Download or read book Radiative Transfer in the Stochastic Interstellar Medium written by C. Cechhi-Pestellini and published by . This book was released on 1997 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiative Transfer in the Interstellar Medium written by Sudha Srivastava and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transfer of Radiation in Spectral Lines written by Vsevolod Vladimirovich Ivanov and published by . This book was released on 1973 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Physical Conditions Radiative Transfer and Shocks in the Interstellar Medium written by Cheng-Hsuan Lyu and published by . This book was released on 1992 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transfer of Radiation in Stochastic Media written by George B.. Rybicki and published by . This book was released on 1965 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Radiative Transfer written by Hélène Frisch and published by Springer Nature. This book was released on 2022-05-26 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses analytic and asymptotic methods relevant to radiative transfer in dilute media, such as stellar and planetary atmospheres. Several methods, providing exact expressions for the radiation field in a semi-infinite atmosphere, are described in detail and applied to unpolarized and polarized continuous spectra and spectral lines. Among these methods, the Wiener–Hopf method, introduced in 1931 for a stellar atmospheric problem, is used today in fields such as solid mechanics, diffraction theory, or mathematical finance. Asymptotic analyses are carried out on unpolarized and polarized radiative transfer equations and on a discrete time random walk. Applicable when photons undergo a large number of scatterings, they provide criteria to distinguish between large-scale diffusive and non-diffusive behaviors, typical scales of variation of the radiation field, such as the thermalization length, and specific descriptions for regions close and far from boundaries. Its well organized synthetic view of exact and asymptotic methods of radiative transfer makes this book a valuable resource for both graduate students and professional scientists in astrophysics and beyond.
Download or read book Molecular Collisions in the Interstellar Medium written by David Flower and published by Cambridge University Press. This book was released on 2007-03-22 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the interstellar medium - the space between the stars in galaxies - new stars are born from material that is replenished by the debris ejected by stars when they die. This book is a comprehensive manual for studying the collisional and radiative processes observed in the interstellar medium. This second edition has been thoroughly updated and extended to cover related topics in radiation theory. It considers the chemistry of the interstellar medium both at the present epoch and in the early Universe, and discusses the physics and chemistry of shock waves. The methods of calculation of the rates of collisional excitation of interstellar molecules and atoms are explained, emphasising the quantum mechanical method. This book will be ideal for researchers involved in the interstellar medium and star formation, and physical chemists specialising in collision theory or in the measurement of the rates of collision processes.
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 Stochastic Processes in the Interstellar Medium written by Emeric Bron and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, I have tackled two seemingly unrelated problems in the modeling of the neutral interstellar medium (ISM). The first is the description of H2 formation on interstellar dust grains under realistic conditions. The precise determination of the H2 formation rate and abundance is crucial, as it controls most of the subséquent development of the chemical complexity in the ISM, as well as part of its physics. The temperature of small grains (less than 10 nm) fluctuâtes constantly as those grains are sensitive to the energy of individual UV photons, and the surface mechanisms of H2 formation, which are sensitive to the grain temperature, are kept out of equilibrium by the fluctuations. I have developed an exact resolution formalism for the statistical equilibrium of this system, and implemented its numerical resolution. Among other results, taking the fluctuations into account leads to large differences for the Langmuir-Hinshelwood mechanism, whose efficiency is increased in atomic gas and decreased inside molecular gas. The second problem is related to the ubiquitous presence of molecules such as CH+, whose formation is highly endothermic, in the diffuse ISM where the observed gas temperature (less than 100 K) is insufficient to trigger their formation. It has been proposed that the intermittent dissipation of turbulence could inject the necessary energy, creating hot spots, which could also explain the observed rotational excitation of H2 in such regions. At small scales, the gas is thus perturbed by strong fluctuations of the energy injection rate. I propose a model for the Lagrangian evolution the local physico-chemical state of the gas based on stochastic processes, and apply it to derive the distribution of the gas temperature in the diffuse atomic medium, and the average excitation of H2 in the diffuse molecular gas. Both problems are thus similar and can be described in a more abstract way as systems whose state is perturbed by strong fluctuations of their environment. In order to derive the statistical equilibrium of the system in our two cases, similar methods are used based on the framework of (markovian) stochastic processes. The results obtained here demonstrate the usefulness of this approach, and possible developments for other applications are discussed. Finally, I also present the modeling of the PDR NGC7023 Northwest with the Meudon PDR Code in comparison to Hershel observations, showing the excellent capacity of the Meudon PDR Code to reproduce the observables in dense and intense PDRs.
Download or read book Radiative Transfer in Inhomogeneous Media and Its Influence on the Physical and Chemical State Ot the Interstellar and Circumstellar Medium written by and published by . This book was released on 2011 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiative Transfer in Curved Media written by K. K. Sen and published by World Scientific. This book was released on 1990 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the methods described in this book can be used with cosmetic modifications to solve transfer problems of greater complexity. All attempts have been made to make the book self-contained.
Download or read book Radiative Energy Transfer written by Robert Goulard and published by Elsevier. This book was released on 2017-07-26 with total page 677 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiative Energy Transfer presents the proceedings of the symposium on interdisciplinary aspects of radiative energy transfer held in Philadelphia, Pennsylvania on February 24-26, 1966. The book includes topics on the two main classical directions of radiative transfer: diagnostic techniques and energy exchanges. The text also covers topics on molecular band models, inversion techniques, scattering problems, and shock-wave structure. Topics on high-speed shocks, stellar atmospheres, and meteorology are also encompassed.
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 on Discrete Spaces written by Rudolph W. Preisendorfer and published by Elsevier. This book was released on 2014-07-18 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pure and Applied Mathematics, Volume 74: Radiative Transfer on Discrete Spaces presents the geometrical structure of natural light fields. This book describes in detail with mathematical precision the radiometric interactions of light-scattering media in terms of a few well established principles. Organized into four parts encompassing 15 chapters, this volume begins with an overview of the derivations of the practical formulas and the arrangement of formulas leading to numerical solution procedures of radiative transfer problems in plane-parallel media. This text then constructs radiative transfer theory in three ways. Other chapters consider the development of discrete radiative transfer theory from the local interaction principle. This book discusses as well the development of continuous radiative transfer theory. The final chapter deals with the task of formulating a mathematical foundation for radiative transfer theory. This book is a valuable resource for researchers in the field of radiative transfer theory whose interests transcend the physical and numerical aspects of the interaction of light with matter.
Download or read book Radiative Transfer in Scattering and Absorbing Atmospheres written by Jacqueline Lenoble and published by . This book was released on 1985 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiative Transfer written by Subrahmanyan Chandrasekhar and published by . This book was released on 1960 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
