Gaia FGK benchmark stars: Spectral library and abundances of α and Fe-peak elements of the third version
Year: 2025
Type: article
Abstract: Context . Accurate determination of the chemical abundances in stars plays a pivotal role in understanding stellar structure and evolution, nucleosynthesis, and the chemical enrichment history of the Milky Way. Benchmark stars with precise and accurate atmospheric parameters and abundances are indispensable for calibrating spectroscopic surveys and testing stellar atmosphere models. Aims . This study focuses on the compilation of high-quality spectra and the determination of chemical abundances of iron-peak and α elements for the third version of the Gaia FGK benchmark stars (GBSv3). Methods . We compiled spectra of the GBSv3 from public archives and complemented these with our observations. We used fundamental atmospheric parameters to perform a spectroscopic analysis using the public code iSpec and derived the chemical abundances. Results . We compiled a homogeneous spectral library of high-resolution (42 000) and high signal-to-noise (>100) normalised spectra for 202 stars, including the 192 GBSv3, nine stars with indirect measurement of the angular diameter from previous Gaia FGK benchmark versions, and the Sun. Using four radiative transfer codes, we derived chemical abundances of 13 chemical species (Fe I, Fe II, Mg I, Si I, Ca I, Ti I, Ti II, Sc II, V I, Cr I, Mn I, Co I, Ni I). We performed an in-depth study of several sources of error. Conclusions . The GBSv3 contributes to the legacy samples of spectroscopic reference stars through improved statistics and homogeneity. This work offers the community a homogeneous spectral library and robust reference abundances for iron-peak and α elements, supported by an extensive analysis of the associated uncertainties.
Source: Astronomy and Astrophysics
Institutions: Université Paris Cité, Université Paris Sciences et Lettres, Observatoire de Paris, Sorbonne Université, CY Cergy Paris Université, Centre National de la Recherche Scientifique, Université de Bordeaux, Laboratoire d'Astrophysique de Bordeaux, Universidad Diego Portales, Center for Astrophysics Harvard & Smithsonian, UniDistance Suisse, Instituto de Astrofísica de Canarias, Gran Telescopio Canarias (Spain), Uppsala University, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, CEA Paris-Saclay, Universidad de Santiago de Chile, Millennium Institute of Astrophysics, Pontificia Universidad Católica de Chile, Université Côte d'Azur, Observatoire de la Côte d’Azur, Institut d'Estudis Espacials de Catalunya, Institut de Ciències del Cosmos, Universitat de Barcelona, Osservatorio di Astrofisica e Scienza dello Spazio, National Institute for Astrophysics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: National Aeronautics and Space Administration, European Commission, Swedish National Space Agency, Centre National de la Recherche Scientifique, Universitat de Barcelona, Agencia Nacional de Investigación y Desarrollo, HORIZON EUROPE Framework Programme, Departamento de Investigaciones Científicas y Tecnológicas, Universidad de Santiago de Chile, European Regional Development Fund, Agencia Estatal de Investigación, Institut de Ciències del Cosmos
Awards: UNDERSTANDING THE FORMATION OF THE GALACTIC BULGE, Science PlAtform Cloud Infrastructure for Outsize Usage Scenarios, G3089118260, G3309177318, G3480869486, G3780874795, G3870194508, G4677178714, G5080475149, G5311534755, G5915139351, G7084143925, CONSTRAINING THE COMPOSITION OF ROCKY EXOPLANETS USING STELLAR SPECTROSCOPY, G7434936867, G7726027924, REFERENCE LADDER TO MEASURE MILLIONS OF STARS., G7996999566
OpenAlex ID: W4416652189