Seminar by Nick Luber, Columbia
Galaxies grow, transform, and ultimately shut down their star formation through the acquisition, redistribution, and loss of gas. While stars record the integrated history of these processes, the gas itself retains a direct imprint of the physical mechanisms that govern galaxy evolution. In this talk, I will show how deep radio observations of neutral atomic hydrogen provide a uniquely powerful window into how galaxies interact with their surroundings and with the large-scale cosmic web. I will present recent results from high-sensitivity radio interferometric surveys that trace the evolution of extragalactic gas reservoirs across a wide range of masses and environments. These observations reveal distinct evolutionary pathways for galaxies of different mass, and show that environmental processes, including ram-pressure stripping by the cosmic web, can dramatically reshape gaseous disks, often well before their stellar components respond. I will highlight examples from individual low-mass systems, where these effects are particularly pronounced and offer stringent tests of theoretical models, and complement these with larger statistical studies across diverse galaxy populations. Finally, I will discuss how the coming generation of radio observatories will enable direct observational connections between gas dynamics and star formation across scales from individual galaxies to the cosmic web. These next-generation facilities will make it possible to directly map the life cycle of gas in its environmental context with unprecedented detail.
Host: Timothy Halpin-Healy