Dr. Crystal Martin
Title: The Role of
Feedback in Galaxy Formation
Our understanding of
galaxy formation is founded on the well-understood principle of gravitational
amplification of structure but lacks the astrophysical knowledge needed to
predict the properties of galaxies and small scale properties of the
intergalactic medium. While gas cooling and galaxy merging are now modeled with
reasonable accuracy, the complex process of gas reheating by massive stars and
active nuclei is described by simple empirical feedback recipes. Chandra and XMM-Newton observations now provide
direct imaging of this hot gas in nearby starburst galaxies; and outflow
speeds--of cooler gas entrained in hot galactic winds--have been measured over
a large range of galaxy masses and formation epochs. My talk will describe how
these empirical studies help us understand the dynamics of galactic winds and
discuss the consequences for the shape of the galaxy luminosity function and
the enrichment of the intergalactic medium with metals.