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Häftad, Engelska, 1988
544 kr
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Every 5 years since 1967 a meeting has been held to discuss the subject of planetary nebulae and their central stars. Previous meetings have been held in Tatranska Lomnica (Czechoslovakia); Liege (Belgium); Ithaca, New York (U. S. A); and London (Great Britain). IAU Symposium 131 was sponsored by IAU Commision 34, on Interstellar Matter and co-sponsored by IAU Commisions 35 and 36 on Stellar Constitution and Theory of Stellar Atmospheres. The symposium was held at the Universidad Nacional Autonoma de Mexico in Mexico City, October 5-9, 1987. It took place in one of the old buildings of the University of Mexico in the downtown area. The inner patio of the building provided very pleasant surroundings for the poster sessions and for extensive discussions among the participants. The meeting was attended by 160 scientists from 22 countries. The Scientific Organizing Committee,under the chairmanship of J.B. Kaler, prepared a comprehensive scientific program based on a set of invited presentations. All contributed papers were presented in poster form. The Scientific Organizing Committee would like to thank the staff of the University of Illinois Department of Astronomy: Dr. Ron Allen for granting financial support; Carol Stickrod, Louise Browning, Deana Griffin and Sandie Osterbur for their help with the organization. IAU provided economic assistance to a group of young astronomers.
Del 136 - International Astronomical Union Symposia
Center of the Galaxy
Proceedings of the 136th Symposium of the International Astronomical Union, Held in Los Angeles, U.S.A., July 25–29, 1988
Inbunden, Engelska, 1989
2 156 kr
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The investigation of the Galactic nucleus and its surroundings is necessarily a modem endeavor, for traditional observations made at visual wavelengths have not even begun to penetrate the veil of -30 magnitudes of visual extinction that intercedes. On the other hand, infrared, and especially radio observers find a relatively unobstructed view of the central portion of the Galaxy, so the study of this arena has proceeded apace with the development of these branches of astronomy. Thus, it is no accident that the first IAU sponsored conference to be held on the Galactic center is timed to coincide with the initiation, or the immediate aftennath, of major technical developments at long wavelengths, including infrared array detectors, millimeter-wavelength aperture synthesis, and self-calibration and refmed deconvolution algorithms in aperture synthesis radio astronomy. The center of the Galaxy is also accessible to X and gamma-ray observers, and progress at high energies has been steady, especially as imaging capabilities are being realized at X-ray wavelengths. However, one might expect that the revolution in the high energy domain is still ahead of us, as instruments with larger collecting areas and improved spatial resolution are now being developed. The youth of this subject is evidenced by the relatively small number of meetings that have been devoted to it.
Häftad, Engelska, 1989
2 156 kr
Skickas inom 10-15 vardagar
The investigation of the Galactic nucleus and its surroundings is necessarily a modem endeavor, for traditional observations made at visual wavelengths have not even begun to penetrate the veil of -30 magnitudes of visual extinction that intercedes. On the other hand, infrared, and especially radio observers find a relatively unobstructed view of the central portion of the Galaxy, so the study of this arena has proceeded apace with the development of these branches of astronomy. Thus, it is no accident that the first IAU sponsored conference to be held on the Galactic center is timed to coincide with the initiation, or the immediate aftennath, of major technical developments at long wavelengths, including infrared array detectors, millimeter-wavelength aperture synthesis, and self-calibration and refmed deconvolution algorithms in aperture synthesis radio astronomy. The center of the Galaxy is also accessible to X and gamma-ray observers, and progress at high energies has been steady, especially as imaging capabilities are being realized at X-ray wavelengths. However, one might expect that the revolution in the high energy domain is still ahead of us, as instruments with larger collecting areas and improved spatial resolution are now being developed. The youth of this subject is evidenced by the relatively small number of meetings that have been devoted to it.
Del 134 - International Astronomical Union Symposia
Active Galactic Nuclei
Proceedings of the 134th Symposium of the International Astronomical Union, Held in Santa Cruz, California, August 15–19, 1988
Inbunden, Engelska, 1989
2 156 kr
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IAU Symposium No. 134 on Active Galactic Nuclei was hosted by the Lick Observatory, as part of the celebration of its centennial, for the Observatory went into operation as part of the University of California on June 1, 1888. Twenty years later, in 1908, Lick Observatory graduate student Edward A. Fath recognized the unusual emission-line character of the spectrum of the nucleus of the spiral "nebula" NGC 1068, an object now well-known as one of the nearest and brightest Seyfert galaxies and active galactic nuclei. Ten years after that, and seventy years before this Symposium, Lick Observatory faculty member Heber D. Curtis published his description of the "curious straight ray" in M 87, "apparently connected with the nucleus by a thin line of matter," which we now recognize as an example of one of the jets which are the subject of so much current AGN research. The symposium was held at Kresge College on the campus of the University of California, Santa Cruz, only a short walk through the redwood groves to the Lick Observatory offices. A total of 232 astronomers and astrophysicists from 24 countries attended and took part in the Symposium. About 200 more had applied to come, but could not be accepted in order to keep the meeting at a reasonable size. Most of the participants lived in the Kresge College apartments immediately adjacent to the Kresge Town Hall in which the oral sessions took place.
Häftad, Engelska, 1989
2 156 kr
Skickas inom 10-15 vardagar
IAU Symposium No. 134 on Active Galactic Nuclei was hosted by the Lick Observatory, as part of the celebration of its centennial, for the Observatory went into operation as part of the University of California on June 1, 1888. Twenty years later, in 1908, Lick Observatory graduate student Edward A. Fath recognized the unusual emission-line character of the spectrum of the nucleus of the spiral "nebula" NGC 1068, an object now well-known as one of the nearest and brightest Seyfert galaxies and active galactic nuclei. Ten years after that, and seventy years before this Symposium, Lick Observatory faculty member Heber D. Curtis published his description of the "curious straight ray" in M 87, "apparently connected with the nucleus by a thin line of matter," which we now recognize as an example of one of the jets which are the subject of so much current AGN research. The symposium was held at Kresge College on the campus of the University of California, Santa Cruz, only a short walk through the redwood groves to the Lick Observatory offices. A total of 232 astronomers and astrophysicists from 24 countries attended and took part in the Symposium. About 200 more had applied to come, but could not be accepted in order to keep the meeting at a reasonable size. Most of the participants lived in the Kresge College apartments immediately adjacent to the Kresge Town Hall in which the oral sessions took place.
Inbunden, Engelska, 1989
1 619 kr
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IAU Symposium 135 on Interstellar Dust was hosted and co-sponsored by NASA's Ames Research Center from July 26-30, 1988. The symposium was held at the lovely campus of Santa Clara University situated around the historic Santa Clara Mission in California. The meeting was made possible by generous grants from the Astron omy and Relativity Branch of the National Aeronautics and Space Administration and the Galactic Astronomy Program of the National Science Foundation. The International Astronomical Union provided travel grants to a few participants from countries with limited travel funds. We are particularly grateful for the support and services rendered by the dedicated staff at NASA's Ames Research Center and to the" SET! Institute for professionally and expeditiously administering the U.S. grants. This symposium brought together 199 scientists representing 19 different coun tries. The wide range of interest and expertise of the participants - all in some way related to interstellar dust - is reflected in the great variety of topics that were discussed during the symposium ranging from UV, visible and IR observations of interstellar extinction to quantum-statistical calculations of the IR emission from highly vibrationally excited molecules. During the course of the meeting, 41 invited review papers and 140 contributed papers were presented. This book is a collection of the invited review papers. The contributed papers have been published in a companion volume, NASA CP-3036, available from National Technical Information Service, Springfield, Virginia 22161, USA.
Häftad, Engelska, 1989
1 619 kr
Skickas inom 10-15 vardagar
IAU Symposium 135 on Interstellar Dust was hosted and co-sponsored by NASA's Ames Research Center from July 26-30, 1988. The symposium was held at the lovely campus of Santa Clara University situated around the historic Santa Clara Mission in California. The meeting was made possible by generous grants from the Astron omy and Relativity Branch of the National Aeronautics and Space Administration and the Galactic Astronomy Program of the National Science Foundation. The International Astronomical Union provided travel grants to a few participants from countries with limited travel funds. We are particularly grateful for the support and services rendered by the dedicated staff at NASA's Ames Research Center and to the" SET! Institute for professionally and expeditiously administering the U.S. grants. This symposium brought together 199 scientists representing 19 different coun tries. The wide range of interest and expertise of the participants - all in some way related to interstellar dust - is reflected in the great variety of topics that were discussed during the symposium ranging from UV, visible and IR observations of interstellar extinction to quantum-statistical calculations of the IR emission from highly vibrationally excited molecules. During the course of the meeting, 41 invited review papers and 140 contributed papers were presented. This book is a collection of the invited review papers. The contributed papers have been published in a companion volume, NASA CP-3036, available from National Technical Information Service, Springfield, Virginia 22161, USA.
Häftad, Engelska, 1989
544 kr
Skickas inom 10-15 vardagar
Solar and stellar photospheres constitute the layers most accessible to observations, forming the interface between the interior and the outside of the stars. The solar atmosphere is a rich physics laboratory, in which the whole spectrum of radiative, dynamical, and magnetic processes that tranfer energy into space can be observed. As the fundamental processes take place on very small spatial scales, we need high· resolution observations to explore them. On the other hand the small-scale processes act together to form global properties of the sun, which have their origins in the solar interior. The rapid advances in observational techniques and theoreticallllodelling over the past decade made it very timely to bring together scientists from east and west to the first lAU Symposium on this topic. The physics of the photosphere involves complicated interactions between magnetic fields, convection, waves, and radiation. During the past decade our understanding of these gener ally small-scale structures and processes has been dramatically advanced. New instrumen tations, on ground and in space, have given us new means to study the granular convection. Diagnostic methods in Stokes polarimetry have allowed us to go beyond the limitations of spatial resolution to explore the structure and dynamics of the subarcsec magnetic struc tures. Extensive numerical simulations of the interaction between convection and magnetic fields using powerful supercomputers are providing deepened physical insight. Granulation, magnetic fields, and dynamo processes are being explored in the photospheres of other stars, guided by our improved understanding of the solar photosphere.
Del 140 - International Astronomical Union Symposia
Galactic and Intergalactic Magnetic Fields
Proceedings of the 140th Symposium of the International Astronomical Union Held in Heidelberg, F.R.G., June 19–23, 1989
Inbunden, Engelska, 1990
2 156 kr
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This Symposium, the first devoted entirely to the measurement and the role of magnetic fields in the non-solar Universe, was held in Heidelberg, on June 19-23, 1989. The meeting began with review talks on magnetic phenomena near the solar photosphere, corona, and in stellar winds, since these nearby "laboratories", studied for many years, provide much of the prior knowl edge of magnetic effects in astrophysical plasmas. The Symposium contained presentations of considerable new work concerning the role of magnetic fields in accretion disks, bipolar outflows, and related magnetic phenomena in molecular clouds and star forming regions. Both observa tions and related theory of the large-scale magnetic fields in the Milky Way were covered, in addition to a session on the more general theme of magnetohydrodynamics of galactic magnetic fields. Dynamo mechanisms were discussed in considerable detail. It was apparent that recent observational data on polarized emission from external galaxies are now of sufficiently high quality that meaningful tests of large-scale field amplification, and of ideas on the origin of galactic magnetic fields, can be undertaken. Both new observations and numerical simulation work were described in the context of active galaxy nuclei, supernova remnants, radio source jets and extended lobes, and also in the environment of galaxy clusters. Recent large-scale computer simulations incorporating magnetic fields in star formation, radio source jets, and many other phenomena were presented, and much of this was very new.
Häftad, Engelska, 1990
2 156 kr
Skickas inom 10-15 vardagar
This Symposium, the first devoted entirely to the measurement and the role of magnetic fields in the non-solar Universe, was held in Heidelberg, on June 19-23, 1989. The meeting began with review talks on magnetic phenomena near the solar photosphere, corona, and in stellar winds, since these nearby "laboratories", studied for many years, provide much of the prior knowl edge of magnetic effects in astrophysical plasmas. The Symposium contained presentations of considerable new work concerning the role of magnetic fields in accretion disks, bipolar outflows, and related magnetic phenomena in molecular clouds and star forming regions. Both observa tions and related theory of the large-scale magnetic fields in the Milky Way were covered, in addition to a session on the more general theme of magnetohydrodynamics of galactic magnetic fields. Dynamo mechanisms were discussed in considerable detail. It was apparent that recent observational data on polarized emission from external galaxies are now of sufficiently high quality that meaningful tests of large-scale field amplification, and of ideas on the origin of galactic magnetic fields, can be undertaken. Both new observations and numerical simulation work were described in the context of active galaxy nuclei, supernova remnants, radio source jets and extended lobes, and also in the environment of galaxy clusters. Recent large-scale computer simulations incorporating magnetic fields in star formation, radio source jets, and many other phenomena were presented, and much of this was very new.
Häftad, Engelska, 1990
1 082 kr
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Stellar flares represent one of the most challenging problems of contemporary astrophysics. Both solar and stellar observations have shown the flare phenomenon to be very complex, and in recent years important progress has been made from simultaneous observations over wide wavelength ranges. Some similarities exist between solar and stellar flares, but im portant differences have also been established. Such topics, as well as theoretical aspects, were discussed in detail at the Palo Alto IAU Colloquium No. 104, Solar and Stellar Flares, in 1988. Another approach to the study of stellar flares is through observations of flare stars in physical systems. The possibility of detecting flare stars in star clusters and associations with wide angle telescopes have allowed observations of systems with quite different ages. The classical works of G. Haro and V. A. Ambartsumian demonstrated the evolutionary nature of the flare phenomenon. Flares occur at the earliest stages of dwarf star evolution. The photographic observations of flare stars in systems of different ages turned out to be significant not only for the evolutionary study of flare stars, but also for the study of their physical nature. This observational fact was conditioned by very large diversity of flare star luminosities, i.e. of scales of flares produced by them and by peculiarities of stellar flares observed in star clusters and associations.
Häftad, Engelska, 1990
544 kr
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IA U Symposium Number 141 "Inertial Coordinate System on the Sky" was held in Leningrad, USSR from 17-21 October 1989. The symposium also commemorated the 150th anniversary of the founding of Pulkovo Observatory. The scientific program was presented in ten half-day sessions. Most sessions were held at the Pulkovskaya Hotel, but one session which highlighted Pulkovo's current programs was held at Pulkovo Observatory. The sessions were organized into general categories pertaining to the legacy of Pulkovo for inertial systems; current programs at Pulkovo Observatory; concepts, definitions and models; and the realization and comparision of reference frames. More than 140 scientific papers were presented, either orally or in poster form. Extensive use was made of electronic mail and computer-readable communications, and more than two-thirds of the authors made use of the opportunity to submit papers for formatting by the editors. The meeting was truly a symposium in the Greek sense of the word-a free-flowing exchange of ideas and opinions. The final two papers presented at the symposium by Wilkins and by Westerhout are presented at an eady stage in the published proceedings, in order to help focus the reader's attention on the concepts and problems explored in subsequent papers. As pointed out by G.
Häftad, Engelska, 1990
1 082 kr
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The galactic and extragalactic background radiation components are of major importance in astrophysical studies of a variety of problems related to galactic structure, interstellar matter, the distribution and evolution of galaxies and intergalactic matter, and cosmology. The back ground radiation is a unique source of information in cases where the source is of a truly diffuse nature, as with scattering and emission by interstellar dust and gas, or where the discrete emission sources are so faint (e. g. , very distant galaxies) that they can be observed only by their integrated emission. The galactic and extragalactic background must be discussed together because they are observationally entangled and their proper separation requires a knowledge of both components. The above points are equally valid for the entire electromag netic spectrum, from gamma rays to long radio waves. Thus, the study of the galactic and extragalactic background radiation is interdisciplinary in its character, and a multi wavelength approach would appear to be dictated by the nature of the topic. The proper separation of the galactic and extragalactic background components requires a knowledge of both. In addition, the foreground components, i. e. , zodiacal light, airglow, and atmospheric scattered light, must be treated carefully.
Inbunden, Engelska, 1990
2 156 kr
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Much of the excitement in modern Solar Physics has come from the realisation that the Sun is a plasma and that this plasma is interacting with the magnetic field in a wide variety of subtle ways. As well as being of great interest in their own right the observed plasma phenomena on the Sun are of much wider importance, since they reveal to us details of basic phenomena that are expected to be occurring throughout the universe. It was with this in mind that 173 solar physicists from 17 countries gathered together in Bangalore with an air of anticipation. We were not disappointed as we received the warmest of welcomes from our graceful and charming host,Vinod Krishan. She and her colleagues worked tirelessly to make our stay a most memorable one and to ensure that the meeting ran with calm and efficiency. In addition to being stimulated by an excellent series of talks on the up-to-the minute advances in our subject, it was a pleasure to make new friendships from so many countries and to learn, in particular, of the Solar Physics being done in India which has a great tradition and is of a high standard. Furthermore, we enjoyed hearing about Indian culture and appreciating its beauty, especially on our day's tour into the countryside to visit some Hindu and Jain temples.
Häftad, Engelska, 1990
2 156 kr
Skickas inom 10-15 vardagar
Much of the excitement in modern Solar Physics has come from the realisation that the Sun is a plasma and that this plasma is interacting with the magnetic field in a wide variety of subtle ways. As well as being of great interest in their own right the observed plasma phenomena on the Sun are of much wider importance, since they reveal to us details of basic phenomena that are expected to be occurring throughout the universe. It was with this in mind that 173 solar physicists from 17 countries gathered together in Bangalore with an air of anticipation. We were not disappointed as we received the warmest of welcomes from our graceful and charming host,Vinod Krishan. She and her colleagues worked tirelessly to make our stay a most memorable one and to ensure that the meeting ran with calm and efficiency. In addition to being stimulated by an excellent series of talks on the up-to-the minute advances in our subject, it was a pleasure to make new friendships from so many countries and to learn, in particular, of the Solar Physics being done in India which has a great tradition and is of a high standard. Furthermore, we enjoyed hearing about Indian culture and appreciating its beauty, especially on our day's tour into the countryside to visit some Hindu and Jain temples.
Del 143 - International Astronomical Union Symposia
Wolf-Rayet Stars and Interrelations with other Massive Stars in Galaxies
Proceedings of the 143RD Symposium of the International Astronomical Union, Held in Sanur, Bali, Indonesia, June 18–22, 1990
Inbunden, Engelska, 1991
2 156 kr
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The first ideas for the symposium were generated in Brussels in the summer of 1986, dur ing exquisite lunches in between HST proposal consortium meetings. At the time it was expected that soon after the previous IAU symposium (No. 116) devoted to luminous hot massive stars, a bonanza of new exciting observational material would become available, together with significant advances on the theoretical front. Also it was felt that Wolf Rayet stars should feature predominantly, because that had not been the case since IAU Symposium No. 99 in 1981. Tradition requires that IAU symposia on hot massive stars take place in high lumi nosity beach resorts, and after Buenos Aires, Qualicum Beach, Cozumel and Porto Heli, Bali sounded like a reasonable place. Therefore we were only too pleased with the invitation of the Indonesian astronomical community to host the symposium in Sanur (Denpasar). The aim of the symposium was to bring together both observers and theoreticians active in the field of Wolf-Rayet stars and related objects, to present and discuss their recent results, in order to expose to what extent consensus exists as to the physical and chemical properties of Wolf-Rayet stars, their evolutionary status and their interrelations with other massive stars in galaxies.
Häftad, Engelska, 1991
2 156 kr
Skickas inom 10-15 vardagar
The first ideas for the symposium were generated in Brussels in the summer of 1986, dur ing exquisite lunches in between HST proposal consortium meetings. At the time it was expected that soon after the previous IAU symposium (No. 116) devoted to luminous hot massive stars, a bonanza of new exciting observational material would become available, together with significant advances on the theoretical front. Also it was felt that Wolf Rayet stars should feature predominantly, because that had not been the case since IAU Symposium No. 99 in 1981. Tradition requires that IAU symposia on hot massive stars take place in high lumi nosity beach resorts, and after Buenos Aires, Qualicum Beach, Cozumel and Porto Heli, Bali sounded like a reasonable place. Therefore we were only too pleased with the invitation of the Indonesian astronomical community to host the symposium in Sanur (Denpasar). The aim of the symposium was to bring together both observers and theoreticians active in the field of Wolf-Rayet stars and related objects, to present and discuss their recent results, in order to expose to what extent consensus exists as to the physical and chemical properties of Wolf-Rayet stars, their evolutionary status and their interrelations with other massive stars in galaxies.
Inbunden, Engelska, 1991
1 619 kr
Skickas inom 10-15 vardagar
Proceedings of the 146th Symposium of the International Astronomical Union, held in Paris, France, June 4-9, 1990
Häftad, Engelska, 1991
1 619 kr
Skickas inom 10-15 vardagar
Proceedings of the 146th Symposium of the International Astronomical Union, held in Paris, France, June 4-9, 1990
Inbunden, Engelska, 1991
2 156 kr
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Symposium 148 "The Magellanic Clouds and their Dynamical Interaction with the Milky Way" was the first IAU Symposium held in Australia since 1973. In all, 23 countries were represented by 149 participants. The Symposium was held from July 9 to 13, 1990 at Womens College, the University of Sydney. The last symposium on the Magellanic Clouds' was held in 1983 in Ttibingen, Germany. Since then new ground-and satellite-based instruments have become available. A range of results from these instruments were presented at IAU Symposium 148 and are published in these proceedings. IAU Symposium 148 was timed to coincide with the commissioning of the Australia Telescope, and indeed, a few of the first results from that instrument were presented at this Symposium Over the next decade the Australia Telescope is destined to make a major impact on Magellanic Cloud research. Papers are arranged in five main sections reflecting the Symposium timetable: • Large-Scale Structure and Kinematics • Star Formation and Clustering • Stellar Evolution • The Interstellar Medium • The LMC-SMC-Galaxy System These are preceeded by both the introduction to and the summary of the Symposium. Questions and answers from the oral sessions are reproduced at the end of each section.
Häftad, Engelska, 1991
2 156 kr
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Symposium 148 "The Magellanic Clouds and their Dynamical Interaction with the Milky Way" was the first IAU Symposium held in Australia since 1973. In all, 23 countries were represented by 149 participants. The Symposium was held from July 9 to 13, 1990 at Womens College, the University of Sydney. The last symposium on the Magellanic Clouds' was held in 1983 in Ttibingen, Germany. Since then new ground-and satellite-based instruments have become available. A range of results from these instruments were presented at IAU Symposium 148 and are published in these proceedings. IAU Symposium 148 was timed to coincide with the commissioning of the Australia Telescope, and indeed, a few of the first results from that instrument were presented at this Symposium Over the next decade the Australia Telescope is destined to make a major impact on Magellanic Cloud research. Papers are arranged in five main sections reflecting the Symposium timetable: • Large-Scale Structure and Kinematics • Star Formation and Clustering • Stellar Evolution • The Interstellar Medium • The LMC-SMC-Galaxy System These are preceeded by both the introduction to and the summary of the Symposium. Questions and answers from the oral sessions are reproduced at the end of each section.
Del 145 - International Astronomical Union Symposia
Evolution of Stars
The Photospheric Abundance Connection
Inbunden, Engelska, 1991
2 156 kr
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G. MICHAUD Dipartement de Physique Universiti de Montrial c. P. 6128, succursale A Montrial, Que. , H3C 317 Canada The aim of IAU Symposium 145 was to use the photospheric abundances of the chemical elements to give us some hint of the past evolution and of the current structure of stars. At the invitation on the Bulgarian Academy o/Sciences, it brought together one hundred and fifty one scientists from 21 countries to 71atni Pjasaci (Golden Sands), Bulgaria, for a five day meeting. The processes discussed included accretion, mass loss, mass exchange, convection, turbulence, meridional circulation, and diffusion in addition to nuclear reactions. Observationally, spectroscopy was involved. New telescopes and instruments have considerably extended the scope of spectroscopy over the last few years. Space telescopes, such as IUE, have allowed the development of far UV spectroscopy. The access to the infrared has proven critical for probing cool stars. Large ground based telescopes have allowed fainter objects to be observed especially when they are equipped with more efficient detectors such as CCDs and Reticons. The co-adding of digitalized photographic plates has extended their usefulness. It has become possible to make high resolution, high signal to noise observations of objects that could only be observed at low resolution in former days. Weak lines can now be measured with accuracy, allowing the precise determination of the abundances of elements as rare as lithium and the determination of precise limits to isotopic ratios.
Häftad, Engelska, 1991
2 156 kr
Skickas inom 10-15 vardagar
G. MICHAUD Dipartement de Physique Universiti de Montrial c. P. 6128, succursale A Montrial, Que. , H3C 317 Canada The aim of IAU Symposium 145 was to use the photospheric abundances of the chemical elements to give us some hint of the past evolution and of the current structure of stars. At the invitation on the Bulgarian Academy o/Sciences, it brought together one hundred and fifty one scientists from 21 countries to 71atni Pjasaci (Golden Sands), Bulgaria, for a five day meeting. The processes discussed included accretion, mass loss, mass exchange, convection, turbulence, meridional circulation, and diffusion in addition to nuclear reactions. Observationally, spectroscopy was involved. New telescopes and instruments have considerably extended the scope of spectroscopy over the last few years. Space telescopes, such as IUE, have allowed the development of far UV spectroscopy. The access to the infrared has proven critical for probing cool stars. Large ground based telescopes have allowed fainter objects to be observed especially when they are equipped with more efficient detectors such as CCDs and Reticons. The co-adding of digitalized photographic plates has extended their usefulness. It has become possible to make high resolution, high signal to noise observations of objects that could only be observed at low resolution in former days. Weak lines can now be measured with accuracy, allowing the precise determination of the abundances of elements as rare as lithium and the determination of precise limits to isotopic ratios.
Häftad, Engelska, 1991
544 kr
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A few years ago, a motivation for organizing one more IAU Symposium on star for mation in Grenoble, was the anticipated completion of the IRAM interferometer on the Plateau de Bures, close to Grenoble. This choice was also a sort of late celebration of the genius of Joseph Fourier, born in Grenoble, whose work is the very fondation of in terferometry. At the time when we finally announced the advent of this conference, the first reactions we got from the community were expressions of saturation and even reject, the Symposium being unfortunately scheduled almost simultaneously as two other major meetings on closely related topics, and sponsored by different organizations. A wave of disappointment then reached the organizers. Some of us were enthusiastic enough to help the others overcome their discouragement. Let them be thanked here. There was, indeed, a deeper motivation for organizing this conference. It was to trigger the meeting and communication of physicists and astrophysicists since many of the difficulties met now in understanding the physics of the interstellar medium and its evolution toward star formation are common to several, if not most, other fields of physics. They are assigned to one origin: complexity.
Inbunden, Engelska, 1991
2 156 kr
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Highly ionized atoms in the general interstellar gas of the galactic disk were first detected through interstellar absorption line observations of 0 VI with the Copernicus satellite (Rogerson et al. 1973). Survey measurements by Jenkins (1978) of interstellar 0 VI absorption toward 72 stars demonstrated the general presence of 0 VI in the interstellar medium of the galactic disk. This researcIi. and parallel observational studies of the soft X-ra}' background (Williamson et al. 1974; McCammon et al. 1983; Marshall and ClarK 1984) provided direct evidence for the existence of hot low density gas in the mterstellar medium of the galactic disk. The extension of the aDsorption line studies to the distant gas of the galactic halo required the launch of the International Ultraviolet Explorer (IUE) satellite in 1978. The first measures of highly ionized gas m the galactic halo were obtained with the IDE when it was used to record high resolution spectra of bright stars in the Large Magellanic Cloud (Savage and de Boer 1979). Those early spectra revealed the presence of absorption by Si IV and C IV in the galactic nalo and have been followed by a number of surveys with IUE of nighly ionized gas in the galactic disk and halo (Savage and de Boer 1981; Pettini and West 1982; Savage and Massa 1987). The study of UV emission from highly ionized gas in the halo has progressed more slowly because of the intrinsic faintness of the emission.
Häftad, Engelska, 1991
2 156 kr
Skickas inom 10-15 vardagar
Highly ionized atoms in the general interstellar gas of the galactic disk were first detected through interstellar absorption line observations of 0 VI with the Copernicus satellite (Rogerson et al. 1973). Survey measurements by Jenkins (1978) of interstellar 0 VI absorption toward 72 stars demonstrated the general presence of 0 VI in the interstellar medium of the galactic disk. This researcIi. and parallel observational studies of the soft X-ra}' background (Williamson et al. 1974; McCammon et al. 1983; Marshall and ClarK 1984) provided direct evidence for the existence of hot low density gas in the mterstellar medium of the galactic disk. The extension of the aDsorption line studies to the distant gas of the galactic halo required the launch of the International Ultraviolet Explorer (IUE) satellite in 1978. The first measures of highly ionized gas m the galactic halo were obtained with the IDE when it was used to record high resolution spectra of bright stars in the Large Magellanic Cloud (Savage and de Boer 1979). Those early spectra revealed the presence of absorption by Si IV and C IV in the galactic nalo and have been followed by a number of surveys with IUE of nighly ionized gas in the galactic disk and halo (Savage and de Boer 1981; Pettini and West 1982; Savage and Massa 1987). The study of UV emission from highly ionized gas in the halo has progressed more slowly because of the intrinsic faintness of the emission.
Häftad, Engelska, 1992
544 kr
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One approach to learning about stellar populations is to study them at three different levels of resolution. First in our own galaxy; secondly from nearby galaxies where stars can still be resolved; and thirdly in remote galaxies in which the stellar population can only be studied in integrated light. This International Astronomical Union Symposium covered the range of galaxies in its study of their stellar populations. Interspersed with theoretical papers, the observational papers provide a presentation of the progress that has been made in the field.
Inbunden, Engelska, 1992
3 231 kr
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This book contains the proceedings of IAU Symposium No 151 :Evolutionary Processes in Interacting Binary Stars", which was held from 5 to 9 August 1991 in Cordoba, Argentina. The primary aim of this conference was to review and evaluate current understanding of the evolutionary pocesses in a wide variety of interacting binary stars from their births to their deaths. Subjects include the formation of binaries, mass flow and transfer, accretion processes and binaries with collapsed components, such as novae, x-ray binaries and binary pulsars. As the field covered is both broad and diverse, there were in all 37 invited talks; 62 contributed papers were also presented. In addition, these proceedings contain comments from a panel discussion of the major unsolved problems of interacting binary stars.
Häftad, Engelska, 1992
3 231 kr
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This book contains the proceedings of IAU Symposium No 151 :Evolutionary Processes in Interacting Binary Stars", which was held from 5 to 9 August 1991 in Cordoba, Argentina. The primary aim of this conference was to review and evaluate current understanding of the evolutionary pocesses in a wide variety of interacting binary stars from their births to their deaths. Subjects include the formation of binaries, mass flow and transfer, accretion processes and binaries with collapsed components, such as novae, x-ray binaries and binary pulsars. As the field covered is both broad and diverse, there were in all 37 invited talks; 62 contributed papers were also presented. In addition, these proceedings contain comments from a panel discussion of the major unsolved problems of interacting binary stars.
Inbunden, Engelska, 1992
1 619 kr
Skickas inom 10-15 vardagar
This symposium was devoted to a new celestial mechanics whose aim has become the study of such "objects" as the planetary system, planetary rings, the asteroidal belt, meteor swarms, satellite systems, comet families, the zodiacal cloud, the preplanetary nebula and more. Looking at the three-body problem, instead of individual orbits, the text considers the topology of extended regions of its phase space. This symposium was one step in the effort to close the ties between two scientific families: the observationally-oriented scientists and the theoretically-oriented scientists.