J/AJ/107/2067ivo://CDS.VizieR/J/AJ/107/2067doi:10.26093/cds/vizier.51072067CDSGebhardt K.Pryor C.Williams T.B.Hesser J.E.2023-04-06T16:50:06Z1997-12-09T20:16:47ZCDS support team

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

cds-question@unistra.frglobular-star-clustersradial-velocityWe report the first use of the Rutgers Imaging Fabry-Perot Spectrophotometer to study the dynamics of the cores of globular clusters. We have obtained velocities for cluster stars by tuning the Fabry-Perot to take a series of narrowband (0.8A FWHM at 5890A) images at different wavelengths across one of the Na D (5890A) absorption lines. Measuring the flux in every frame yields a short portion of the spectrum for each star simultaneously. This proves to be a very efficient method for obtaining accurate stellar velocities; in crowded regions we are able to measure hundreds of velocities in 3-4h of observing time. We have measured velocities with uncertainties of less than 5km/s for 216 stars within 1.5' of the center of the globular cluster M15 (NGC 7078). The velocity dispersion profile shows a sharp rise from 7 to 12km/s at 0.6' (1.8parsec), and then appears to flatten into our innermost point at 0.1'. A rotation amplitude of 1.4+/-0.8km/s is detected. The rotation has been measured at a radius of 0.6' using stellar velocities and at 0.2' using the integrated light profile. The amplitude and position angle are the same at both radii, indicating a constant rotation profile in this region. Combining our two epochs of Fabry-Perot observation with published measurements, we have repeat velocity measurements for 67 stars. We calculate a binary fraction of about 7% for binary periods between 0.2 and 20 years and mass ratios larger than 0.22, which is in agreement with measurements for other globular clusters.1994AJ....107.2067Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/107/2067CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/106/154 : HST Observations in inner region of M15 (Ferraro+ 1993)J/AJ/107/1745 : HST UVI photometry of M15. II. (Yanny+, 1994)J/AJ/110/704 : RR Lyrae in M15 (Silbermann+ 1995)J/ApJ/347/251 : Dynamics of Globular Cluster M15 (Peterson+ 1989)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/107/2067https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/107/2067http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/107/2067https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/107/2067https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/107/2067http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/107/2067GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AJ/107/2067/table1M15 starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar ID, blank indicates continuations (1)meta.id;meta.maincharXoffX offset from cluster center (2)arcsecpos.projfloatYoffY offset from cluster center (2)arcsecpos.projfloatFPVmagFabry-Perot V magnitudemagphot.mag;em.opt.VfloatRVelVelocity (3)km/sphys.veloc;pos.heliocentricfloate_RVelError in velocitykm/sstat.errorfloatr_RVelSource for velocity (4)meta.refcharChiSq[]? Chi-square for multiple measurements (5)stat.fit.chi2floatNoteNotes (6)meta.notechar