Suggestions for D.Phil. Projects (2014)

Irradiation-Induced Circulation in Hot Jupiters and X-Ray Binaries (see Poster)

The irradiation of close planets by their central stars or the companions in X-ray binaries and millisecond-pulsar systems drives circulation currents and redistributes the irradiation energy around the star. This does not only affect the appearance of the irradiated objects but also their structure and evolution. The objective of this project is to simulate the effects of this external radiation numerically, applying and extending 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. The main applications of this work will be hot Jupiters and/or the companions of X-ray binaries and millisecond pulsars

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 the recently discovered superluminous supernovae, 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.