[PDF] Accretion And Winds eBook

Author : Vasily S. Beskin
Publisher : Springer Science & Business Media
Page : 425 pages
File Size : 14,52 MB
Release : 2009-12-08
Category : Science
ISBN : 3642012906

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Accretion flows, winds and jets of compact astrophysical objects and stars are generally described within the framework of hydrodynamical and magnetohydrodynamical (MHD) flows. Analytical analysis of the problem provides profound physical insights, which are essential for interpreting and understanding the results of numerical simulations. Providing such a physical understanding of MHD Flows in Compact Astrophysical Objects is the main goal of this book, which is an updated translation of a successful Russian graduate textbook. The book provides the first detailed introduction into the method of the Grad-Shafranov equation, describing analytically the very broad class of hydrodynamical and MHD flows. It starts with the classical examples of hydrodynamical accretion onto relativistic and nonrelativistic objects. The force-free limit of the Grad-Shafranov equation allows us to analyze in detail the physics of the magnetospheres of radio pulsars and black holes, including the Blandford-Znajek process of energy extraction from a rotating black hole immersed in an external magnetic field. Finally, on the basis of the full MHD version of the Grad-Shafranov equation the author discusses the problems of jet collimation and particle acceleration in Active Galactic Nuclei, radio pulsars, and Young Stellar Objects. The comparison of the analytical results with numerical simulations demonstrates their good agreement. Assuming that the reader is familiar with the basic physical and mathematical concepts of General Relativity, the author uses the 3+1 split approach which allows the formulation of all results in terms of physically clear language of three dimensional vectors. The book contains detailed derivations of equations, numerous exercises, and an extensive bibliography. It therefore serves as both an introductory text for graduate students and a valuable reference work for researchers in the field.

Author : Gerhard Klare
Publisher : Springer Science & Business Media
Page : 378 pages
File Size : 35,48 MB
Release : 2012-12-06
Category : Science
ISBN : 3642762387

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In order to bring the scientific events of the meetings of the Astronomische Gesellschaft (AG) to the attention of the worldwide astronomical community, an annual publication, Reviews in Modern Astronomy, was established. It is devoted exclusively to . the invited reviews, the Karl Schwarz schild lectures, and the high light contributions from leading scientists reporting on recent progress and scientific achievements at their respective institutes. This third volume continues the yearbook series of publications of the society. It comprises the complete set of contributions presented during the spring meeting of the AG at Berlin in March 1990, which was dedicated to the topic "Accretion and Winds". In addition four latecomers (two review and two highlight papers) delivered at the fall meeting at Graz, Austria in September 1989 close this volume. Heidelberg, September 1990 G: Klare Contents Some New Elements in Accretion Disk Theory By F. Meyer (With 5 Figures) . . . . . . . . . . . . . . . . . . . . . . . 1 Mass Transfer and Evolution in Close Binaries By A. R. King (With 4 Figures) . . . . . . . . . . . . . . . . . . . . . . . 14 Radiation Hydrodynamics of the Boundary Layer of Accretion Disks in Cataclysmic Variables By W. Kley (With 6 Figures) . . . . . . . . . . . . . . . . . . . . . . . . 21 Curious Observations of Cataclysmic Variables By F. V. Hessman (With 10 Figures) . . . . . . . . . . . . . . . . . . . 32 Accretion in AM Herculis Stars 44 By A. D. Schwope (With 12 Figures) X-ray Diagnostics of Accretion Disks By G. Hasinger (With 12 Figures) . . . . . . . . . . . . . . . . . . . . . 60 Accretion Phenomena at Neutron Stars By A. Rebetzky, H. Herold, U. Kraus, H. -P. Nollert, and H. Ruder (With 13 Figures) . . . . . . . . . . . . . . . . . . . . . .

Author : Lee Hartmann
Publisher : Cambridge University Press
Page : 260 pages
File Size : 42,16 MB
Release : 2000-11-15
Category : Science
ISBN : 9780521785204

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This first comprehensive account of the dynamical processes in the formation of stars and disks from which planets ultimately form.

Author : James Matthews
Publisher : Springer
Page : 243 pages
File Size : 47,33 MB
Release : 2017-08-01
Category : Science
ISBN : 3319591835

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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 :
Publisher :
Page : 11 pages
File Size : 44,32 MB
Release : 2008
Category :
ISBN :

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We provide a brief review of the physical processes behind the radiative driving of the winds of OB stars and the Bondi-Hoyle-Lyttleton capture and accretion of a fraction of the stellar wind by a compact object, typically a neutron star, in detached high-mass X-ray binaries (HMXBs). In addition, we describe a program to develop global models of the radiatively-driven photoionized winds and accretion flows of HMXBs, with particular attention to the prototypical system Vela X-1. The models combine XSTAR photoionization calculations, HULLAC emission models appropriate to X-ray photoionized plasmas, improved models of the radiative driving of photoionized winds, FLASH time-dependent adaptive-mesh hydrodynamics calculations, and Monte Carlo radiation transport. We present two- and three-dimensional maps of the density, temperature, velocity, ionization parameter, and emissivity distributions of representative X-ray emission lines, as well as synthetic global Monte Carlo X-ray spectra. Such models help to better constrain the properties of the winds of HMXBs, which bear on such fundamental questions as the long-term evolution of these binaries and the chemical enrichment of the interstellar medium.