Proceedings of the NATO Advanced Study Institute, Cambridge, U.K., August 4-15, 1986

Galactic Distance Scales.- Comparison of the Galaxy with External Spiral Galaxies.- The Galactic Center.- The High Energy Galaxy.- Molecular Clouds in the Galaxy.- The Morphology of Cool, Diffuse Gas and Dust in the Galaxy.- Highly Evolved Stars in the Galaxy as Seen by IRAS and in OH Surveys.- Nonlinear Phenomena in Spiral Galaxies.- Stellar Superclusters and Groups.- An Investigation of the Relations Between Age, Chemical Composition and Parameters of Velocity Distribution Based on uvbyß Photometry of F Stars within 100 Parsec.- The Multivariate Stellar Distribution Function.- The Structure of the Galactic Halo.- Kinematics of Old Stars.- Population Studies of the Galaxy - Constraints on the Thin Disk, Thick Disk and the Halo.- Kinematics and Galactic Structure.- Galactic Chemical Evolution.- Mass Loss from Single and Close Binary Stars.- Dynamical Evolution of the Galactic Disk.- The Galaxy in Action Space.- The Formation of the Galaxy.

The Milky Way Galaxy offers a unique opportunity to study the structure and contents of a major stellar system in three dimensions, at high spatial and spectral resolution, and to very large galactocentric distances. This potential can be realised only by statistical surveys of large areas of the sky, and by detailed study of specific regions with exceptional properties, such as the Galactic centre, and of specific classes of object, such as the globular clusters. The acquisition of such data from a variety of ground-based and satellite surveys has been a primary topic of Galactic research for some years. Several such surveys have been completed recently, and have led to a substantial modification of our understanding of Galactic structure and evolution. The importance of the ability of satellite observatories to survey and to study wavelengths which are inaccessible from the ground is evident in the wealth of data discussed and analysed in this volume which is derived from satellites, specifically COS-B, HEAD-I, HEAO-3, IRAS, PIONEER-lO, SAS-2, and TENMA. The cru cial role of ground-based observations to complement and comprehend the satellite data is also well evident. Similarly, the major ground-based studies whose results are reported here illustrate the necessity for carefully conceived and executed very large scale surveys of many types of object and many parts of parameter space before a coherent picture of the Galaxy will be available.