On the occasion of the retirement of Ulrich Schwarz, a symposium was held in Groningen in May of 1996, celebrating his contributions to the study of the int- stellar medium, including his work on the high-velocity clouds. The coming together of many specialists in the latter ?eld prompted the idea of compiling a book c- taining their contributions, and summarizing the status of our understanding of the high-velocity cloud phenomenon. This seemed especially worthwhile at the time, since many exciting developments were taking place. After the discovery of some H i clouds with high velocities, about 40 years ago, the subject had been dominated by 21-cm observations of H i emission. Starting in the mid-1980s much progress was being made because of the availability of new instruments, such as large ground-based optical telescopes and UV observatories in space. The connections between the work on high-velocity clouds and other studies of the properties of the (hot) interstellar medium also became clearer.
Erscheinungsdatum: 29.09.2004

edited by Hugo van Woerden ... [et al.]

M. Peters; P. Trifonas

Woerden, Hugo van

Dordrecht ; London: Kluwer Academic

Springer-Verlag New York, LLC

Kluwer Academic Publishers

Astrophysics and space science library -- v. 312, Dordrecht, London, Netherlands, 2004

Astrophysics and space science library, 1st ed. 2005, Dordrecht, 2005

Astrophysics and space science library, 312, Dordrecht, 2005

United States, United States of America

1 edition, December 31, 1899

2004, 2010

2004, 2006

Cut-off text on some pages due to tight binding.

Symposium held in May 1996, Groningen, Netherlands, to celebrate the retirement of Ulrich Schwarz, and his contributions to the study of the interstellar medium, including his work on the high-velocity clouds - preface.
Includes bibliographical references and index.

1 online resource (x, 400 pages) :
"This book contains 17 chapters reviewing our knowledge of the high-velocity clouds (HVCs) as of 2004, bringing this together in one place for the first time. Each of the many different aspects of HVC research is addressed by one of the experts in that subfield. These include a historical overview of HVC research and analyses of the structure and kinematics of HVCs."--Jacket
Includes bibliographical references and index
Print version record
COVER -- TABLE OF CONTENTS -- PREFACE -- 1. HISTORY OF HVC RESEARCH -- AN OVERVIEW -- 1.1 Discovery; research until 1963 -- 1.2 Early radio research: 1963-1968 -- 1.3 Developments 1968-1980 -- 1.4 Developments 1981-1991 -- 1.5 Developments 1992-1999 -- 1.6 New Developments since 1999 -- 2. HVC/IVC MAPS AND HVC DISTRIBUTION FUNCTIONS -- 2.1 Introduction -- 2.2 Basic HVC and IVC data -- 2.3 Features of the H i sky -- 2.4 Column density distribution -- 2.5 Volume density distribution -- 2.6 Distributions of cloud parameters -- 2.7 Conclusions and outlook -- 3. KINEMATICS OF HV AND IV GAS -- 3.1 General considerations -- 3.2 Defining the HV and IV gas sample -- 3.3 Systematic motions of high-velocity (HV) gas -- 3.4 Systematic motions of intermediate-velocity (IV) gas -- 3.5 Systematic motions from optical and UV observations -- 3.6 Simple kinematical considerations -- 3.7 N(H i) distribution and infall velocity -- 3.8 Some results from further statistical analyses -- 3.9 Conclusions -- 4. INTERMEDIATE-VELOCITY CLOUDS -- 4.1 Introduction: what are intermediate-velocity clouds? -- 4.2 The distribution of IVCs in space and in velocity -- 4.3 Distances of intermediate-velocity clouds -- 4.4 IVCs and their relationship to low- and high-velocity gas -- 4.5 Abundances and physical conditions -- 4.6 Speculations on the origin and significance of IVCs -- 4.7 Directions for future work -- 5. HVCS RELATED TO THE MAGELLANIC SYSTEM -- 5.1 Introduction -- 5.2 The Magellanic Bridge -- 5.3 The Magellanic Stream -- 5.4 The Leading Arm -- 5.5 Theoretical origin models -- 5.6 Relationships to other HVCs? -- 6. HIGH-VELOCITY H i GAS IN EXTERNAL GALAXIES -- 6.1 Introduction -- 6.2 H i halos of spiral galaxies -- 6.3 Interactions and accretions -- 6.4 Concluding remarks -- 7. THE LARGE- AND SMALL-SCALE STRUCTURE OF HVCS -- 7.1 Introduction -- 7.2 Observations -- 7.3 Physical characteristics -- 7.4 Characterization of small-scale structure -- 7.5 Discussion and conclusions -- 8. IONIZED GAS ASSOCIATED WITH HVCS -- 8.1 Introduction -- 8.2 The observations: high-resolution Fabry-Pérot spectroscopy of emission lines -- 8.3 A brief summary of recent emission-line observations -- 8.4 Are HVCs extragalactic? The evidence from Ha -- 8.5 Measuring metal abundances in HVCs ... the ionization correction -- 8.6 The disk/halo connection -- 8.7 Conclusions and future directions -- 9. THE COLDEST PHASE IN HALO HIGH-VELOCITY GAS: DUST AND MOLECULES -- 9.1 Measurements of dust and molecules in the Milky Way Halo -- 9.2 Presence of dust in halo gas -- 9.3 Measurements of molecules in halo gas -- 9.4 Molecular "globules" in the outer halo? -- 9.5 Concluding remarks -- 10. DISTANCES AND METALLICITIES OF HVCS -- 10.1 Introduction -- 10.2 Methods of distance determination -- 10.3 Distance determination from absorption lines -- 10.4 Distances of high-velocity clouds -- 10.5 Metallicity determination -- requirements and problems -- 10.6 Ion abundances and metallicities of HVCs -- 10.7 Origins -- 10.8 Needs and prospects -- 11. THE HOT HALO -- 11.1 Toward the concept of a hot halo -- 11.2 Absorption by highly-ion

<p><P>This book contains 17 chapters reviewing our knowledge of the high-velocity clouds (HVCs) as of 2004, bringing this together in one place for the first time. Each of the many different aspects of HVC research is addressed by one of the experts in that subfield. These include a historical overview of HVC research and analyses of the structure and kinematics of HVCs. <p>Separate chapters address the intermediate-velocity clouds, the Magellanic Stream, and neutral hydrogen HVCs discovered in external galaxies. Reviews are presented of the Ha emission and of optical and UV absorption-line studies, followed by discussions of the hot Galactic Halo and of the interactions between HVCs and their surroundings. <p>Four chapters summarize the ideas about the origin of the high-velocity gas, with detailed discussions of connections between HVCs and the Galactic Fountain, tidally-stripped material, and remnants of the Milky Way's formation. A chapter outlining what we do not know completes the book. <p>The book comes at a time when knowledge and understanding of the HVCs are making rapid progress, owing to technological, observational, and theoretical developments.</p>

"This book contains 17 chapters reviewing our knowledge of the high-velocity clouds (HVCs) as of 2004, bringing this together in one place for the first time. Each of the many different aspects of HVC research is addressed by one of the experts in that subfield. These include a historical overview of HVC research and analyses of the structure and kinematics of HVCs."--Résumé de l'éditeur

Studies in the lato 1930s had revealed multiple interstellar absorption components in spectra of early-type stars (Beals 1938).

2023-06-28