Galactic Structure
What is the Structure of the Galaxy?
The Milky Way is a large spiral galaxy with small central bar, looking something like the picture at left, and containing several hundred bilion stars. The disk is about 100,000 light-years in diameter and of order 1,000 light-years in thickness and includes the Sun, located about 28,000 light years from the centre. A dark matter halo surrounds the galaxy.
Current research areas
Galactic Archaeology
What can we learn about the formation processes of galaxies from studying the present structure of our own Milky Way, and nearby galaxies? Members of our group participate in international collaborations to observe structures in the outskirts of both the Milky Way and the Andromeda galaxies, thought to be remnants of interactions with smaller systems. Combining such observations with numerical simulations is an effective way for galaxy formation and evolutionary models to be tested.
Galactic Cannibalism
Galactic cannibalism occurs throughout the universe but, close to home, small dwarf galaxies are torn apart by the much more massive Milky Way and Andromeda Galaxy. Using telescopes from around the world, including the 10-m Keck telescope in Hawaii, Geraint Lewis has mapped the tell-tale signs of tidal disruption and destruction, providing important clues to how large galaxies have grown over time.
For more information contact Geraint Lewis or see the Gravitational Astrophysics Group website