J/A+A/454/333ivo://CDS.VizieR/J/A+A/454/333doi:10.26093/cds/vizier.34540333CDSCastelli F.Kurucz R.L.2006-12-20T15:06:25Z2006-12-20T16:04:37ZCDS support team

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

cds-question@unistra.frastronomical-modelsstellar-atmospheresmetallicityvisible-astronomyh-beta-photometryGrids of H{beta} indices based on updated (new-ODF) ATLAS9 model atmospheres were computed for solar and scaled solar metallicities [+0.5], [+0.2], [0.0], [-0.5], [-1.0], [-1.5], [-2.0], [-2.5] and for alpha enhanced compositions [+0.5a], [0.0a], [-0.5a], [-1.0a], [-1.5a], [-2.0a], [-2.5a], and [-4.0a]. Indices for Teff>5000K were computed with the same methods as described by Lester, Gray & Kurucz (1986ApJS...61..509L) (LGK86) except for a different normalization of the computed natural system to the standard system. LGK86 used special ODFs to compute the fluxes. For Teff less or equal to 5000K we computed the fluxes using the synthetic spectrum method. In order to assess the accuracy of the computed indices comparisons were made with the indices computed by Smalley & Dworetsky (1995A&A...293..446S) (MD95) and with the empirical relations Teff-H{beta} given by Alonso et al. (1996A&A...313..873A) for several metallicities. Furthermore, for cool stars, temperatures inferred from the computed indices were compared with those of the fundamental stars listed by MD95. The same kind of comparison was made between gravities for B-type stars. The temperatures from the computed indices are in good agreement, within the error limits, with the literature values for Teff between 4750K and 8000K, while the gravities agree for Teff>9000K. The computed H{beta} indices for the Sun and for Procyon are very close to the observed values. The comparison between the observed and computed H{beta} indices as function of the observed H{beta} has shown a very small trend which almost completely disappears when only stars hotter than 10000K are considered. The trend due to the cool stars is probably related with the low accuracy of the fundamental Teff which are affected by large errors for most of the stars.2006A&A...454..333Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/454/333CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/454/333https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/454/333http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/454/333https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/454/333https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/454/333http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/454/333GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/454/333/table1H{beta} indices for 16 different metallicities and Vturb=2km/s and for [M/H]=0.0 and Vturb=0.recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential designation of the model (1)meta.id;meta.maincharModel[1/476] Model number for given [M/H] and Vturbmeta.idintTeffEffective temperatureKphys.temperature.effectiveintloggGravity surfacelog(cm.s**-2)phys.gravityfloat[M/H]Fixed metallicity, log[N(Fe)/N(Fe_Sun_)] (2)log(Sun)phys.abund.Fefloatn_[M/H][a] "a" indicates enhanced abundances by 0.4dex for the alpha elementsmeta.notecharVturb[0.00/2.00] Fixed microturbulent velocitykm/sphys.velocfloatl/HMixing-length parameterstat.paramfloatsmallMagnitude through the small filter at the star surfacemagphot.mag;meta.modelledfloatbigMagnitude through the big filter at the star surfacemagphot.mag;meta.modelledfloatbetaH{beta} index normalized to Vegamagphot.colorfloat