J/A+A/591/A145ivo://CDS.VizieR/J/A+A/591/A145doi:10.26093/cds/vizier.35910145CDSGran F.Minniti D.Saito R.K.Zoccali M.Gonzalez O.A.Navarrete C.,Catelan M.Contreras Ramos R.Elorrieta F.Eyheramendy S.Jordan A.2018-04-09T15:03:09Z2016-10-24T14:35:12ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyvariable-starsinfrared-sourcesThe VISTA Variables in the Via Lactea (VVV) is a near-IR time-domain survey of the Galactic bulge and southern plane. One of the main goals of this survey is to reveal the 3D structure of the Milky Way through their variable stars. In particular, enormous numbers of RR Lyrae stars have been discovered in the inner regions of the bulge (-8{deg}<~b<~-1{deg}) by optical surveys such as OGLE and MACHO, but leaving an unexplored window of more than ~47 sq deg (-10.0{deg}<~l<~+10.7{deg} and -10.3{deg}<~b<~-8.0{deg}) observed by the VVV Survey. Our goal is to characterize the RR Lyrae stars in the outer bulge in terms of their periods, amplitudes, Fourier coefficients, and distances in order to evaluate the 3D structure of the bulge in this area. The distance distribution of RR Lyrae stars will be compared to that of red clump stars, which is known to trace a X-shaped structure, in order to determine whether these two different stellar populations share the same Galactic distribution. A search for RR Lyrae stars was performed in more than ~47 sq deg at low Galactic latitudes (-10.3{deg}<~b<~-8.0{deg}). In the procedure the {chi}^2^ value and analysis of variance (AoV) statistic methods were used to determine the variability and periodic features of the light curves, respectively. To prevent misclassifications, the analysis was performed only on the fundamental mode RR Lyrae stars (RRab) owing to similarities found in the near-IR light curve shapes of contact eclipsing binaries (W UMa) and first overtone RR Lyrae stars (RRc). On the other hand, the red clump stars of the same analyzed tiles were selected, and cuts in the color-magnitude diagram were applied and the maximum distance restricted to ~20kpc in order to construct a similar catalog in terms of distances and covered area compared to the RR Lyrae stars. We report the detection of more than 1000 RR Lyrae ab-type stars in the VVV Survey located in the outskirts of the Galactic bulge. A few of them are possibly associated with the Sagittarius Dwarf Spheroidal Galaxy. We calculated colours, reddening, extinction, and distances of the detected RR Lyrae stars in order to determine the outer bulge 3D structure. Our main result is that, at the low galactic latitudes mapped here, the RR Lyrae stars trace a centrally concentrated spheroidal distribution. This is a noticeably different spatial distribution to the one traced by red clump stars known to follow a bar and X-shaped structure. We estimate the completeness of our sample at 80% for K_s_<=15mag.2016A&A...591A.145Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/591/A145CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)II/337 : VISTA Variables in the Via Lactea Survey DR1 (Minniti+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/591/A145https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/591/A145http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/591/A145https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/591/A145https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/591/A145http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/591/A145GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/591/A145/tablea1 (VVV RRab variables)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/591/A145/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/591/A145/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/591/A145/tablea1?GETtext/xml+votable180.050000true268.7462917-41.52697220.0055555555555555565/7168-7169 7172-7173 7184-7185 7187 7190-7191 7234-7235 7241 11946-11947 6/28700-28701 28744-28745 28752 28754-28755 28758-28759 28788-28789 28954 28960-28961 28963 28976 42325 42327 47802-47803 47806-47807 47850https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/591/A145?format=asciiInfrareddefaultJ/A+A/591/A145/tablea1VVV RRab variablesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVVVVVV designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_VVV[* ] indicates stars matched in GCVS (*) or OGLE-IV (**) in tablea2meta.notecharRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainGLON[] Galactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latfloatKsmagKs magnitudemagphot.mag;em.IR.KfloatPerPerioddtime.perioddoubleAmpAmplitude of variationmagarith.rate;phot.magfloatDistDistancekpcpos.distance;pos.heliocentricfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/591/A145/tablea2207 VVV RRab matching a variable in the General Cataloge of Variable Stars (GCVS) and 3 VVV RRab previously discovered by OGLE-IVGCVSGCVS namemeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVVVCorrect VVV designation (JHHMMSS.ss+DDMMSS.s) (added by CDS)meta.id;meta.maincharOGLEOGLE-IV designation (OGLE-BLG-RRLYR-NNNN)meta.idcharvvvErroneous VVV name, as in original table2meta.idcharSimbadSimbad column added by the CDSmeta.ref.urlchar