Publication: Calibrating the metallicity of M dwarfs in wide physical binaries with F-, G-, and K-primaries -I: High-resolution spectroscopy with HERMES: stellar parameters, abundances, and kinematics
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Oxford Univ Press
We investigated almost 500 stars distributed among 193 binary or multiple systems made of late-E, G-, or earl y-K-primaries and late-K- or M-dwarf companion candidates, For all of them, we compiled or measured coordinates, J-band magnitudes, spectral types, distances, and proper motions. With these data, we established a sample of 192 physically bound systems. In parallel, we carried out observations with HERMES/Mercator and obtained high-resolution spectra for the 192 primaries and five secondaries. We used these spectra and the automatic STEPAR code for deriving precise stellar atmospheric parameters: T-eff, log g, xi, and chemical abundances for 13 atomic species, including [Fe/H]. After computing Galactocentric space velocities for all the primary stars, we performed a kinematic analysis and classified them in different Galactic populations and stellar kinematic groups of very different ages, which match our own metallicity determinations and isochronal age estimations. In particular, we identified three systems in the halo and 33 systems in the young Local Association, Ursa Major and Castor moving groups, and IC 2391 and Hyades superclusters. We finally studied the exoplanet-metallicity relation in our 193 primaries and made a list 13 M-dwarf companions with very high metallicity that can be the targets of new dedicated exoplanet surveys. All in all, our dataset will be of great help for future works on the accurate determination of metallicity of M dwarfS.
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This research made use of the SIMBAD database and VizieR catalogue access tool, operated at Centre de Donnees astronomiques de Strasbourg, France, the Spanish Virtual Observatory, the NASA's Astrophysics Data System, and the Washington Double Star catalogue maintained at the U.S. Naval Observatory. Financial support was provided by the Universidad Complutense de Madrid, the Comunidad Autónoma de Madrid, the Spanish Ministerio de Economía y Competitividad (MINECO) and the Fondo Europeo de Desarrollo Regional (FEDER/ERF) under grants AYA2016-79425-C3-1/2-P, AYA2015-68012-C2-2-P, AYA2014-56359-P, RYC-2013-14875, and FJCI-2014-23001, the Conserjería de Educación, Juventud y Deporte de la Comunidad de Madrid, and the Fondo Social Europeo y la Iniciativa de Empleo Juvenil (YEI) under grant PEJD-2016/TIC-2347, and the Spanish Ministerio de Educación, Cultura y Deporte, programa de Formación de Profesorado Universitario under fellowship FPU15/01476. Finally, we would like to thank the anonymous referee for helpful comments and corrections.