Author: James Matthews
Publisher: Springer
ISBN: 3319591835
Category : Science
Languages : en
Pages : 243
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Book Description
This thesis describes the application of a Monte Carlo radiative transfer code to accretion disc winds in two types of systems spanning 9 orders of magnitude in mass and size. In both cases, the results provide important new insights. On small scales, the presence of disc winds in accreting white dwarf binary systems has long been inferred from the presence of ultraviolet absorption lines. Here, the thesis shows that the same winds can also produce optical emission lines and a recombination continuum. On large scales, the thesis constructs a simple model of disc winds in quasars that is capable of explaining both the observed absorption and emission signatures – a crucial advance that supports a disc-wind based unification scenario for quasars. Lastly, the thesis also includes a theoretical investigation into the equivalent width distribution of the emission lines in quasars, which reveals a major challenge to all unification scenarios.
Author: C. G. Campbell
Publisher: Springer
ISBN: 331997646X
Category : Science
Languages : en
Pages : 481
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Book Description
Magnetism in binary stars is an area of central importance in stellar astrophysics. The second edition of "Magnetohydrodynamics in Binary Stars" is a major revision of the first edition. The material has been updated and extended, including additional chapters on the origins of the stellar magnetic fields and accretion disc magnetic winds. A comprehensive account is given of the subject, from the early work up to the latest results. The unifying theme remains the redistribution of angular momentum by magnetic stresses. This occurs in a wide variety of ways, including magnetic stellar and orbital coupling, magnetic channelling of accretion streams, magnetic stellar coupling to accretion discs, dynamo field coupling in discs, and magnetic stellar and disc winds. The associated stellar spin and orbital evolution problems, including stability, are also considered. Although the main focus is on binary stars, much of the work on accretion discs and wind flows has more general astrophysical relevance. Convenient formulae are included that can be compared to observations, making the book useful to observers as well as theorists, and there are extensive reference lists. The material is mainly aimed at research workers, but parts of the text could be useful for postgraduate courses in magnetic stellar astrophysics topics.
Author: Wolf-Rainer Hamann
Publisher: Universitätsverlag Potsdam
ISBN: 3940793337
Category : Stellar winds
Languages : en
Pages : 262
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Book Description
Author: Nikolay Shakura
Publisher: Springer
ISBN: 3319930095
Category : Science
Languages : en
Pages : 437
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Book Description
This book highlights selected topics of standard and modern theory of accretion onto black holes and magnetized neutron stars. The structure of stationary standard discs and non-stationary viscous processes in accretion discs are discussed to the highest degree of accuracy analytic theory can provide, including relativistic effects in flat and warped discs around black holes. A special chapter is dedicated to a new theory of subsonic settling accretion onto a rotating magnetized neutron star. The book also describes supercritical accretion in quasars and its manifestation in lensing events. Several chapters cover the underlying physics of viscosity in astrophysical discs with some important aspects of turbulent viscosity generation. The book is aimed at specialists as well as graduate students interested in the field of theoretical astrophysics.
Author: C.G. Campbell
Publisher: Springer Science & Business Media
ISBN: 9781402003776
Category : Science
Languages : en
Pages : 324
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Book Description
Magnetic stresses were discussed as a possible means of angular momentum transport in the development of accretion disc theory, in the late sixties and early seventies. Interest in the role of magnetic fields in close binary stars steadily increased after the discovery of the nature of AM Herculis in 1976. The observed lack of an accretion disc and the synchronous rotation of the white dwarf suggested strong magnetic effects, consistent with the high degree of optical polarization. Similar systems were soon discovered. Evidence for large magnetic fields was subsequently found in the X-ray binary pulsars and the intermediate polar binaries, both believed to include systems with partially disrupted accretion discs. A magnetically channelled wind from the main sequence secondary star has been invoked to explain the higher mass transfer rates observed in binaries above the period gap, and in an explanation of the gap. Magnetically influenced winds from accretion discs have been suggested as contributing to the inflow by removing angular momentum. Magnetism in binary stars is now an area of central importance in stellar astrophysics. Magnetic fields are believed to playa fundamental role even in apparently non-magnetic binaries. They provide the most viable means, through shear instabilities, of generating the turbulence in accretion discs necessary to drive the inflow via the resulting magnetic and viscous stresses.
Author: Cosimo Bambi
Publisher: Springer Nature
ISBN: 9811969604
Category :
Languages : en
Pages : 5912
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Book Description
Author: Dimitri Mihalas
Publisher: Courier Corporation
ISBN: 0486135888
Category : Science
Languages : en
Pages : 753
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Book Description
Excellent, informative volume focuses on dynamics of nonradiating fluids, problems involving waves, shocks and stellar winds, physics of radiation, radiation transport, and the dynamics of radiating fluids. 1984 edition.
Author: Henrik Beuther
Publisher: University of Arizona Press
ISBN: 0816598762
Category : Science
Languages : en
Pages : 945
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Book Description
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.
Author: Jean-Pierre Rozelot
Publisher: Springer
ISBN: 3642306489
Category : Science
Languages : en
Pages : 255
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Book Description
Based on lectures given at a CNRS summer school in France, this book covers many aspects of stellar environments (both observational and theoretical) and offers a broad overview of the field. More specifically, Part I of the book focuses on the Sun, the properties of the ejected plasma, of the solar wind and on space weather. The second part deals with tides in planetary systems and in binary stellar systems, as well as with interactions in massive binary stars as seen by interferometry. Finally the chapters of Part III discuss the environments of young or evolved stars, stellar winds, agnetic fields and disks. With its broad approach the book will provide advanced students as well as researchers with a good overview of the environments of the Sun and the stars.
Author: G.A.M. van Kuik
Publisher: IOS Press
ISBN: 1643682792
Category : Science
Languages : en
Pages : 162
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Book Description
The first rotor performance predictions were published by Joukowsky exactly 100 years ago. Although a century of research has expanded the knowledge of rotor aerodynamics enormously, and modern computer power and measurement techniques now enable detailed analyses that were previously out of reach, the concepts proposed by Froude, Betz, Joukowsky and Glauert for modelling a rotor in performance calculations are still in use today, albeit with modifications and expansions. This book is the result of the author's curiosity as to whether a return to these models with a combination of mathematics, dedicated computations and wind tunnel experiments could yield more physical insight and answer some of the old questions still waiting to be resolved. Although most of the work included here has been published previously, the book connects the various topics, linking them in a coherent storyline. “The Fluid Dynamic Basis for Actuator Disc and Rotor Theories” was first published in 2018. This Revised Second Edition (2022) will be of interest to those working in all branches of rotor aerodynamics – wind turbines, propellers, ship screws and helicopter rotors. It has been written for proficient students and researchers, and reading it will demand a good knowledge of inviscid (fluid) mechanics. Jens Nørkær Sørensen, DTU, Technical University of Denmark: “(...) a great piece of work, which in a consistent way highlights many of the items that the author has worked on through the years. All in all, an impressive contribution to the classical work on propellers/wind turbines.” Peter Schaffarczyk, Kiel University of Applied Sciences, Germany: “(...) a really impressive piece of work!” Carlos Simão Ferreira, Technical University Delft: “This is a timely book for a new generation of rotor aerodynamicists from wind turbines to drones and personal air-vehicles. In a time where fast numerical solutions for aerodynamic design are increasingly available, a clear theoretical and fundamental formulation of the rotor-wake problem will help professionals to evaluate the validity of their design problem. ‘The Fluid Dynamic Basis for Actuator Disc and Rotor Theories’ is a pleasure to read, while the structure, text and figures are just as elegant as the theory presented.” The cover shows ‘The Red Mill’, by Piet Mondriaan, 1911, collection Gemeentemuseum Den Haag. Cover image: © 2022 Mondrian/Holtzman Trust.
