The main goal of this research project is to achieve expertise in numerical methods to study and simulate in full general relativity high-energy astrophysical phenomena relative to neutron stars in X-ray binary systems. This will lead to a better understanding of the accretion flows onto the compact star and potentially, a new way to constrain its properties and to learn about its equation of state. This research is well within the scope of the FAPESP Thematic Project Superdense Matter in Universe (2013/26258-4) and will complement the research done by the group on the equation of state of these magnificent stars.The project is divided in two interconnected and closely related practical tasks as stated below.Task  is to develop a comprehensive model to explain the high frequency quasi-periodic oscillations (QPOs) in neutron star low-mass X-ray binaries based upon a model where a torus orbits the compact star in a self-sustained way. Task  is to develop models and/or test existing models to explain the time lags of the QPOs, complementing the development of models that explain the mechanisms of the QPOs. For these two tasks we will not only count on powerful numerical tools to model the QPOs but also we already have plenty of timing data about eight different QPOs detected in the neutron star low-mass X-ray binary 4U 1636--53 which we have been studying for a long period of time. We also have the means to obtain spectral data from the public archives of XMM-Newton satellite in cases where they will be needed to constrain more precisely the physical dimensions of the region where we believe most of the radiative processes occur.
News published in Agência FAPESP Newsletter about the scholarship: