Quantifying Bubble-Driven Feedback in the Interstellar Medium

Within our Galaxy, theory predicts the formation of ~250 solar mass stars each year; observationally, however, we typically see one. Studies have attributed this discrepancy in the star formation rate to short GMC lifetimes and feedback from magnetic fields, and turbulence. In an effort to quantify this feedback, we study the expansion of large, shell-like structures of gas, typically referred to as “bubbles,” and analyze the impact they have on their surroundings. To carry out this study, we obtain a comprehensive list of bubbles identified by citizen scientists in the Milky Way Project. Of the 5000 bubbles identified, 26 are within range of view of the GALFA HI, THOR HI, GRS ¹³CO (1-0), VGPS continuum, and WSRT continuum surveys. We use the aforementioned surveys to determine the radial velocities, kinematic distances, atomic and molecular masses, and radio flux densities of each bubble. From these calculations, we estimate the shells’ kinetic energy input and momentum ejection, and estimate their place in the stellar feedback ladder.