J/A+A/658/A194ivo://CDS.VizieR/J/A+A/658/A194doi:10.26093/cds/vizier.36580194CDSPassegger V.M.Bello-Garcia A.Ordieres-Mere J.Antoniadis-Karnavas A.,Marfil E.Duque-Arribas C.Amado P.J.Delgado-Mena E.Montes D.,Rojas-Ayala B.Schweitzer A.Tabernero H.M.Bejar V.J.S.Caballero J.A.,Hatzes A.P.Henning T.Pedraz S.Quirrenbach A.Reiners A.Ribas I.2022-10-12T08:49:45Z2022-02-24T07:33:16ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frm-starsmetallicityeffective-temperaturespectroscopyvisible-astronomyDeriving metallicities for solar-like stars follows well-established methods, but for cooler stars such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been developed in recent years to determine accurate stellar parameters for these cool stars (Teff<4000K). However, significant differences can be found at times when comparing metallicities for the same star derived using different methods. In this work, we determine the effective temperatures, surface gravities, and metallicities of 18 well-studied M dwarfs observed with the CARMENES high-resolution spectrograph following different approaches, including synthetic spectral fitting, analysis of pseudo-equivalent widths, and machine learning. We analyzed the discrepancies in the derived stellar parameters, including metallicity, in several analysis runs. Our goal is to minimize these discrepancies and find stellar parameters that are more consistent with the literature values. We attempted to achieve this consistency by standardizing the most commonly used components, such as wavelength ranges, synthetic model spectra, continuum normalization methods, and stellar parameters. We conclude that although such modifications work quite well for hotter main-sequence stars, they do not improve the consistency in stellar parameters for M dwarfs, leading to mean deviations of around 50-200K in temperature and 0.1-0.3dex in metallicity. In particular, M dwarfs are much more complex and a standardization of the aforementioned components cannot be considered as a straightforward recipe for bringing consistency to the derived parameters. Further in-depth investigations of the employed methods would be necessary in order to identify and correct for the discrepancies that remain.2022A&A...658A.194Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/658/A194CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/658/A194https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/658/A194http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/658/A194https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/658/A194https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/658/A194http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/658/A194GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/658/A194/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/658/A194/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/658/A194/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/658/A194/stars?GETtext/xml+votable180.050000true1.68-7.53805560.0055555555555555566/2737 5420 5534 7264 8163 13688 17348 20100 22807 24227 26327 26583 27459 28548 31781 32491 44921https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/658/A194?format=asciiOpticaldefaultJ/A+A/658/A194/starsList of studied starsDEJ2000Declination (J2000)pos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKarmnCarmencita identifier (JHHMMM+DDd)meta.id;meta.maincharRAJ2000Simbad right ascension (J2000)pos.eq.ra;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/658/A194/tablec1Stellar parameters from Runs A and BTeffAEffective temperature Run AKphys.temperature.effectiveintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKarmnCarmencita identifier (JHHMMM+DDd)meta.id;meta.maincharMethodMethodmeta.code;obschare_TeffAError effective temperature Run AKstat.errorintloggA? Surface gravity Run Alog(cm.s**-2)phys.gravityfloatnullablee_loggA? Error surface gravity Run Alog(cm.s**-2)stat.errorfloatnullable[Fe/H]AMetallicity Run Aphys.abund.Fefloate_[Fe/H]AError metallicity Run Astat.error;phys.abund.FefloatTeffB? Effective temperature Run BKphys.temperatureintnullablee_TeffB? Error effective temperature Run BKstat.errorintnullableloggB? Surface gravity Run Blog(cm.s**-2)phys.gravityfloatnullablee_loggB? Error surface gravity Run Blog(cm.s**-2)stat.errorfloatnullable[Fe/H]B? Metallicity Run Bphys.abund.Fefloatnullablee_[Fe/H]B? Error metallicity Run Bstat.error;phys.abund.FefloatnullableJ/A+A/658/A194/tablec2Stellar parameters from Runs C and C2MethodMethod (1)meta.code;obscharTeffCEffective temperature Run CKphys.temperature.effectiveintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKarmnCarmencita identifier (JHHMMm+DDd)meta.id;meta.mainchare_TeffCError effective temperature Run CKstat.errorintloggC? Surface gravity Run Clog(cm.s**-2)phys.gravityfloatnullablee_loggC? Error surface gravity Run Clog(cm.s**-2)stat.errorfloatnullable[Fe/H]CMetallicity Run Cphys.abund.Fefloate_[Fe/H]CError metallicity Run Cstat.error;phys.abund.FefloatTeffC2? Effective temperature Run C2Kphys.temperature.effectiveintnullablee_TeffC2? Error effective temperature Run C2Kstat.errorintnullableloggC2? Surface gravity Run C2log(cm.s**-2)phys.gravityfloatnullablee_loggC2? Error surface gravity Run C2log(cm.s**-2)stat.errorfloatnullable[Fe/H]C2? Metallicity Run C2phys.abund.Fefloatnullablee_[Fe/H]C2? Error metallicity Run C2stat.error;phys.abund.Fefloatnullable