University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Wednesday, November 19th 2014
1:25 pm:
Nuclear Physics Seminar in 435 Physics
Speaker:  Zhen Yuan, University of Minnesota
Subject: Chemical Evolution Model of Fornax Dwarf Spheroidal Galaxy

In this talk I will focus on the constrains and predictions of my chemical evolution model for Fornax dwarf spheroidal galaxy (dSph), following the first talk I gave in cosmology seminar this September. With all new observational data of nearby dwarf galaxies and numerical tools of galaxy formation, we are nonetheless still at the first stage to understand chemical evolution of these small systems. Observations strongly indicate that chemical enrichment in dSphs remains inhomogeneous until the end of their star formation despite their small size. Using supernova nucleosynthesis yields as
input, I simulated stochastic and inhomogeneous mixing of newly-synthesized elements by supernovae and compare the results with the observed metallicity distributions and scatter in abundances of individual elements of e.g., Mg, Si, Ca, Ti, and Fe. The extension to r-process elements, especially Eu will be also discussed.This approach not only can test supernova nucleosynthesis models, but also provides insights into mixing of supernova ejecta with the interstellar medium (ISM). I found that this mixing depends on large-scale gas flows, the clumpy structure of the ISM, and the differences between environments of core-collapse and Type Ia supernovae.

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