RT Journal Article
T1 The CARMENES search for exoplanets around M dwarfs Photospheric parameters of target stars from high-resolution spectroscopy
A1 Cortés Contreras, Miriam
A1 Montes Gutiérrez, David
A1 otros, ...
AB Context. The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Aims. Characterising our target sample is important for constraining the physical properties of any planetary systems that are detected. The aim of this paper is to determine the fundamental stellar parameters of the CARMENES M-dwarf target sample from high-resolution spectra observed with CARMENES. We also include several M-dwarf spectra observed with other high-resolution spectrographs, that is CAFE, FEROS, and HRS, for completeness. Methods. We used a chi(2) method to derive the stellar parameters effective temperature T-eff, surface gravity log g, and metallicity [Fe/H] of the target stars by fitting the most recent version of the PHOENIX-ACES models to high-resolution spectroscopic data. These stellar atmosphere models incorporate a new equation of state to describe spectral features of low-temperature stellar atmospheres. Since Teff, log g, and [Fe/H] show degeneracies, the surface gravity is determined independently using stellar evolutionary models. Results. We derive the stellar parameters for a total of 300 stars. The fits achieve very good agreement between the PHOENIX models and observed spectra. We estimate that our method provides parameters with uncertainties of sigma(Teff) = 51 K, sigma(logg) = 0 : 07, and sigma[(Fe/H)] = 0.16, and show that atmosphere models for low-mass stars have significantly improved in the last years. Our work also provides an independent test of the new PHOENIX-ACES models, and a comparison for other methods using low-resolution spectra. In particular, our effective temperatures agree well with literature values, while metallicities determined with our method exhibit a larger spread when compared to literature results.
PB EDP Sciences S A
SN 1432-0746
YR 2018
FD 2018-07-03
LK https://hdl.handle.net/20.500.14352/12247
UL https://hdl.handle.net/20.500.14352/12247
LA eng
NO © ESO 2018. Artículo firmado por 17 autores. We thank the anonymous referee for her/his comments that helped to improve the quality of this paper. VMP would like to thank Denis Shulyak for fruitful discussions. CARMENES is an instrument for the Centro Astronómico Hispano-Alemán de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Científicas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Institut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucía. IR acknowledges support from the Spanish Ministry of Economy and Competitiveness (MINECO) through grant ESP2014-57495-C2-2-R. VJSB is supported by programme AYA2015-69350-C3-2-P from Spanish Ministry of Economy and Competitiveness (MINECO) Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut fur Astronomie and the Instituto de Astrofísica de Andalucía. This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23.
NO German Max-Planck-Gesellschaft (MPG)
NO Spanish Consejo Superior de Investigaciones Científicas (CSIC)
NO European Union through FEDER/ERF
NO Max-Planck-Institut fur Astronomie
NO Instituto de Astrofísica de Andalucía
NO Landessternwarte Konigstuhl
NO Institut de Ciencies de l'Espai
NO Institut fur Astrophysik Gottingen
NO Universidad Complutense de Madrid
NO Thuringer Landessternwarte Tautenburg
NO Instituto de Astrofísica de Canarias
NO Hamburger Sternwarte;
NO Centro de Astrobiología
NO Centro Astronómico Hispano-Alemán
NO Spanish Ministry of Economy
NO German Science Foundation
NO DFG Research Unit "Blue Planets around Red Stars"
NO Klaus Tschira Stiftung;
NO State of Baden-Wurttemberg
NO State of Niedersachsen
NO Junta de Andalucía
NO Spanish Ministry of Economy and Competitiveness (MINECO)
DS Docta Complutense
RD 4 may 2024