J/MNRAS/504/4160ivo://CDS.VizieR/J/MNRAS/504/4160doi:10.26093/cds/vizier.75044160CDSSong Y.-Y.Mateo M.Bailey J.I.Walker M.G.Roederer I.U.,Olszewski E.W.Reiter M.Kremin A.2024-11-06T20:33:42Z2024-05-27T15:47:35ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsphotometrymetallicitystellar-associationsvisible-astronomyWe present spectroscopy of individual stars in 26 Magellanic Cloud (MC) star clusters with the aim of estimating dynamical masses and V-band mass-to-light (M/LV) ratios over a wide range in age and metallicity. We obtained 3137 high-resolution stellar spectra with M2FS on the Magellan/Clay Telescope. Combined with 239 published spectroscopic results of comparable quality, we produced a final sample of 2787 stars with good quality spectra for kinematic analysis in the target clusters. Line-of-sight velocities measured from these spectra and stellar positions within each cluster were used in a customized expectation-maximization (EM) technique to estimate cluster membership probabilities. Using appropriate cluster structural parameters and corresponding single-mass dynamical models, this technique ultimately provides self-consistent total mass and M/LV estimates for each cluster. Mean metallicities for the clusters were also obtained and tied to a scale based on calcium IR triplet metallicities. We present trends of the cluster M/LV values with cluster age, mass, and metallicity, and find that our results run about 40 per cent on average lower than the predictions of a set of simple stellar population (SSP) models. Modified SSP models that account for internal and external dynamical effects greatly improve agreement with our results, as can models that adopt a strongly bottom-light IMF. To the extent that dynamical evolution must occur, a modified IMF is not required to match data and models. In contrast, a bottom-heavy IMF is ruled out for our cluster sample as this would lead to higher predicted M/LV values, significantly increasing the discrepancy with our observations.2021MNRAS.504.4160Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/504/4160CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/AJ/123/855 : Magellanic Clouds Photometric Survey: the SMC (Zaritsky+, 2002)J/AJ/128/1606 : Magellanic Clouds Photometric Survey: the LMC (Zaritsky+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/504/4160https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/504/4160http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/504/4160https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/504/4160https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/504/4160http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/504/4160GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/504/4160/table2 (Positions and structural parameters of star clusters in our sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/504/4160/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/504/4160/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/504/4160/table2?GETtext/xml+votable180.050000true6.1915833-72.79386110.005555555555555556Cone search capability for table J/MNRAS/504/4160/table5 (Final all stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/504/4160/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/504/4160/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/504/4160/table5?GETtext/xml+votable180.050000true6.42051111-72.862261110.0055555555555555566/32790 32983 33076 33078 33088 33111 33113 33117 33120-33121 33124 33126-33127 33138-33139 33287 33304 33306-33307 33315-33318 33320 33328-33329 33793 37386 37410 37550-37551 389163.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/504/4160?format=asciiOpticaldefaultJ/MNRAS/504/4160/table1General properties of star clusters in our sampleClusterCluster name host (Cluster)meta.id;meta.maincharSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyGalaxy name host (Galaxy)meta.id.parentcharVmagApparent magnitude in V band (Vap)magphot.mag;em.opt.Vfloate_VmagMean error on Vmag (e_Vmag)magstat.error;phot.magfloatAperAperture radius used for measuring the Vap magnitude (Aper)arcsecphys.angSizefloatn_VmagReferences on Vmag (Ref.) (1)meta.noteintAgeAge (Age)Gyrtime.agefloate_AgeMean error on Age(e_Age)Gyrstat.error;time.agefloat(m-M)0Gap between apparent and absolute magnitudemagphot.mag.distModfloate_(m-M)0Mean error on (m-M)0 (m-M0error)magstat.errorfloatAvExtinction in V band (Av)magphys.absorptionfloate_AvMean error on Av (e_Av)magstat.errorfloatn_AvNote on Av (Ref) (1)meta.noteint[Fe/H]Abundance [Fe/H] ([Fe/H]) (2)phys.abundfloatJ/MNRAS/504/4160/table2Positions and structural parameters of star clusters in our samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyGalaxy name host (Galaxy)meta.id.parentcharClusterCluster name host (Cluster)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.maincK62Concentration parameter(1)stat.paramfloatE_cK62Upper limit of cK62 (E_cK62)stat.error;stat.maxfloate_cK62Lower limit of cK62 (e_cK62)stat.errorfloatr0K62King radius (r0,K62) (2)arcsecphys.angSize;srcfloatE_r0K62Upper limit of r0,K62 (E_r0,K62)arcsecstat.error;stat.maxfloate_r0K62Lower limit of r0,K62 (e_r0,K62)arcsecstat.errorfloatn_r0K62References of r0,K62 (3)meta.notecharcK66Concentration parameter (cK66) (1)stat.paramfloatE_cK66Upper limit of cK66 (E_cK66)stat.error;stat.maxfloate_cK66Lower limit of cK66 (e_cK66)stat.errorfloatr0K66King radius (r0,K66) (4)arcsecphys.angSize;srcfloatE_r0K66Upper limit of r0,K66 (E_r0,K66)arcsecstat.error;stat.maxfloate_r0K66Lower limit of r0,K66 (e_r0,K66)arcsecstat.errorfloatn_r0K66? References of r0,K66 (3)meta.noteintnullableJ/MNRAS/504/4160/table5Final all starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyGalaxy name host (Galaxy)meta.id.parentcharClusterCluster name host (Cluster)meta.id.parentcharIDName ID (ID)meta.id;meta.maincharRAJ2000Right ascension expressed (J2000)degpos.eq.ra;meta.mainDEJ2000Declination expressed (J2000)degpos.eq.dec;meta.mainGmag? Apparent magnitude in G band (G)magphot.mag;em.optfloatnullableBP-RP? Apparent magnitude gap (GBP-GRP)magphot.color;em.opt.B;em.opt.RfloatnullableTeff? Effective temperature (Teff)Kphys.temperature.effectiveintnullableGaiaDR2? GaiaDR2 ID (GaiaDR2_ID)meta.idnullableS/N? Signal to noise ratio (S/N) (1)stat.snrfloatnullableVlosLOS velocity (vlos)km/sphys.veloc;pos.heliocentricfloate_VlosMean error on Vlos (e_Vlos)km/sstat.errorfloatlogg? Log (Surface gravity) (log(g)log(cm.s**-2)arith.zpfloatnullablee_logg? Mean error on log(g) (e_log)log(cm.s**-2)stat.errorfloatnullable[Fe/H]? Abundance [Fe/H] ([Fe/H])phys.abundfloatnullablee_[Fe/H]? Mean error on [Fe/H] (e_[Fe/H])stat.error;phys.abund.FefloatnullablePMThe preliminary membership probability (PM)stat.probabilityfloatP'MThe preliminary membership probability where significant contamination by a single unflagged non-member appears to be present (P'M)meta.code.memberfloatFlagSeven digits flags (Flag) (2)meta.code.errorintRefsReference sources (Source) (3)meta.ref;pos.framechar