J/A+A/489/1255ivo://CDS.VizieR/J/A+A/489/1255doi:10.26093/cds/vizier.34891255CDSNardetto N.Stoekl A.Bersier D.BarnesT.G.2017-10-12T13:00:42Z2008-11-30T14:07:15ZCDS support team

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

cds-question@unistra.frvariable-starsspectroscopyradial-velocityWe show that residual {gamma}-velocities (compared to a axisymmetric rotation model of the milky Way) are an intrinsic property of Cepheids. We observed eight galactic Cepheids with the HARPS spectroscope, focusing specifically on 17 spectral lines. For each spectral line of each star, we computed the {gamma}-velocity (resp. {gamma}-asymmetry) as an average value of the interpolated radial velocity (resp. line asymmetry) curve. For each Cepheid in our sample, a linear relation is found between the {gamma}-velocities of the various spectral lines and their corresponding {gamma}-asymmetries, showing that residual {gamma}-velocities stem from the intrinsic properties of Cepheids. We also provide a physical reference to the stellar {gamma}-velocity: it should be zero when the {gamma}-asymmetry is zero. Following this definition, we provide very precise and physically calibrated estimates of the {gamma}-velocities for all stars of our sample.2008A&A...489.1255Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/489/1255CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/453/309 : HARPS observations of nine galactic Cepheids (Nardetto+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/489/1255https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/489/1255http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/489/1255https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/489/1255https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/489/1255http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/489/1255GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/489/1255/table1 (Observed sample of Cepheids sorted by increasing period and main results)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/489/1255/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/489/1255/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/489/1255/table1?GETtext/xml+votable180.050000true229.9404719-66.49603580.0055555555555555566/23922 29104 33804 37268 39244 39410 41385 43060https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/489/1255?format=asciiOpticaldefaultJ/A+A/489/1255/table1Observed sample of Cepheids sorted by increasing period and main resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharprimaryHDHD numbermeta.idintPerPulsation period (1)dtime.perioddoubleVgGCDGCD {gamma}-velocities (2)km/sphys.veloc;pos.barycenterfloata0Slope of the relation (3)stat.fit.paramfloate_a0Uncertainty on a0stat.errorfloatb0Zero-Point of the relation (3)km/sstat.fit.paramfloate_b0Uncertainty on b0km/sstat.errorfloatChi2Reduced Chi^2 of the fitstat.fit.chi2;stat.fit.param;meta.modelledintVgStarPhysically calibrated {gamma}-velocity of the star (4)km/sphys.veloc;pos.barycenterfloate_VgStarUncertainty on VgStarkm/sstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/489/1255/table2Gamma-velocities and {gamma}-asymmetriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharIonSpecies metallic spectral linemeta.id;spect.index;spect.linecharLineWavelength of the spectral line0.1nmem.wl;spect.linedoubleAgGamma-asymmetry in % of the FWHM (1)%stat.fit.paramfloate_AgUncertainty on Ag%stat.errorfloatVgGamma-velocitykm/sphys.veloc;pos.barycenterfloate_VgUncertainty on Vgkm/sstat.errorfloat