Download or read book High Angular Resolution Studies of the Structure and Evolution of Protoplanetary Disks written by Joshua Eisner and published by Universal-Publishers. This book was released on 2005 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Young stars are surrounded by massive, rotating disks of dust and gas, which supply a reservoir of material that may be incorporated into planets or accreted onto the central star. In this dissertation, I use high angular resolution observations at a range of wavelengths to understand the structure, ubiquity, and evolutionary timescales of protoplanetary disks. First, I describe a study of Class I protostars, objects believed to be at an evolutionary stage between collapsing spherical clouds and fully-assembled young stars surrounded by protoplanetary disks. I use a Monte Carlo radiative transfer code to model new 0.9 micron scattered light images, 1.3 mm continuum images, and broadband spectral energy distributions. This modeling shows that Class I sources are probably surrounded by massive protoplanetary disks embedded in massive infalling envelopes. For the best-fitting models of the circumstellar dust distributions, I determine several important properties, including envelope and disk masses, mass infall rates, and system inclinations, and I use these results to constrain the evolutionary stage of these objects. Second, I discuss observations of the innermost regions of more evolved disks around T Tauri and Herbig Ae/Be stars, obtained with the Palomar Testbed and Keck Interferometers. I constrain the spatial and temperature structure of the circumstellar material at sub-AU radii, and demonstrate that lower-mass stars are surrounded by inclined disks with puffed-up inner edges 0.1-1 AU from the star. In contrast, the truncated inner disks around more massive stars may not puff-up, indicating that disk structure depends on stellar properties. I discuss the implications of these results for disk accretion, terrestrial planet formation and giant planet migration. Finally, I put these detailed studies of disk structure into a broader context by constraining the mass distribution and evolutionary timescales of circumstellar disks. Using the Owens Valley Millimeter Array, I mapped the millimeter continuum emission toward >300 low-mass stars in the NGC 2024 and Orion Nebula clusters. These observations demonstrate that the average disk mass in each cluster is comparable to the "minimum-mass protosolar nebula," and that there may be disk evolution on one million year timescales.
Download or read book A Few Tens au Scale Physical and Chemical Structures Around Young Low Mass Protostars written by Yoko Oya and published by Springer Nature. This book was released on 2022-11-08 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book characterizes the kinematic and chemical structures of disk-forming regions around low-mass protostellar sources and their interplay based on Atacama Large Millimeter/submillimeter Array (ALMA) observations. It describes the chemical evolution of molecules formed in an interstellar gas using the ALMA observations of 5 Sun-like protostars at a spatial resolution of a few tens au scale, which unveils the physical mechanism of star and planetary formation. The book reviews the author’s successful works, focusing on two key findings: (i) A drastic change in the chemical composition of the gas around the centrifugal barrier of the infalling-rotating envelopes, and (ii) the chemical composition in the disk-forming regions, which varies from source to source depending on the chemical characteristics of the parent molecular cloud. These findings are based on the fine characterization of physical structures based on careful kinematic analyses. An additional attraction is the inclusion of the skillful reviews of ALMA observatory and its observation and physical models to describe the observed gas structure.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Literature 1988 Part 2 written by Astronomisches Rechen-Institut and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 1308 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: "Astronomy and Astrophysics Abstracts has appeared in semi-annual volumes since 1969 and it has already become one of the fundamental publications in the fields of astronomy, astrophysics and neighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. ...The abstracts are classified under more than a hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world." Space Science Reviews#1 "Dividing the whole field plus related subjects into 108 categories, each work is numbered and most are accompanied by brief abstracts. Fairly comprehensive cross-referencing links relevant papers to more than one category, and exhaustive author and subject indices are to be found at the back, making the catalogues easy to use. The series appears to be so complete in its coverage and always less than a year out of date that I shall certainly have to make a little more space on those shelves for future volumes." The Observatory Magazine#2
Download or read book Advances in Geochemistry Analytical Chemistry and Planetary Sciences written by Vladimir P. Kolotov and published by Springer Nature. This book was released on 2023-02-28 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents 41 selected articles written by leading researchers from the Vernadsky Institute of Geochemistry and Analytical Chemistry, part of the Russian Academy of Sciences. The articles are grouped by the following topics: (1) Geochemistry, (2) Meteoritics, Cosmochemistry, Lunar and Planetary Sciences, (3) Biogeochemistry and Ecology, and (4) Analytical Chemistry, Radiochemistry, and Radioecology. The articles present recent experimental data, theoretical investigations, critical reviews, the results of computer modeling in the above-mentioned fields. Intended to provide a scientific “snapshot” of the institute, the book also includes content on its history, main scientific achievements and current goals, together with detailed descriptions of its 25 laboratories and three museums so as to promote new international collaborations. Given its scope, the book will be of interest to all scientists and graduate students working in the areas of geochemistry, analytical chemistry and radiochemistry, earth and environmental sciences, biogeosciences, meteoritics and planetary science, and to those seeking new collaboration opportunities in these areas in Russia.
Download or read book Turbulence and Self Organization written by Mikhail Ya Marov and published by Springer Science & Business Media. This book was released on 2013-01-16 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book deals with the development of continual models of turbulent natural media. Such models serve as a ground for the statement and numerical evaluation of the key problems of the structure and evolution of the numerous astrophysical and geophysical objects. The processes of ordering (self-organization) in an originally chaotic turbulent medium are addressed and treated in detail with the use of irreversible thermodynamics and stochastic dynamics approaches which underlie the respective models. Different examples of ordering set up in the natural environment and outer space are brought and thoroughly discussed, the main focus being given to the protoplanetary discs formation and evolution.
Download or read book Planetary Systems written by Marc Ollivier and published by Springer Science & Business Media. This book was released on 2008-11-27 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past ten years, the discovery of extrasolar planets has opened a new field of astronomy, and this area of research is rapidly growing, from both the observational and theoretical point of view. The presence of many giant exoplanets in the close vicinity of their star shows that these newly discovered planetary systems are very different from the solar system. New theoretical models are being developed in order to understand their formation scenarios, and new observational methods are being implemented to increase the sensitivity of exoplanet detections. In the present book, the authors address the question of planetary systems from all aspects. Starting from the facts (the detection of more than 300 extraterrestrial planets), they first describe the various methods used for these discoveries and propose a synthetic analysis of their global properties. They then consider the observations of young stars and circumstellar disks and address the case of the solar system as a specific example, different from the newly discovered systems. Then the study of planetary systems and of exoplanets is presented from a more theoretical point of view. The book ends with an outlook to future astronomical projects, and a description of the search for life on exoplanets. This book addresses students and researchers who wish to better understand this newly expanding field of research.
Download or read book Space Studies Board Annual Report 2010 written by National Research Council and published by National Academies Press. This book was released on 2011-01-01 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Space Studies Board (SSB) was established in 1958 to serve as the focus of the interests and responsibilities in space research for the National Academies. The SSB provides an independent, authoritative forum for information and advice on all aspects of space science and applications, and it serves as the focal point within the National Academies for activities on space research. It oversees advisory studies and program assessments, facilitates international research coordination, and promotes communications on space science and science policy between the research community, the federal government, and the interested public. The SSB also serves as the U.S. National Committee for the International Council for Science Committee on Space Research (COSPAR). This volume reviews the organization, activities, and reports of the SSB for the year 2010.
Download or read book Newsletter written by and published by . This book was released on 1998 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science with the Atacama Large Millimeter Array written by Rafael Bachiller and published by Springer Science & Business Media. This book was released on 2008-04-03 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently under construction in Northern Chile, the Atacama Large Millimeter Array (ALMA) is the most ambitious astronomy facility under construction. This book describes the enormous capabilities of ALMA, the state of the project, and most notably the scientific prospects of such a unique facility. The book includes reviews and recent results on most hot topics of modern astronomy. It looks forward to the revolutionary results that are likely to be obtained with ALMA.
Download or read book JET Simulations Experiments and Theory written by Christophe Sauty and published by Springer. This book was released on 2019-08-02 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2008, the European FP6 JETSET project ended. JETSET, for Jet, Simulations, Experiments, and Theory, was a joint research network of European expert teams on protostellar jets. The present proceedings are a collection of contributions presenting new results obtained by those groups since the end of the JETSET program. This is also the occasion to celebrate Kanaris Tsinganos’ important contributions to this network and for his enlightening insight in the subject that inspired us all. Some of the former JETSET students are now in the academic world and the subject has never been so alive. So we present here a collection of results of what has been done in the field of protostellar jets in the past ten years from the theoretical, numerical, observational and experimental point of view. We also present new challenges in the field of protostellar jets and what we should expect from the development of new instruments and new numerical codes in the near future. We also gather results on the impact of the study of protostellar jets on other jet studies in particular on relativistic jets. As a matter of fact, it is time for a new network.
Download or read book Protostars and Planets VI written by Henrik Beuther and published by University of Arizona Press. This book was released on 2014-12-18 with total page 945 pages. Available in PDF, EPUB and Kindle. Book excerpt: The revolutionary discovery of thousands of confirmed and candidate planets beyond the solar system brings forth the most fundamental question: How do planets and their host stars form and evolve? Protostars and Planets VI brings together more than 250 contributing authors at the forefront of their field, conveying the latest results in this research area and establishing a new foundation for advancing our understanding of stellar and planetary formation. Continuing the tradition of the Protostars and Planets series, this latest volume uniquely integrates the cross-disciplinary aspects of this broad field. Covering an extremely wide range of scales, from the formation of large clouds in our Milky Way galaxy down to small chondrules in our solar system, Protostars and Planets VI takes an encompassing view with the goal of not only highlighting what we know but, most importantly, emphasizing the frontiers of what we do not know. As a vehicle for propelling forward new discoveries on stars, planets, and their origins, this latest volume in the Space Science Series is an indispensable resource for both current scientists and new students in astronomy, astrophysics, planetary science, and the study of meteorites.
Download or read book Workshop on the Origins of Solar Systems written by Joseph A. Nuth and published by . This book was released on 1988 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topics addressed include: interstellar chemistry and primitive bodies; astronomical measurements and nebula models; solar nebula models and meteorite; and planetary accumulation and evolution.
Download or read book Protostars and Planets V written by Bo Reipurth and published by University of Arizona Press. This book was released on 2007 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Protostars and Planets V' builds on the latest results from recent advances in ground and space-based astronomy and in numerical computing techniques to offer the most detailed and up-to-date picture of star and planet formation - including the formation and early evolution of our own solar system.
Download or read book Rent Resources Technologies written by Alberto Quadrio Curzio and published by Springer Science & Business Media. This book was released on 1999-08-19 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rent, resources, and technologies are three crucial issues to the understanding of history and economics. The scarcity of resources, its interplay with technology, and the role of rent in explaining both economic growth and income distribution are investigated by adopting a multi-sectoral and non-proportional model, where scarce resources impose several scale constraints that may slow growth, but may contribute to further development of new technologies. In this dynamic framework the category of rent acquires new dimensions with far-reaching implications for both the system of prices and the distribution of income. The analytical and formal-theoretical perspective of this book could be used as a basis for future historical and quantitative studies.
Download or read book Cosmological Inflation Dark Matter and Dark Energy written by Kazuharu Bamba and published by MDPI. This book was released on 2019-11-14 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various cosmological observations support not only cosmological inflation in the early universe, which is also known as exponential cosmic expansion, but also that the expansion of the late-time universe is accelerating. To explain this phenomenon, the existence of dark energy is proposed. In addition, according to the rotation curve of galaxies, the existence of dark matter, which does not shine, is also suggested. If primordial gravitational waves are detected in the future, the mechanism for realizing inflation can be revealed. Moreover, there exist two main candidates for dark matter. The first is a new particle, the existence of which is predicted in particle physics. The second is an astrophysical object which is not found by electromagnetic waves. Furthermore, there are two representative approaches to account for the accelerated expansion of the current universe. One is to assume the unknown dark energy in general relativity. The other is to extend the gravity theory to large scales. Investigation of the origins of inflation, dark matter, and dark energy is one of the most fundamental problems in modern physics and cosmology. The purpose of this book is to explore the physics and cosmology of inflation, dark matter, and dark energy.
Download or read book Very High Angular Resolution Imaging written by J.G. Robertson and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1990s are proving to be a very exciting p&iod for high angular resolution astronomy. At radio wavelengths a combination of new array instruments and pow erful imaging algorithms have generated images of unprecedented resolution and quality. In the optical and infrared, the great technical difficulties associated with constructing separated-aperture interferometers have been largely overcome, and many new instruments are now operating or are being developed. As these pro grams start to produce observational results they will be able to draw extensively on the experience gained by the radio-interferometry community. Thus it seemed that the time was ripe for a meeting which would bring together workers from all wavelength ranges to discuss the details of the science and art of "Very High Angular Resolution Imaging" . While the main emphasis of Symposium No. 158 was on high resolution tech niques from the radio, mm-wave, infrared and optical bands, it also provided an opportunity for presentation of astronomical results from these techniques. As well as giving our colleagues from the Northern Hemisphere a break from midwinter, the location of the Symposium in Australia recognised the continuing development of astronomical interferometry in this country, especially the recent completion of the Australia Telescope radio array, and the progress toward com missioning of the Sydney University Stellar Interferometer. A number of the par ticipants visited these instruments during the post-symposium tour.
