Galaxies & Cosmology Seminar - Andrew Emerick (Columbia)


Tuesday, October 2, 2018, 12:00pm to 1:00pm



"Feedback and Chemical Enrichment in Low Mass Dwarf Galaxies: Insights from Simulations Tracking Individual Stars"

Abstract:  Galactic chemical evolution is driven by the complicated interplay of gas accretion, galaxy mergers, star formation, stellar feedback, mixing and turbulence in the ISM, and galactic outflows. Stellar feedback is fundamental in this evolution. How metals -- ejected in stellar winds and supernovae -- mix with a multi-phase ISM and couple to galactic winds depends sensitively on feedback physics that is poorly understood. Improving our theoretical understanding of both stellar feedback and galactic chemical evolution is becoming increasingly important as number and quality of observations of stellar and gas phase abundances in nearby galaxies continues to grow. We use high resolution, hydrodynamics simulations of isolated, low mass dwarf galaxies to better understand the complex relationship between feedback and galactic chemical evolution. By following stars as individual star particles, we can model both stellar feedback and stellar yields in unprecedented detail. Our star-by-star feedback model includes stellar winds from massive stars and AGB stars, photoelectric heating, stellar ionizing radiation followed through a ray-tracing radiative transfer method, core collapse supernovae, and Type Ia supernovae. We have used these simulations to explore differences in how metals with different nucleosynthetic origins mix within the ISM and couple to galactic winds. I will summarize these results to-date and present ongoing work in understanding the role each component of our multi-channel stellar feedback model plays in driving the chemical evolution of galaxies.

See also: Seminars, 2018 - 19