Galactic Winds and Supernovae

Gaseous outflows appear to be a ubiquitous property of star-forming galaxies across cosmic time. Cosmological hydrodynamical simulations require higher outflow efficiencies in lower mass galaxies in order to explain the observed distribution of galaxy stellar masses and gas-phase metallicities. Yet typical dwarf galaxies have very low specific star formation rates today, raising the question “Can we observe strong feedback in low mass galaxies?” Studying feedback in dwarf galaxies with extreme emission-line spectra provides some answers and offers insight into the interplay between radiative and mechanical feedback in young galaxies. These galaxies have an extremely dense star cluster, and I will present new integral field spectroscopy that reveals how the young, low-metallicity stars change the gas kinematics and excitation of the surrounding interstellar medium. The results suggest that the EUV spectrum is harder than that produced by typical star clusters, the escape of Lyman continuum radiation is anisotropic, and fast outflows may be impacting the densest interstellar gas.