Galaxy Formation & Dark Matter Modelling in the Era of the Square Kilometre Array

TL;DR

This paper discusses recent advances in galaxy formation modeling, focusing on cold gas properties, and explores how these models can be applied to upcoming SKA radio surveys to test dark matter theories.

Contribution

It introduces new modeling techniques linking star formation rates to molecular hydrogen, improving predictions for cold gas properties in galaxies relevant to SKA observations.

Findings

Models now reproduce atomic and molecular hydrogen properties of observed galaxies.

Linking star formation to molecular hydrogen enhances model accuracy.

Highlights challenges and methods for comparing models with SKA data.

Abstract

Theoretical galaxy formation models are an established and powerful tool for interpreting the astrophysical significance of observational data, particularly galaxy surveys. Such models have been utilised with great success by optical surveys such as 2dFGRS and SDSS, but their application to radio surveys of cold gas in galaxies has been limited. In this chapter we describe recent developments in the modelling of the cold gas properties in the models, and how these developments are essential if they are to be applied to cold gas surveys of the kind that will be carried out with the SKA. By linking explicitly a galaxy's star formation rate to the abundance of molecular hydrogen in the galaxy rather than cold gas abundance, as was assumed previously, the latest models reproduce naturally many of the global atomic and molecular hydrogen properties of observed galaxies. We review some of the key results of the latest models and highlight areas where further developments are necessary. We discuss also how model predictions can be most accurately compared with observational data, what challenges we expect when creating synthetic galaxy surveys in the SKA era, and how the SKA can be used to test models of dark matter.