The review papers in this volume provide an in-depth examination of complex astrophysical phenomena of star formation via multi-wavelength observations and modeling. Among the fundamental issues discussed in the book are: The role of gravity and magnetized turbulence in the formation and evolution of molecular clouds The stellar feedback (supernovae, HII regions, winds, cosmic rays) in regulating star formation The origin of the stellar initial mass function and its universality across various environments Jets, magnetic fields and high energy particles in stellar clusters The origin of the first stars and black holes The goal of these papers is to review the major processes governing star formation and to investigate how they are interlinked. In doing so, they provide an in-depth look at the tremendous theoretical and observational progress that has been made in the recent past and also outline future perspectives. Previously published in Space Science Reviews in the Topical Collection "Star Formation"

The discovery of chemical elements in celestial bodies and the first estimates of the chemical composition of the solar atmosphere were early results of Astrophysics - the subdiscipline of Astronomy that was originally concerned with the general laws of radiation and with spectroscopy. Following the initial quantitative abundance studies by Henry Norris Russell and by Cecilia Payne-Gaposchkin, a tremendous amount of theoretical, observa tional, laboratory and computational work led to a steadily improving body of knowledge of photospheric abundances - a body of knowledge that served to guide the theory of stellar evolution. Solar abundances determined from photospheric spectra, together with the very similar abundances determined from carbonaceous chondrites (where extensive information on isotopic composition is available as well), are nowadays the reference for all cosmic composition measures. Early astrophysical studies of the solar photospheric composition made use of atmosphere models and atomic data. Consistent abundances derived from different atmospheric layers and from lines of different strength helped to confirm and estab lish both models and atomic data, and eventually led to the now accepted, so-called "absolute" abundance values - which, for practical reasons, however, are usually given relative to the number of hydrogen nuclei.

The knowledge of the amount and nature of matter present in the Universe is undoubtedly one of the most relevant topics in astrophysics and cosmology. It started with the pioneering work of Zwicky in 1933, who found the need for a large amount of dark matter in the Coma cluster. An important step has been the recent finding through the observation of distant type Ia supernovae of the presence of a significant vacuum energy density causing an accelerating expansion of the Universe. Nevertheless, the nature of most of the matter in the Universe is still unknown. Its solution requires the interplay of several fields of astrophysics and cosmology as well as particle physics, all of which are covered in this volume: Cosmic Microwave Background radiation, large scale structures, galaxy clusters, intergalactic absorption, dark matter components of galaxies, globular clusters, supernovae of type Ia distance measurements, gravitational lensing, X-ray observations, Lyman-alpha observations, dark energy, direct detection of weakly interacting massive particles (WIMPS), detection of neutrino oscillations, particle candidates for dark matter, and Big Bang nucleosynthesis of baryonic matter.

Therefore, this volume presents a very useful synopsis of all constituents of matter in the Universe.

This volume gives a comprehensive and integrated overview of current knowledge about cosmic rays in the heliosphere. It is the result of a workshop at ISSI, where experimental space physicists as well as theorists presented and discussed their views on the behaviour of cosmic rays during the currently prevalent solar minimum conditions, when the heliosphere has a well-ordered and relatively simple configuration. An unprecedented array of spacecraft - Ulysses, Pioneer, Voyager, IMP-8, Wind, to name a few - in conjunction with ever more sophisticated numerical models made this possible, gave us our first clear view of the three-dimensional heliosphere at solar minimum, and have significantly advanced our knowledge. The status of the field is first presented in a series of introductory papers; these are followed by four Working Group reports attempting to synthesise this knowledge, make progress in our understanding, and point out directions of future research. A summary of the parameters used in cosmic ray modulation and an epilogue on conditions and consequences expected at the upcoming solar maximum conclude the volume. The book is intended to provide active researchers in space physics with an up-to-date status report and also to introduce the advanced graduate student to the field.

The variability of the Sun is well established, as well as that of the Earth's climate. To what extent the two are connected, in the sense that solar variability drives climate, is the subject of considerable research and, in some cases, controversy. After an earlier workshop at the International Space Science Institute (ISS!) on Solar Composition and its Evolution, two ofthe participants came up with the idea to initiate a similar project on the topic of Solar Variability and Climate, a work shop aimed at obtaining an overview of the current knowledge of the variability of the Sun and of the Earth's Climate, and of their possible connections. A further, equally important objective was the strengthening of the interaction between the two, often diverse communities of solar physicists and climatologists. ISSI took up this idea and invited six convenors, E. Friis-Christensen, C. Froh lich, J. Haigh, J. Hansen, M. Schussler, and S. Solanki, who subsequently formu lated the aims and goals of the workshop, nominated a list of invitees, drafted a programme of introductory talks, and structured the workshop into three sections. For each section there was a concluding discussion session moderated by two co chairs. Moreover, there was a number of contributed poster papers for which there were two viewing sessions. The main intent of this format was to leave ample time for open, informal discussions, which is one of the principal aims of ISSI.

The SOHO and Cluster missions form a single ESA cornerstone. Yet they observe very different regions in our solar system: the solar atmosphere on one hand and the Earth's magnetosphere on the other. The Ulysses mission provides observations in the third dimension of the heliosphere, and many others add to the picture from the Lagrangian point L1 to the edge of the heliosphere. It is the aim of this ISSI volume to tie these observations together in addressing the topic of Solar Dynamics and its Effects on the Heliosphere and Earth, thus contributing to the International Living With a Star program. The volume starts out with an assessment of the reasons for solar dynamics and how it couples into the heliosphere. The three subsequent sections are each devoted to following one chain of events from the Sun all the way to the Earth's magnetosphere and ionosphere. The final section is devoted to common physical processes occurring both at the Sun and in the magnetosphere.

In summary, we can conclude that the contributions of the different ionization processes to the total ionization rate for the most abundant interstellar species are basically known. The ionization of the noble gases He and Ne is almost completely dominated by photoionization, whereas for H charge-exchange with the solar wind is most important. For other species, such as 0 and Ar, both processes contribute significantly. Electron impact ionization can typically contribute by '" 10% to the total rate in the inner Solar System. Because direct measurements of the solar EUV flux are not yet continuously available, the variation of the ionization rate over the solar cycle still contains a relatively large uncertainty. The recent measurements of pickup ion distributions and of the neutral helium gas provide an independent tool to determine the total ionization rate that can be used to cross calibrate with the results obtained for the individual ionization processes. Acknowledgements The authors are grateful to M. Allen for supplying us with new data on photoioniza tion cross-sections compiled by him. We thank also M. Gruntman for drawing our attention to and support in collecting the most recent data on charge-exchange cross-sections. D. R. was supported by grant No. 2 P03C. 004. 09 from the Com mittee for Scientific Research (Poland). This work was also supported in part through NASA contract NAS7-918, NSF Grant INT-911637, NASA Grant NAGW- 2579.

This volume in the Space Sciences Series of ISSI is dedicated to the detennination of the Earth's gravity field, which was the topic of a workshop organized by ISSI from 11 to 15 March 2002 in Bern. The aim of the meeting was to gather active researchers from various fields (satellite geodesy, gravity field modelling, solid Earth physics, oceanography, etc.) to assess the exciting new developments that are made possible by space missions currently in orbit or about to be launched. Following some general enquiries with the scientific community concerning the desirability of organising a workshop on the proposed topic, a group of four con- venors (Gerhard Beutler, Univ. of Bern; Mark Drinkwater, ESA-ESTEC, Noord- wijk; Reiner Rummel, Techn. Univ. Miinchen; Rudolf von Steiger, ISS I, Bern) for- mulated the aims and goals of the workshop, structured the workshop into six sec- tions, nominated a list of session chairs (Georges Balmino, GRGS-CNES, Toulouse; Roberto Sabadini, Univ. of Milano, Christian Le Provost, Obs. Midi-Pyrenees, Toulouse; Philip Woodworth, Bidston Observatory, Birkenhead; Miguel Aguirre, ESA-ESTEC, Noordwijk), who in turn set up a programme of introductory talks. The workshop was organized such as to have only plenary sessions with typically half-hour presentations and ample time for discussions. The last day was devoted to conclusions and future objectives.

R. DIEHL, R. KALLENBACH, E. PARIZOT and R. VON STEIGER / The Astrophysics of Galactic Cosmic Rays 3 I: KEY OBSERVATIONS ON GALACTIC COSMIC RAYS M. E. WIEDENBECK, N. E. YANASAK, A. c. CUMMINGS, AJ. DAVIS, I. S. GEORGE, R. A. LESKE, R. A. MEWALDT, E. C. STONE, P. L. HINK, M. H. ISRAEL, M. LIJOWSKI, E. R. CHRISTIAN and TT VON ROSENVINGE / The Origin of Primary Cosmic Rays: Constraints from ACE Elemental and Isotopic Composition Observations 15 R. A. MEWALDT, N. E. YANASAK, M. E. WIEDENBECK, AJ. DAVIS, w. R. BINNS, E. R. CHRISTIAN, A. C. CUMMINGS, P. L. HINK, R. A. LESKE, S. M. NIEBUR, E. C. STONE and TT VON ROSENVINGE / Radioactive Clocks and Cosmic-Ray Transport in the Galaxy 27 J. J. CONNELL / Cosmic-Ray Composition as Observed by Ulysses 41 R. RAMATY, R. E. LINGENFELTER and B. KOZLOVSKY / Spallogenic Light Elements and Cosmic-Ray Origin 51 E. PARIZOT / Galactic Cosmic Rays and the Light Elements 61 G. MEYNET, M. ARNOULD, G. PAULUS and A. MAEDER / Wolf-Rayet Star Nucleosynthesis and the Isotopic Composition of the Galactic Cosmic Rays 73 S. P. SWORDY / The Energy Spectra and Anisotropies of Cosmic Rays 85 G. TARLE and M. SCHUBNELL / Antiparticles 95 D. MULLER / Cosmic Rays Beyond the Knee 105 II: LESSONS FROM THE HELIOSPHERE G. M. MASON / Heliospheric Lessons for Galactic Cosmic-Ray Acceleration 119 R. A.

The review papers in this volume provide an in-depth examination of complex astrophysical phenomena of star formation via multi-wavelength observations and modeling. Among the fundamental issues discussed in the book are: The role of gravity and magnetized turbulence in the formation and evolution of molecular clouds The stellar feedback (supernovae, HII regions, winds, cosmic rays) in regulating star formation The origin of the stellar initial mass function and its universality across various environments Jets, magnetic fields and high energy particles in stellar clusters The origin of the first stars and black holes The goal of these papers is to review the major processes governing star formation and to investigate how they are interlinked. In doing so, they provide an in-depth look at the tremendous theoretical and observational progress that has been made in the recent past and also outline future perspectives. Previously published in Space Science Reviews in the Topical Collection "Star Formation"

Knowledge about the outer heliosphere and the interstellar medium, which were long treated as two separate fields, has improved dramatically over the past 25 years as a consequence of recent developments: The discovery of interstellar pickup ions and neutral helium inside the heliosphere, the determination of the interstellar hydrogen distribution in the heliosphere obtained using backscattered solar Lyman-alpha radiation, the prediction and subsequent detection of the hydrogen wall just outside of the heliopause, the development of detailed global models for the interaction of solar wind plasma with the interstellar medium, and most recently, direct in-situ plasma and field measurements inside of the heliosheath. At the same time, our understanding of the nearby galactic environment, including the composition and dynamics of the warm gas clouds and hot gas in the local bubble, has benefited greatly from absorption-line spectroscopy using nearby stars as background sources and dynamic modeling. The present volume provides a synopsis of these developments organised into seven sections: Dominant physical processes in the termination shock and heliosheath, three-dimensional shape and structure of the dynamic heliosphere, relation of the plasmas and dust inside and outside of the heliosphere, origin and properties of the very local interstellar medium, energy and pressure equilibria in the local bubble, physical processes in the multiphase interstellar medium inside of the local bubble, and the roles that magnetic fields play in the outer heliosphere and the local bubble. The last theme is probably the most basic of all as magnetic fields play important roles in most of the phenomena discussed here. The volume concludes with four papers providing the "big picture" by looking at the time evolution of both the heliosphere and the local bubble, looking beyond the local bubble, and finally addressing the challenges in modeling the interface between the two media.

This fascinating book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75. Thus far, it is the only book on Mercury which balances a wide range of Earth-based observations, made under difficult conditions, with the only available space-based data. The text is based on continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of this mysterious planet 's interior evolution.

Knowledge about the outer heliosphere and the interstellar medium, which were long treated as two separate fields, has improved dramatically over the past 25 years as a consequence of recent developments: The discovery of interstellar pickup ions and neutral helium inside the heliosphere, the determination of the interstellar hydrogen distribution in the heliosphere obtained using backscattered solar Lyman-alpha radiation, the prediction and subsequent detection of the hydrogen wall just outside of the heliopause, the development of detailed global models for the interaction of solar wind plasma with the interstellar medium, and most recently, direct in-situ plasma and field measurements inside of the heliosheath. At the same time, our understanding of the nearby galactic environment, including the composition and dynamics of the warm gas clouds and hot gas in the local bubble, has benefited greatly from absorption-line spectroscopy using nearby stars as background sources and dynamic modeling. The present volume provides a synopsis of these developments organised into seven sections: Dominant physical processes in the termination shock and heliosheath, three-dimensional shape and structure of the dynamic heliosphere, relation of the plasmas and dust inside and outside of the heliosphere, origin and properties of the very local interstellar medium, energy and pressure equilibria in the local bubble, physical processes in the multiphase interstellar medium inside of the local bubble, and the roles that magnetic fields play in the outer heliosphere and the local bubble. The last theme is probably the most basic of all as magnetic fields play important roles in most of the phenomena discussed here. The volume concludes with four papers providing the "big picture" by looking at the time evolution of both the heliosphere and the local bubble, looking beyond the local bubble, and finally addressing the challenges in modeling the interface between the two media.

The variability of the Sun is well established, as well as that of the Earth's climate. To what extent the two are connected, in the sense that solar variability drives climate, is the subject of considerable research and, in some cases, controversy. After an earlier workshop at the International Space Science Institute (ISS!) on Solar Composition and its Evolution, two ofthe participants came up with the idea to initiate a similar project on the topic of Solar Variability and Climate, a work shop aimed at obtaining an overview of the current knowledge of the variability of the Sun and of the Earth's Climate, and of their possible connections. A further, equally important objective was the strengthening of the interaction between the two, often diverse communities of solar physicists and climatologists. ISSI took up this idea and invited six convenors, E. Friis-Christensen, C. Froh lich, J. Haigh, J. Hansen, M. Schussler, and S. Solanki, who subsequently formu lated the aims and goals of the workshop, nominated a list of invitees, drafted a programme of introductory talks, and structured the workshop into three sections. For each section there was a concluding discussion session moderated by two co chairs. Moreover, there was a number of contributed poster papers for which there were two viewing sessions. The main intent of this format was to leave ample time for open, informal discussions, which is one of the principal aims of ISSI.

The present volume, the fourth one in the "Space Sciences Series of ISSI" (Inter national Space Science Institute), contains the proceedings of a workshop on "Pri mordial Nuclei and Their Galactic Evolution", which was held at ISSI in Bern on 6-10 May 1997. This topic was chosen following some general enquiries with the scientific community concerning its desirability and timeliness. Five convenors, D. Duncan, C. Hogan, J. Linsky, N. Prantzos, and H. Reeves (chair) subsequently set up the workshop, nominated a list of invitees, structured the workshop into a series of introductory talks and into six topical working groups (early Universe extragalactic objects -low-Z stars - galactic disk and galactic evolution - solar nebula -local interstellar medium), and described the tasks of the working groups in a list of keywords. It is the main task of ISSI to bring together space scientists, ground-based observers, and theorists from different fields and to give them the opportunity to discuss and compare their results, thus contributing to the achievement of a deeper understanding, adding value to those results through multi-disciplinary research in an atmosphere of international co-operation. In that spirit the convenors selected participants working in fields ranging from Big Bang theory to observers oftoday's Solar System, thus spanning the widest possible range both in time and space.

The discovery of chemical elements in celestial bodies and the first estimates of the chemical composition of the solar atmosphere were early results of Astrophysics - the subdiscipline of Astronomy that was originally concerned with the general laws of radiation and with spectroscopy. Following the initial quantitative abundance studies by Henry Norris Russell and by Cecilia Payne-Gaposchkin, a tremendous amount of theoretical, observa tional, laboratory and computational work led to a steadily improving body of knowledge of photospheric abundances - a body of knowledge that served to guide the theory of stellar evolution. Solar abundances determined from photospheric spectra, together with the very similar abundances determined from carbonaceous chondrites (where extensive information on isotopic composition is available as well), are nowadays the reference for all cosmic composition measures. Early astrophysical studies of the solar photospheric composition made use of atmosphere models and atomic data. Consistent abundances derived from different atmospheric layers and from lines of different strength helped to confirm and estab lish both models and atomic data, and eventually led to the now accepted, so-called "absolute" abundance values - which, for practical reasons, however, are usually given relative to the number of hydrogen nuclei.

In summary, we can conclude that the contributions of the different ionization processes to the total ionization rate for the most abundant interstellar species are basically known. The ionization of the noble gases He and Ne is almost completely dominated by photoionization, whereas for H charge-exchange with the solar wind is most important. For other species, such as 0 and Ar, both processes contribute significantly. Electron impact ionization can typically contribute by '" 10% to the total rate in the inner Solar System. Because direct measurements of the solar EUV flux are not yet continuously available, the variation of the ionization rate over the solar cycle still contains a relatively large uncertainty. The recent measurements of pickup ion distributions and of the neutral helium gas provide an independent tool to determine the total ionization rate that can be used to cross calibrate with the results obtained for the individual ionization processes. Acknowledgements The authors are grateful to M. Allen for supplying us with new data on photoioniza tion cross-sections compiled by him. We thank also M. Gruntman for drawing our attention to and support in collecting the most recent data on charge-exchange cross-sections. D. R. was supported by grant No. 2 P03C. 004. 09 from the Com mittee for Scientific Research (Poland). This work was also supported in part through NASA contract NAS7-918, NSF Grant INT-911637, NASA Grant NAGW- 2579.

This fascinating book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75. Thus far, it is the only book on Mercury which balances a wide range of Earth-based observations, made under difficult conditions, with the only available space-based data. The text is based on continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of this mysterious planet s interior evolution."

In every scientific discipline there are milestones - periods of significant accom plishment when it is appropriate to pause and summarize the state of the field. Such is the case for the study of the behavior of cosmic rays in the heliosphere. We are just passing through solar minimum conditions, when the heliosphere has a well-ordered and relatively simple configuration. We have been fortunate to have an array of spacecraft - unprecedented in the history of space exploration and unlikely to be repeated for generations - to provide comprehensive measurements of cosmic rays throughout the heliosphere. Ulysses has completed its historic first exploration of the heliosphere at high heliographic latitudes. Pioneer and Voyager have been exploring the outer heliosphere. The durable IMP-8 and now the WIND spacecraft have provided detailed baseline measurements at Earth. Concurrently, there has been a steady improvement in theoretical understanding of cosmic ray behavior through the use of ever more sophisticated numerical models. This milestone in cosmic ray studies was celebrated with a Workshop on Cos mic Rays in the Heliosphere which was convened by L. A. Fisk, J. R. Jokipii."

This volume helps the reader to understand the ways and means of how dynamical phenomena are generated at the Sun, how they travel through the Heliosphere, and how they affect Earth. It provides an integrated account of the three principal chains of events all the way from the Sun to Earth: the normal solar wind, coronal mass ejections, and solar energetic particles.

This is an EXACT reproduction of a book published before 1923. This IS NOT an OCR'd book with strange characters, introduced typographical errors, and jumbled words. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process. We believe this work is culturally important, and despite the imperfections, have elected to bring it back into print as part of our continuing commitment to the preservation of printed works worldwide. We appreciate your understanding of the imperfections in the preservation process, and hope you enjoy this valuable book.