Jim Geach, McGill University
The Cosmic Evolution of the Molecular Gas Content of Galaxies and Prospects for Future Molecular Gas Surveys
Despite the great progress made in the field of galaxy evolution over the past 30 years, we lack a comprehensive empirical understanding of the evolution of the molecular gas content of galaxies. This is a fundamental piece of the galaxy evolution puzzle, since it is the consumption/replenishment of molecular fuel that underpins the growth of galaxies. Until recently, routine detection of cold gas in "normal" galaxies beyond the local Universe has been extremely challenging. However, thanks to improvements in mm/cm instrumentation, in just the past two years the "parameter space" of extragalactic gas studies has expanded dramatically. I will present a first glimpse of the evolution of the molecular gas fraction of "normal" star-forming galaxies over 10 billion years of cosmic history, and discuss the rich astrophysics encoded within this observable. Finally, I describe a new model for the evolution of the space density of molecular gas reservoirs in the Universe, and the prospects for ambitious blind (and semi-blind) molecular line redshift surveys of galaxies right back to the era of re-ionization, utilizing current and future sensitive sub-mm/mm/cm/radio facilities such as ALMA, EVLA, CCAT, SKA and its pathfinders.
Host: Martha Haynes
