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Spectral Line Formation

Author: John T. Jefferies

Publisher:

Published: 1968

Total Pages: 328

ISBN-13:

The purpose of this book is to discuss certain aspects of the theory of the formation and analysis of the line spectrum of a hot gas. The underlying motivation for most of the studies discussed here lies in a desire to develop a physically sound procedure for interpreting the line spectrum of a stellar atmosphere ; correspondingly, the major emphasis is given to problems encountered in astrophysics.

Progress in Stellar Spectral Line Formation Theory

Author: J.E. Beckman

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 452

ISBN-13: 9400953720

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Spectral line formation theory is at the heart of astrophysical diagnostic. Our knowledge of abundances, in both stellar and interstellar contexts, comes almost enti rely from line analysis, as does a major fraction of our ability to model stellar atmospheres. As new facets of the universe become observable so the techniques of high reso lution spectroscopy are brought to bear, with great reward. Improved instruments, such as echelle spectrographs, employ ing detectors of high quantum efficiency, have revolutioned our ability to observe high quality line profiles, although until now this ability has been confined to the brightest stars. Fabry-Perot interferometers and their modern deriva tives are bringing new ranges of resolving power to studies of atomic and ionic interstellar lines, and of course radio techniques imply exceedingly high resolution for the cool interstellar medium of molecules and radicals. Telescopes in space are extending the spectral range of these types of observations. Already the Copernicus and IUE high resolution spectrographs have given us a tantalizing glimmer of what it will be like to obtain ultraviolet spectra with resolution and signal to noise ratio approaching those obtainable on the ground. Fairly soon Space Telescope will be producing high resolution spectroscopic data of unparal leled quali ty and distance range. As often happens in astro physics the challenge is now coming from the observers to the theorists to provide interpretational tools which are adequate to the state of the data.

Spectroscopy for Amateur Astronomers

Author: Marc F. M. Trypsteen

Publisher: Cambridge University Press

Published: 2017-07-20

Total Pages: 167

ISBN-13: 1107166187

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This accessible guide presents the astrophysical concepts behind astronomical spectroscopy, covering both theoretical and practical elements. Suitable for anyone with only a little background knowledge and access to amateur-level equipment, it will help you understand and practise the scientifically important and growing field of amateur astronomy.

Polarization in Spectral Lines

Author: M. Landi Degl'Innocenti

Publisher: Springer Science & Business Media

Published: 2006-05-17

Total Pages: 899

ISBN-13: 1402024150

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The scientific research based on spectropolarimetric techniques is undergoing a phase of rapid growth. Instruments of unprecedented sensitivity are nowadays available, particularly for solar observations. To fully exploit the rich diagnostic content of such observations, it is necessary to understand the physical mechanisms involved in the generation and transfer of polarized radiation in astrophysical (or laboratory) plasmas. After an introductory part based on classical physics, this book tackles the subject by a rigorous quantum-mechanical approach. The transfer equations for polarized radiation and the statistical equilibrium equations for the atomic density matrix are derived directly from the principles of Quantum Electrodynamics. The two sets of equations are then used to present a number of applications, mainly concerning the diagnostics of solar magnetic fields. This book is primarily addressed to scientists working in the field of spectropolarimetry. It may also serve as a textbook for a course at the graduate or advanced undergraduate level.

B[e] Stars

Author: Anne Marie Hubert

Publisher: Springer Science & Business Media

Published: 1998-09-30

Total Pages: 312

ISBN-13: 9780792352082

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These proceedings provide a broad overview of the research carried out to date on B-type stars with forbidden emission lines and dusty envelopes. These objects may represent an important transition stage in the evolution of many early-type stars, but they have been little studied until now. The book brings together the information available on the distribution, absolute magnitude, spectra in all wavelength ranges, photometric properties and variability of these objects. Also discussed are the different theoretical models proposed for explaining the amazing variety of phenomena observed.

Radiation Transport in Spectral Lines

Author: R.G. Athay

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 275

ISBN-13: 9401028885

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The usual book on the theory of spectral line formation begins with an in-depth dis cussion of radiation transfer, including the elegant methods of obtaining analytical solutions for special cases, and of the physics of line broadening. Neither of those features will be found in this book. It is assumed that the reader is already familiar with the essentials of transport theory and of line broadening and is ready to investi gate some of the particular applications of the theory to the flow of line photons through the outer layers of a star, or other tenuous media. The main thrust of this book is toward the compilation and presentation of a vast quantity of computational material available to the author in the form of computer output. The material presented represents a highly filtered sample of the published work in this subject plus an extensive set of previously unpublished results. To present large quantities of computer output in an intelligible and efficient way is a difficult task, for which I have found no really satisfactory solution. Chapters III and IV, in particular, contain almost exclusively this type of presentation. The reader may find these chapters somewhat tedious because of the level of condensation of the material. I have tried to reach a reasonable balance between over condensation and excessive detail, which in the long run may be irrelevant.

Exoplanet Atmospheres

Author: Sara Seager

Publisher: Princeton University Press

Published: 2010-08-02

Total Pages: 258

ISBN-13: 1400835305

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Over the past twenty years, astronomers have identified hundreds of extrasolar planets--planets orbiting stars other than the sun. Recent research in this burgeoning field has made it possible to observe and measure the atmospheres of these exoplanets. This is the first textbook to describe the basic physical processes--including radiative transfer, molecular absorption, and chemical processes--common to all planetary atmospheres, as well as the transit, eclipse, and thermal phase variation observations that are unique to exoplanets. In each chapter, Sara Seager offers a conceptual introduction, examples that combine the relevant physics equations with real data, and exercises. Topics range from foundational knowledge, such as the origin of atmospheric composition and planetary spectra, to more advanced concepts, such as solutions to the radiative transfer equation, polarization, and molecular and condensate opacities. Since planets vary widely in their atmospheric properties, Seager emphasizes the major physical processes that govern all planetary atmospheres. Moving from first principles to cutting-edge research, Exoplanet Atmospheres is an ideal resource for students and researchers in astronomy and earth sciences, one that will help prepare them for the next generation of planetary science. The first textbook to describe exoplanet atmospheres Illustrates concepts using examples grounded in real data Provides a step-by-step guide to understanding the structure and emergent spectrum of a planetary atmosphere Includes exercises for students

Star-Formation Rates of Galaxies

Author: Andreas Zezas

Publisher: Cambridge University Press

Published: 2021-04-29

Total Pages: 318

ISBN-13: 1316877523

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Star-formation is one of the key processes that shape the current state and evolution of galaxies. This volume provides a comprehensive presentation of the different methods used to measure the intensity of recent or on-going star-forming activity in galaxies, discussing their advantages and complications in detail. It includes a thorough overview of the theoretical underpinnings of star-formation rate indicators, including topics such as stellar evolution and stellar spectra, the stellar initial mass function, and the physical conditions in the interstellar medium. The authors bring together in one place detailed and comparative discussions of traditional and new star-formation rate indicators, star-formation rate measurements in different spatial scales, and comparisons of star-formation rate indicators probing different stellar populations, along with the corresponding theoretical background. This is a useful reference for students and researchers working in the field of extragalactic astrophysics and studying star-formation in local and higher-redshift galaxies.

The Astrophysics of Emission-Line Stars

Author: Tomokazu Kogure

Publisher: Springer Science & Business Media

Published: 2010-05-05

Total Pages: 544

ISBN-13: 0387689958

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Emission line stars are attractive to many people because of their spectacular phenomena and their amazing varieties and variability. This book offers general information on emission line stars, starting from a brief introduction to stellar astrophysics and then moving to a broad overview of emission line stars including early and late type stars as well as pre-main sequence stars.

Transfer of Radiation in Spectral Lines

Author: Vsevolod Vladimirovich Ivanov

Publisher:

Published: 1973

Total Pages: 480

ISBN-13:

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