Preparing for Low Surface Brightness Astronomy with the Rubin Observatory

Speaker: Professor Sarah Brough 
Affiliation: The University of New South Wales

Abstract

Rubin Observatory is approaching completion in Chile with the goal of compiling the deepest, widest image of the Universe at optical wavelengths. Its ten-year survey, the Legacy Survey of Space and Time (LSST), is set to begin in 2024 and will survey the entire southern sky approximately every 3 nights using a specially designed 8.4 m diameter telescope with an extremely wide field of view. I will introduce the LSST, and the low surface brightness astronomy that LSST will revolutionise, including study of the intra group/cluster light in groups and clusters of galaxies. The intra-group light (IGL) is the diffuse light that spreads across the centre of galaxy groups, concentrated around the brightest central galaxy. This light is composed of stars unbound from their host galaxy due to interactions so it forms a fossil record of the dynamical processes a group of galaxies has undergone. Thus, the study of the IGL provides a holistic view of the system's mass assembly history. However, the faint and diffuse nature of the IGL presents a technical challenge as it is typically detected at very low surface brightnesses, hardly detected in past surveys I will then present analyses of the IGL and ICL in Hyper-Suprime Cam observations of a similar depth to LSST, showing the kind of measurements we will be able to make for hundreds of thousands of systems.