J/A+A/324/505ivo://CDS.VizieR/J/A+A/324/505doi:10.26093/cds/vizier.33240505CDSDubath P.Meylan G.Mayor M.1997-12-09T17:00:29Z1997-12-09T18:00:26ZCDS support team

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

cds-question@unistra.frglobular-star-clustersradial-velocitygalaxy-kinematicsWe present, for 25 Galactic and 10 old Magellanic globular clusters, projected velocity dispersion ({sigma}_p_) measurements obtained by applying a cross-correlation technique to integrated-light spectra. In order to understand and estimate the statistical errors of these measurements due to small numbers of bright stars dominating the integrated light, we provide an extensive discussion based on detailed numerical simulations. These errors are smaller if the integration area is larger and/or the cluster concentration higher. The simulations show that measurements are reliable when the integrated light within the integration area is brighter than a given magnitude. The statistical errors on the {sigma}_p_ measurements of Magellanic globular clusters are small because of a physically large integration area, whereas they can be important for measurements carried out over small central areas in Galactic clusters. The present observational results are used to outline a few characteristics of the globular cluster fundamental plane. In this respect, the old Magellanic globular clusters appear similar to the Galactic clusters.1997A&A...324..505Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/324/505CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/324/505https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/324/505http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/324/505https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/324/505https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/324/505http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/324/505GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/324/505/table67Radial velocities and core velocity dispersionse_HRVrms uncertainty on HRVkm/sstat.errorfloatObsObservation numbermeta.id;obscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLocLocalication (Gal, LMC or SMC)meta.id.parentcharNGCNGC numbermeta.id;meta.maincharHRVDerived heliocentric radial velocitykm/sphys.veloc;pos.heliocentricfloatsigCCFStandard deviation of the cross-correlation function (CCF)km/sstat.stdevfloate_sigCCFrms uncertainty on sigCCFkm/sstat.errorfloatDepthRelative depth of the CCF%phot.flux.density;arith.ratiofloatS/NSignal-to-noise ratio of the spectrumstat.snrfloatepsUncertainty epsilon of HRV and sigCCF due to the spectrum noisekm/sstat.errorfloatsigrefValue used for the intrinsic standard deviation from the standard CCFskm/sstat.stdevfloate_sigrefrms uncertainty on sigrefkm/sstat.errorfloatsigpObs? Observed cluster core projected velocity dispersionkm/sphys.veloc.dispersionfloatE_sigpObs? Error in sigpObs (upper limit) due to the instrumental error and to the spectrum noisekm/sstat.errorfloate_sigpObs? Error in sigpObs (lower limit) due to the instrumental error and to the spectrum noisekm/sstat.errorfloatStatErru? Statistical error (upper limit) due to the small sample of bright stars observed through the slitkm/sstat.errorfloatu_StatErruUncertainty flag on StatErrumeta.code.errorcharStatErrl? Statistical error (lower limit) due to the small sample of bright stars observed through the slitkm/sstat.errorfloatsigp? Calculated cluster core projected velocity dispersion (1)km/sphys.veloc.dispersionfloatE_sigp? Error in sigp (upper limit) (2)km/sstat.errorfloatu_E_sigpUncertainty flag on E_sigpmeta.code.errorchare_sigp? Error in sigp (lower limit) (2)km/sstat.errorfloat