Global Gas Content Trends Across the Galaxy Population

by Sheila Kannappan (UNC)

Patterns in global atomic and molecular gas content as a function of mass, environment, and evolutionary state provide key insights into the physics of gas accretion and star formation in galaxies. I will present results from several z=0 surveys, including first results from the volume-limited RESOLVE survey, pointing to strong mass and environment dependence in cosmic gas accretion. These results highlight clear transitions between accretion-dominated, processing-dominated, and quenched regimes of galaxy growth. Interestingly, "high mass" dwarf galaxies (with baryonic mass ~109-1010 Msun) are accretion-dominated in low-density environments, with high specific star formation rates consistent with exponential growth. Moreover, we find evidence that gas-rich merger remnants in the same mass regime are accreting fresh gas and (re)building spiral disks.