ThlS volume contalns a serles of lectures presented at the NATO Advanced Study Instltute on Hlgh Energy Phenomena Around Collapsed Stars, held ln Cargese, CorSlca from September 2 tlll Septemcer 13, 1985. The course was planned ln collaboratlon wlth a SClentlflC Organiz ing Commlttee (C. Cesarsky, France; A. Lyne, U.K.; D. Plnes, USA; J. Trlimper, W. Germany; E. Van den Heuvel, The Netherlands and L. Wolt]er, E.S.O., Mlinlch) and was fully supported by the NATO SClentlflc Affalrs Dlvlsion. It was organized wlth the alm of provldlng students and young researchers with an up-to-date account on the subject of galactlc hlgh energy astrophyslCS and was attended by about 60 researchers from many countrles. The lectures and seminars dld represent a complete coverage of our present knowledge and understandlng of Supernovae, Supernovae Remnants, Pulsars, sources of hlgh energy photons and partlcles. Most of them are reproduced ln thlS volume although unfortunately a few speakers chose not to submlt thelr text Slnce they felt that the materlal was already amply avallable ln the eXlstlng llterature. I wlsh to express my gratltude to the SClentlflc Affalrs Dlvislon of the North Atlantlc Treaty Organlzatlon for the generous support glven to the Instltute and to the lecturers and particlpants who contributed so much to the success of the course."

The search for Dark Matter in the Universe has established itself as one of the most exciting and central fields of astrophysics, particle physics and cosmology. The lectures and talks in this book emphasize the experimental and theoretical status and future perspectives, stressing in particular the interplay between astro- and particle physics.

This book presents the proceedings of the IVth Azores International Advanced School in Space Sciences entitled "Asteroseismology and Exoplanets: Listening to the Stars and Searching for New Worlds". The school addressed the topics at the forefront of scientific research being conducted in the fields of asteroseismology and exoplanetary science, two fields of modern astrophysics that share many synergies and resources. These proceedings comprise the contributions from 18 invited lecturers, including both monographic presentations and a number of hands-on tutorials.

This book serves as a good introduction to the physics of pulsars by explaining the subject matter in simple terms which are understandable to both undergraduate physics students and also the general public. On the Pulsar links together ideas about physics, informatics and biology, and contains many original examples, problems and solutions. It starts with simple examples about the regular structures that are possible in strong magnetic fields and the author then suggests that special conditions on the pulsar can result in some forms of self-organization. It will also make a valuable teaching guide.

In addition to being fascinating astrophysical laboratories in their own right, Herbig-Haro flows have in recent years emerged as key phenomena in our attempts to understand the complex and violent processes that govern the birth of low mass stars. This work provides an overview of the major advances which the study of Herbig-Haro jets has enjoyed since 1995. On the observational side, Hubble Space Telescope images have revealed the intricate details of the shock structures in these supersonic flows, millimetre interferometry and infrared imaging can now probe the detailed structure of the molecular component of deeply embedded jets, and sub-millimetre and radio continuum maps now enable us to study the near environment of the optically invisible driving sources of jets. On the theoretical side, detailed numerical and analytical magnetohydrodynamic models have reached a level of sophistication that allows realistic comparison with observations and insights into the jet formation mechanisms. Similarly detailed observational and theoretical studies of the disks and winds of T Tauri stars are now gradually being linked to the Herbig-Haro flows, providing a first glimpse of how stars can be born by both accreting and ejecting infalling material.

1-Pre-White Dwarf Evolution and White Dwarf Cooling.- New pre-white dwarf evolutionary tracks.- Influence of the phase diagram in the cooling of white dwarfs.- PG1159 stars and the PNN-white dwarf connection.- Analysis of the soft X-ray data from the central star of NGC 7293.- Planetary Nebulae Nuclei with white dwarf spectra.- Atmospheric parameters of subluminous B stars.- White dwarf space densities and birth rates reconsidered.- A spectroscopic determination of the mass distribution of DA white dwarfs.- The age and formation of the Galaxy: clues from the white dwarf luminosity function.- Early results from the ROSAT Wide Field Camera.- The stellar component of the Hamburg Schmidt Survey.- White dwarfs in the Hamburg Schmidt Survey.- 2-Asteroseismology of White Dwarfs.- Asteroseismology of white dwarf stars with the Whole Earth Telescope.- A measurement of the evolutionary timescale of the cool white dwarf G117-B15A with WET.- On the interpretation of the dP/dt measurement in G117-B15A.- The boundaries of the ZZ Ceti instability strip.- Long term variations in ZZ Cetis: G191-16 and HL Tau 76.- Predicting the white dwarf light curves.- A wavelet analysis of the ZZ Ceti star G191 16.- An adiabatic survey for ZZ Ceti stars based on a finite element code.- A study of period change rates in post-AGB stars I. PG 1159-035.- Nonadiabatic nonradial pulsations for DAV white dwarf stars.- 3-Atmospheres and Envelopes.- NLTE Analysis of four PG1159 stars.- A search for trace amounts of hydrogen in DB stars.- Abundances of trace heavy elements in hot DA white dwarfs.- New results on radiative forces on iron in hot white dwarfs.- The effective temperature of the DBV's, and the sensitivity of DB model atmospheres to input physics.- The modified hydrostatic equilibrium equations for stratified high gravity stellar atmospheres.- The DBAQ G35-26.- LP 790-29: preliminary model atmospheres for this strongly polarized carbon white dwarf.- Some effect of the UV radiation from white dwarfs on the accretion of interstellar hydrogen.- Convection in white dwarfs: application of CM theory to helium envelope WDs.- Abundances in cool DZA and DAZ white dwarfs: new results using laboratory damping constants.- Evidence for fractionated accretion of metals on cool white dwarfs.- A new look at old friends: 40 Eri B and GD 323.- The Lyman Alpha line wing in hydrogen-rich white dwarf atmospheres.- Atmospheric parameters for DA white dwarfs in the vicinity of the ZZ Ceti instability strip.- Space Telescope observations of white dwarf stars.- 4-White Dwarfs in Binaries.- A deep spectroscopic survey of white dwarfs in common proper motion binaries.- Double degenerate common proper motion binaries.- Close binary white dwarfs.- New results on cataclysmic variable white dwarfs.- Whole Earth Telescope observations of the interacting white dwarf binary system AM CVn: first results.- IUE observations of V803 Cen in high and low states.- Whole Earth Telescope observations of PG1346+082.- On the origin of LMXRBS: the ONEMG case.

This book presents the status of research on very massive stars in the Universe. While it has been claimed that stars with over 100 solar masses existed in the very early Universe, recent studies have also discussed the existence and deaths of stars up to 300 solar masses in the local Universe. This represents a paradigm shift for the stellar upper-mass limit, which may have major implications far beyond the field of stellar physics. The book comprises 7 chapters, which describe this discipline and provide sufficient background and introductory content for graduate (PhD) students and researchers from different branches of astronomy to be able to enter this exciting new field of very massive stars.

The presentations of this NATO Advanced Study Institute centre around X-ray clusters of galaxies and their role in understanding the structure and evolution of the universe. Reminiscences of the beginning of the extra-solar X-ray astronomy some 30 years ago, of subsequent X-ray satellites which, among other discoveries, found galaxy clusters to be an important new class of intrinsically bright X-ray sources, and highlights from the most recent All Sky Survey by ROSAT serve as an introduction. The topics range from X-ray clusters and cluster environments to cluster masses and dynamics, cooling flows and chemical abundances, cluster lensing and the Sunyaev-Sel'dovich effect, cluster formation and evolution to large-scale structure in the universe and cosmological parameters. The reviews, introducing the various topics, generally conclude with presentations of current and future work and are frequently followed by shorter research notes pertaining to ongoing projects. More than 200 figures illustrate the discussions, more than 20 tables and many quotations in the text provide numerical data for almost 100 clusters of galaxies and give new estimates for the cosmological parameters. Together with a sample of equations, this text should constitute a useful collection of empirical and theoretical quantities and relations in extragalactic X-ray astronomy and cosmology.

Proceedings of IAU Symposium No. 44 held in Uppsala, Sweden, August 10-14, 1970

This text comprises selected lectures presented in the 9th course of the International School of Cosmic-Ray Astrophysics held at the Ettore Majorana Centre in Erice, Sicily, May 7-18, 1994. Devoted to problems and prospects in high-energy astrophysics and cosmology, the major areas explored are: gamma- ray, X-ray, and neutrino astronomies; cosmic rays; pulsars and supernova remnants; and cosmology, as well as cosmogony. Among the principal developments in gamma-ray astrophysics are those generated by the Compton Gamma Ray Observatory. Cosmic neutrinos at MeV energies, i.e. those from the Sun and from Supernova 1987a are discussed, as well as neutrino masses in astrophysics. The source composition of cosmic rays and extensive air shower experiments receive special attention. The early universe according to COBE data, and as viewed by theorists of cosmology, is reviewed.

This Symposium on fundamental stellar properties was held to honour Emeritus Professor Robert Hanbury Brown on the occasion of his 80th birthday. The speakers described current advances in interferometry, astrometry, spectroscopy and in theoretical models of stellar atmospheres and interiors. The emphasis was on the critical assessment of the quality, accuracy, and prospects for improvement of the observational data and theoretical models, on the outstanding problems in stellar astrophysics, and on the feasibility of achieving the observational and theoretical advances required for their solution. These proceedings should be of interest to researchers and graduate students in all fields of astrophysics.

This book highlights selected topics of standard and modern theory of accretion onto black holes and magnetized neutron stars. The structure of stationary standard discs and non-stationary viscous processes in accretion discs are discussed to the highest degree of accuracy analytic theory can provide, including relativistic effects in flat and warped discs around black holes. A special chapter is dedicated to a new theory of subsonic settling accretion onto a rotating magnetized neutron star. The book also describes supercritical accretion in quasars and its manifestation in lensing events. Several chapters cover the underlying physics of viscosity in astrophysical discs with some important aspects of turbulent viscosity generation. The book is aimed at specialists as well as graduate students interested in the field of theoretical astrophysics.

This timely volume provides comprehensive coverage of all aspects of cosmology and extragalactic astronomy at an advanced level. Beginning with an overview of the key observational results and necessary terminology, it covers important topics: the theory of galactic structure and galactic dynamics, structure formation, cosmic microwave background radiation, formation of luminous galaxies in the universe, intergalactic medium and active galactic nuclei. This self-contained text has a modular structure, and contains over one hundred worked exercises. It can be used alone, or in conjunction with the previous two accompanying volumes (Volume I: Astrophysical Processes, and Volume II: Stars and Stellar Systems).

Olbers' paradox states that given the Universe is unbounded, governed by the standard laws of physics, and populated by light sources, the night sky should be ablaze with light. Obviously this is not so. However, the paradox does not lie in nature but in our understanding of physics. A Universe with a finite age, such as follows from big-bang theory, necessarily has galaxies of finite age. This means we can only see some of the galaxies in the Universe, which is the main reason why the night sky is dark. Just how dark can be calculated using the astrophysics of galaxies and stars and the dynamics of relativistic cosmology.
We know from the dynamics of individual galaxies and clusters of galaxies that the majority of matter that exerts gravitational forces is not detectable by conventional telescopes. This dark matter could have many forms, and candidates include various types of elementary particles as well as vacuum fluctuations, black holes, and others. Most of these candidates are unstable to decay and produce photons. So dark matter does not only affect the dynamics of the Universe, but the intensity of intergalactic radiation as well. Conversely, we can use observations of background radiation to constrain the nature and density of dark matter.
By comparing observational data with cosmological theory based on general relativity and particle physics, Dark Sky, Dark Matter reviews our present understanding of the universe and the astrophysics of the night sky and dark matter.

Shot with ultra-high definition cameras, this book of amazing photographs showcases a period of unusually high solar activity in the Northern Lights. The northern lights, also known as the aurora borealis, put on remarkable shows of light and motion in high latitudes - Alaska being the perfect place to see them. These new photos take full advantage of the latest advances in photographic technology and especially active solar storms of the past several years that cause the lights. With 160 images that have never been collected in book form, we are witnessing the interaction of charged particles in the earth's atmosphere clash with electrons and protons released by the sun. Photographers Calvin Hall and Daryl Pederson are dedicated aurora borealis hunters, enduring frigid nights in remote locations to get the best shots. The results are amazing.

4. Census of the Catalogue The catalogue contains information on 277 objects. 137 (50%) of them are stars whose outburst spectra or unambiguous mInImUm characteristics classify them as novae beyond doubt. 123 of them could be identified at minimum. 78 (28 %) are stars with amplitudes and light curve forms which makes nova classifi cation likely. 60 of them could be identified at minimum. Thus, 78 % ofthe objects in this catalogue are confirmed and suspected classical novae. 16 (6%) have properties compatible with both novae and related objects. 15 are identified at minimum. Furthermore, the catalogue and atlas contains data on 12 (4 %) dwarf novae of long cycle length or suspected dwarf novae for which only one outburst has been observed. Examples are WZ Sge and CI Gern. 6 (2%) recurrent novae or suspected recurrent novae are listed. Examples are T CrB and AS Psc. 6 (2%) X-ray novae are listed. Examples are V616 Mon and KY TrA. 6 (2%) symbiotic stars and symbiotic novae are listed. Examples are RT Ser and V352 Aql. 11 (4 %) Mira stars or suspected Mira stars, which at some time were believed to be novae, are listed. Examples are V607 Aql and V927 Sgr."

This is a review of the basic elements directly connected to the evolution of galaxies. Owing to advances in observational astronomy and astrophysics, data has become available about remote galaxies, which are consequently in the first stages of their evolution. It is therefore essential to link these data to the observation of very old populations in our own Galaxy, which are the remnants of the populations which existed in the first stages of galactic evolution. In this meeting, the relationship between these two different points of view is emphasized in the texts presented by well-known specialists as well as by young researchers active in the field. The difficulties of the problem and the remaining uncertainties are discussed.

Research of the interstellar medium (ISM) has been advancing rapidly during the last 10 years, mainly due to immensely improved observational facilities and techniques in all wavelength ranges. We are now able to investigate the ISM in external galaxies and even the intergalactic and intracluster medium in great detail. Increased spatial and spectral resolution have provided us with a great deal of information on the interstellar gas in its various phases, the magnetic field and the cosmic rays, and of course, also the stellar component, which is the driving agent of the interstellar matter cycle.
Since only fairly recently, a sufficient amount of computing power has become available to tackle these problems with some prospect of obtaining a self-consistent picture of the ISM, a major goal of this workshop was to bring together observers and theoreticians sufficiently close, so that intense discussions about the necessities and desiderata of modelling the ISM could be stimulated. Observers have shown in great detail on this conference of what is seen on all scales of the ISM, near and far, and what boundary conditions would be appropriate for realistic models, and theoreticians pointed out what assumptions and simplifications their codes need, and how future observations could test their models. As a first step towards this goal, some self-consistent numerical simulations with a minimum number of relevant physical processes were also presented on this meeting. There was wide agreement, that this approach - to keep observers and theoreticians in close contact and also in sometimes quite controversial discussions - will bear fruitful results in the near future.

In this Symposium, researchers specializing in pulsation, rotation, magnetic fields and stellar winds are brought together for the first time in order to broaden our understanding of O and B stars. Thanks to advances in digital spectroscopy, new types of pulsating B stars have been discovered. The pulsations can be understood in terms of the recent revision of metal opacities, but the effects of rapid rotation and magnetic fields need further study. Observations in the UV and X-ray regions demonstrate that many B and Be stars show other activity, besides pulsation which is not yet understood. The reason for the enhanced mass loss in B stars is a question which dominates the Symposium and which remains unanswered, although it is surely to be found in activity at or near the photosphere coupled with rotation. It is shown that the geometry of the circumstellar envelopes around Be stars is indeed a flattened disk as they can now be optically resolved. The variability of radiatively-driven winds from O and B stars are likely related to the rotation of the star. This underlines the central theme of the book: that the various phenomena seen in these stars cannot be studied in isolation.

In July 1992, over 300 astronomers attended the Third Tetons Summer School on the subject of "The Environment and Evolution of Galaxies". This book presents 28 papers based on invited review talks and a panel discussion on "The Nature of High Redshift Objects". The major themes include: the interstellar and intergalactic medium, galaxy formation and evolution, cooling flows, quasars and radiation backgrounds, and interactions between galaxies/AGNs and their environment. Recent advances with the ROSAT, COBE and Hubble Space Telescope are discussed, together with current theoretical developments. The tutorial nature of the papers should make this book a useful supplement for professional astonomers, graduate students, and senior undergraduates. As with previous Tetons conferences, this book provides both the current state of observational and theoretical research and material complementary to courses in extragalactic and interstellar astrophysics.

The papers in this study cover a range of scenarios, from disk and envelope around young stellar objects and protostars through to more aged stars and highly-evolved objects which exhibit considerable mass loss features. Significant advances and developments in observing facilities, instrumentation, computing power and techniques are described, together with a variety of theories, suggestions, observations and models. The formation, composition, effects and evolution of the material surrounding a stellar environment are also included.

The motivation for the workshop on which this book is based was the discovery in recent years of a large number of binary and millisecond radio pulsars, in the galactic disk as well as in globular star clusters, the oldest stellar systems in our galaxy. These discoveries have revolutionized our thinking on many aspects concerning the interior structure and evolution of neutron stars, and have revived the interest in the study of neutron star physics in general. In this book some three dozen of the world's experts in the field of radio pulsars, X-ray binaries, stellar evolution, neutron star interiors and stellar dynamics review the latest observational discoveries as well as the current theoretical thinking on the formation and physics of binary X-ray sources and of the binary and milli-second pulsars. These include discoveries such as that of the elevent millisecond pulsars in the globular cluster 47 Tucanae, the relativistic effects in the new double neturon star system PSR 1534+12 and spectacular results from Germany's ROSAT X-Ray Observatory.

Foreword; J. Davies, D. Burstein. Introductory Remarks; M. Disney. Interstellar grain evolution and temperatures in spiral galaxies; J. Mayo Greenberg, A. Li. Radiative transfer models; G. Bruzual A. Radiative transfer in dusty galaxies; A.N. Witt. Opacity Diagnostics in spiral galaxies; N.D. Kylafis. Modeling dusty galaxies; G. Magris C., G. Bruzual A. Inclination-dependence of spiral galaxy physical properties: history and tests; D. Burstein, et al. Why a distance selection effect invalidates the Burstein, Haynes and Faber opacity test; J.I. Davies, et al. Statistical tests for opacity; E.A. Valentijn. Statistical measures of internal absorption in spiral galaxies; B. Cunow. The distribution of galactic inclinations; H. Jones, et al. Optical thickness of Sb-Scd galaxies from the Tully--Fisher relation; L. Gouguenhei, et al. Extinction in Sc galaxies at I band and in the 21cm line; R. Giovanelli. Extinction in the galaxy and in galactic discs; G. de Vaucouleurs. Properties of dust in backlit galaxies; W. Keel, R.E. White. The optical depth through NGC 3314A; P. James, P. Puxley. Dust extinction in highly inclined spirals; J. Knapen, et al. An optical search for dusty disks; M. Naslund, S. Joersater. Photometric asymmetry and dust opacity of spiral galaxies; Y.I. Byun. The scale-length test for dust in face-on spirals; J.E. Beckman, et al. Color gradients in spiral galaxies; S. Courteau, J. Holtzman. Constraints on the opacity of spiral disks from near-infrared observations; H.W. Rix. Arcsecond resolution of cold dust in spiral galaxies using optical and NIR imaging -- dust masses increase by nine hundred percent; D.L. Block, et al. Unveiling stars and dust in spiral galaxies;R.F. Pelletier, et al. Azimuthal distribution of dust in NGC 2997; P. Grosbol, et al. Internal extinction in spiral galaxies at optical and near infrared wavelengths; A. Boselli, G. Gavazzi. The opacity of spiral galaxy disks; N. Devereux. The far infrared/stellar energy balance; R. Evans. Opacity from luminosity functions; M. Trewhella, et al. Estimating disk opacities using infrared images; W. van Driel. DIRBE observations of galactic extinction; R.G. Arendt, et al. Kinematics of edge-on galaxies and the opacity of spiral disks; A. Bosma. Spectroscopic studies of the disk and halo of M82; C.D. McKeith, et al. Disk origin and evolution; J. Silk. The luminosity and opacity of galaxies; B. Wang. Dust obscuration in starburst galaxies; D. Calzetti. Polarimetry of dusty edge-on galaxies; R.D. Wolstencroft, S.M. Scarrott. HII regions and extinction in the spiral galaxy M83; S. Ryder, et al. A search for dust in galactic halos; D. Zaritsky. Concluding thoughts and reflections: dust in galaxies; H.A. Thronson Jr.

Planetary nebulae are a keystone for the understanding of the evolution of stars, for deep insights into the physical processes prevailing in highly excited dilute nebulae, and for the chemical evolution in galaxies. These objects, displaying an intriguing morphology, have a "short" lifetime of a few tens of thousands of years, and have become one of the best studied classes of celestial sources. However, despite large and successful efforts from both the observational and theoretical side, planetary nebulae still keep some of their secrets (like the widely unknown distances) and will undoubtedly also be objects of thorough investigations in the years to come.