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AR 17055 (Archival Research)

Sat Jul 20 09:07:02 GMT 2024

Principal Investigator: Jeremy Bailin
PI Institution: University of Alabama
Investigators (xml)

Title: Photometric Abundance Measurements in Globular Clusters
Cycle: 30

Abstract
Elemental abundance variations in globular clusters are universal but not well understood. HST photometry has been instrumental in detecting these populations, but does not directly provide the underlying elemental abundances, which are the physical property that can be compared to theoretical models; those measurements come from spectroscopic data for which it is very difficult to obtain large samples. We propose to combine literature spectroscopic measurements of O, Na, and Fe abundances of red giants with archival HST photometry of the same stars spanning 57 globular clusters. We will use this combined data set to train a machine learning regression model to predict the abundances for the vast majority of red giants in the HST data without spectroscopic measurements, and use them to build full elemental distribution functions and chemospatial maps of the clusters.