3D modelling of nearby galaxies

Nearby galaxies like the Southern Pinwheel Galaxy, M83, are well-studied neighbours to our Milky Way. Being external galaxies we get an outsiders view of them, allowing us to see these galaxies as a whole, yet they are close enough to resolve structures like spiral arms, HII regions and even stars in our nearest neighbours. These galaxies have been observed across the electro magnetic spectrum, from the ultraviolet to Infrared and radio. Now we are even obtaining 3D optical spectroscopy (or integral field spectroscopy) of these galaxies, making maps of every wavelength. 

However, we only obtain a 2D image of these galaxies, and miss out on the 3D structure of the stars, dust and gas. Using radiative transfer modelling we can obtain insights into the 3D structures of these galaxy, and understand how this structure depends on the size of the galaxy and its environment.

TThis project involves using axi-symmetric 3D radiative transfer codes to model the azimuthally averaged surface brightness distributions of a nearby face-on spiral galaxy with TYPHOON integral field spectrscopic data and multiwavelength photometry (eg M83, NGC1365, NGC2667). The student will Learn the ray-tracing radiative transfer code of Popescu & Tuffs & apply it the galaxy. The fitting of the panchromatic images is done through an interactive, intelligent guess algorithm, which capitalises on the orthogonality of the main parameters of the model. The student will introduce realistic gas models to the radiative transfer code (HII regions and diffuse ionised gas).

From there the student could expand to a full non axi-symmetric 3D modelling of the galaxy, or apply the improved 2D modelling to a much larger number of galaxies. From these we will gain insights into how the distribution of gas and stars varies across the disk and spiral arms in galaxies, and how this depends upon the history and environment of that galaxy and how they grow across cosmic time.

For more details of this project, please contact the supervisors.