Events in Physics
Pratika Dyal (University of Durham)
The first billion years of galaxy formation in cold and warm dark matter cosmologies
Over the past few years, instruments such as the Hubble Space Telescope have provided tantalising glimpses of a time when the earliest galaxies were just assembling in an infant Universe. In this talk, I will present a theoretical framework that captures the key physics of supernova feedback in ejecting gas from low-mass halos, and tracks the resulting impact on the subsequent growth of more massive systems via halo mergers and gas re-accretion in early galaxies at z~5-15. In addition to successfully explaining a wide rage of observed data sets, our model naturally predicts the evolution of the faint end slope of the luminosity function and yields a census of the cosmic stellar mass density at these early epochs. I will show how this framework will be a powerful testbed for Warm Dark Matter models accessible with the forthcoming James Webb Space Telescope. I will end by showing the implications of early galaxy formation for reionization in both cold and warm Dark Matter cosmologies.