Lithium on the lower red giant branch of five Galactic globular clusters

Vista sencilla de ítem
dc.contributor.authorAguilera-Gómez, C.
dc.contributor.authorMonaco, L.
dc.contributor.authorMucciarelli, A.
dc.contributor.authorSalaris, M.
dc.contributor.authorVillanova, S.
dc.contributor.authorPancino, E.
dc.date.accessioned2022-07-20T20:34:24Z
dc.date.available2022-07-20T20:34:24Z
dc.date.issued2022-01-01
dc.descriptionIndexación Scopuses
dc.description.abstractContext. Lithium is one of the few elements produced during Big Bang nucleosynthesis in the early universe. Moreover, its fragility makes it useful as a proxy for stellar environmental conditions. As such, the lithium abundance in old systems is at the core of various astrophysical investigations. Aims. Stars on the lower red giant branch are key to studies of globular clusters where main sequence stars are too faint to be observed. We use these stars to analyze the initial Li content of the clusters and compare it to cosmological predictions, to measure spreads in Li between different stellar populations, and to study signs of extra depletion in these giants. Methods. We used the GIRAFFE spectra to measure the lithium and sodium abundances of lower red giant branch stars in five globular clusters. These cover an extensive range in metallicity, from [Fe/H] ∼-0.7 to [Fe/H] ∼-2.3 dex. Results. We find that the lithium abundance in these lower red giant branch stars forms a plateau, with values from A(Li)NLTE = 0.84 to 1.03 dex, showing no clear correlation with metallicity. When using stellar evolutionary models to calculate the primordial abundance of these clusters, we recover values of A(Li)NLTE = 2.1 - 2.3 dex, consistent with the constant value observed in warm metal-poor halo stars, namely the Spite plateau. Additionally, we find no difference in the lithium abundance of first and second population stars in each cluster. We also report the discovery of a Li-rich giant in the cluster NGC 3201, with A(Li)NLTE = 1.63 ± 0.18 dex, where the enrichment mechanism is probably pollution from external sources.es
dc.identifier.citationAstronomy and Astrophysics Volume 657 1 January 2022 Article number A33es
dc.identifier.doi10.1051/0004-6361/202141750en
dc.identifier.issn0004-6361
dc.identifier.urihttps://repositorio.unab.cl/xmlui/handle/ria/23291
dc.language.isoenes
dc.publisherEDP Scienceses
dc.rights.licenseAttribution 4.0 International (CC BY 4.0)en
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/en
dc.subjectGlobular clusters: generales
dc.subjectPrimordial nucleosynthesises
dc.subjectStars: abundanceses
dc.subjectStars: chemically peculiares
dc.titleLithium on the lower red giant branch of five Galactic globular clusterses
dc.typeArtículoes
Archivos
Bloque original
Mostrando 1 - 1 de 1
Miniatura
Nombre:
Lithium-on-the-lower-red-giant-branch-of-five-Galactic-globular-clustersAstronomy-and-Astrophysics.pdf
Tamaño:
839.95 KB
Formato:
Adobe Portable Document Format
Descripción:
TEXTO COMPLETO EN INGLÉS
Descargar
Bloque de licencias
Mostrando 1 - 1 de 1
No hay miniatura disponible
Nombre:
license.txt
Tamaño:
1.71 KB
Formato:
Item-specific license agreed upon to submission
Descripción:
Descargar
Colecciones
FCE - Artículos de Revista