This award will support a multifaceted theoretical study of the mergers of various types of compact objects such as neutron stars. Understanding the full sequence of events in these mergers is a great interdisciplinary challenge of high current interest. The work will model binary formation and gravitational wave-driven inspiral; the hydrodynamics of mergers; the viscous, thermal and nuclear evolution of the post merger remnant; the general relativistic radiation hydrodynamics of the collapse to neutron stars and black holes (with its associated gravitational wave signals); and the nuclear and radiation hydrodynamics of the unbound ejecta that produces observable electromagnetic (light, radio wave, etc.) signals.
A major motivation is to model both gravity wave and electromagnetic signatures from these mergers. The two types of signatures provide important information about different regions of the sources. Gravitational waves will determine the 'engine' of the sources, their masses, spins, and inclinations. The electromagnetic signals will provide the precise locations, compositions, and their relation to the rest of astrophysics (nucleosynthesis, pulsars, magnetars, transients, Type Ia supernovae, formation rates and progenitors).
The project will contribute to the training of graduate students and in regular student exchanges between the participating institutions. Members of the research team will continue their efforts to give non-technical lectures for the public, high schools and undergraduate institutions, and consult on curricula, films, TV and radio. The results of this research, on topics that tend to generate broad interest (stellar collisions, explosions, collapse to black holes, gravitational waves in space-time), will be incorporated into these activities. The team will also make the results from this study widely available to the astrophysics community.
