J/AJ/109/1055ivo://CDS.VizieR/J/AJ/109/1055doi:10.26093/cds/vizier.51091055CDSPerelmuter J.M.Racine M.2023-04-06T16:50:09Z1997-12-09T20:21:52ZCDS support team

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

cds-question@unistra.frgalaxiesvisible-astronomyglobular-star-clustersphotometrygalaxy-classification-systemsWe have obtained photometric BVR, morphological, and astrometric information on 3774 objects located within a 25' radius of M81. This catalogue is complete for 15 <= V <= 21; it is used here to identify globular cluster candidates in M81 and as a database for a statistical analysis of the system as a whole. The M81 globular cluster system is revealed as a strong surface density excess of ~70 objects within an 11 kpc galactocentric radius. The total population is estimated at N_T = 210 +/- 30 globulars. The spatial, (B-V), and (V-R) distributions are very similar to those of the Milky Way and of M31. Small but significant systematic errors in Madore et al.'s [AJ, 106, 2243 (1993)] photometry could be responsible for an overestimate of the Cepheid distance to M81 [(m-M)0 = 27.8] and we propose a revised modulus of (m-M)0 = 27.5 +/- 0.3. The globular cluster luminosity function then reaches its maximum at M_V* = -7.5 +/- 0.4, as it does in the galaxy and in M31. There is suggestive evidence that 13 +/- 5 objects are globulars seen through the disk of M81; spectroscopy or high-resolution imaging will resolve this issue. Using the (B-R)0 index to trace [Fe/H], we notice a weak dependence of mean metallicity on galactocentric distance, as observed in the galaxy and in M31. This result argues in favour of in situ globular formation during the continuous collapse and self-enrichment of an early-type spiral host.1995AJ....109.1055Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/109/1055CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/109/1055https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/109/1055http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/109/1055https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/109/1055https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/109/1055http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/109/1055GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/109/1055/table6 (Catalogue of objects in the M81 field)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/109/1055/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/109/1055/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/109/1055/table6?GETtext/xml+votable180.050000true149.1888166769.167138890.0055555555555555566/7601 7603-7604 7606 7609 7612https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/109/1055?format=asciiOpticaldefaultJ/AJ/109/1055/table6Catalogue of objects in the M81 fieldrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification number [PR95]meta.id;meta.mainintRA2000Right ascension (2000)pos.eq.ra;meta.mainDE2000Declination (always blank)pos.eq.dec;meta.mainnullableEpochMean epoch of observationyrtime.epochfloatVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colormagphot.color;em.opt.B;em.opt.VfloatV-RV-R colormagphot.color;em.opt.V;em.opt.RfloatNNumber of plates object detected uponmeta.numberintpmGlonProper motion in galactic longitudemas/yrpos.pmintpmGlatProper motion in galactic latitudemas/yrpos.pmintpmSig*Level of significance of total PMstat.fit.paramfloat