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Author: J.E. Beckman
Publisher: Springer Science & Business Media
ISBN: 9400953720
Category : Science
Languages : en
Pages : 452
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Book Description
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.
Author: J.E. Beckman
Publisher: Springer Science & Business Media
ISBN: 9400953720
Category : Science
Languages : en
Pages : 452
Get Book Here
Book Description
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.
Author: S. Böhme
Publisher: Springer Science & Business Media
ISBN: 3662123525
Category : Science
Languages : en
Pages : 1157
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Book Description
Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysics, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 39 records literature published in 1985 and received before August 15, 1985. Some older documents which we received late and which are not surveyed in earlier volumes are included too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. On account of the introduction of an object index the scope of index information will be considerably enlarged beginning with this volume. In connection with the subject index an additional source to satisfy the needs of retrieval is opened up. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Mona El-Choura, Ms. Monika Kohl, Ms. Sylvia Matyssek. Ms. Karin Burkhardt, Ms. Susanne Schlotelburg, and Mr. Stefan Wagner supported our task by careful proofreading. It is a pleasure to thank them all for their encouragement. Heidelberg, September 1985 The Editors Contents Introduction . . . . . . . . . . . .
Author: John T. Jefferies
Publisher:
ISBN:
Category : Astronomical spectroscopy
Languages : en
Pages : 328
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Book Description
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.
Author: John E. Beckman
Publisher:
ISBN:
Category : Astronomical spectroscopy
Languages : en
Pages : 448
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Book Description
Author: International Astronomical Union. Symposium
Publisher: Springer Science & Business Media
ISBN: 9789027726957
Category : Science
Languages : en
Pages : 670
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Book Description
Proceedings of the 132nd Symposium of the International Astronomical Union, held in Paris, France, June 29-July 3, 1987
Author: Jean-Pierre Swings
Publisher: Springer Science & Business Media
ISBN: 9400947429
Category : Science
Languages : en
Pages : 647
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Book Description
The XIXth General Assembly of the International Astronomical Union was held in New Delhi, India, from November 19 to 28, 1985. It was dedicated to the memory of a former IAU President, Professor M. K. V. Bappu, who tragically passed away on August 19, 1982. On the occasion of the Delhi General Assembly, the IAU Minor Planet Center announced that Minor Planet (asteroid) No. 2596 henceforth will carry the name Vainu Sappu. The full text of the announcement reads: "(2596) VAINU BAPPU = 1979 KN (diameter about 8 kilometers, period 5 years 4 months, mean distance from the Sun around 450 million kilometers) Discovered 1979, May 19, by R. M. West at the European Southern Observatory. Named in memory of Manali f
Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1146
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Book Description
Author: A. Peacock
Publisher: Springer Science & Business Media
ISBN: 9400954484
Category : Science
Languages : en
Pages : 711
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Book Description
Algol is a triple system containing a 70 hr eclipsing binary (K IV and B8 V) in a 694 day orbit with an A V star. The X-ray emission from this system (Schnopper et al 1976) is thought to be associated with a corona surrounding the lobe filling and synchron ously rotating K IV star. This is based on the similarity of the X-ray spectrum and luminosity of this system to that of the RS CVn binaries which also contain K sub-giants with similar rotation periods and the fact that the luminosity of any coronae surrounding the B8 V and AV companion stars should not be enhanced by rapid rotation (Pallavicini et al 1980, White et al 1980). The Einstein SSS measurement showed the X-ray spectrum to be two component with 6 7 temperatures of 7. 10 K and 3. 10 K (White et al. 1980). As dis cussed by Swank et al. (1981), the problem in understanding stellar coronae in general is how to scale up the solar model to account for the enhanced luminosities. The close to 900 inclination and similar sizes for the Band K stars of 3. 6 and 3. 8 R0 respectively make Algol an ideal candidate for an X-ray eclipse measurement wherein the size of the X-ray emitting coronal structures can be directly measured. In this paper we report a continuous observation through the secondary eclipse of Algol using the EXOSAT Observatory. 2.
Author: C. Mattok
Publisher:
ISBN:
Category : Interferometry
Languages : en
Pages : 286
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Book Description
Author: Richard Marrus
Publisher: Springer Science & Business Media
ISBN: 146130833X
Category : Science
Languages : en
Pages : 474
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Book Description
The progress in the physics of highly-ionized atoms since the last NATO sponsored ASI on this subject in 1982 has been enormous. New accelerator facilities capable of extending the range of highly-ionized ions to very high-Z have come on line or are about to be completed. We note particularly the GANIL accelerator in Caen, France, the Michigan State Superconducting Cyclotrons in East Lansing both of which are currently operating and the SIS Accelerator in Darmstadt, FRG which is scheduled to accelerate beam in late 1989. Progress i~ low-energy ion production has been equally dramatic. The Lawrence Livermore Lab EBIT device has produced neon-like gold and there has been continued improvement in ECR and EBIS sources. The scientific developments in this field have kept pace with the technical developments. New theoretical methods for evaluating relativistic and QED effects have made possible highly-precise calcula tions of energy levels in one-and two-electron ions at high-Z. The calculations are based on the MCDF method and the variational method and will be subject to rigorous experimental tests. On the experimental side, precision x-ray and UV measurements have probed the Lamb shift in the one and two electron ions up to Z=36 with increasing precision.
