These are notebooks from an astrophysics summer research project in 2023 which was investigating the origin of scatter in the galaxy stellar mass-halo mass relationship (SHMR), specifically in the IllustrisTNG hydrodynamical simulation. The project was undertaken at the University of St Andrews under the supervision of Dr Rita Tojeiro.

The code was created an ran on the JuptyterLab server to avoid having to download the simulation data. Therefore, it will not run on a local machine without some small modifications which can be found in the Getting started guide.

• data_collection.ipynb - Contains all code necessary to pull and process relevant data from the simulation.
• shmr.ipynb - Plots of the stellar/halo mass relation, as well as the gas/halo and baryon/halo mass relations.
• halo_properties.ipynb - Plots of the evolution of some halo properties over time as a function of halo mass - the main focus of this project.
• mass-history.ipynb -Investigating how the different mass components evolve over time as a function of halo formation time.

• h5py
• loess

• Change basic tqdm loops to widgets
• Helper files for downloading the simulation data