J/ApJ/807/127ivo://CDS.VizieR/J/ApJ/807/127doi:10.26093/cds/vizier.18070127CDSMuraveva T.Palmer M.Clementini G.Luri X.Cioni M.-R.L.,Moretti M.I.Marconi M.Ripepi V.Rubele S.2017-11-03T13:02:17Z2017-09-27T09:11:07ZCDS support team

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

cds-question@unistra.frvariable-starsmagellanic-cloudsmetallicityinfrared-photometryWe present results of the analysis of 70 RR Lyrae stars located in the bar of the Large Magellanic Cloud (LMC). Combining the spectroscopically determined metallicity of these stars from the literature with precise periods from the OGLE III catalog (Soszynski et al. 2009, J/AcA/59/1) and multi-epoch K_s_ photometry from the VISTA survey of the Magellanic Clouds system, we derive a new near-infrared period-luminosity-metallicity (PL_Ks_Z) relation for RR Lyrae variables. In order to fit the relation we use a fitting method developed specifically for this study. The zero-point of the relation is estimated two different ways: by assuming the value of the distance to the LMC and by using Hubble Space Telescope parallaxes of five RR Lyrae stars in the Milky Way (MW). The difference in distance moduli derived by applying these two approaches is ~0.2 mag. To investigate this point further we derive the PL_Ks_Z relation based on 23 MW RR Lyrae stars that had been analyzed in Baade-Wesselink studies. We compared the derived PL_Ks_Z relations for RR Lyrae stars in the MW and LMC. Slopes and zero-points are different, but still consistent within the errors. The shallow slope of the metallicity term is confirmed by both LMC and MW variables. The astrometric space mission Gaia is expected to provide a huge contribution to the determination of the RR Lyrae PL_Ks_Z relation; however, calculating an absolute magnitude from the trigonometric parallax of each star and fitting a PL_Ks_Z relation directly to period and absolute magnitude leads to biased results. We present a tool to achieve an unbiased solution by modeling the data and inferring the slope and zero-point of the relation via statistical methods.2015ApJ...807..127Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/807/127CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/145/11 : AGAPEROS: variable stars in the LMC Bar (Melchior+, 2000)J/AcA/53/93 : OGLE RR Lyrae in LMC (Soszynski+, 2003)J/A+A/421/937 : Metal abundances of LMC RR Lyrae (Gratton+, 2004)J/A+A/430/603 : BVI photometry of LMC bar variables (Di Fabrizio+, 2005)J/A+A/502/505 : Ks photometry of LMC RR Lyrae (Borissova+, 2009)J/AcA/59/1 : VI light curves of LMC RR Lyrae stars (Soszynski+, 2009)J/MNRAS/437/2702 : MC Cepheids, RR Lyrae stars and binaries (Moretti+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/807/127https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/807/127http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/807/127https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/807/127https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/807/127http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/807/127GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/807/127/table1 (Properties of the 70 RR Lyrae Stars in the Bar of the LMC Analyzed in This Paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/807/127/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/807/127/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/807/127/table1?GETtext/xml+votable180.050000true80.5272917-70.46544440.0055555555555555566/33052 33053 33054https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/807/127?format=asciiInfrareddefaultJ/ApJ/807/127/table1Properties of the 70 RR Lyrae Stars in the Bar of the LMC Analyzed in This PaperrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar identification from Di Fabrizio et al. (2005, J/A+A/430/603) (ANNNNN, BNNNNN) (1)meta.id;meta.maincharOGLEOGLE identification (2)meta.idcharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainType[RRc RRab] Subtype of RR Lyr starsrc.classchar[Fe/H]Metallicity from Gratton et al. (2004, J/A+A/421/937)log(Sun)phys.abund.Zfloate_[Fe/H]Uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.FefloatPerPeriod (2)dtime.perioddoubleKsmagDereddened mean K_s_ magnitude (3)magphot.mag;em.IR.Kfloate_KsmagUncertainty in Ksmagmagstat.error;phot.mag;em.IR.KfloatSimbadSimbad column added by the CDSmeta.ref.urlchar