RSAA Colloquia / Seminars / Feast-of-Facts: Thursday, 19 November 2015, 11:00-12:00; Duffield Lecture Theatre

Barbara Catinella

"Gas and star formation properties of massive galaxies"

The main obstacle to understanding the formation and evolution of galaxies is our limited knowledge of the role played by gas. In particular, we still lack measurements of the cold hydrogen gas, which is the reservoir for future star formation, for large and unbiased samples for which ancillary data on stellar and star formation properties are also available. Fortunately, the Square Kilometre Array (SKA) and its precursor telescopes promise to fill this gap, ushering a golden era for studies of gas in galaxies. In this talk, I will show how pre-SKA facilities are already allowing us to make significant progress in this field. By taking advantage of atomic hydrogen (HI) observations obtained as part of the GALEX Arecibo SDSS and ALFALFA surveys, I will demonstrate that the combination of deep, targeted observations and spectral stacking of blind, large-area shallow surveys is critical in order to characterize how the gas content of galaxies depends on their structure, star formation activity and environment. I will also discuss the properties of the highest-redshift HI detections to date, and point out the relevance of all these findings for the next-generation HI surveys.