Download or read book Impact of Radiative Transfer and Chemistry on the Formation of Molecular Clouds written by Valeska Valdivia and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interstellar medium (ISM) is a highly complex system. It corresponds to an intermediate scale between stars and galaxies. The interstellar gas is present throughout the galaxy, filling the volume between stars. A wide variety of coupled processes, such as gravity, magnetic fields, turbulence and chemistry, participate in its evolution, making the modeling of the ISM a challenging problem. A correct description of the ISM requires a good treatment of the magnetohydrodynamics (MHD) equations, gravity, thermal balance, and chemical evolution within the molecular clouds.This thesis work aims at a better understanding of the formation and evolution of molecular clouds, specially how they become "molecular", paying particular attention to the transition HI-to-H2. We have performed ideal MHD simulations of the formation of molecular clouds and the formation of molecular hydrogen under the influence of gravity and turbulence, using accurate estimates for the shielding effects from dust and the self-shielding for H2, calculated with a Tree-based method, able to provide fast estimates of column densities.We find that H2 is formed faster than predicted by the usual estimates due to local density enhancements created by the gas turbulent motions. Molecular hydrogen, formed at higher densities, could then migrate toward low density warmer regions.Total H2 column densities show that the HI-to-H2 transition occurs at total column densities of a few 10^20 cm-2. We have calculated the populations of rotational levels of H2 at thermal equilibrium, and integrated along several lines of sight. These two results reproduce quite well the values observed by Copernicus and FUSE, suggesting that the observed transition and the excited populations could arise as a consequence of the multi-phase structure of molecular clouds. As H2 formation is prior to further molecule formation, warm H2 could possibly allow the development of a warm chemistry, and eventually explain some aspects of the molecular richness observed in the ISM.
Download or read book Radiative Transfer Through Inhomogeneous Molecular Clouds and Its Implications written by Thomas J. Bethell and published by . This book was released on 2006 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fragmentation of Molecular Clouds and Star Formation written by E. Falgarone and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Analysis and Control of Complex Nonlinear Processes in Physics Chemistry and Biology written by L. Schimansky-Geier and published by World Scientific. This book was released on 2007 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlinear dynamics of complex processes is an active research field with large numbers of publications in basic research, and broad applications from diverse fields of science. Nonlinear dynamics as manifested by deterministic and stochastic evolution models of complex behavior has entered statistical physics, physical chemistry, biophysics, geophysics, astrophysics, theoretical ecology, semiconductor physics and -optics, etc. This field of research has induced a new terminology in science connected with new questions, problems, solutions and methods. New scenarios have emerged for spatio-temporal structures in dynamical systems far from equilibrium. Their analysis and possible control are intriguing and challenging aspects of the current research.The duality of fundamental and applied research is a focal point of its main attractivity and fascination. Basic topics and foundations are always linked to concrete and precise examples. Models and measurements of complex nonlinear processes evoke and provoke new fundamental questions that diversify and broaden the mathematical concepts and tools. In return, new mathematical approaches to modeling and analysis enlarge the scope and efficiency of applied research.
Download or read book Origins of the Earth Moon and Life written by Akio Makishima and published by Elsevier. This book was released on 2017-01-27 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Origins of the Earth, Moon, and Life: An Interdisciplinary Approach presents state-of-the-art knowledge that is based on theories, experiments, observations, calculations, and analytical data from five astro-sciences, astronomy, astrobiology, astrogeology, astrophysics, and cosmochemistry. Beginning with the origin of elements, and moving on to cover the formation of the early Solar System, the giant impact model of the Earth and Moon, the oldest records of life, and the possibility of life on other planets in the Solar System, this interdisciplinary reference provides a complex understanding of the planets and the formation of life. Synthesizing concepts from all branches of astro-sciences into one, the book is a valuable reference for researchers in astrogeology, astrophysics, cosmochemistry, astrobiology, astronomy, and other space science fields, helping users better understand the intersection of these sciences. Includes extensive figures and tables to enhance key concepts Uses callout boxes throughout to provide context and deeper explanations Presents up-to-date information on the universe, stars, planets, moons, and life in the solar system Combines knowledge from the fields of astrogeology, astrophysics, cosmochemistry, astrobiology, and astronomy, helping readers understand the origins of the Earth, the moon, and life in our solar system
Download or read book Ultraviolet Astronomy and the Quest for the Origin of Life written by Ana I. Gomez de Castro and published by Elsevier. This book was released on 2021-03-27 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultraviolet Astronomy and the Quest for the Origin of Life addresses the use of astronomical observations in the ultraviolet range to better understand the generation of complex, life-precursor molecules. The origin of RNA is still under debate but seems to be related to the generation of pools of complex organic molecules submitted to heavy cycles of solution in water and drying. This book investigates whether these cycles require a planetary surface or may occur in space by examining both the theoretical and observational aspects of the role of UV radiation in the origin of life. This book offers the latest advances in these studies for astronomers, astrobiologists and planetary scientists. Addresses both the theoretical and observational aspects of the role of Ultraviolet (UV) radiation in the origin of life Builds on the requirements to produce prebiotic molecules in space and the implications for the origin of RNA Investigates the use of ultraviolet observations related to planetary system formation, the evolution of young planetary disks, and the interaction of stars with planetary atmospheres
Download or read book Radiative Transfer and Chemistry in Spheroidal Interstellar Clouds written by Philip Thomas O'Neill and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1976 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry as a Diagnostic of Star Formation written by National Research Council Canada and published by NRC Research Press. This book was released on 2003 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication contains presentations & poster papers of a conference that focussed on the many aspects of astrochemistry related to star formation. Topics covered include: the next generation of telescopes & detectors; studies of fundamental chemical processes both in the lab & in the field; an exploration of the connections between chemistry & physics in star-forming regions; the unique problems of high-mass star formation; the formation of hydrogen; deuterated molecules; molecular depletion; observations & modelling of embedded protostars; accretion disks & circumstellar disks; interstellar dust; and the chemistry, physical conditions, & structure of dark clouds. Includes indexes of subjects, authors, & astronomical objects.
Download or read book The Physics and Chemistry of the Interstellar Medium written by A. G. G. M. Tielens and published by Cambridge University Press. This book was released on 2005-08-25 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description
Download or read book Earth as an Evolving Planetary System written by Kent C. Condie and published by Academic Press. This book was released on 2011-08-22 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth as an Evolving Planetary System, Second Edition, explores key topics and questions relating to the evolution of the Earth's crust and mantle over the last four billion years. This updated edition features exciting new information on Earth and planetary evolution and examines how all subsystems in our planet—crust, mantle, core, atmosphere, oceans and life—have worked together and changed over time. It synthesizes data from the fields of oceanography, geophysics, planetology, and geochemistry to address Earth’s evolution. This volume consists of 10 chapters, including two new ones that deal with the Supercontinent Cycle and on Great Events in Earth history. There are also new and updated sections on Earth's thermal history, planetary volcanism, planetary crusts, the onset of plate tectonics, changing composition of the oceans and atmosphere, and paleoclimatic regimes. In addition, the book now includes new tomographic data tracking plume tails into the deep mantle. This book is intended for advanced undergraduate and graduate students in Earth, Atmospheric, and Planetary Sciences, with a basic knowledge of geology, biology, chemistry, and physics. It also may serve as a reference tool for structural geologists and professionals in related disciplines who want to look at the Earth in a broader perspective. Kent Condie's corresponding interactive CD, Plate Tectonics and How the Earth Works, can be purchased from Tasa Graphic Arts here: http://www.tasagraphicarts.com/progptearth.html Two new chapters on the Supercontinent Cycle and on Great Events in Earth history New and updated sections on Earth's thermal history, planetary volcanism, planetary crusts, the onset of plate tectonics, changing composition of the oceans and atmosphere, and paleoclimatic regimes Also new in this Second Edition: the lower mantle and the role of the post-perovskite transition, the role of water in the mantle, new tomographic data tracking plume tails into the deep mantle, Euxinia in Proterozoic oceans, The Hadean, A crustal age gap at 2.4-2.2 Ga, and continental growth
Download or read book Publications written by United States. National Bureau of Standards and published by . This book was released on 1975 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of Atmospheric Chemistry written by Guy P. Brasseur and published by Cambridge University Press. This book was released on 2017-06-19 with total page 631 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical modeling of atmospheric composition is a formidable scientific and computational challenge. This comprehensive presentation of the modeling methods used in atmospheric chemistry focuses on both theory and practice, from the fundamental principles behind models, through to their applications in interpreting observations. An encyclopaedic coverage of methods used in atmospheric modeling, including their advantages and disadvantages, makes this a one-stop resource with a large scope. Particular emphasis is given to the mathematical formulation of chemical, radiative, and aerosol processes; advection and turbulent transport; emission and deposition processes; as well as major chapters on model evaluation and inverse modeling. The modeling of atmospheric chemistry is an intrinsically interdisciplinary endeavour, bringing together meteorology, radiative transfer, physical chemistry and biogeochemistry, making the book of value to a broad readership. Introductory chapters and a review of the relevant mathematics make this book instantly accessible to graduate students and researchers in the atmospheric sciences.
Download or read book Molecular Hydrogen in Space written by F. Combes and published by Cambridge University Press. This book was released on 2000-11-06 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first multi-disciplinary review of our new understanding of molecular hydrogen in space, and its role in the early Universe.
Download or read book The Physics and Chemistry of the Interstellar Medium written by A. G. G. M. Tielens and published by Cambridge University Press. This book was released on 2005-08-25 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work provides a comprehensive overview of our theoretical and observational understanding of the interstellar medium of galaxies. With emphasis on the microscopic physical and chemical processes in space, and their influence on the macroscopic structure of the interstellar medium of galaxies, the book includes developments in this area of molecular astrophysics. The various heating, cooling, and chemical processes relevant for the rarefied gas and submicron-sized dust grains that constitute the interstellar medium are discussed in detail. This provides a firm foundation for an in-depth understanding of the ionized, neutral atomic, and molecular phases of the interstellar medium. The physical and chemical properties of large polycyclic aromatic hydrocarbon molecules and their role in the interstellar medium are highlighted, and the physics and chemistry of warm and dense photodissociation regions are discussed. This is an invaluable reference source for advanced undergraduate and graduate students, and research scientists.
Download or read book Physics of the Interstellar and Intergalactic Medium written by Bruce T. Draine and published by Princeton University Press. This book was released on 2010-12-20 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a comprehensive and richly illustrated textbook on the astrophysics of the interstellar and intergalactic medium--the gas and dust, as well as the electromagnetic radiation, cosmic rays, and magnetic and gravitational fields, present between the stars in a galaxy and also between galaxies themselves. Topics include radiative processes across the electromagnetic spectrum; radiative transfer; ionization; heating and cooling; astrochemistry; interstellar dust; fluid dynamics, including ionization fronts and shock waves; cosmic rays; distribution and evolution of the interstellar medium; and star formation. While it is assumed that the reader has a background in undergraduate-level physics, including some prior exposure to atomic and molecular physics, statistical mechanics, and electromagnetism, the first six chapters of the book include a review of the basic physics that is used in later chapters. This graduate-level textbook includes references for further reading, and serves as an invaluable resource for working astrophysicists. Essential textbook on the physics of the interstellar and intergalactic medium Based on a course taught by the author for more than twenty years at Princeton University Covers radiative processes, fluid dynamics, cosmic rays, astrochemistry, interstellar dust, and more Discusses the physical state and distribution of the ionized, atomic, and molecular phases of the interstellar medium Reviews diagnostics using emission and absorption lines Features color illustrations and detailed reference materials in appendices Instructor's manual with problems and solutions (available only to teachers)
Download or read book The Role of Magnetic Fields in the Formation of Stars written by Derek Ward-Thompson and published by Frontiers Media SA. This book was released on 2020-06-29 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
