case western reserve university



Massive stars as a population and recent highlights on feedback effects

Sally Oey (University of Michigan)

The population of the most massive stars is responsible for driving major evolutionary processes in star-forming galaxies through mechanical, radiative, and chemical feedback. Spatially resolved studies of this stellar population yield simple parameterizations of clustering and the stellar upper-mass limit. These lead to a straightforward analytic understanding of resulting feedback processes, including a threshold star-formation rate above which galactic superwinds shred the ISM, releasing ionizing radiation from the parent galaxies. Another implication is a new paradigm for inhomogeneous galactic chemical evolution, which offers an opposite extreme to the purely homogeneous Simple Model. Observations of some Milky Way stellar populations will be examined.