Radial Velocities of Stars in M4J/ApJ/443/124ivo://CDS.VizieR/J/ApJ/443/124doi:10.26093/cds/vizier.14430124CDSPeterson R.C.Rees R.F.Cudworth K.M.2013-03-05T06:34:44Z1997-12-09T20:52:29ZCDS support team
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
cds-question@unistra.frglobular-star-clustersradial-velocityastrometryphotometryThe internal stellar velocity distribution of the globular cluster M4 is evaluated from nearly 200 new radial velocity measurements good to 1 km/s and a rederivation of existing proper motions. The mean radial velocity of the cluster is 70.9 +/- 0.6 km/s. The velocity dispersion is 3.5 +/- 0.3 km/s at the core, dropping marginally towards the outskirts. Such a low internal dispersion is somewhat at odds with the cluster's orbit, for which the perigalacticon is sufficiently close to the galactic center that the probability of cluster disruption is high; a tidal radius two-thirds the currently accepted value would eliminate the discrepancy. The cluster mass-to-light ratio is also small, M/L_V = 1.0 +/- 0.4 in solar units. M4 thus joins M22 as a cluster of moderate mass and concentration with a mass-to-light ratio among the lowest known. The astrometric distance to the cluster is also smaller than expected, 1.72 +/- 0.14 kpc. This is only consistent with conventional estimates of the luminosity of horizontal branch stars provided an extinction law R = A_V/E(B-V) ~ 4 is adopted, as has been suggested recently by several authors.1995ApJ...443..124Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/443/124CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/443/124https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/443/124http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/443/124https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/443/124https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/443/124http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/443/124GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/443/124/table1 (Velocities for M4 members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/443/124/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/443/124/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/443/124/table1?GETtext/xml+votable180.050000true245.6628689-26.57875010.005555555555555556Cone search capability for table J/ApJ/443/124/table2 (*Velocities for M4 nonmembers)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/443/124/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/443/124/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/443/124/table2?GETtext/xml+votable180.050000true245.7548078-26.39161960.0055555555555555566/42955https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/443/124?format=asciiOpticaldefaultJ/ApJ/443/124/table1Velocities for M4 membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA1950Right ascension (equinox 1950.0)pos.eq.ra;meta.mainDE1950Declination (equinox 1950.0)pos.eq.dec;meta.mainDistRadial distance from cluster centerarcminphys.angSizefloatPAPosition angle positive north through eastdegpos.posAngfloatVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colormagphot.color;em.opt.B;em.opt.VfloatDateJulian date of each observationdtime.epoch;obsdoubleRVMeasured radial velocitykm/sphys.veloc;pos.heliocentricfloate_RVInternal uncertainty in RVkm/sstat.errorfloatMemb[]? Percent probability of membership%statintnullableIDIdentificationmeta.id;meta.mainchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexed
J/ApJ/443/124/table2*Velocities for M4 nonmembersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA1950Right ascension (equinox 1950.0)pos.eq.ra;meta.mainDE1950Declination (equinox 1950.0)pos.eq.dec;meta.mainDistRadial distance from cluster centerarcminphys.angSizefloatPAPosition angle positive north through eastdegpos.posAngfloatVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colormagphot.color;em.opt.B;em.opt.VfloatDateJulian date of each observationdtime.epoch;obsdoubleRVMeasured radial velocitykm/sphys.veloc;pos.heliocentricfloate_RVInternal uncertainty in RVkm/sstat.errorfloatMemb[]? Percent probability of membership%statintnullableIDIdentificationmeta.id;meta.mainchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)pos.eq.decnullableindexed
J/ApJ/443/124/table3Duplicate velocitiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateJulian date of each observationdtime.epoch;obsdoubleRVMeasured radial velocitykm/sphys.veloc;pos.heliocentricfloate_RVInternal uncertainty in RVkm/sstat.errorfloatIDNumber from Lee 1977, A&AS, 27, 367meta.id;meta.mainchar
J/ApJ/443/124/table5Proper-motion data superseding Table 3 of Cudworth & Rees =1990AJ.....99.1491CrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNamesStar namesmeta.id;meta.maincharXX coordinate relative to cluster centerarcsecpos.cartesian.x;instr.platefloatYY coordinate relative to cluster centerarcsecpos.cartesian.y;instr.platefloatmu_xRelative proper motion in X coordinatemas/yrpos.pm;pos.cartesian.xfloate_mu_xStandard error in mu_xmas/yrstat.errorfloatmu_yRelative proper motion in Y coordinatemas/yrpos.pm;pos.cartesian.yfloate_mu_yStandard error in mu_ymas/yrstat.errorfloatVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colormagphot.color;em.opt.B;em.opt.VfloatPrProbability of membership based on relative proper motion%statint