J/A+A/555/A91ivo://CDS.VizieR/J/A+A/555/A91doi:10.26093/cds/vizier.35550091CDSVasquez S.Zoccali M.Hill V.Renzini A.Gonzalez O.A.Gardner E.,Debattista Victor P.Robin A.C.Rejkuba M.Baffico M.Monelli M.,Motta V.Minniti D.2014-01-18T13:19:54Z2014-01-18T13:07:31ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyradial-velocityinfrared-photometryvisible-astronomyphotometrygiant-starsThe Galactic bulge is X-shaped, caused by the two southern arms of the X both crossing the lines of sight, producing a double red clump (one bright and one faint) in the color magnitude diagram. In this paper the authors measure the radial velocities and proper motions for a sample of 454 individual bulge giant stars, roughly equally distributed between the two red clumps to determine how such a structure could be formed from bar instabilities. The radial velocity distribution of stars in the bright red clump, which traces the closer overdensity of bulge stars, shows an excess of stars moving towards the Sun. Similarly, an excess of stars receding from the Sun is seen in the more distant overdensity, which is traced by faint red clump stars. This can be explained by the presence of stars on elongated orbits, which are most likely streaming along the arms of the X-shaped bulge. Proper motions for these stars are consistent with qualitative predictions of dynamical models of peanut-shaped bulges. Surprisingly, stars on elongated orbits have preferentially metal-poor (subsolar) metallicities, while the metal rich ones, in both overdensities, are preferentially found in more axisymmetric orbits.2013A&A...555A..91Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/555/A91CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/317 : The PPMXL Catalog (Roeser+ 2010)II/270 : TCS-CAIN: NIR Survey of the Galactic plane (Cabrera-Lavers+, 2006)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/MNRAS/421/3362 : Kinematics of galactic red clump stars (Bilir+, 2012)J/AJ/143/57 : New RVs from the spectroscopic survey BRAVA II (Kunder+, 2012)J/A+A/546/A57 : Spectroscopy of red giants in the Bulge (Uttenthaler+, 2012)J/A+A/534/A91 : Galactic Bulge Valinhos Observatory Catalog (Teixeira+, 2011)J/A+A/534/A80 : Metallicity of clump giants in Baade's window (Hill+, 2011)J/A+A/530/A54 : Abundances of 650 bulge red giants (Gonzalez+, 2011)J/A+A/527/A40 : Faint Galactic red clump stars (Saguner+, 2011)J/ApJ/732/108 : Abundances of 92 giants in Plaut's window (Johnson+, 2011)J/AcA/61/83 : OGLE-III photometric maps of Galactic Bulge (Szymanski+, 2011)J/A+A/522/A79 : High-Galactic-latitude red clump stars (Valentini+, 2010)J/ApJ/721/L28 : Red clump stars in Galactic Bulge from OGLE-III (Nataf+, 2010)J/ApJ/691/1387 : Spectroscopy of the Galactic bar. I. (Rangwala+, 2009)J/A+A/486/177 : Bulge field stars from FLAMES-GIRAFFE spectra (Zoccali+, 2008)J/AJ/134/1432 : Proper motions in Plaut's window (Vieira+, 2007)J/MNRAS/348/1439 : OGLE II Galactic center proper motions (Sumi+, 2004)J/MNRAS/340/1346 : Bulge SC1 proper motions (Sumi+, 2003)J/A+A/385/67 : HST VI photometry & PMs in NGC 6528 (Feltzing+, 2002)J/AJ/112/171 : K Giants in Baade's Window. II (Sadler+ 1996)J/AJ/110/1774 : K giants in Baade's window (Terndrup+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/555/A91https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/555/A91http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/555/A91https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/555/A91https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/555/A91http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/555/A91GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/555/A91/bulge_rc (Kinematics for bulge red clump stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/555/A91/bulge_rc?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/555/A91/bulge_rc?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/555/A91/bulge_rc?GETtext/xml+votable180.050000true272.4809583-31.98920.0055555555555555566/28768 287707.952274030004205e-20 3.9865436196254505e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/555/A91?format=asciiOpticalInfrareddefaultJ/A+A/555/A91/bulge_rcKinematics for bulge red clump starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Pointing hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Pointing degree of declination (J2000)pos.eq.dec;meta.mainRA1deg? Right ascension for epoch 1 (J2000) (1)degpos.eq.ranullableDE1deg? Declination for epoch 1 (J2000) (1)degpos.eq.decnullableRA2deg? Right ascension for epoch 2 (J2000) (1)degpos.eq.ranullableDE2deg? Declination for epoch 2 (J2000) (1)degpos.eq.decnullableVmag[16.1/17.3] ESO WFI V-band magnitudemagphot.mag;em.opt.VfloatImag[14.7/15.5] ESO WFI Ic-band magnitudemagphot.mag;em.opt.IfloatJmag? J-band magnitudemagphot.mag;em.IR.JfloatnullableHmag? H-band magnitudemagphot.mag;em.IR.HfloatnullableKmag? K-band magnitudemagphot.mag;em.IR.KfloatnullableHRV[-347.4/267.7] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[0.4/3.3] Heliocentric radial velocity errorkm/sstat.errorfloat2MDisplay the 2MASS data within 0.5" (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar