2005/06/20 by E. F. del Peloso, L. da Silva, G. F. Porto de Mello +1 · 6 citations
Physics and Astronomy · #Astronomical and nuclear sciences #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20053307
published as Astron.Astrophys. 440 (2005) 1153 · 7 pages, 5 Postscript figures, accepted for publication in Astronomy & Astrophysics
arxiv created 2005/06/20 · openalex publication_date 2005/09/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
The first determination of the age of the Galactic thin disk from Th/Eu nucleocosmochronology was accomplished by us in Papers I and II. The present work aimed at reducing the age uncertainty by expanding the stellar sample with the inclusion of seven new objects – an increase by 37%. A set of [Th/Eu] abundance ratios was determined from spectral synthesis and merged with the results from Paper I. Abundances for the new, extended sample were analyzed with the aid of a Galactic disk chemical evolution (GDCE) model developed by us is Paper II. The result was averaged with an estimate obtained in Paper II from a conjunction of literature data and our GDCE model, providing our final, adopted disk age with a reduction of 0.1 Gyr (6%) in the uncertainty. This value is compatible with the most up-to-date white dwarf age determinations (≲10 Gyr). Considering that the halo is currently presumed to be old, our result prompts groups developing Galactic formation models to include an hiatus of between the formation of halo and disk.