The Physics of Wind-Fed Accretion

The Physics of Wind-Fed Accretion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

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Book Description
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.

The Physics of Wind-Fed Accretion

The Physics of Wind-Fed Accretion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

Get Book Here

Book Description
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.

The Physics of Accretion onto Black Holes

The Physics of Accretion onto Black Holes PDF Author: Maurizio Falanga
Publisher: Springer
ISBN: 1493922270
Category : Science
Languages : en
Pages : 483

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Book Description
Provides a comprehensive summary on the physical models and current theory of black hole accretion, growth and mergers, in both the supermassive and stellar-mass cases. This title reviews in-depth research on accretion on all scales, from galactic binaries to intermediate mass and supermassive black holes. Possible future directions of accretion are also discussed. The following main themes are covered: a historical perspective; physical models of accretion onto black holes of all masses; black hole fundamental parameters; and accretion, jets and outflows. An overview and outlook on the topic is also presented. This volume summarizes the status of the study of astrophysical black hole research and is aimed at astrophysicists and graduate students working in this field. Originally published in Space Science Reviews, Vol 183/1-4, 2014.

Astrophysics

Astrophysics PDF Author: James Binney
Publisher: Oxford University Press
ISBN: 0198752857
Category : Science
Languages : en
Pages : 177

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Book Description
Astrophysics is said to have been born when Isaac Newton saw an apple drop in his orchard and had the electrifying insight that the Moon falls just like that apple. James Binney shows how the application of physical laws derived on Earth allows us to understand objects that exist on the far side of the Universe.

Rotation and Accretion Powered Pulsars

Rotation and Accretion Powered Pulsars PDF Author: Pranab Ghosh
Publisher: World Scientific
ISBN: 9812708464
Category : Science
Languages : en
Pages : 793

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Book Description
This book is an introduction to pulsars, a key area in high energy astrophysics with continuing potential for fundamental discoveries. Throughout the book runs the unifying thread of the evolutionary link between rotation-powered pulsars and accretion-powered pulsars OCo a milestone of modern astrophysics. Early textbooks on pulsars dealt almost entirely with rotation-powered ones, while accounts of pulsars in volumes on X-ray binaries focused almost exclusively on accretion-powered ones. This is the first textbook to treat these two kinds of pulsars simultaneously with equal importance, stressing the fact that both are rotating, magnetic neutron stars, operating under different conditions during different parts of their lives. It describes the observational properties of both kinds of pulsars, summarizes our physical understanding of these properties, and pays detailed attention to the physics of superdense matter which neutron stars are composed of, as well as to the superfluidity which is expected to occur in neutron stars. Evolution from rotation-power to accretion-power, and vice versa, are carefully described. The effects of the strong magnetic fields of neutron stars on themselves, their emission properties, and their environments are discussed, as are the origin and evolution of such magnetic fields. Also treated is the superbly accurate verification of Einstein''s theory of general relativity through timing studies of binary pulsars, which led to the award of the Nobel Prize to Hulse and Taylor in 1993. On each topic, the book starts with simple, basic physical concepts, and builds up the exposition to the point where the latest and most exciting developments become accessible to the reader."

Cool Discs, Hot Flows

Cool Discs, Hot Flows PDF Author: Magnus Axelsson
Publisher: American Institute of Physics
ISBN:
Category : Science
Languages : en
Pages : 252

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Book Description
All papers have been peer-reviewed. These proceedings contain research papers from the participants of the astrophysics conference “Cool discs, hot flows”. The main focus of the conference was on physical processes of accreting compact objects. Topics covered include wind-fed accretion, neutron stars and white dwarfs, ultraluminous X-ray sources and temporal variability.

Science with Minisat 01

Science with Minisat 01 PDF Author: Alvaro Gimenez
Publisher: Springer Science & Business Media
ISBN: 9401006865
Category : Science
Languages : en
Pages : 334

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Book Description
This book includes the proceedings of the Workshop held in Madrid, April 1999 to celebrate 2 years of successful operation of the first Spanish small scientific satellite in orbit. It contains discussions about the overall philosophy of small mission programs, the design of the satellite and its payload as well as the most relevant scientific outcome of the mission. Also included are additional contributions to the workshop, which are of importance to Minisat 01 in order to put its results within context. Finally, the future of small missions for space sciences is reviewed together with the main technological challenges for new studies. Out of the technological and scientific results of Minisat 01, the measurement of the EUV airglow spectrum and the flux of some stars in the same range can be highlighted together with the dismiss of the massive neutrino decay theory. The high-energy experiment analyzed the characterization of the radiation environment in LEO and the behaviour of different kind of detectors, as well as the use of coded masks for imaging and the measurement of some specific sources. The book's level is intended for specialists in EUV and Hard X-Ray astrophysicists as well as for engineers and technicians involved in space science experiments and missions.

Accretion Power in Astrophysics

Accretion Power in Astrophysics PDF Author: Juhan Frank
Publisher: Cambridge University Press
ISBN: 9780521629577
Category : Science
Languages : en
Pages : 390

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Book Description
Accretion Power in Astrophysics examines accretion as a source of energy in both binary star systems containing compact objects, and in active galactic nuclei. Assuming a basic knowledge of physics, the authors describe the physical processes at work in accretion discs and other accretion flows. The first three chapters explain why accretion is a source of energy, and then present the gas dynamics and plasma concepts necessary for astrophysical applications. The next three chapters then develop accretion in stellar systems, including accretion onto compact objects. Further chapters give extensive treatment of accretion in active galactic nuclei, and describe thick accretion discs. A new chapter discusses recently discovered accretion flow solutions. The third edition is greatly expanded and thoroughly updated. New material includes a detailed treatment of disc instabilities, irradiated discs, disc warping, and general accretion flows. The treatment is suitable for advanced undergraduates, graduate students and researchers.

Feeding Compact Objects (IAU S290)

Feeding Compact Objects (IAU S290) PDF Author: Chengmin Zhang
Publisher: Cambridge University Press
ISBN: 9781107033795
Category : Science
Languages : en
Pages : 0

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Book Description
This decade has seen a large number of high-energy space missions, which, alongside ground-based optical and radio telescopes, have enabled the detailed study of accreting compact objects. IAU S290 addresses the state-of-the-art research on accretion in astrophysical objects and systems ranging in scale from active galactic nuclei down to stellar black holes, neutron stars and white dwarfs, by bringing together scientists from each of these fields. It focuses on understanding the common physics of slow and relativistic outflows in these objects and features reviews on modelling, observations and instrumentation. Specific topics covered in this volume include: the physics of accreting systems, the magnetic environment around compact objects, large scale properties of accretion, the accretion-ejection connection, jets and outflows, and instrumentation. The fundamentals of accretion and its applications are reviewed in several of the papers, making this a useful reference guide for researchers and graduate students in astrophysics.

Physics of Binary Star Evolution

Physics of Binary Star Evolution PDF Author: Thomas M Tauris
Publisher: Princeton University Press
ISBN: 0691239266
Category : Science
Languages : en
Pages : 865

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Book Description
A graduate-level textbook on the astrophysics of binary star systems and their evolution Physics of Binary Star Evolution is an up-to-date textbook on the astrophysics and evolution of binary star systems. Theoretical astrophysicists Thomas Tauris and Edward van den Heuvel cover a wide range of phenomena and processes, including mass transfer and ejection, common envelopes, novae and supernovae, X-ray binaries, millisecond radio pulsars, and gravitational wave (GW) sources, and their links to stellar evolution. The authors walk through the observed properties and evolution of different types of binaries, with special emphasis on those containing compact objects (neutron stars, black holes, and white dwarfs). Attention is given to the formation mechanisms of GW sources—merging double neutron stars and black holes as well as ultra-compact GW binaries hosting white dwarfs—and to the progenitors of these sources and how they are observed with radio telescopes, X-ray satellites, and GW detectors (LIGO, Virgo, KAGRA, Einstein Telescope, Cosmic Explorer, and LISA). Supported by illustrations, equations, and exercises, Physics of Binary Star Evolution combines theory and observations to guide readers through the wonders of a field that will play a central role in modern astrophysics for decades to come. 465 equations, 47 tables, and 350+ figures More than 80 exercises (analytical, numerical, and computational) Over 2,500 extensive, up-to-date references

Physics of Neutron Star Interiors

Physics of Neutron Star Interiors PDF Author: D. Blaschke
Publisher: Springer
ISBN: 3540445781
Category : Science
Languages : en
Pages : 521

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Book Description
Neutron stars are the densest observable bodies in our universe. Born during the gravitational collapse of luminous stars - a birth heralded by spectacular supernova explosions - they open a window on a world where the state of the matter and the strengths of the fields are anything but ordinary. This book is a collection of pedagogical lectures on the theory of neutron stars, and especially their interiors, at the forefront of current research. It addresses graduate students and researchers alike, and should be particularly suitable as a text bridging the gap between standard textbook material and the research literature.