Metal SLUG - Developing a tool for stochastic nucleosynthesis

Most heavy elements are made by nucleosynthesis in stars. Calculations of element production usually assume for simplicity that the population of stars producing the elements is large enough that it samples all possible stellar masses and evolutionary states. For small galaxies however, this assumption is probably not valid. Instead, the stellar population samples from the available masses and evolutionary states of stars only stochastically, and this should produce a large spread in the abundance patterns of the nuclei produced. At present this effect is completely unquantified.

The student will work with Professor Krumholz to extend the SLUG (Stochastically Lighting Up Galaxies) code that he and his students have developed so it can tackle this problem. SLUG is a stochastic stellar population synthesis code that can do large numbers of Monte Carlo realizations of stellar populations. Currently it predicts the light output from those stars, as illustrated in the image, which shows the probability distribution for the spectra of star clusters of different ages populated by different stellar mass distributions. However, it does not yet include element production.

The student will add tables of nucleosynthetic yields to the code, and, once this new capability is working, will develop software (tentatively titled Metal SLUG) to explore the expected spread in element abundances at low metallicity that results from stochastic sampling of the stellar mass function. The results will be compared to observations of abundance patterns in nearby dwarf galaxies.

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