J/AJ/156/257ivo://CDS.VizieR/J/AJ/156/257doi:10.26093/cds/vizier.51560257CDSSpencer M.E.Mateo M.Olszewski E.W.Walker M.G.McConnachie A.W.,Kirby E.N.2022-10-07T14:26:10Z2019-05-10T07:15:53ZCDS support team

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

cds-question@unistra.frgalaxiesmultiple-starsgiant-starsspectroscopyeffective-temperaturemetallicityradial-velocityMeasuring the frequency of binary stars in dwarf spheroidal galaxies (dSphs) requires data taken over long time intervals. We combine radial velocity measurements from five literature sources taken over the course of ~30 years to yield the largest multi-epoch kinematic sample for stars in the dSphs Draco and Ursa Minor. With this data set, we are able to implement an improved version of the Bayesian technique described in Spencer et al. (2017, J/AJ/153/254) to evaluate the binary fraction of red giant stars in these dwarf galaxies. Assuming Duquennoy & Mayor (1991A&A...248..485D) period and mass ratio distributions, the binary fractions in Draco and Ursa Minor are 0.50_-0.06_^+0.04^ and 0.78_-0.08_^+0.09^, respectively. We find that a normal mass ratio distribution is preferred over a flat distribution, and that log-normal period distributions centered on long periods ({mu}_logP_>3.5) are preferred over distributions centered on short ones. We reanalyzed the binary fractions in Leo II, Carina, Fornax, Sculptor, and Sextans, and find that there is <1% chance that binary fraction is a constant quantity across all seven dwarfs, unless the period distribution varies greatly. This indicates that the binary populations in Milky Way dSphs are not identical in regard to their binary fractions, period distributions, or both. We consider many different properties of the dwarfs (e.g., mass, radius, luminosity, etc.) and find that binary fraction might be larger in dwarfs that formed their stars quickly and/or have high velocity dispersions.2018AJ....156..257Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/156/257CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/110/2131 : M/L for Draco and UMi. I. (Armandroff+ 1995)J/AJ/121/841 : RV photometry of Draco dwarf spheroidal galaxyJ/AJ/123/2511 : RV photometry of Draco dwarf spheroidal galaxyJ/AJ/124/3222 : VI photometry of Draco and UMi galaxies (Bellazzini+, 2002)J/MNRAS/330/792 : Radial velocity in Draco (Kleyna+, 2002)J/ApJ/617/L41 : Red giant variable candidates in UMi dSph (Mighell+, 2004)J/ApJS/191/352 : Abundances in stars of Milky Way dwarf satellitesJ/AJ/144/4 : Properties of dwarf galaxies in the Local GroupJ/MNRAS/448/2717 : Bayesian analysis of resolved stellar spectraJ/ApJ/821/54 : XMM spectral analysis of Draco dSph (Sonbas+, 2016)J/AJ/153/254 : Velocities of RGB stars in the Leo II dwarf galaxyhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/156/257https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/156/257http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/156/257https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/156/257https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/156/257http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/156/257GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/156/257/table2 (New MMT/Hectochelle data from individual observations of RGB candidates in Ursa Minor)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/257/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/257/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/257/table2?GETtext/xml+votable180.050000true227.7302566.78144440.005555555555555556Cone search capability for table J/AJ/156/257/table2m (Hectochelle weighted means for stars with multiple observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/257/table2m?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/257/table2m?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/257/table2m?GETtext/xml+votable180.050000true227.7302566.78144440.005555555555555556Cone search capability for table J/AJ/156/257/table3 (Velocities of RGB stars in Draco)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/257/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/257/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/257/table3?GETtext/xml+votable180.050000true258.900166757.80955560.005555555555555556Cone search capability for table J/AJ/156/257/table4 (Velocities of RGB stars in Ursa Minor)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/257/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/257/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/257/table4?GETtext/xml+votable180.050000true226.2322566.47775280.005555555555555556Cone search capability for table J/AJ/156/257/list (List of spectra for Ursa Minor)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/257/list?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/257/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/257/list?GETtext/xml+votable180.050000true225.6654211166.378028890.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/AJ/156/2575/2922 6/10181-10183 10188-10189 10192 11694-11695 12032-12033 12036-12037https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/156/257?format=asciidefaultJ/AJ/156/257/table2New MMT/Hectochelle data from individual observations of RGB candidates in Ursa MinorS-log(g)[-2/1.7] The log(g) skewness (1)stat.fit.paramfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainHJDHeliocentric Julian Datedtime.epochdoubleS/N[0.3/45.7] Median signal-to-noise ratio per pixelstat.snr;instr.pixelfloatvlos[-444.5/82.3] Line-of-sight velocity (G1)km/sphys.veloc;pos.heliocentricfloate_vlos[0.4/3.8] Uncertainty in vloskm/sstat.errorfloatS-vlos[-0.6/0.7] The vlos skewness (1)stat.fit.paramfloatK-vlos[2.4/4] The vlos kurtosis (1)stat.fit.paramfloatTeff[4308/7472] Effective temperatureKphys.temperature.effectiveinte_Teff[50/1137] Uncertainty in TeffKstat.error;phys.temperature.effectiveintS-Teff[-0.9/3.5] The Teff skewness (1)stat.fit.paramfloatK-Teff[1.8/21.5] The Teff kurtosis (1)stat.fit.paramfloatlog(g)[0.7/5.6] Log surface gravitylog(cm.s**-2)phys.gravityfloate_log(g)[0.1/1.3] Uncertainty in log(g)log(cm.s**-2)stat.errorfloatK-log(g)[1.9/8.3] The log(g) kurtosis (1)stat.fit.paramfloat[Fe/H][-3.53/1.19] Metallicitylog(Sun)phys.abund.Zfloate_[Fe/H][0.05/1.08] Uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.FefloatS-[Fe/H][-1.2/1.7] The [Fe/H] skewness (1)stat.fit.paramfloatK-[Fe/H][1.6/9.3] The [Fe/H] kurtosis (1)stat.fit.paramfloatJ/AJ/156/257/table2mHectochelle weighted means for stars with multiple observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainvlosmean[-444.5/82.3] Weighted mean line-of-sight velocity (G1)km/sphys.veloc;pos.heliocentric;stat.meanfloate_vlosmean[0.2/3.5] Uncertainty in vlosmeankm/sstat.errorfloatTeffmean[4315/7302] Weighted mean effective temperatureKphys.temperature.effective;stat.meaninte_Teffmean[25/1137] Uncertainty in TeffmeanKstat.errorintlog(g)mean[0.7/5.6] Weighted mean log surface gravitylog(cm.s**-2)phys.gravity;stat.meanfloate_log(g)mean[0.1/1.3] Uncertainty in log(g)meanlog(cm.s**-2)stat.errorfloat[Fe/H]mean[-3.53/1.19] Weighted mean metallicitylog(Sun)phys.abund.Fe;stat.meanfloate_[Fe/H]mean[0.03/1.08] Uncertainty in [Fe/H]meanlog(Sun)stat.error;phys.abund.FefloatNobs[1/5] Number of independent observationsmeta.numberintJ/AJ/156/257/table3Velocities of RGB stars in DracoIDStar identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNRV[2/11] Number of velocities for IDmeta.numberintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainHJDHeliocentric Julian Datedtime.epochdoubleRV[-335.9/-206.7] Radial velocity (1)km/sphys.veloc;pos.heliocentricfloate_RV[0.2/11.8] Uncertainty in RVkm/sstat.errorfloatr_RVReference from which the velocity measurement originated (2)meta.ref;pos.framecharJ/AJ/156/257/table4Velocities of RGB stars in Ursa MinorIDStar identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNRV[2/11] Number of velocities for IDmeta.numberintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainHJDHeliocentric Julian Datedtime.epochdoubleRV[-335.9/-206.7] Radial velocity (1)km/sphys.veloc;pos.heliocentricfloate_RV[0.2/11.8] Uncertainty in RVkm/sstat.errorfloatr_RVReference from which the velocity measurement originated (2)meta.ref;pos.framecharJ/AJ/156/257/listList of spectra for Ursa MinorrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainHJDHeliocentric Julian Date of observationdtime.epochdoublespShow the spectrummeta.ref.urlcharFileNameName of FITS file in subdirectory umisp (1)meta.id;meta.fitschar