The Impact of Galactic Outflows Across Cosmic Scales
Romeel Dave (Arizona)
Feedback from supernova-driven winds is an important driver of
galaxy evolution, particularly during the heydey of star formation
in the universe. I will present new cosmological SPH simulations
incorporating heuristic models of superwind feedback, and study their
impact on the properties of galaxies and intergalactic gas during
the heydey of galaxy formation at z~2-6. I will focus particularly
on metal enrichment as a unique observational tracer of such outflows.
Remarkably, by parameterizing the outflow properties of galaxies at those
epochs based on what is seen in local observations of rare starbursts,
it is possible to reproduce a wide range of galaxy and IGM metallicity
observations. I will further show that such agreement is unique to a
rather narrow class of outflow models. Our simulations yield new and
non-conventional interpretations for several puzzling observations, such
as the constancy of CIV absorption in the high-z IGM, and the low scatter,
uniformity, and slow evolution of the galaxy mass-metallicity relation.
Our results suggests a strong connection between galactic outflows from
the reionization epoch until today, and offer promise that this major
uncertainty in galaxy formation theory will soon be well-constrained.