Interaction of Massive Stars with Gas Clouds in the Milky Way:from shooting stars to breaking bubbles

Massive stars, with a mass more than 8 Solar-masses, have a strong destructive impact on the clouds of gas and dust where they are born. My thesis examines the formation of massive stars and their impact on the surrounding gas environment. I use observations with a ground-based radiotelescope, a space-based infrared telescope, and an infrared telescope which flies in the stratosphere. To interpret these data, I use models of radiative transfer and chemical evolution of interstellar clouds.The thesis begins with high angular resolution radio observations of massive star-forming regions. To characterize the initial phases of massive star formation, we look for radio jets, a common phenomenon in low-mass star formation. The remainder of the thesis analyzes the surfaces of interstellar clouds adjacent to massive stars, as well as the influence of protostellar feedback via jets and outflows. The thesis concludes with a study of the dynamics of the ionization front in the Orion Nebula, the nearest massive star formation region to Earth