus based on direct interpretation of the observations; the infrared activity of galaxies; the physics of radio galaxies and their jets, emphasizing the physics ofgas flow and high-energy particle interactions as well as shock acceleration. These are all discussed in considerable depth and presented inself-contained chapters with exhaustive reference lists of the scientific literature.

Extinction and standardization corrections to infrared measurements are of the utmost importance in astronomy. Various views on these concepts and problems of implementation in infrared photometry are discussed thoroughly and recommendations are presented. Among these are: the adoption of narrower broad-band "Johnson" filters that are better centered in the atmospheric water windows than is currently the case; the measurements of atmospheric water vapor content concurrent with the astronomical measurements; the use of appropriate atmospheric models to treat the extinction adequately; and the publication of complete details of the systemic passbands and their transformability to other systems. To conclude the volume, R. Bell summarizes and comments on the contributions to the symposium, and the editor adds a concluding postscript on post-meeting developments and perspectives.

Indispensable for the building of cosmological models are precise observational data. To provide such data is the main purpose of this book. First, an analysis of recent cosmological observations using artificial satellites and large ground-based telescopes is given. Among these are the observation of the spatial distribution of galaxies and clusters, the detection of peculiar velocity fields in large regions, and the measurement of anisotropies in the microwave background radiation. Second, the authors present theoretical models which best fit the given observational data. The book addresses graduate students and astronomers and astrophysicists.

This volume gives a comprehensible survey of BL Lac objects: contributors summarize observations on these interesting astrophysical objects and present theoretical models to explain them. Understanding these objects should help to give a better insight into the physics of black holes and relativistic plasmas. Topics addressed cover radio jets expanding at superluminal velocities, possible effects of relativistic jets on interstellar matter, the continuum emission over the whole electromagnetic system and its variability, and the impact of these observations on gravitational lensing and cosmological evolution. The book should be immensely useful for graduate students.

This book contains the contributed papers and reviews from IAU Colloquium Number 114 on White Dwarfs held at Dartmouth College in August 1988. All the current fields of research in this area are covered including the evolution of white dwarfs, links to progenitors, luminosity functions of white dwarfs, evolution of white dwarfs in binaries, spectroscopy and atmospheric abundances, diffusion, accretion and convective mixing, the mass-radius relation, gravitational redshifts, masses of white dwarfs, and magnetic white dwarfs. Special emphasis has been placed on the intrinsic properties of single white dwarfs. All the articles are by internationally known authorities and contain the most up-to-date information available at the time of writing.

Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysics, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 39 records literature published in 1985 and received before August 15, 1985. Some older documents which we received late and which are not surveyed in earlier volumes are included too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. On account of the introduction of an object index the scope of index information will be considerably enlarged beginning with this volume. In connection with the subject index an additional source to satisfy the needs of retrieval is opened up. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Mona El-Choura, Ms. Monika Kohl, Ms. Sylvia Matyssek. Ms. Karin Burkhardt, Ms. Susanne Schlotelburg, and Mr. Stefan Wagner supported our task by careful proofreading. It is a pleasure to thank them all for their encouragement. Heidelberg, September 1985 The Editors Contents Introduction . . . . . . . . . . . .

Advances in the dynamics of stellar systems have been made recently by applying mathematical methods of ergodic theory and chaotic dynamics, by numerous computer simulations, and by observations with the most powerful telescopes. This has led to a considerable change of our view on stellar systems. These systems appear much more chaotic than was previously thought and subject to various instabilities leading to new paths of evolution than previously thought. The implications are fundamental for our views on the evolution of the galaxies and the universe. Such questions are addressed in this book, especially in the 8 review papers by leading experts on various aspects of the N-body problem, explaining at the graduate/postgraduate level the concepts, methods, techniques and results.

The volume consists of up-to-date reviews and a selection of contributed papers on subjects including the structure and physical properties of molecular clouds, their role in the star formation process, their dust and chemical properties, molecular cloud surveys of the Milky Way, cloud evolution, problems in cloud mass determinations (a panel discussion and review), the CO properties of external galaxies, nuclei of galaxies as revealed by molecular observations, and galactic spiral structure as reflected by molecular cloud distributions. The abstracts of poster papers on these topics presented at the conference are also included. This book is both a valuable reference and a compendium of current knowledge in this field. It should be of special interest to all students and researchers who work on the physics of star formation, the interstellar medium, molecular clouds and galactic structure.

Meant as a review for students of astrophysics and particle physics, this book contains a selection of survey articles and seminar reports on "high energy cosmology." Included are contributions on topics ranging from classical cosmology, large scale structure, and primordial nucleosynthesis to quantum cosmology, covering both the theoretical aspects and the most important observations.

This book begins with a very readable survey "The Sun Today" by J.-C. Pecker. It is followed by thorough reviews from leading experts covering theory and observations. The focus shifts from the solar core, studied via neutrino emissions and helioseismology, through the interface regions where it is believed the large-scale magnetic fields are generated, to the corona, where most of the high temperature phenomena characteristic of this region may be studied directly. As energetic particles play such a vigorous role in this part of the sun, a separate session was devoted to their transport and storage in the corona.

This ESO workshop, which took place in September 1995 on a topic that at a first glance could be considered rather specialized, attracted an unpre dictably large number of scientists. This certainly reflects the importance of this field, which has lost its seemingly esoteric character, in a wider astro physical context. To give as much room as possible in these proceedings to the targeted talks, no presentation of the Very Large Telescope Observatory has been included. All readers missing such a presentation are reminded that up-to date in-depth information about the VLT status is available electronically.1 Papers were given concerning observations in the entire electromagnetic spectrum from x-rays to mm-waves, i.e., exceeding 22 octaves in frequency. The VLT as any ground-based optical observatory can only address at best 7 octaves. Nevertheless the VLT, most likely the only ground-based observa tory specifically designed to access all these 7 octaves of the electromagnetic spectrum practically in parallel, will undoubtedly be a tool of extreme value to this field.

A detailed study of the science, engineering and applications of terahertz technology, based on room-temperature solid-state devices, which are seen as the key technology for wider applications in this frequency range. The relative merits of electronic and optical devices are discussed and new device principles identified. Issues of terahertz circuit design, implementation and measurement are complemented by chapters on current and future applications in communications, sensing and remote surveillance. Audience: The unique coverage of all aspects of terahertz technology will appeal to both new and established workers in the field, as well as providing a survey for the interested reader.