{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/chemical-evolution-in-the-milky-way-rotation","title":"Chemical Evolution in the Milky Way: Rotation-based ages for APOGEE-Kepler cool dwarf stars","arxiv_id":"1911.04518","date":"2019-11-11","proceeding":null,"authors":["Zachary R. Claytor","Jennifer L. van Saders","Angela R. G. Santos","Rafael A. Garcia","Savita Mathur","Jamie Tayar","Marc H. Pinsonneault","Matthew Shetrone"],"abstract":"We use models of stellar angular momentum evolution to determine ages for $\\sim500$ stars in the APOGEE-\\textit{Kepler} Cool Dwarfs sample. We focus on lower main-sequence stars, where other age-dating tools become ineffective. Our age distributions are compared to those derived from asteroseismic and giant samples and solar analogs. We are able to recover gyrochronological ages for old, lower-main-sequence stars, a remarkable improvement over prior work in hotter stars. Under our model assumptions, our ages have a median relative uncertainty of $14\\%$, comparable to the age precision inferred for more massive stars using traditional methods. We investigate trends of galactic $\\alpha$-enhancement with age, finding evidence of a detection threshold between the age of the oldest $\\alpha$-poor stars and that of the bulk $\\alpha$-rich population. We argue that gyrochronology is an effective tool reaching ages of 10--12 Gyr in K- and early M-dwarfs. Finally, we present the first effort to quantify the impact of detailed abundance patterns on rotational evolution. We estimate a $\\sim15\\%$ bias in age for cool, $\\alpha$-enhanced (+ 0.4 dex) stars when standard solar-abundance-pattern rotational models are used for age inference, rather than models that appropriately account for $\\alpha$-enrichment.","url_abs":"http://arxiv.org/abs/1911.04518v1","url_pdf":"http://arxiv.org/pdf/1911.04518v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"chemical-evolution-in-the-milky-way-rotation","repo_url":"https://github.com/zclaytor/kiauhoku","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}