The age of the Galactic thin disk from Th/Eu nucleocosmochronology III. Extended sample

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dc.creatordel Peloso, E. F.
dc.creatorda Silva, L.
dc.creatorde Mello, G. F. Porto
dc.creatorArany-Prado, L. I.
dc.date2005-06-20
dc.date.accessioned2026-07-07T02:18:01Z
dc.date.available2026-07-07T02:18:01Z
dc.descriptionThe 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 T_G = (8.8 +/- 1.7) Gyr 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 (13.5 +/- 0.7) Gyr old, our result prompts groups developing Galactic formation models to include an hiatus of (4.7 +/- 1.8) Gyr between the formation of halo and disk.
dc.description7 pages, 5 Postscript figures, accepted for publication in Astronomy & Astrophysics
dc.identifierhttps://arxiv.org/abs/astro-ph/0506458
dc.identifierhttp://arxiv.org/abs/astro-ph/0506458
dc.identifierAstron.Astrophys. 440 (2005) 1153
dc.identifierdoi:10.1051/0004-6361:20053307
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/9332
dc.subjectAstrophysics
dc.titleThe age of the Galactic thin disk from Th/Eu nucleocosmochronology III. Extended sample
dc.typetext

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