J/A+A/713/A24ivo://CDS.VizieR/J/A+A/713/A24CDSMuratore F.Legnardi M.V.Milone A.P.Cordoni G.,Mastrobuono-Battisti A.Marino A.F.Ziliotto T.Dondoglio E.,Bortolan E.Lagioia E.P.2026-09-07T07:30:45Z2026-09-07T08:30:09ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsstellar-associationsgalaxy-classification-systemsvisible-astronomyBinary stars are key tracers of the dynamical evolution of star clusters and provide important constraints on stellar populations and mass functions. The Magellanic Clouds host clusters with a wide range of ages and masses, offering an ideal laboratory to investigate these properties in regimes poorly sampled in the Milky Way. We aim to characterize the binary populations, mass functions (MFs), blue straggler (BS) content, and structural parameters of intermediate-age Magellanic Cloud clusters, and to explore their dependence on global cluster properties. We analyzed high-precision Hubble Space Telescope photometry for 16 clusters obtained with ACS/WFC and WFC3/UVIS. Structural parameters were derived from stellar density profiles. Binary fractions were measured using the binary map technique, focusing on systems with mass ratios q>0.7. We derived MFs accounting for unresolved binaries and identified candidate BS populations from color-magnitude diagrams. The fraction of binaries with q>0.7 ranges from 5% in NGC 2121 up to 13% in NGC 2173, with a mass-ratio distribution that is consistent with being flat on average. By combining our results with literature data, we confirm a clear anticorrelation between the core binary fraction and cluster mass, while no significant dependence on cluster age is found. The clusters follow the established relation between age and core radius, although with substantial scatter at fixed age. Within the narrow age range explored here, clusters exhibiting steeper MFs are found to have smaller core radii. We find no evidence of a correlation between the fractions of binaries and BS fractions. These findings are consistent with a scenario in which dynamical evolution plays a primary role in the formation of binary populations. The connection between MF slope and structural parameters provides new constraints on cluster evolution and suggests a link between MF slope and structural evolution.2026A&A...713A..24Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/713/A24CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/713/A24https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/713/A24http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/713/A24https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/713/A24https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/713/A24http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/713/A24GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/713/A24/table1 (Parameters of target clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/713/A24/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/713/A24/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/713/A24/table1?GETtext/xml+votable180.050000true16.983125-71.76780560.0055555555555555566/33045 33053 33076 33084 33088 33099 33108 33113 33121 33124 33127 33130 33304 33328 37410https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/713/A24?format=asciiOpticaldefaultJ/A+A/713/A24/table1Parameters of target clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameClustermeta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainlogAgeAgelog(yr)time.agedoublercoreCore radiusarcsecphys.angSize;srcdoublee_rcoreUncertainty on core radiusarcsecstat.errorfloatr50Radius with 50% of stellar countsarcsecphys.angSize;srcfloate_r50Uncertainty on r50arcsecstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlcharmu0Central density from EEF profilearcsec**-2phot.mag.sbfloate_mu0Uncertainty on mu0arcsec**-2stat.errorfloatgammaParameter from EEF profilestat.fit.paramfloate_gammaUncertainty on gammastat.errorfloataParameter from EEF profilestat.fit.paramfloate_aUncertainty on astat.errorfloatJ/A+A/713/A24/table2Inferred parameter of target clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameClustermeta.id;meta.maincharlogAgeAgelog(yr)time.agedoublefbinFraction of binaries within cluster radiusmeta.numberfloate_fbinUncertainty on the fraction of binariesstat.errorfloatfbinrcFraction of binaries within core radiusmeta.numberfloate_fbinrcUncertainty on the fraction of binaries within core radiusstat.errorfloatfbinR50Fraction of binaries within R50meta.numberfloate_fbinR50Uncertainty on the fraction of binaries within R50stat.errorfloatfbinextrExtrapolated Fraction of binaries within cluster radiusmeta.numberfloate_fbinextrUncertainty on the extrapolated fraction of binariesstat.errorfloatRqRatio of last two bins of mass ratio distributionstat.fit.paramfloate_RqUncertainty on the ratiostat.errorfloatJ/A+A/713/A24/table3Fraction of blue stragglers in target clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameClustermeta.id;meta.maincharlogAgeAgelog(yr)time.agedoublefbssFraction of BSs within the cluster radiusmeta.numberfloate_fbssUncertainty on the fraction of BSs within the cluster radiusstat.errorfloatfbssrcFraction of BSs within the core radiusmeta.numberfloate_fbssrcUncertainty on the fraction of BSs within the core radiusstat.errorfloatalphaSlope of MFmeta.crypticfloate_alphaUncertainty on the alpha slopestat.error;pos.eq.rafloat[Fe/H]Fe/H from isochrone fittingphys.abund.Fefloat(m-M)0(m-M)0 from isochrone fittingmagphot.mag.distModfloatE(B-V)E(B-V) from isochrone fittingmagphot.color.excessfloat