The Dynamical Evolution of Massive Star Forming Regions (Dr Nick Wright, Prof Rob Jeffries)

Most stars, including the Sun, are born in clusters ranging in size from 100 to 1 million members. These clustered environments may be of the utmost importance in the early lives of stars and their circumstellar material - close stellar encounters in high density regions can shape planetary systems, whilst the ionising radiation from nearby, high mass stars can photoevaporate discs and drive gas from the star forming region. Most clusters do not survive longer than 10 million years, but the reasons for this are poorly understood - are they born in an unbound state, or does expulsion of residual gas lead to their disruption?

In this project the student will use exquisitely accurate tangential velocities derived from long time-series of cluster images to examine the dynamics of high-mass star forming regions - large clusters containing more than 10,000 stars. These studies will be complemented by spectroscopy from massive spectroscopic surveys such as the Gaia-ESO survey at the VLT and new data from WEAVE at the William Herschel Telescope, in order to identify cluster members, and will take advantage of the first releases of data from the European Gaia astrometric satellite. The aim of the project will be to obtain diagnostics of how these clusters formed, their present dynamical state and their future evolution. These diagnostics will be compared with state-of-the art N-body numerical models. An important part of the project will be to perform detailed simulations of how the sensitivity and biases inherent in real, imperfect observations affect the comparison with these models and to design new diagnostics that are largely immune to such biases. Such diagnostics and techniques will be widely applicable to many other projects using the Gaia data