Radio Recombination Lines

Radio Recombination Lines PDF

Author: M.A. Gordon

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 369

ISBN-13: 9401002614

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Recombination lines at radio wavelengths have been - and still are - a pow erful tool for modern astronomy. For more than thirty years they have allowed astronomers to probe the gases from which stars form. They have even been detected in the Sun. In addition, observations of these spectral lines facilitate basic research into the atom, in forms and environments that can only exist in the huge dimensions and extreme conditions of cosmic laboratories. We intend this book to serve as a tourist's guide to the world of Radio Recombination Lines. It contains three divisions: a history of their discovery, the physics of how they form and how their voyage to us influences their spectral profiles, and a description of their many astronomical contributions to date. The appendix includes supplementary calculations that may be useful to some astronomers. This material also includes tables of line frequencies from 12 MHz to 30THz (AlOJLm) as well as FORTRAN computer code to calculate the fine structure components of the lines, to evaluate radial matrix integrals, and to calculate the departure coefficients of hydrogen in a cosmic environment. It also describes how to convert observational to astrophysical units. The text includes extensive references to the literature to assist readers who want more details.

Radio Recombination Lines

Radio Recombination Lines PDF

Author: P.A. Shaver

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 281

ISBN-13: 9400990243

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Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientists to review the field and discuss these questions of interpretation. A broad concensus has emerged: the subtleties of the line-formation process are understood, and the conditions under which reliable in formation can easily be extracted from the line measurements are known. It thus appears likely that the emphasis will shift increasingly from the study of the line phenomenon itself to further application in other areas of astrophysics, ranging from physical processes in plasmas (temperatures, densities, ionization structure), to the large-scale properties of our galaxy (abundances, kinematics, structure), and studies of extragalactic systems.

Radiative Processes in Astrophysics

Radiative Processes in Astrophysics PDF

Author: George B. Rybicki

Publisher: John Wiley & Sons

Published: 2008-09-26

Total Pages: 400

ISBN-13: 352761818X

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Radiative Processes in Astrophysics: This clear, straightforward, and fundamental introduction is designed to present-from a physicist's point of view-radiation processes and their applications to astrophysical phenomena and space science. It covers such topics as radiative transfer theory, relativistic covariance and kinematics, bremsstrahlung radiation, synchrotron radiation, Compton scattering, some plasma effects, and radiative transitions in atoms. Discussion begins with first principles, physically motivating and deriving all results rather than merely presenting finished formulae. However, a reasonably good physics background (introductory quantum mechanics, intermediate electromagnetic theory, special relativity, and some statistical mechanics) is required. Much of this prerequisite material is provided by brief reviews, making the book a self-contained reference for workers in the field as well as the ideal text for senior or first-year graduate students of astronomy, astrophysics, and related physics courses. Radiative Processes in Astrophysics also contains about 75 problems, with solutions, illustrating applications of the material and methods for calculating results. This important and integral section emphasizes physical intuition by presenting important results that are used throughout the main text; it is here that most of the practical astrophysical applications become apparent.

Tools of Radio Astronomy

Tools of Radio Astronomy PDF

Author: K. Rohlfs

Publisher:

Published: 2004

Total Pages: 462

ISBN-13: 9783662032664

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This substantially rewritten and expanded fourth edition outlines the most up-to-date methods and tools of radio astronomy. Tools of Radio Astronomy gives a unified treatment of the entire field of radio astronomy, from centimeter to sub-millimeter wavelengths and using single telescopes as well as interferometers. The basic physical principles are described and a complete outline of the instrumentation, observational techniques, and methods of measurement and analysis are given. The goal of this standard reference and text is to prepare readers to carry out observations and relate the data to physical processes in interstellar space. In this fourth edition, the chapter on interferometry and aperture synthesis has been thoroughly revised in the light of most recent developments, as has been the chapter on molecules in interstellar space, and material on receiver technology. From reviews of previous editions: "People use this book so much because it describes what one needs in order actually to do radio astronomy ... and it will remain relevant for a long time...This book is an excellent graduate level text - the best available by far. It is also the best reference book for the practising astronomer who wants to do radio astronomy properly, to interpret the jargon or to understand some of the details of current literature." Physics Today "This is the one book you should buy if you want to become a radio astronomer. (...) I have used the first and second editions as a postgraduate textbook for many years, and will now recommend the third edition to my students." The Observatory.

Essential Radio Astronomy

Essential Radio Astronomy PDF

Author: James J. Condon

Publisher: Princeton University Press

Published: 2016-04-05

Total Pages: 376

ISBN-13: 069113779X

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The ideal text for a one-semester course in radio astronomy Essential Radio Astronomy is the only textbook on the subject specifically designed for a one-semester introductory course for advanced undergraduates or graduate students in astronomy and astrophysics. It starts from first principles in order to fill gaps in students' backgrounds, make teaching easier for professors who are not expert radio astronomers, and provide a useful reference to the essential equations used by practitioners. This unique textbook reflects the fact that students of multiwavelength astronomy typically can afford to spend only one semester studying the observational techniques particular to each wavelength band. Essential Radio Astronomy presents only the most crucial concepts—succinctly and accessibly. It covers the general principles behind radio telescopes, receivers, and digital backends without getting bogged down in engineering details. Emphasizing the physical processes in radio sources, the book's approach is shaped by the view that radio astrophysics owes more to thermodynamics than electromagnetism. Proven in the classroom and generously illustrated throughout, Essential Radio Astronomy is an invaluable resource for students and researchers alike. The only textbook specifically designed for a one-semester course in radio astronomy Starts from first principles Makes teaching easier for astronomy professors who are not expert radio astronomers Emphasizes the physical processes in radio sources Covers the principles behind radio telescopes and receivers Provides the essential equations and fundamental constants used by practitioners Supplementary website includes lecture notes, problem sets, exams, and links to interactive demonstrations An online illustration package is available to professors

Radio Recombination Lines

Radio Recombination Lines PDF

Author: M.A. Gordon

Publisher: Springer

Published: 2009-01-31

Total Pages: 360

ISBN-13: 9780387096049

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This guide to the physics and observations of Radio Recombination Lines from astronomical sources includes history, theory, applications, 250 equations and 110 illustrations. This soft cover edition contains corrections and updates from hardbound edition.

Radio Recombination Lines

Radio Recombination Lines PDF

Author: P.A. Shaver

Publisher: Springer

Published: 1980-03-31

Total Pages: 289

ISBN-13: 9789027711038

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Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientists to review the field and discuss these questions of interpretation. A broad concensus has emerged: the subtleties of the line-formation process are understood, and the conditions under which reliable in formation can easily be extracted from the line measurements are known. It thus appears likely that the emphasis will shift increasingly from the study of the line phenomenon itself to further application in other areas of astrophysics, ranging from physical processes in plasmas (temperatures, densities, ionization structure), to the large-scale properties of our galaxy (abundances, kinematics, structure), and studies of extragalactic systems.