J/A+A/687/A312ivo://CDS.VizieR/J/A+A/687/A312doi:10.26093/cds/vizier.36870312CDSOlivares Carvajal J.Zoccali M.De Leo M.Contreras Ramos R.Quezada C.,Rojas-Arriagada A.Valenti E.Albarracin R.Valenzuela Navarro A.2024-11-29T20:04:11Z2024-07-30T09:38:44ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyvariable-starsradial-velocityinfrared-photometrymetallicityThe structure and kinematics of the old component of the Galactic bulge are still a matter of debate. It is clear that the bulk of the bulge as traced by red clump stars includes two main components, which are usually identified as the metal-rich and metal-poor components. They have different shapes, kinematics, mean metallicities, and alpha-element abundances. It is our current understanding that they are associated with a bar and a spheroid, respectively. On the other hand, RR Lyrae variables trace the oldest population of the bulge. While it would be natural to think that they follow the structure and kinematics of the metal-poor component, the data analysed in the literature show conflicting results. We aim to derive a rotation curve for bulge RR Lyrae stars in order to determine that the old component traced by these stars is distinct from the two main components observed in the Galactic bulge. This paper combines APOGEE-2S spectra with OGLE-IV light curves, near-IR photometry, and proper motions from the VISTA Variables in the Via Lactea survey for 4193 RR Lyrae stars. Six-dimensional phase-space coordinates were used to calculate orbits within an updated Galactic potential and to isolate the stars. The stars that stay confined within the bulge represent 57% of our sample. Our results show that bulge RR Lyrae variables rotate more slowly than metal-rich red clump stars and have a lower velocity dispersion. Their kinematics is compatible with them being the low-metallicity tail of the metal-poor component. We confirm that a rather large fraction of halo RR Lyrae stars pass by the bulge within their orbits, increasing the velocity dispersion. A proper orbital analysis is therefore critical to isolate bona fide bulge variables. Finally, bulge RR Lyrae seem to trace a spheroidal component, although the current data do now allow us to reach a firm conclusion about the spatial distribution.2024A&A...687A.312Ohttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/687/A312CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AcA/69/321 : OGLE RR Lyrae stars in Galactic bulge & disk (Soszynski+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/687/A312https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/687/A312http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/687/A312https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/687/A312https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/687/A312http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/687/A312GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/687/A312/table1 (Observational parameters of the RRLs in our sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/687/A312/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/687/A312/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/687/A312/table1?GETtext/xml+votable180.050000true261.08221889-29.1186870.0055555555555555564/1803 5/7178-7180 7182-7183 7192 7194-7195 7205 7209 7211 7216-7217 7226-7227 7230 7312-7313 6/28698-28699 28707 28709-28711 28724 28726-28727 28772 28774-28775 28792 28794 28801 28804-28805 28816-28817 28819 28828-28829 28835 28841 28872-28873 28876-28877 28880 28882 28888 28896 28898-28899 28902-28903 28914 29200-29201 29205 29207 29260 29264-292667.952274030004205e-20 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/687/A312?format=asciiInfrareddefaultJ/A+A/687/A312/table1Observational parameters of the RRLs in our sampleSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOGLEOGLE identifier, OGLE BLG-RRLYR-NNNNN in Simbadmeta.id;meta.mainintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainVsystSystemic radial velocitykm/sphys.velocfloate_VsystSystemic radial velocity errorkm/sstat.errorfloatVGCGalactocentric radial velocitykm/sspect.dopplerVeloc;pos.galactocentricfloatKsmagMean magnitude in the Ks bandmagphot.mag;em.IR.KfloatJmagMean magnitude in the J bandmagphot.mag;em.IR.Jfloat[Fe/H]? Photometric metallicityphys.abund.Zfloatnullablee_[Fe/H]? Photometric metallicity errorstat.error;phys.abund.FefloatnullablepmlProper motion in Galactic longitudemas/yrpos.pm;pos.galactic.lonfloate_pmlProper motion error in Galactic longitudemas/yrstat.errorfloatpmbProper motion in Galactic latitudemas/yrpos.pm;pos.galactic.latfloate_pmbProper motion error in Galactic latitudemas/yrstat.errorfloatDistDistancekpcpos.distancefloate_Dist? Distance errorkpcstat.errorfloatnullableFlag[012] Quality flag (1)meta.code.errorcharJ/A+A/687/A312/table2Orbital parameters derived for the RRLsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOGLEOGLE identifiermeta.id;meta.mainintEtotTotal energykm**2.s**-2phys.energydoubleLzAngular momentum in Zkpc.km/sphys.angMomentumfloatApoApocenter radiuskpcphys.size.radiusfloatPeriPericenter radiuskpcphys.size.radiusfloatZmaxMaximun heightkpcpos.cartesian.x;pos.galacticfloatEccEccentricitysrc.orbital.eccentricityfloatTime2.5Time percentage within a radius of 2.5kpc%stat.fit.paramfloat