The evolution of galaxies is self-regulated by feedback processes. After stars form from the gravitational collapse of gas clouds, they inject energy back into their surroundings from stellar winds and supernovae, thereby making it harder for further stars to form. Galaxies also host supermassive black holes, which grow from the accretion of gas in the galaxy. The energy released from this accretion (often referred to as an active galactic nucleus) can potentially blow out the galaxy’s gas and/or choke the supply of fresh gas to the galaxy. Understanding these processes is crucial to explaining how galaxies end up with the mass, morphology, and composition that we observe them to have. There is still scientific progress to made in this field.
This project will focus on modelling either stellar or black-hole feedback in galaxy evolution. An analytic framework will first be set up to mathematically describe the process, and this will then be coded and folded into the DARK SAGE semi-analytic model of galaxy formation. The scholar will examine how the properties of galaxies respond to choices in their model, exploring the model’s physical viability and freedom by comparing to observations. While many established models like DARK SAGE can describe galaxies in the local Universe well, concurrently reproducing galaxies in the early Universe (high redshift) can be challenging. An updated description of feedback should go some way towards rectifying this. There is freedom for the scholar to explore the properties of galaxies that most interest them at their favourite epoch. Contribution to the codebase will lead to co-authorship on the next DARK SAGE paper.
DARK SAGE is a code written in C, which is publicly available.
Dr Claudia Lagos
Senior Research Fellow and ASTRO 3D FellowRead More