HST VI photometry and proper motions in NGC 6528J/A+A/385/67ivo://CDS.VizieR/J/A+A/385/67doi:10.26093/cds/vizier.33850067CDSFeltzing S.Johnson R.A.2012-11-13T12:40:53Z2002-07-13T21:20:23ZCDS support team
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
cds-question@unistra.frglobular-star-clustersphotometryproper-motionsUsing two epochs of HST/WFPC2 images of the metal-rich globular cluster NGC 6528 we derive the proper motions of the stars and use them to separate the stars belonging to NGC 6528 from those of the Galactic bulge. The stellar sequences in the resulting colour-magnitude diagram for the cluster are significantly better determined than in previously published data. From comparison of the colour-magnitude diagram with the fiducial line for NGC 6553 from Zoccali et al. (2001AJ....121.2638Z) we conclude that the two globular clusters have the same age. Further, using alpha-enhanced stellar isochrones, NGC 6528 is found to have an age of 11+/-2Gyr. This fitting of isochrones also give that the cluster is 7.2kpc away from us. From the measured velocities both the proper motion of the cluster and the velocity dispersion in the Galactic bulge are found. NGC 6528 is found to have a proper motion relative to the Galactic bulge of <mu_l_>=0.006 and <mu_b_>=0.044 arcsec per century. Using stars with 14<V_555_<19 (i.e. the red giant branch and horizontal branch) we find, for the Galactic bulge, sigma_l_=0.33+/-0.03 and sigma_b_=0.25+/-0.02 arcsec per century. This give sigma_l/sigma_b=1.32+/-0.16, consistent both with previous proper motion studies of K giants in the Galactic bulge as well as with predictions by models of the kinematics of bulge stars.2002A&A...385...67Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/385/67CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+AS/127/167 : V,I CCD photometry of NGC 6528 (Richtler+ 1998)J/AJ/84/1305 : UBV photometry in NGC 6528 (van den Bergh+, 1979)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/385/67https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/385/67http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/385/67https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/385/67https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/385/67http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/385/67GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/385/67/tablea1 (Stellar data derived in this work from WF2-chip)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/385/67/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/385/67/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/385/67/tablea1?GETtext/xml+votable180.050000true271.18937-30.043490.005555555555555556Cone search capability for table J/A+A/385/67/tablea2 (Stellar data derived in this work from WF3-chip)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/385/67/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/385/67/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/385/67/tablea2?GETtext/xml+votable180.050000true271.20978-30.048750.005555555555555556Cone search capability for table J/A+A/385/67/tablea3 (Stellar data derived in this work from WF4-chip)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/385/67/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/385/67/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/385/67/tablea3?GETtext/xml+votable180.050000true271.2062-30.058440.0055555555555555566/287782.0401237512456292e-19 4.2441532724171825e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/385/67?format=asciiOpticaldefaultJ/A+A/385/67/tablea1Stellar data derived in this work from WF2-chiprecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpmGLONProper motion in galactic longitude10mas/yrpos.pm;pos.galactic.lonfloatpmGLATProper motion in galactic latitude10mas/yrpos.pm;pos.galactic.latfloatGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latpmXProper motion in x coordinate on the chippixpos.cartesian.x;instr.detfloatpmYProper motion in y coordinate on the chippixpos.cartesian.y;instr.detfloatXposX coordinate on the WFPC2 chippixpos.cartesian.x;instr.detfloatYposY coordinate on the WFPC2 chippixpos.cartesian.y;instr.detfloatV555magMagnitude in F555W (HST in-flight system)magphot.mag;em.opt.Vfloate_V555magMagnitude error in V555magmagstat.error;phot.mag;em.opt.VfloatI814magMagnitude in F814W (HST in-flight system)magphot.mag;em.opt.Ifloate_I814magMagnitude error in I814magmagstat.error;phot.mag;em.opt.Ifloat_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into account (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into account (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed
J/A+A/385/67/tablea2Stellar data derived in this work from WF3-chipXposX coordinate on the WFPC2 chippixpos.cartesian.x;instr.detfloatYposY coordinate on the WFPC2 chippixpos.cartesian.y;instr.detfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpmGLONProper motion in galactic longitude10mas/yrpos.pm;pos.galactic.lonfloatpmGLATProper motion in galactic latitude10mas/yrpos.pm;pos.galactic.latfloatGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latpmXProper motion in x coordinate on the chippixpos.cartesian.x;instr.detfloatpmYProper motion in y coordinate on the chippixpos.cartesian.y;instr.detfloatV555magMagnitude in F555W (HST in-flight system)magphot.mag;em.opt.Vfloate_V555magMagnitude error in V555magmagstat.error;phot.mag;em.opt.VfloatI814magMagnitude in F814W (HST in-flight system)magphot.mag;em.opt.Ifloate_I814magMagnitude error in I814magmagstat.error;phot.mag;em.opt.Ifloat_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into account (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into account (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed
J/A+A/385/67/tablea3Stellar data derived in this work from WF4-chiprecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintpmGLONProper motion in galactic longitude10mas/yrpos.pm;pos.galactic.lonfloatpmGLATProper motion in galactic latitude10mas/yrpos.pm;pos.galactic.latfloatGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latpmXProper motion in x coordinate on the chippixpos.cartesian.x;instr.detfloatpmYProper motion in y coordinate on the chippixpos.cartesian.y;instr.detfloatXposX coordinate on the WFPC2 chippixpos.cartesian.x;instr.detfloatYposY coordinate on the WFPC2 chippixpos.cartesian.y;instr.detfloatV555magMagnitude in F555W (HST in-flight system)magphot.mag;em.opt.Vfloate_V555magMagnitude error in V555magmagstat.error;phot.mag;em.opt.VfloatI814magMagnitude in F814W (HST in-flight system)magphot.mag;em.opt.Ifloate_I814magMagnitude error in I814magmagstat.error;phot.mag;em.opt.Ifloat_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into account (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into account (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed