The astrophysics of accretion in compact binaries

Unlike our Sun, the majority of stars find themselves in gravitationally bound pairs known as binary stars. The interaction between the two stars often leads to the formation of a compact pair with the lower mass donor star losing mass onto the more massive primary. Such interactions can produce very energetic objects as the potential energy that is released is converted into radiation and heat. The most extreme examples contain a very small but massive remnant of a star, which can be either a white dwarf for a star the mass of our Sun, or a neutron star or black hole for more massive stars. These two stars can orbit around each other in as little as a few minutes. I propose to employ novel imaging techniques, which are very similar to the CAT scanning methods used in hospitals, in order to study this interaction using the latest telescopes and instruments. This allows us to reconstruct images and even movies that show this interaction in detail despite the fact that such double stars are not resolved in even our biggest telescopes. I will use these reconstructed images of binaries to study the wide variety of physical processes that occur in these systems. These include turbulence, tidal interactions, outflows and jets, relativistic physics near black holes and the structure of matter under extreme conditions. My work relies on exploiting the latest suite of ground-based telescopes in conjunction with space-based observations at wavelengths that are not accessible from earth. In order to determine how binaries affect the populations of stars in galaxies such as our Milky Way, I also intend to search for many new systems using wide-field digital cameras attached to large telescopes. This combination will allow me to test our current ideas concerning the formation, structure and time evolution of a wide range of binary systems.