Galactic and Extra-Galactic Radio Astronomy

ISBN-13: 9781468462425 / Angielski / Miękka / 2012 / 402 str.

Gerrit L. Verschuur; Kenneth I. Kellermann

Opis

The present set of chapters by members of the staff of the National Radio Astronomy Observatory deals with the basic fields of research concerned with radio astronomy outside the solar system. The emphasis in this volume is on the type of data available and its interpretation. Basic theory is considered only where absolutely necessary, and little discussion of receivers or techniques is entered into in most of the chapters. The book is intended to take over where most textbooks on radio astronomy leave off, that is, in the discussion of what is actually known from the research done. In addition there is a chapter on the technical aspects of inter- ferometry and aperture synthesis, since so much of modern radio astronomy depends, and will depend in an ever increasing manner, on such tools. The editors want to stress that the chapters were not necessarily expected to be compre- hensive reviews of any of the fields being covered, but rather, overall outlines which the in- dividual authors felt would be suitable for graduate students and interested workers in other fields. As a result, the lists of references are not complete. This only reflects the preferences of the individual authors and not the relative merit of those references included or omitted.

Spis treści

1 Galactic Nonthermal Continuum Emission.- Physical Mechanisms.- Observations of Galactic Nonthermal Radio Radiation.- The Spectrum of Galactic Cosmic Ray Electrons.- 2 Interstellar Neutral Hydrogen and Its Small-Scale Structure.- General Theoretical Considerations.- Absorption Spectra and Emission Spectra Contrasted.- Presentation of 21-cm Data.- Observations of the Small-Scale Structure in the Interstellar HI.- 21-cm Absorption Experiments.- “Nonplanar” Neutral Hydrogen.- Anomalous Velocity Neutral Hydrogen.- 3 The Radio Characteristics of HII Regions and the Diffuse Thermal Background.- Ionized Interstellar Hydrogen.- Radiation Transfer.- Continuum Thermal Emission (Bremsstrahlung).- Radio Recombination Lines.- Radio Recombination Lines and the Physical Characteristics of HII Regions.- Diffuse Thermal Background.- The Anomalous Recombination Lines.- Measurements of the Relative Abundance of Helium and Hydrogen.- 4 The Large-Scale Distribution of Neutral Hydrogen in the Galaxy.- Determination of Galactic Structure from Hydrogen Observations.- The Neutral Hydrogen Layer.- Neutral Hydrogen in the Galactic Nucleus.- Radial Motions in the Central Region.- 5 Supernova Remnants.- Optical Properties of Supernovae.- The Crab Nebula.- The Remnant Cassiopeia A.- Supernova Remnants in the Galaxy.- Summary.- 6 Pulsars.- Basic Properties.- Amplitude Fluctuations.- Scintillation.- Polarization.- Correlation of Pulsar Properties.- Pulsar Models.- 7 Radio Stars.- The Early Years.- The Dawn of Stellar Radio Astronomy.- The Future of Stellar Radio Astronomy.- 8 The Galactic Magnetic Field.- Observing the Galactic Magnetic Field.- Discussion of the Observations.- The Structure of the Magnetic Field.- The Magnetic Field Strength.- Summary.- 9 Interstellar Molecules.- Observations of Interstellar Molecules at Radio Wavelengths.- Observations of Interstellar Molecules at Optical and Ultraviolet Wavelengths.- Microwave Molecular Observations As Probes of Interstellar Clouds.- “Missing” Molecules and Their Implications.- Formation and Destruction of Interstellar Molecules.- Conclusions.- Addendum.- 10 Interferometry and Aperture Synthesis.- Basic Concepts.- A Working Interferometer.- Aperture Synthesis.- Inversion Techniques.- 11 Mapping Neutral Hydrogen in External Galaxies.- Integral Properties of Galaxies.- Mapping HI in Galaxies.- Observations with a Single Dish.- Interferometric Observations.- Aperture Synthesis Observations.- High-Resolution Maps.- Conclusions.- 12 Radio Galaxies and Quasars.- Radio Surveys.- Optical Identifications.- Radio Properties.- Theories of Radio Sources.- Summary.- 13 Cosmology.- General Problems.- Basic Theory.- World Models.- Optical Observations.- Radio Observations.- Summary.