A Search for Correlations between Turbulence and Star Formation in THINGS Galaxies

Abstract

The spatial range for feedback from star formation varies from molecular cloud disruption on parsec scales to supershells and disk blowout on kiloparsec scales. The relative amounts of energy and momentum given to these scales are important for understanding the termination of star formation in any one region and the origin of interstellar turbulence and disk stability in galaxies as a whole. Here, we measure, for 11 THINGS galaxies, the excess kinetic energy, velocity dispersion, and surface density of H i gas associated with regions of excess star formation, where the excess is determined from the difference between the observed local value and the azimuthal average. We find small decreases in the excess kinetic energy and velocity dispersion in regions of excess star formation rate density, suggesting that most of the feedback energy does not go into local H i motion. Most likely, it disrupts molecular clouds and dissipates rapidly at high gas density. Some could also be distributed over larger regions, filling in spaces between the peaks of star formation and contributing to other energy sources from self-gravity and spiral arm shocks.