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AR 13900 (Archival Research)

Thu Jul 25 12:08:53 GMT 2024

Principal Investigator: Guy Worthey
PI Institution: Washington State University
Investigators (xml)

Title: Stellar Evolutionary Isochrones for Galaxy Evolution
Cycle: 22

Abstract
We will combine new ab initio stellar evolution calculations with onging stellar flux and photometric improvements to provide HST and other missions with greatly improved stellar evolutionary isochrones and accompanying integrated light models for unraveling galaxy evolution using spacebourne and groundbased filter sets. We propose to add the following capabilities currently unavailable: {1} carbon star populations, {2} nearly arbitrary chemical mixture, {3} stars with M < 0.6 Mo, down to 0.08 Mo, {4} realistic metallicity spreads in populations, {5} immediate and full transformations to space-based photometric systems including HST and also quantities as a function of redshift, and {6} where possible, empirical adjustments to colors and certain evolutionary phases. Furthermore, we will provide web calculator pages yielding a broad array of color-calibration and isochrone-author choices, all of which are interchangeable. We currently give color-magnitude diagrams in graphical and plottable text form for 6 isochrone author choices and about 200 photometric filters. What would be added if this proposal is granted funding is {1} new evolution and improved color choices, {2} integrated light output for a variety of IMF choices and metallicity distribution functions, and {3} optional extra output of integrated quantites as a function of redshift.