Disentangling Stellar Age Estimates from Galactic Chemodynamical Evolution

Stellar ages are key for determining the formation history of the Milky Way, but are difficult to measure precisely. Furthermore, methods that use chemical abundances to infer ages may entangle the intrinsic evolution of stars with the chemodynamical evolution of the Galaxy. In this paper, we presen...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2024-01, Vol.960 (1), p.84
Main Authors: Shen, Jeff, Speagle, Joshua S., Mackereth, J. Ted, Ting, Yuan-Sen, Bovy, Jo
Format: Article
Language:English
Subjects:
Apogees
Astrophysics
Astrostatistics
Chemical evolution
Chronology
Estimates
Galactic archaeology
Galactic evolution
Galaxies
Metallicity
Milky Way
Milky Way disk
Milky Way evolution
Stars
Stellar age
Stellar ages
Stellar evolution
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Stellar ages are key for determining the formation history of the Milky Way, but are difficult to measure precisely. Furthermore, methods that use chemical abundances to infer ages may entangle the intrinsic evolution of stars with the chemodynamical evolution of the Galaxy. In this paper, we present a framework for making probabilistic predictions of stellar ages, and then quantify the contribution of both stellar evolution and Galactic chemical evolution to those predictions using SHapley Additive exPlanations. We apply this interpretable prediction framework to both a simulated Milky Way sample containing stars in a variety of evolutionary stages and an APOGEE-mocked sample of red clump stars. We find that in the former case, stellar evolution is the dominant driver for age estimates, while in the latter case, the more restricted evolutionary information causes the model to proxy ages through the chemical evolution model. We show that as a result of the use of nonintrinsic Galactic chemical information, trends estimated with the predicted ages, such as the age–metallicity relation, can deviate from the truth.
ISSN:0004-637X
1538-4357
DOI:10.3847/1538-4357/ad0559