Suggestions for D.Phil. Projects (2011)

Irradiation-Driven Evolution in X-ray Binaries and Millisecond Pulsars (see Poster)

The objective of this project is to simulate the effects of external irradiation on the secondary stars in X-ray binaries and millisecond pulsar binaries, specifically the re-distribution of the irradiation energy by circulation currents and how this affects the structure and ultimately the evolution of the companion star and the binary on the whole. This will involve applying and further developing a three-dimensional circulation code originally developed by Martin Beer. While the project is mainly computational, an important aspect of the project will be to model the observational effects of the circulation currents in order to test and constrain the illumination model. Other applications of the code may involve simulating hot Jupiters, i.e. massive planets being roasted by their parent stars.

Hydrodynamical Modelling of Common-Envelope Evolution and Stellar Mergers

Common-envelope evolution, where two two stars spiral towards each other inside a surrounding gaseous envelope, is one of the most important, but also one of the least understood phases of binary evolution. The objective of this project is to model this phase using different complementary approaches (combining 1-d stellar hydro calculations with realistic input physics and more approximate 3-d SPH simulations) and to assess the importance of various physical processes (e.g. recombination energy, accretion energy). The goal is to develop realistic physical criteria for the ejection of common envelopes and the merging of the stars with applications to gamma-ray bursts, planetary nebulae and supernova progenitors.

Other potential project area:

The Fireworks Initiative: Understanding Cosmic Explosions

This project is part of an international collaboration trying to understand the diversity of cosmic explosions, such as supernovae of various types, hypernovae and gamma-ray bursts, and their implications for the evolution of galaxies and the chemical evolution of the Universe. As part of this project, the student will explore theoretically how various progenitor channels can account for the observed diversity, examining the role of rotation, binary evolution and metallicity. This will involve performing stellar and binary evolution calculations and possibly simulations of whole stellar populations. One of the objectives is to develop observational predictions that can be tested within the framework of the fireworks project.