Low frequency quasi-periodic oscillations (LFQPOs) in microquasars remain an important and subtle astrophysical puzzle. This project will investigate the theoretical possibility that LFQPOs are the result of asymmetric engines, including spirals, hotspots and warps. The accretion ejection instability has already been shown to produce spiral waves and hotspots in magnetized disks, and provides a starting point for this further study. Simulations will be used to develop synthetic spectra and light curves. The development of analytic formulae for non-axisymmetric disk surface profiles, including shadowing and time dependence, will allow practical testing of the ideas, as will comparison of the time-dependent model spectra with detailed diagnostics developed from an analysis of archived data.
The research will provide significant undergraduate research opportunities in X-ray data analysis, numerical simulation, and analytical modeling. The investigators will also develop and supervise a weekly astrophysics radio show, designed to be broadcast by undergraduates.
