Navegação Ciências Exatas e da Terra por Assunto "Abundância estelar"
Resultados 1-9 de 9
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Abundances from integrated spectra of 47 Tucanae (NGC 104)
(2020) [Artigo de periódico]47 Tucanae is among the most studied and observed globular clusters, given its proximity. The aim of this work is to study in detail the integrated spectrum of 47 Tucanae, as a template, in order to have a list of reliable ... -
Carbon, isotopic ratio 12C/13C, and nitrogen in solar twins : constraints for the chemical evolution of the local disc
(2020) [Artigo de periódico]Abundances of light elements in dwarf stars of different ages are important constraints for stellar yields, Galactic chemical evolution and exoplanet chemical composition studies. We have measured C and N abundances and ... -
Chemical abundances in Seyfert galaxies : VII. Direct abundance determination of neon based on optical and infrared emission lines
(2021) [Artigo de periódico]For the first time, neon abundance has been derived in the narrow line region from a sample of Seyfert 2 nuclei. In view of this, we compiled from the literature fluxes of optical and infrared (IR) narrow emission lines ... -
Dissecting stellar chemical abundance space with t-SNE
(2018) [Artigo de periódico]In the era of large-scale Galactic astronomy and multi-object spectroscopic stellar surveys, the sample sizes and the number of available stellar chemical abundances have reached dimensions in which it has become difficult ... -
High-resolution abundance analysis of four red giants in the globular cluster NGC 6558
(2018) [Artigo de periódico]Context. NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H] ≈ −1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. ... -
SDSS-IV MaNGA : exploring the local scaling relations for N/O
(2022) [Artigo de periódico]We present, for the first time, the relationship between local stellar mass surface density, Σ*, and N/O derived from SDSS-IV MaNGA data, using a sample of 792,765 high signal-to-noise ratio star-forming spaxels. Using a ... -
StarHorse results for spectroscopic surveys and Gaia DR3 : chrono-chemical populations in the solar vicinity, the genuine thick disk, and young alpha-rich stars
(2023) [Artigo de periódico]The Gaia mission has provided an invaluable wealth of astrometric data for more than a billion stars in our Galaxy. The synergy between Gaia astrometry, photometry, and spectroscopic surveys gives us comprehensive information ... -
The 16th data release of the sloan digital sky surveys : first release from the APOGEE-2 Southern Survey and full release of eBOSS spectra
(2020) [Artigo de periódico]Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July–2017 July). This ... -
The impact of the uncertainties in the 12C(α, γ ) 16O reaction rate on the evolution of low- to intermediate-mass stars
(2022) [Artigo de periódico]One of the largest uncertainties in stellar evolutionary computations is the accuracy of the considered reaction rates. The 12C(α, γ ) 16O reaction is particularly important for the study of low- and intermediate-mass stars ...