J/A+A/676/A136ivo://CDS.VizieR/J/A+A/676/A136doi:10.26093/cds/vizier.36760136CDSGroenewegen M.A.TLub J.2025-05-19T20:01:10Z2023-08-23T08:14:20ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsvariable-starsstellar-distancevisible-astronomytrigonometric-parallaxThe spectral energy distributions (SEDs) of a sample of 142 LMC and 77 SMC fundamental mode classical Cepheids (CCs) were constructed using photometric data in the literature. The data was whenever possible representative of mean light, or averaged over the light curve. The sample was build from stars that have a metallicity determination from high-resolution spectroscopy, have been used in Baade-Wesselink type of analysis, have a radial velocity curve published in Gaia DR3, have Walraven photometry, or have their light- and radial-velocity curves modelled by pulsation codes. The SEDs were fitted with stellar photosphere models to derive the best-fitting luminosity and effective temperature. Distance and reddening were taken from the literature. The stars were plotted in a Hertzsprung-Russell diagram (HRD) and compared to evolutionary tracks for CCs and to theoretical instability strips. For the large majority of stars, the position in the HRD is consistent with the instability strip. Period-luminosity (PL) and period-radius relations are derived and compared to these relations in the MW. For a fixed slope, the zero point of the bolometric PL relation does not depend on metallicity, contrary to recent findings of a significant metallicity term when considering the PL relation in different photometric bands. The mass-luminosity (ML) relation is derived and it points to an over luminosity of about +0.3dex with respect to a canonical ML relation. The most intriguing result concerns the flux-weighted gravity (FWG, a quantity derived from gravity and effective temperature) and its relation to period and luminosity. Both relations agree with theory, with the results for the MW, and with the independent estimates from the six known LMC eclipsing binaries that contain CCs. However, the FWG as determined from dedicated high-resolution spectroscopy for the sample is too low by about 0.8dex in 90% of the cases. Recent work on time-series data on 20 CCs in the MW was analysed to find a similar (but less extreme) offset in gravity and the FWG. Importantly, other time-series data on the same 20 CCs are in full agreement with the FWG-period relation however. The observed time-series of spectroscopic data and from a two-dimensional hydrodynamical cepheid model was used to investigate the so-called effective gravity, that is, the gravity corrected for a dynamical term related to the time derivative of the radial velocity. There is a reasonable good correspondence between the predicted effective gravity and the observed gravity as a function of pulsation phase, which potentially would allow for an independent estimate of the projection factor, but the dynamical term is too small to explain the overall difference between the observed (flux weighted) gravity, and the (flux weighted) gravity derived from the SED modelling and stellar mass estimates.2023A&A...676A.136Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/676/A136CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AcA/65/297 : OGLE4 LMC and SMC Cepheids (Soszynski+, 2015)J/ApJ/898/L7 : Predicted masses of Gal. Cepheids from Gaia (Marconi+, 2020)J/AJ/163/152 : ~650000 stars stellar parameters with APOGEE (Sprague+, 2022)J/A+A/658/A29 : LMC classical Cepheids Fe and O content (Romaniello+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/676/A136https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/676/A136http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/676/A136https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/676/A136https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/676/A136http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/676/A136GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/676/A136/table1 (stars with parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/676/A136/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/676/A136/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/676/A136/table1?GETtext/xml+votable180.050000true70.8368631-69.22994720.0055555555555555565/8274 8280 6/32955 33001 33051-33054 33073 33076-33078 33084 33094-33095 33100-33101 33103-33104 33106-33108 33110 33112-33114 33124 33126-33127 33136-33137 33144 33294-33295 33298-33299 33304 33306 33316-33318 333283.403972620454305e-19 6.228366585108648e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/676/A136?format=asciiOpticaldefaultJ/A+A/676/A136/table1stars with parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWphotindicates mean VBLUW photometry in table A2 and/or individual Walraven observations in table A1meta.ref.urlcharNameThe identifier used in this paper, which is related to the identifier used by OGLE (1)meta.id;meta.maincharHV? Harvard variable (HV) identifier, when available (SV* HV NNNNN in Simbad)meta.idintnullableprimarydThe adopted distance. For the LMC objects this includes the geometric correctionkpcpos.distancefloatAVThe adopted reddening value A_V_ based on Skowron at al, 2021ApJS..252...23S, Cat. J/ApJS/252/23, see main text.magphys.absorptionfloatTeff? Effective temperature in the literature. For references 3 and 6 an uncertainty of 100K has been adoptedKstat.error;phys.temperature.effectiveintnullablee_Teff? Effective temperature errorKstat.error;phys.temperature.effectiveintnullablelogg? log gravity in the literature. For references 3, 4 and 6 an uncertainty of 0.1dex has been adoptedlog(cm.s**-2)meta.ref;phys.gravityfloatnullablee_logg? log gravity errorlog(cm.s**-2)stat.errorfloatnullableRef? Reference for Teff and logg (2)meta.ref;pos.frameintnullableLumLuminosity with error bar from the SED fittingsolLumphys.luminosityfloate_LumLuminosity with error bar from the SED fittingsolLumstat.errorfloatTeffp(photometric) effective temperature from the SED fittingKphys.temperature.effectiveinte_Teffp(photometric) effective temperature error bar from the SED fittingKstat.errorintRRadius, derived from L and TeffsolRadphys.size.radiusfloate_RRadius error bar, derived from L and TeffsolRadstat.errorfloatMassAdopted stellar masssolMassphys.massfloate_MassAdopted stellar mass errrosolMassstat.error;phys.massfloatn_Mass[)] ) for mass and (flux-weighted) gravity are not used to calculate loggFmeta.notecharlogg2log gravity determined from mass and radiuslog(cm.s**-2)phys.gravityfloate_logg2log gravity determined from mass and radius errorlog(cm.s**-2)stat.errorfloatloggFFlux-weighted gravity calculated from from the gravity and T_eff_ (3)log(cm.s**-2)phys.gravity;meta.modelledfloate_loggFFlux-weighted gravity calculated from from the gravity and T_eff_ errorlog(cm.s**-2)stat.errorfloatrchi2The reduced chi-square of the fit to the SEDstat.fit.param;meta.modelledfloat_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.mainPerPulsation period.dtime.periodfloatSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/A+A/676/A136/tablea1Individual Walraven observations for 46 starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHVHV numbermeta.id;meta.mainintHJDHeliocentric Julian date (HJD-2400000.0)dtime.epochdoubleVmagWalraven V magnitudemagphot.mag;em.opt.VfloatV-BWalraven V-B colour indexmagphot.color;em.opt.V;em.opt.BfloatB-UWalraven B-U colour indexmagphot.color;em.opt.B;em.opt.UfloatU-WWalraven U-W colour indexmagphot.color;em.opt.U;em.opt.UfloatB-LWalraven B-L colour indexmagphot.color;em.opt.B;em.opt.UfloatQFlagQuality flag in the VBLUW bands, respectively (1)meta.code.qualintJ/A+A/676/A136/tablea2Mean VBLUW photometrye_VmagWalraven V magnitude errormagstat.error;phot.magfloatAmpVAmplitude in Walraven V magnitudemagsrc.var.amplitudefloate_AmpVAmplitude in Walraven V magnitudemagstat.errorfloato_VmagNumber of data points in Walraven V filtermeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHVHV number (1)meta.id;meta.mainintVmagWalraven V magnitudemagphot.mag;em.opt.VfloatBmag? Walraven B magnitudemagphot.mag;em.opt.Bfloatnullablee_Bmag? Walraven B magnitude errormagstat.error;phot.magfloatnullableAmpB? Amplitude in Walraven B magnitudemagsrc.var.amplitudefloatnullablee_AmpB? Amplitude in Walraven B magnitude errormagstat.errorfloatnullableo_Bmag? Number of data points in Walraven B filtermeta.numberintnullableLmag? Walraven L magnitudemagphot.mag;em.opt.Ufloatnullablee_Lmag? Walraven L magnitude errormagstat.error;phot.magfloatnullableAmpL? Amplitude in Walraven L magnitudemagsrc.var.amplitudefloatnullablee_AmpL? Amplitude in Walraven L magnitude errormagstat.errorfloatnullableo_Lmag? Number of data points in Walraven L filtermeta.numberintnullableUmag? Walraven U magnitudemagphot.mag;em.opt.Ufloatnullablee_Umag? Walraven U magnitude errormagstat.error;phot.magfloatnullableAmpU? Amplitude in Walraven U magnitudemagsrc.var.amplitudefloatnullablee_AmpU? Amplitude in Walraven U magnitude errormagstat.errorfloatnullableo_Umag? Number of data points in Walraven U filtermeta.numberintnullableWmag? Walraven W magnitudemagphot.mag;em.opt.Ufloatnullablee_Wmag? Walraven W magnitude errormagstat.error;phot.magfloatnullableAmpW? Amplitude in Walraven W magnitudemagsrc.var.amplitudefloatnullablee_AmpW? Amplitude in Walraven W magnitude errormagstat.errorfloatnullableo_Wmag? Number of data points in Walraven W filtermeta.numberintnullableJ/A+A/676/A136/tableb1Different mass estimatesPerPerioddtime.periodfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIdentifier (sources are sorted by period)meta.id;meta.maincharMass1Mass estimate from the period-luminosity-mass-effective_temperature- metallicity relation (1)solMassphys.massfloate_Mass1Error on Mass1solMassstat.errorfloatMass2Mass estimate from Eq. (1), based on the models of Anderson et al. (2016A&A...591A...8A)solMassphys.massfloate_Mass2Error on Mass2solMassstat.errorfloatMass3Mass estimate from the relation in Ragosta et al. (2019MNRAS.490.4975R)solMassphys.massfloate_Mass3Error on Mass3solMassstat.errorfloatMass4Mass estimate from the relation in Pilecki et al. (2018ApJ...862...43P)solMassphys.massfloate_Mass4Error on Mass4solMassstat.errorfloatMass5Mass estimate from the relation in Marconi et al. (2020ApJ...898L...7M, Cat. J/ApJ/898/L7)solMassphys.massfloate_Mass5Error on Mass5solMassstat.errorfloatMassAdopted mass based on the median and the MAD (see text)solMassphys.massfloate_MassError on MasssolMassstat.error;phys.massfloatn_Mass[)] Note on Mass (2)meta.notechar