Download or read book Radio Recombination Lines written by M.A. Gordon and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book HII Regions and Radio Recombination Lines written by Mark A. Gordon and published by . This book was released on 1988 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Recombination Lines written by P.A. Shaver and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Radio Recombination Lines from H II Regions written by Peter Robert Silverglate and published by . This book was released on 1978 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Recombination Line Observations of HII Regions and Planetary Nebulae written by Pieter Roelf Roelfsema and published by . This book was released on 1987 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Recombination Line Emission from Ultracompact HII Regions written by Edward B. Churchwell and published by . This book was released on 1989 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Recombination Lines written by P.A. Shaver and published by Springer. This book was released on 1980-03-31 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Physics and Chemistry of the Interstellar Medium written by A. G. G. M. Tielens and published by Cambridge University Press. This book was released on 2005-08-25 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description
Download or read book Tools of Radio Astronomy written by K. Rohlfs and published by . This book was released on 2004 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Search for Radio Recombination Lines in Selected Ultra compact HII Regions written by and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-mass star formation -- Ultracompact HII region -- Radio recombination lines -- Radio continuum -- Interferometry.
Download or read book Physical Processes in the Interstellar Medium written by Lyman Spitzer, Jr. and published by John Wiley & Sons. This book was released on 2008-11-20 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical Processes in the Interstellar Medium discusses the nature of interstellar matter, with a strong emphasis on basic physical principles, and summarizes the present state of knowledge about the interstellar medium by providing the latest observational data. Physics and chemistry of the interstellar medium are treated, with frequent references to observational results. The overall equilibrium and dynamical state of the interstellar gas are described, with discussions of explosions produced by star birth and star death and the initial phases of cloud collapse leading to star formation.
Download or read book Essential Radio Astronomy written by James J. Condon and published by Princeton University Press. This book was released on 2016-04-05 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book A survey of radio recombination lines from H I one regions and H II two regions written by Vernon Pankonin and published by . This book was released on 1977 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radio Recombination Lines 25 Years of Investigation written by M.A. Gordon and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Text no 1 Radio Recombination Lines (RRLs), discovered in the USSR in 1964, have become a powerful research tool for astronomers. Available throughout the radio spectrum, these lines carry information regarding the density, temperature, turbulence and velocity of thermal plasmas. Their very existance shows the presence of thermal gas. They also can carry information regarding magnetic fields if Zeeman splitting were to be detected. Containing the proceedings of an IAU Colloquium celebrating the 25th anniversary of their detection, this volume tells us what has happened since. It contains the story of the detection of RRLs and reviews of many areas of physics of the interstellargas from which stars form, HII regions excited by newly formed stars, planetary nebulae involving dying stars, and the structure of our Milky Way and other galaxies reflecting the large-scale morphology of the star formation process. In addition there is an article describing modern laboratory studies of Rydberg atoms to probe the basic physics of atomic structure, and articles describing the theory of collisions and radiation upon Rydberg atoms leading to observate effects to be used as diagnostic tools in astromony. This book focuses on the 25 years of astronomical research with radio recombination lines (RRLs) since their discovery in 1965. It covers a wide range of topics: papers dealing with research into Rydberg atoms both in the laboratory and in the interstellar medium of our galaxy and others; papers on the interaction of radiation and atomic systems, as well as with the effects of inadiabatic collisions between these atoms and both ions and electrons. It deals with astronomical observations of atoms with `diameters' ranging from 0.08 to 50 mum a size factor of 625. It deals with RRLs in absorption, in emission and as true masers. And it deals with plasmas with temperatures ranging from 10 to greater than 104 kelvins, and with an even greater range of volume densities. Much new work is reported, including low frequency RRLs discovered in 1980 and the maser RRLs from the star MWC349, discovered in 1989. The advent of aperture synthesis telescopes and large single-element telescopes have made possible RRL studies with high angular resolution. The sum total of the work reported here will make the volume a platform from which to search new horizons in RRL research.
Download or read book A 10 5 GHz Radio Recombination Line Map of the HII Region W3 written by and published by . This book was released on 1976 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of the Interstellar and Intergalactic Medium written by Bruce T. Draine and published by Princeton University Press. This book was released on 2011 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential resource for graduate students and astrophysicists This is a comprehensive and richly illustrated textbook on the astrophysics of the interstellar and intergalactic medium—the gas and dust, as well as the electromagnetic radiation, cosmic rays, and magnetic and gravitational fields, present between the stars in a galaxy and also between galaxies themselves. Topics include radiative processes across the electromagnetic spectrum; radiative transfer; ionization; heating and cooling; astrochemistry; interstellar dust; fluid dynamics, including ionization fronts and shock waves; cosmic rays; distribution and evolution of the interstellar medium; and star formation. While it is assumed that the reader has a background in undergraduate-level physics, including some prior exposure to atomic and molecular physics, statistical mechanics, and electromagnetism, the first six chapters of the book include a review of the basic physics that is used in later chapters. This graduate-level textbook includes references for further reading, and serves as an invaluable resource for working astrophysicists. Essential textbook on the physics of the interstellar and intergalactic medium Based on a course taught by the author for more than twenty years at Princeton University Covers radiative processes, fluid dynamics, cosmic rays, astrochemistry, interstellar dust, and more Discusses the physical state and distribution of the ionized, atomic, and molecular phases of the interstellar medium Reviews diagnostics using emission and absorption lines Features color illustrations and detailed reference materials in appendices Instructor's manual with problems and solutions (available only to teachers)
Download or read book On the Electron Temperatures of HII Regions written by Janet Pagdin Simpson and published by . This book was released on 1970 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: