The prevalence and properties of cold gas inflows and outflows around galaxies in the local Universe

We perform a stacking analysis of the neutral Na D lambda lambda 5889, 5895 angstrom ISM doublet using the SUSS DR7 spectroscopic data set to probe the prevalence and characteristics of cold (T less than or similar to 10(4) K) galactic-scale gas flows in local (0.025 <= z <= 0.1) inactive and AGN-host galaxies across the SFR-M-*. plane. We find low-velocity outflows to be prevalent in regions of high SFRs and stellar masses (10 less than or similar to log M-*/M-circle dot less than or similar to 11.5), however we do not find any detections in the low-mass (log M-*/M-circle dot less than or similar to 10) regime. We also find tentative detections of inflowing gas in high-mass galaxies across the star-forming population. We derive mass outflow rates in the range of 0.14-1.74 M-circle dot yr (-1) and upper limits on inflow rates <1 M-circle dot yr(-1), allowing us to place constraints on the mass-loading factor (eta = (M) over dot(out)/SFR) for use in simulations of the local Universe. We discuss the fate of the outflows by comparing the force provided by the starburst to the critical force needed to push the outflow outward, and find the vast majority of the outflows unlikely to escape the host system. Finally, as outflow detection rates and central velocities do not vary strongly with the presence of a (weak) active supermassive black hole, we determine that star formation appears to be the primary driver of outflows at z similar to 0.