PhD opportunity: The formation and evolution of discs around young stars

Supervisor: Professor Matthew Bate

Advances in observational facilities, particularly the advent of the Atacama Large Millimetre Array (ALMA) and the VLT/SPHERE instrument, have recently provided images of discs around young stars at unprecedented resolutions and sensitivities. These observations are providing large samples of discs with measured masses and sizes, and that display a wide variety of structures (e.g. dust rings, spirals, and dust arcs).

The aim of this PhD project is to use hydrodynamical models of disc formation and evolution to extend our understanding of the origin of the diversity of protoplanetary discs and the physical processes that drive their evolution. Recently, I published the first study of the properties of discs resulting from a radiation hydrodynamical simulation of star cluster formation (Bate 2018). The bulk properties of the discs produced by this calculation are in surprisingly good agreement with those that have been observed in nearby star-forming regions. However, this raises the question of how disc properties depend on environment. How might discs differ in regions of lower or higher stellar density, or at different metallicities, or at high redshift? I have a number of calculations that are similar to that analysed by Bate (2018), but that model star formation in different environments. The first part of the PhD project would be to analyse the disc properties from these other simulations to determine how the star formation environment affects the properties of protoplanetary discs.

Following this initial project, there are a number of directions in which the PhD may proceed. Active areas of research that I am involved in include understanding the evolution of dust in protoplanetary discs, the effects of magnetic fields on disc formation and evolution, and the dynamics of discs in binary and multiple star systems (e.g. time-variable accretion from a circumbinary disc onto the embedded stars, or the evolution of discs that are misaligned with the orbit of a binary system). Some of this work may involve working with observers at Exeter and elsewhere to model specific star/disc systems.

This project will involve performing and analysing radiation hydrodynamical simulations of star formation and protoplanetary discs uding a state-of-the-art smooth particle hydrodynamics (SPH) code. You will learn aspects of astrophysics fluid dynamics and magnetohydrodynamics along the way. The simulations may also include magnetic fields, chemistry, and may model both the gas and dust components of the discs. You will learn how to analyse and visualise large computational datasets. The project is likely to involve some parallel programming (both OpenMP and MP), and comparison of numerical models with analytical theory and observations. For further information please visit my webpage, look at my paper or email me.