This thesis describes the application of a Monte Carlo radiative transfer code to accretion disc winds in two types of systems spanning 9 orders of magnitude in mass and size. In both cases, the results provide important new insights. On small scales, the presence of disc winds in accreting white dwarf binary systems has long been inferred from the presence of ultraviolet absorption lines. Here, the thesis shows that the same winds can also produce optical emission lines and a recombination continuum. On large scales, the thesis constructs a simple model of disc winds in quasars that is capable of explaining both the observed absorption and emission signatures – a crucial advance that supports a disc-wind based unification scenario for quasars. Lastly, the thesis also includes a theoretical investigation into the equivalent width distribution of the emission lines in quasars, which reveals a major challenge to all unification scenarios.

The first comprehensive introduction to the observations and theories of stellar winds; a long-awaited graduate textbook, written by two founders of the field.

Magnetism in binary stars is an area of central importance in stellar astrophysics. The second edition of "Magnetohydrodynamics in Binary Stars" is a major revision of the first edition. The material has been updated and extended, including additional chapters on the origins of the stellar magnetic fields and accretion disc magnetic winds. A comprehensive account is given of the subject, from the early work up to the latest results. The unifying theme remains the redistribution of angular momentum by magnetic stresses. This occurs in a wide variety of ways, including magnetic stellar and orbital coupling, magnetic channelling of accretion streams, magnetic stellar coupling to accretion discs, dynamo field coupling in discs, and magnetic stellar and disc winds. The associated stellar spin and orbital evolution problems, including stability, are also considered. Although the main focus is on binary stars, much of the work on accretion discs and wind flows has more general astrophysical relevance. Convenient formulae are included that can be compared to observations, making the book useful to observers as well as theorists, and there are extensive reference lists. The material is mainly aimed at research workers, but parts of the text could be useful for postgraduate courses in magnetic stellar astrophysics topics.

This book highlights selected topics of standard and modern theory of accretion onto black holes and magnetized neutron stars. The structure of stationary standard discs and non-stationary viscous processes in accretion discs are discussed to the highest degree of accuracy analytic theory can provide, including relativistic effects in flat and warped discs around black holes. A special chapter is dedicated to a new theory of subsonic settling accretion onto a rotating magnetized neutron star. The book also describes supercritical accretion in quasars and its manifestation in lensing events. Several chapters cover the underlying physics of viscosity in astrophysical discs with some important aspects of turbulent viscosity generation. The book is aimed at specialists as well as graduate students interested in the field of theoretical astrophysics.

Magnetic stresses were discussed as a possible means of angular momentum transport in the development of accretion disc theory, in the late sixties and early seventies. Interest in the role of magnetic fields in close binary stars steadily increased after the discovery of the nature of AM Herculis in 1976. The observed lack of an accretion disc and the synchronous rotation of the white dwarf suggested strong magnetic effects, consistent with the high degree of optical polarization. Similar systems were soon discovered. Evidence for large magnetic fields was subsequently found in the X-ray binary pulsars and the intermediate polar binaries, both believed to include systems with partially disrupted accretion discs. A magnetically channelled wind from the main sequence secondary star has been invoked to explain the higher mass transfer rates observed in binaries above the period gap, and in an explanation of the gap. Magnetically influenced winds from accretion discs have been suggested as contributing to the inflow by removing angular momentum. Magnetism in binary stars is now an area of central importance in stellar astrophysics. Magnetic fields are believed to playa fundamental role even in apparently non-magnetic binaries. They provide the most viable means, through shear instabilities, of generating the turbulence in accretion discs necessary to drive the inflow via the resulting magnetic and viscous stresses.

This book contains lectures on 3D spectroscopy techniques and data. from the seventeenth Winter School of the Canary Islands Astrophysics Institute.