Multielement System Design in Astronomy and Radio Science


Book Description

The multielement systems have been widely used in many fields of astron omy and radio science in the last decades. This is caused by the increasing demands on the resolution and sensitivity of such systems over the wide range of the electromagnetic wavelengths, from gamma up to radio. The ground-based optical and radio interferometers, gamma-ray and X-ray or bital telescopes, antenna arrays of radio telescopes and also some other radio devices belong to scientific instruments using multielement systems. There fore, the current problems of the optimal construction of such systems, or precisely, those of searching for the best arrangement of the elements in them, were formulated. A rather large number of scientific papers, including those of the authors, is devoted to these problems, and we believe that the time has come to integrate the basic results of the papers into the mono graph. The offered book consists of three parts. The first part is concerned with the optimal synthesis of optical and radio interferometers of various types and purposes; the synthesis of non-equidistant antenna arrays is con sidered in the second part; and the methods for the construction of coded masks for X-ray and gamma-ray orbital telescopes are expounded in the third one. Since in the text combinatorial constructions which are little known to astronomers are used, the necessary information is given in the appendices. Various tables containing the parameters of the systems consid ered are also represented.




Stellar Astrophysics


Book Description

The Pacific Rim Conferences for the first decade from the mid 1980's to the mid 1990's were primary concerned with binary stars research. The Conference expanded to all areas of Stellar Astrophysics for the last two meetings in Hong Kong; at Hong Kong University of Science and Technology in 1997 and at the Hong Kong University in 1999. At the conclusion of the very successful Pacific Rim Conference on Stellar Astrophysics held in Hong Kong University, members of the Sci entific Organizing Committee began planning for the next conference. We approached Professor Tan Lu of Nanjing University and Professor Tipei Li of the Institute of High Energy Physics about hosting a con ference in China. The city of Xi'an in Shaanxi province and a city in Yunnan province, were considered to be the most likely locations. It be came crucial to find the right person to serve as Chair (or Co-chairs) for the Local Organizing Committee. Initially, Professor Lu was the logical choice but he declined for personal reasons. Professor Li was invited to lead a new department of Astrophysics at Tsinghua University so he could not take on the additional load of chairing the LOC. Professor Gang Zhao of Beijing Astronomical Observatory was approached to take on the task but he also declined. This has been a busy time for Chinese astronomers. The SOC decided to have the conference dedicated to honor Dr. Helmut A.




Solar and Space Weather Radiophysics


Book Description

This volume is the outgrowth of several international meetings to discuss a vision for the future of solar radio physics: the development of a new radio instrument. From these discussions, the concept for the Frequency Agile Solar Radiotelescope (FASR) was born. Most of the chapters of this book are based oninvitedtalksattheFASRScienceWorkshop,heldinGreenbank,WVinMay 2002, and a special session on Solar and Space Weather Radiophysics held at the 200th American Astronomical Society meeting held in Albuquerque, NM in June 2002. Although many of the chapters deal with topics of interest in planning for FASR, other topics in Solar and Space Weather Radiophysics, such as solar radar and interplanetary scintillation, are covered to round out the discipline. The authors have been asked to write with a tutorial approach, to make the book useful to graduate students and scientists new to radio physics. This book is more than a compilation of FASR science topics. The FASR instrument concept is so revolutionary—by extending capability by an order of magnitude in several dimensions at once (frequency coverage, spatial reso- tion,dynamicrange,timeresolution,polarizationprecision)—thatitchallenges scientiststothinkinnewways. Theauthorsofthefollowingchaptershavebeen taskednotonlywithreviewingthecurrentstateofthe?eld,butalsowithlooking to the future and imagining what is possible. Radio emission is extremely complex because it is generated so readily, and every imaginable plasma parameter affects it. This is both its great strength and its weakness.




Searching the Heavens and the Earth


Book Description

Jesuits established a large number of astronomical, geophysical and meteorological observatories during the 17th and 18th centuries and again during the 19th and 20th centuries throughout the world. The history of these observatories has never been published in a complete form. Many early European astronomical observatories were established in Jesuit colleges. During the 17th and 18th centuries Jesuits were the first western scientists to enter into contact with China and India. It was through them that western astronomy was first introduced in these countries. They made early astronomical observations in India and China and they directed for 150 years the Imperial Observatory of Beijing. In the 19th and 20th centuries a new set of observatories were established. Besides astronomy these now included meteorology and geophysics. Jesuits established some of the earliest observatories in Africa, South America and the Far East. Jesuit observatories constitute an often forgotten chapter of the history of these sciences.




Kristian Birkeland


Book Description

This biography conveys the life and accomplishments of a Norwegian hero to the English speaking world, illustrating the beginnings of collaboration between science and industry. It shows how work in a small country laid the foundation for the green revolution.




Adventures in Order and Chaos


Book Description

The field of Order and Chaos had a remarkable expansion in the last 50 years. The main reason was the use of computers, and the development of new theoretical methods that we call now 'the theory of chaos'. The author describes this fascinating period in a relaxed and sometimes humorous autobiographical way. He relates his interactions with many people in dynamical astronomy and he quotes several anecdotes from these interactions. He refers also to his experiences when he served in various international positions, such as general secretary of the IAU and chairman of the journal Astronomy and Astrophysics. In recent years the theory of chaos has been extended to new areas, like relativity, cosmology and quantum mechanics and it continues expanding in almost all branches of physics. The book describes many important ideas in this field in a simple way. It refers also to problems of more general interest, like writing papers and giving lectures and the interaction of authors and referees. Finally it gives some useful prospects for the future of dynamical astronomy and related fields. George Contopoulos, PhD U.Athens1953; Professor of Astronomy U.Thessaloniki 1957-75; U.Athens 1975-96; Emeritus 1996-; Member, Academy of Athens 1997-. Visiting Professor Yale U., Harvard U., MIT, Cornell U., U.Chicago, U.Maryland, U. Florida, Florida State U., U. Milan; Res. Associate, Yerkes Obs., Inst.Adv.Study Princeton, Inst.Space Studies, Goddard Flight Center, Columbia U., ESO. Author or Editor of 15 books, and about 250 papers on Galactic Dynamics, Relativity and Celestial Mechanics. Positions held: Gen.Secretary of the IAU; Director General Nat.Obs.of Greece, Pres.Hellenic Astron.Soc.; Nat.Representative of Greece in NATO, etc. Distinctions: Amer. Astron.Soc. Brouwer Prize; U.Chicago, Honorary Doctor's Degree; IAU, Pres. Commission 33 (Galaxy); Member Academia Europaea; Associate Royal Astron. Soc.; Chairman of the European Journal "Astronomy and Astrophysics"; Assoc. Editor of "Cel. Mech. Dyn. Astron."; Over 4500 citations and 300 acknowledgements.




Radiation Hazard in Space


Book Description

The mono graph contains 8 chapters, and their contents cover all principal aspects of the problem: 1. Introduction and brief his tory ofthe radiation problem and background information ofradiation hazard in the near-Earth and interplanetary space. 2. General description of radiation conditions and main sources of charged partic1es in the Earth's environment and interplanetary space, effects of space environment on spacecraft. 3. Basic information about physical conditions in space and main sources of charged particles in the Earth's environment and interplanetary space, in the context of "Space W eather" monitoring and prediction. 4. Trapped radiation belts of the Earth (ERB): theory of their origin, spatial and temporal dynamics, and experimental and statistical models. 5. Galactic cosmic rays (GCR): variations of energetic, temporal and spatial characteristics, long-term modulation, and anomalous cosmic ray (ACR) component, modeling oftheir dynamics. 6. Production of energetic particles (SEPs) at/ne ar the Sun: available databases, acceleration, propagation, and prediction of individual SEP event, statistical models of solar cosmic rays (SCR). 7. Existing empirical techniques of estimating, prediction and modeling of radiation hazard, methodical approaches and constraints, some questions of changes in the Earth's radiation environment due to changes of the solar activity level. 8. Unresolved problems of radiation hazard prediction and spacecraft protection, radiation experiments on board the spacecraft, estimating of radiation conditions during interplanetary missions. Space does not allow us to explain every time the solar-terrestrial and radiation physics nomencIature used in current English-language literature.




Integrable Problems of Celestial Mechanics in Spaces of Constant Curvature


Book Description

Introd uction The problem of integrability or nonintegrability of dynamical systems is one of the central problems of mathematics and mechanics. Integrable cases are of considerable interest, since, by examining them, one can study general laws of behavior for the solutions of these systems. The classical approach to studying dynamical systems assumes a search for explicit formulas for the solutions of motion equations and then their analysis. This approach stimulated the development of new areas in mathematics, such as the al gebraic integration and the theory of elliptic and theta functions. In spite of this, the qualitative methods of studying dynamical systems are much actual. It was Poincare who founded the qualitative theory of differential equa tions. Poincare, working out qualitative methods, studied the problems of celestial mechanics and cosmology in which it is especially important to understand the behavior of trajectories of motion, i.e., the solutions of differential equations at infinite time. Namely, beginning from Poincare systems of equations (in connection with the study of the problems of ce lestial mechanics), the right-hand parts of which don't depend explicitly on the independent variable of time, i.e., dynamical systems, are studied.




Solar Journey: The Significance of Our Galactic Environment for the Heliosphere and Earth


Book Description

Written by experts who created the field, this volume explores uncharted scientific territory, with articles discussing the effect of our galactic environment on the heliosphere, planetary system and Earth. Leading experts in diverse fields discuss the physical changes expected as the heliosphere adjusts to its galactic environment. Topics include the interaction between solar wind and interstellar dust and gas, cosmic ray modulation, magnetospheres, variations in the solar environment, and the cosmic ray isotope record preserved in paleoclimate data.




Plasma Astrophysics, Part I


Book Description

This well-illustrated monograph is devoted to classic fundamentals, current practice, and perspectives of modern plasma astrophysics. The level of the book is designed mainly for professional researchers in astrophysics. The book will also be interesting and useful to graduate students in space sciences, geophysics, as well as to advanced students in applied physics and mathematics seeking a unified view of plasma physics and fluid mechanics.