J/MNRAS/447/2404ivo://CDS.VizieR/J/MNRAS/447/2404doi:10.26093/cds/vizier.74472404CDSPancino E.Britavskiy N.Romano D.Cacciari C.Mucciarelli A.,Clementini G.2024-08-14T20:19:41Z2015-02-26T13:17:03ZCDS support team

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

cds-question@unistra.frvariable-starsspectroscopyline-intensitiesWe have analysed a sample of 18 RR Lyrae stars (17 fundamental-mode - RRab - and one first overtone - RRc) and three Population II Cepheids (two BL Her stars and one W Vir star), for which high-resolution (R>=30000), high signal-to-noise (S/N>=30) spectra were obtained with either SARG at the Telescopio Nazionale Galileo (La Palma, Spain) or UVES at the ESO Very Large Telescope (Paranal, Chile). Archival data were also analyzed for a few stars, sampling >~3 phases for each star. We obtained atmospheric parameters (T_eff_, logg, v_t_, and [M/H]) and abundances of several iron-peak and {alpha}-elements (Fe, Cr, Ni, Mg, Ca, Si, and Ti) for different pulsational phases, obtaining <[{alpha}/Fe]>=+0.31+/-0.19dex over the entire sample covering -2.2<[Fe/H]<-1.1dex. We find that silicon is indeed extremely sensitive to the phase, as reported by previous authors, and cannot be reliably determined. Apart from this, metallicities and abundance ratios are consistently determined, regardless of the phase, within 0.10-0.15 dex, although caution should be used in the range 0<~{phi}<~0.15. Our results agree with literature determinations for both variable and non-variable field stars, obtained with very different methods, including low and high-resolution spectroscopy. W Vir and BL Her stars, at least in the sampled phases, appear indistinguishable from RRab from the spectroscopic analysis point of view. Our large sample, covering all pulsation phases, confirms that chemical abundances can be obtained for RR Lyrae with the classical EW-based technique and static model atmospheres, even rather close to the shock phases.2015MNRAS.447.2404Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/447/2404CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/447/2404https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/447/2404http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/447/2404https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/447/2404https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/447/2404http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/447/2404GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/447/2404/table1 (Basic information for the programme stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/447/2404/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/447/2404/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/447/2404/table1?GETtext/xml+votable180.050000true16.29462534.21841670.0055555555555555566/110 2238 4762 10584 10898 11098 15281 16867 17745 26288 26981 28155 28582 30927 31743 35423 36705 40767 45337 46069 48880https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/447/2404?format=asciiOpticaldefaultJ/MNRAS/447/2404/table1Basic information for the programme starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharprimaryn_Star[*] Note on Star (2)meta.notecharRAJ2000Right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)pos.eq.dec;meta.mainTypeVariable type (1)meta.code;src.varcharType2Alternative variable type (1)meta.code;src.varcharNoNumber of observations for this starmeta.numberintnullableNwNumber of equivalent widths for this starmeta.numberintnullableVmin[8.9/12.4] Minimum value of V magnitude (1)magphot.mag;em.opt.VfloatVmax[9.9/13.4] Maximum value of V magnitude (1)magphot.mag;em.opt.VfloatT0Epoch of maximum light (JD-2400000) (3)dtime.epochdoublePerPerioddtime.perioddoubleAVAbsorption in V bandmagphot.mag;em.opt.Vfloatn_AV[)] Origin of AV (4)meta.notechar[Fe/H]1[-2.5/-0.8]? Metallicity from Kinemuchi et al. 2006 (J/AJ/132/1202) (5)log(Sun)phys.abund.Fefloatnullablee_[Fe/H]1? rms uncertainty on [Fe/H]K06log(Sun)stat.error;phys.abund.Fefloatnullable[Fe/H]2[-2.5/-0.8] Metallicity from Beers et al. (2000, Cat. J/AJ/119/2866) (5)log(Sun)phys.abund.FefloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/447/2404/table2Observing logsn_Exp[*] * indicates archival spectrameta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharInstInstrumentmeta.id;instrcharExp[1/10] Exposure number for star+instrumentmeta.idintObsDateObservation date (HJD-2400000)dtime.epoch;obsdoublePhase[0/1] Phasetime.phasefloattexp[3/60] Exposure timemintime.duration;obs.exposurefloatS/N[20/160] Signal-to-noise ratio (at 600nm)stat.snrintJ/MNRAS/447/2404/table4Equivalent wodths and atomic data for individual program stars spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharInstInstrument namemeta.id;instrcharExp[0/9] Exposure number for star+instrumentmeta.idintlambda[4620/7946] Wavelength {lambda} in Angstroms0.1nmem.wldoubleIonElement name and ionization stagephys.atmol.ionStagecharEW[6/111] Equivalent width in milliAngstroms0.1pmspect.line.eqWidthdoublee_EWError on EW in milliAngstroms0.1pmstat.error;spect.line.eqWidthfloatloggfLogarithm of the oscillator strengthphys.atmol.oscStrengthdoubleEPExcitation potential {chi}eVphys.atmol.excitationdouble