What do galaxies and shadow puppets have in common?

Galaxies come in all shapes and sizes. It is hard not to be impressed by the majestic variety in galaxy morphology that the Universe has to offer. Besides creating just pretty images, galaxy shape and morphology also provide important clues on how galaxies formed and evolved. Large computer simulations suggest that collisions between galaxies alter their appearance. The more interactions a galaxy experiences, the rounder it becomes. However, galaxies are so far away that we can only observe them as two-dimensional projections on the celestial sphere. Figuring out the true shape of galaxies is a bit like shadow puppetry without instructions; ever tried twisting your arms and fingers to create the image of an African Unladen Swallow? So, how do astronomers derive the true three-dimensional shape of galaxies? In this talk I will explain how Australian Astronomers have invented an instrument that can do exactly that. These tools now allow us to figure out how galaxies like our Milky Way have formed and evolve.

Dr Jesse van de Sande

Jesse van de Sande is a Research Fellow at the Sydney Institute for Astronomy at the University of Sydney studying how galaxies form and evolve. He tries to solve the big questions such as ‘How was the Milky Way Galaxy formed?’ and ‘What will happen to our Milky Way after it collides with the Andromeda Galaxy?’ Jesse uses the Anglo Australian Telescope with an instrument called SAMI to study the motions of stars within galaxies. For his PhD thesis, he used the Hubble Space Telescope and the Very Large Telescopes in Chilli to investigate the formation and evolution of massive galaxies in the early Universe.