J/A+A/328/349ivo://CDS.VizieR/J/A+A/328/349doi:10.26093/cds/vizier.33280349CDSSmalley B.Kupka F.1997-12-11T14:44:46Z1997-12-11T15:44:31ZCDS support team

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

cds-question@unistra.frastronomical-modelsstellar-atmosphereschemical-abundancesvisible-astronomymedium-band-photometryWe discuss the effects of convection on the theoretical uvby colours of A, F, and G stars. The standard mixing-length theory atlas9 models of Kurucz (1993, ATLAS9, SAO, Cambridge, USA), with and without approximate overshooting, are compared to models using the turbulent convection theory proposed by Canuto & Mazzitelli (1991ApJ...370..295C, 1992ApJ...389..724C) and implemented by Kupka (1996, ASPConf. Proc. 108, 73). Comparison with fundamental Teff and log g stars reveals that the Canuto & Mazzitelli models give results that are generally superior to standard mixing-length theory (MLT) without convective overshooting. MLT models with overshooting are found to be clearly discrepant. This is supported by comparisons of non-fundamental stars, with Teff obtained from the Infrared Flux Method and log g from stellar evolutionary models for open cluster stars. The Canuto & Mazzitelli theory gives values of (b-y)0 and c0 that are in best overall agreement with observations. Investigations of the m0 index reveal that all of the treatments of convection presented here give values that are significantly discrepant for models with Teff<6000K. It is unclear as to whether this is due to problems with the treatment of convection, missing opacity, or some other reason. None of the models give totally satisfactory m0 indices for hotter stars, but the Canuto & Mazzitelli models are in closest overall agreement above 7000K. Grids of uvby colours, based on the CM treatment of convection, are presented. These grids represent an improvement over the colours obtained from models using the mixing-length theory. The agreement with fundamental stars enables the colours to be used directly without the need for semi-empirical adjustments that were necessary with the earlier colour grids. For a description of the uvby photometric system, see e.g. <GCPD/04>1997A&A...328..349Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/328/349CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/328/349https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/328/349http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/328/349https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/328/349https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/328/349http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/328/349GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/328/349/cm_p10*Canuto & Mazzitelli (CM) grid for [M/H] = +1.0recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTeffTeffKphys.temperature.effectiveintlog(g)log glog(cm.s**-2)phys.gravityfloat[M/H]Metallicity [M/H]log(Sun)phys.abundfloatVturbmicroturbulencekm/sphys.veloc.microTurbfloatu-bu-b colour indexmagphot.color;em.opt.U;em.opt.Bfloatb-yb-y colour indexmagphot.color;em.opt.B;em.opt.Vfloatm1m1 colour indexmagphot.colorfloatc1c1 colour indexmagphot.colorfloatJ/A+A/328/349/cm_p05CM grid for [M/H] = +0.5recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTeffTeffKphys.temperature.effectiveintlog(g)log glog(cm.s**-2)phys.gravityfloat[M/H]Metallicity [M/H]log(Sun)phys.abundfloatVturbmicroturbulencekm/sphys.veloc.microTurbfloatu-bu-b colour indexmagphot.color;em.opt.U;em.opt.Bfloatb-yb-y colour indexmagphot.color;em.opt.B;em.opt.Vfloatm1m1 colour indexmagphot.colorfloatc1c1 colour indexmagphot.colorfloatJ/A+A/328/349/cm_p00CM grid for [M/H] = +0.0recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTeffTeffKphys.temperature.effectiveintlog(g)log glog(cm.s**-2)phys.gravityfloat[M/H]Metallicity [M/H]log(Sun)phys.abundfloatVturbmicroturbulencekm/sphys.veloc.microTurbfloatu-bu-b colour indexmagphot.color;em.opt.U;em.opt.Bfloatb-yb-y colour indexmagphot.color;em.opt.B;em.opt.Vfloatm1m1 colour indexmagphot.colorfloatc1c1 colour indexmagphot.colorfloatJ/A+A/328/349/cm_m05CM grid for [M/H] = -0.5recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTeffTeffKphys.temperature.effectiveintlog(g)log glog(cm.s**-2)phys.gravityfloat[M/H]Metallicity [M/H]log(Sun)phys.abundfloatVturbmicroturbulencekm/sphys.veloc.microTurbfloatu-bu-b colour indexmagphot.color;em.opt.U;em.opt.Bfloatb-yb-y colour indexmagphot.color;em.opt.B;em.opt.Vfloatm1m1 colour indexmagphot.colorfloatc1c1 colour indexmagphot.colorfloatJ/A+A/328/349/cm_m10CM grid for [M/H] = -1.0TeffTeffKphys.temperature.effectiveintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlog(g)log glog(cm.s**-2)phys.gravityfloat[M/H]Metallicity [M/H]log(Sun)phys.abundfloatVturbmicroturbulencekm/sphys.veloc.microTurbfloatu-bu-b colour indexmagphot.color;em.opt.U;em.opt.Bfloatb-yb-y colour indexmagphot.color;em.opt.B;em.opt.Vfloatm1m1 colour indexmagphot.colorfloatc1c1 colour indexmagphot.colorfloatJ/A+A/328/349/table5Comparison between evolutionary and grid log grecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHDHD (Cat. <III/135>) numbermeta.id;meta.mainintTeffTeff from Kunzli et al. (1997, Cat. <J/A+AS/122/51>)Kphys.temperature.effectiveintlogglogg from evolutionary models (Kunzli et al., 1997, Cat. <J/A+AS/122/51>)log(cm.s**-2)phys.gravityfloatb-yb-y colour indexmagphot.color;em.opt.B;em.opt.Vfloatc0c0 colour indexmagphot.color.reddFreefloatTeff(CM)Teff from CM (Canuto & Mazzitelli) grid (1)Kphys.temperature.effectiveintlogg(CM)logg from CM gridlog(cm.s**-2)phys.gravityfloatDlogg(CM)Delta logg for CM gridlog(cm.s**-2)phys.gravityfloatTeff(noOV)Teff from MLT (mixing-length theory) noOV gridKphys.temperature.effectiveintlogg(noOV)logg from MLT noOV gridlog(cm.s**-2)phys.gravityfloatDlogg(noOV)Delta logg for MLTnoOV gridlog(cm.s**-2)phys.gravityfloatTeff(OV)Teff from MLT OV gridKphys.temperature.effectiveintlogg(OV)logg from MLT OV gridlog(cm.s**-2)phys.gravityfloatDlogg(OV)Delta logg for MLT OV gridlog(cm.s**-2)phys.gravityfloat