Dynamics Of The Rise Of Magnetic Flux Tubes In Stellar Interiors
DOWNLOAD
Download Dynamics Of The Rise Of Magnetic Flux Tubes In Stellar Interiors PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Dynamics Of The Rise Of Magnetic Flux Tubes In Stellar Interiors book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Dynamics Of The Rise Of Magnetic Flux Tubes In Stellar Interiors
DOWNLOAD
Author : Yori Fournier
language : en
Publisher:
Release Date : 2016
Dynamics Of The Rise Of Magnetic Flux Tubes In Stellar Interiors written by Yori Fournier and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Solar-like stars maintain their magnetic fields thanks to a dynamo mechanism. The Babcock-Leighton dynamo is one possible dynamo that has the particularity to require magnetic flux tubes. Magnetic flux tubes are assumed to form at the bottom of the convective zone and rise buoyantly to the surface. A delayed dynamo model has been suggested, where the delay accounts for the rise time of the magnetic flux tubes; a time, that has been ignored by former studies. The present thesis aims to study the applicability of the flux tube/Babcock-Leighton dynamo to other stars. To do so, we attempt to constrain the rise time of magnetic flux tubes thanks to the first fully compressible MHD simulations of rising magnetic flux tubes in stratified rotating spherical shells. Such simulations are limited to an unrealistic parameter space, therefore, a scaling relation is required to scale the results to realistic physical regimes. We extended earlier works on 2D scaling relations and derived a general scaling law valid for both 2D and 3D. We then...
Dynamics Of Local Isolated Magnetic Flux Tubes In A Fast Rotating Stellar Atmosphere
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1998
Dynamics Of Local Isolated Magnetic Flux Tubes In A Fast Rotating Stellar Atmosphere written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1998 with categories.
Dynamics of magnetic flux tubes in the fast rotating stellar atmosphere is studied. We focus on the effects and signatures of the instability of the flux tube emergence influenced by the Coriolis force. We present the result from a linear stability analysis and discuss its possible signatures in the course of the evolution of G-type and M-type stars. We present a three dimensional magnetohydrodynamical simulation of local isolated magnetic flux tubes under a magnetic buoyancy instability in co-rotating Cartesian coordinates. We find that the combination of the buoyancy instability and the Coriolis effect gives rise to a mechanism, to twist the emerging magnetic flux tube into a helical structure. The tilt angle, east-west asymmetry and magnetic helicity of the Twisted flux tubes in the simulations are studied in detail. The linear and nonlinear analyses provide hints as to what kind of pattern of large spots in young M-type main-sequence stars might be observed. We find that young and old G-type stars may have different distributions of spots while M-type stars may always have low latitudes spots. The size of stellar spots may decrease when a star becomes older, due to the decreasing of magnetic field. A qualitative comparison with solar observations is also presented.
Physics Of Magnetic Flux Tubes
DOWNLOAD
Author : Margarita Ryutova
language : en
Publisher: Springer
Release Date : 2015-02-24
Physics Of Magnetic Flux Tubes written by Margarita Ryutova and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-02-24 with Science categories.
This book is the first account of the physics of magnetic flux tubes from their fundamental properties to collective phenomena in an ensembles of flux tubes. The physics of magnetic flux tubes is absolutely vital for understanding fundamental physical processes in the solar atmosphere shaped and governed by magnetic fields. High-resolution and high cadence observations from recent space and ground-based instruments taken simultaneously at different heights and temperatures not only show the ubiquity of filamentary structure formation but also allow to study how various events are interconnected by system of magnetic flux tubes. The book covers both theory and observations. Theoretical models presented in analytical and phenomenological forms are tailored for practical applications. These are welded with state-of-the-art observations from early decisive ones to the most recent data that open a new phase-space for exploring the Sun and sun-like stars. Concept of magnetic flux tubes is central to various magnetized media ranging from laboratory plasma and Earth's magnetosphere to planetary, stellar and galactic environments The book is a valuable resource for graduate students, solar physicists, astronomers, laboratory and space plasma physicists, geophysicists, and specialists in gas- and hydrodynamics.
Advances In Nonlinear Dynamos
DOWNLOAD
Author : Antonio Ferriz-Mas
language : en
Publisher: CRC Press
Release Date : 2019-07-17
Advances In Nonlinear Dynamos written by Antonio Ferriz-Mas and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019-07-17 with Science categories.
Nonlinear dynamo theory is central to understanding the magnetic structures of planets, stars and galaxies. In chapters contributed by some of the leading scientists in the field, this text explores some of the recent advances in the field. Both kinetic and dynamic approaches to the subject are considered, including fast dynamos, topological methods in dynamo theory, physics of the solar cycle and the fundamentals of mean field dynamo. Advances in Nonlinear Dynamos is ideal for graduate students and researchers in theoretical astrophysics and applied mathematics, particularly those interested in cosmic magnetism and related topics, such as turbulence, convection, and more general nonlinear physics.
The Origin And Dynamics Of Solar Magnetism
DOWNLOAD
Author : M.J. Thompson
language : en
Publisher: Springer Science & Business Media
Release Date : 2009-05-01
The Origin And Dynamics Of Solar Magnetism written by M.J. Thompson and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009-05-01 with Science categories.
Starting in 1995 numerical modeling of the Earth’s dynamo has ourished with remarkable success. Direct numerical simulation of convection-driven MHD- ow in a rotating spherical shell show magnetic elds that resemble the geomagnetic eld in many respects: they are dominated by the axial dipole of approximately the right strength, they show spatial power spectra similar to that of Earth, and the magnetic eld morphology and the temporal var- tion of the eld resembles that of the geomagnetic eld (Christensen and Wicht 2007). Some models show stochastic dipole reversals whose details agree with what has been inferred from paleomagnetic data (Glatzmaier and Roberts 1995; Kutzner and Christensen 2002; Wicht 2005). While these models represent direct numerical simulations of the fundamental MHD equations without parameterized induction effects, they do not match actual pla- tary conditions in a number of respects. Speci cally, they rotate too slowly, are much less turbulent, and use a viscosity and thermal diffusivity that is far too large in comparison to magnetic diffusivity. Because of these discrepancies, the success of geodynamo models may seem surprising. In order to better understand the extent to which the models are applicable to planetary dynamos, scaling laws that relate basic properties of the dynamo to the fundamental control parameters play an important role. In recent years rst attempts have been made to derive such scaling laws from a set of numerical simulations that span the accessible parameter space (Christensen and Tilgner 2004; Christensen and Aubert 2006).
Solar And Stellar Dynamos
DOWNLOAD
Author : Paul Charbonneau
language : en
Publisher: Springer
Release Date : 2012-11-06
Solar And Stellar Dynamos written by Paul Charbonneau and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-11-06 with Science categories.
Astrophysical dynamos are at the heart of cosmic magnetic fields of a wide range of scales, from planets and stars to entire galaxies. This book presents a thorough, step-by-step introduction to solar and stellar dynamos. Looking first at the ultimate origin of cosmic seed magnetic fields, the antagonists of field amplification are next considered: resistive decay, flux expulsion, and flows ruled out by anti-dynamo theorems. Two kinematic flows that can act as dynamos are then studied: the Roberts cell and the CP-flow. Mean-field electrodynamics and derivation of the mean-field dynamo equations lead to the alpha Omega-dynamo, the flux transport dynamo, and dynamos based on the Babcock-Leighton mechanism. Alternatives to the mean-field theory are also presented, as are global MHD dynamo simulations. Fluctuations and grand minima in the solar cycle are discussed in terms of dynamo modulations through stochastic forcing and nonlinear effects. The book concludes with an overview of the major challenges in understanding stellar magnetic fields and their evolution in terms of various dynamo models, global MHD simulations, and fossil fields. Each chapter is accompanied by an annotated bibliography, guiding the readers to the relevant technical literature, which may lead them to carry out their own research in the field of dynamo theory.
The Sun As A Guide To Stellar Physics
DOWNLOAD
Author : Oddbjørn Engvold
language : en
Publisher: Elsevier
Release Date : 2018-11-15
The Sun As A Guide To Stellar Physics written by Oddbjørn Engvold and has been published by Elsevier this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-11-15 with Science categories.
The Sun as a Guide to Stellar Physics illustrates the significance of the Sun in understanding stars through an examination of the discoveries and insights gained from solar physics research. Ranging from theories to modeling and from numerical simulations to instrumentation and data processing, the book provides an overview of what we currently understand and how the Sun can be a model for gaining further knowledge about stellar physics. Providing both updates on recent developments in solar physics and applications to stellar physics, this book strengthens the solar–stellar connection and summarizes what we know about the Sun for the stellar, space, and geophysics communities. Applies observations, theoretical understanding, modeling capabilities and physical processes first revealed by the sun to the study of stellar physics Illustrates how studies of Proxima Solaris have led to progress in space science, stellar physics and related fields Uses characteristics of solar phenomena as a guide for understanding the physics of stars
Encyclopedia Of Astronomy Astrophysics
DOWNLOAD
Author : P Murdin
language : en
Publisher: CRC Press
Release Date : 2001-01-01
Encyclopedia Of Astronomy Astrophysics written by P Murdin and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001-01-01 with Science categories.
In a unique collaboration, Nature Publishing Group and Institute of Physics Publishing have published the most extensive and comprehensive reference work in astronomy and astrophysics. This unique resource covers the entire field of astronomy and astrophysics and this online version includes the full text of over 2,750 articles, plus sophisticated search and retrieval functionality and links to the primary literature. The Encyclopaedia's authority is assured by editorial and advisory boards drawn from the world's foremost astronomers and astrophysicists. This first class resource is an essential source of information for undergraduates, graduate students, researchers and seasoned professionals, as well as for committed amateurs, librarians and lay people wishing to consult the definitive astronomy and astrophysics reference work.
The Be Phenomenon In Early Type Stars
DOWNLOAD
Author : Myron A. Smith
language : en
Publisher:
Release Date : 2000
The Be Phenomenon In Early Type Stars written by Myron A. Smith and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2000 with Science categories.
Annotation Contains 137 papers presented at the June 1999 meeting on Be stars and possible connections to other types of hot stars. The authors report on the results from the use of new missions and technologies, the production of periodic and aperiodic variability in the atmospheres of Be stars, models of circumstellar discs, and the relationship of binary systems to the Be phenomenon. Topics include the Be phenomenon in A-type supergiants, Hipparcos positions of B/Be stars on the HR diagram, and the role of polarimetry as a diagnostic of circumstellar envelopes. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Solar And Stellar Magnetic Activity
DOWNLOAD
Author : C. J. Schrijver
language : en
Publisher: Cambridge University Press
Release Date : 2008-10-30
Solar And Stellar Magnetic Activity written by C. J. Schrijver and has been published by Cambridge University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008-10-30 with Science categories.
This timely volume provides the first comprehensive review and synthesis of current understanding of magnetic fields in the Sun and similar stars. Magnetic activity results in a wealth of phenomena - including starspots, non-radiatively heated outer atmospheres, activity cycles, deceleration of rotation rates, and even, in close binaries, stellar cannibalism - all of which are covered clearly and authoritatively. This book brings together for the first time recent results in solar studies and stellar studies. The result is an illuminating new view of stellar magnetic activity. Key topics include radiative transfer, convective simulations, dynamo theory, outer-atmospheric heating, stellar winds and angular momentum loss. Researchers are provided with a state-of-the-art review of this exciting field, and the pedagogical style and introductory material make the book an ideal and welcome introduction for graduate students.