EPSAM

Magellanic Clouds

Supervisor:  Dr Jacco van Loon

The Milky Way and its Magellanic Clouds neighbours are gas-rich galaxies. The interstellar gas plays an important role in continuing to fuel star formation and thereby chemical evolution of these galaxies. The stars, ultimately return chemically enriched gas to this interstellar medium (ISM). Both the ISM and stellar populations constitute dynamic systems. The stars slowly change their velocities to reflect the global shape of the gravitational potential, gradually losing memory of their birth kinematics. The dynamics of the gas is affected both by the gravitational potential, as well as by hydrodynamical and thermodynamical processes on a variety of scales, from the large scales of interaction between the ISM within and that surrounding the galaxies, down to the small scales of molecular cloud formation and stellar feedback acting upon it. To understand the cosmological evolution of galaxies, one needs to understand the detailed linked behaviour of their stars and their ISM. The goal of this project is to produce new views of the structure and kinematics of stars and gas in the Milky Way and the Magellanic Clouds. The analysis is based principally on two types of data: optical absorption-line spectroscopy of stars, and radio emission-line spectroscopic imaging. The first allows us to measure the stellar kinematics (as well as the temperature and metallicity of the star) and, for the early-type stars, interstellar column densities of the molecular, neutral atomic and mildly-ionized gas. The second allows us to map the column densities and kinematics of the diffuse neutral hydrogen gas (HI). Data have already been obtained, but more are expected to be acquired. The analysis itself entails the combination of different tracers, and the decomposition of complex lines-of-sight.