J/other/Nat/601.ivo://CDS.VizieR/J/other/Nat/601.45CDSMartin N.F.Venn K.A.Aguado D.S.Starkenburg E.,Gonzalez Hernandez J.I.Ibata R.A.Bonifacio P.Caffau E.Sestito F.,Arentsen A.Allende Prieto C.Carlberg R.G.Fabbro S.Fouesneau M.,Hill V.Jablonka P.Kordopatis G.Lardo C.Malhan K.Mashonkina L.I.,McConnachie A.W.Navarro J.F.Sanchez-Janssen R.Thomas G.F.Yuan Z.,Mucciarelli A.2024-07-17T07:31:06Z2023-07-07T13:33:58ZCDS support team

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

cds-question@unistra.frchemically-peculiar-starsspectroscopychemical-abundancesline-intensitiesStellar ejecta gradually enrich the gas out of which subsequent stars form, making the least chemically enriched stellar systems direct fossils of structures formed in the early Universe. Although a few hundred stars with metal content below 1000th of the solar iron content are known in the Galaxy, none of them inhabit globular clusters, some of the oldest known stellar structures. These show metal content of at least approximately 0.2% of the solar metallicity ([Fe/H]>~2.7). This metallicity floor appears universal, and it has been proposed that protogalaxies that merged into the galaxies we observe today were simply not massive enough to form clusters that survived to the present day. Here we report observations of a stellar stream, C-19, whose metallicity is less than 0.05% of the solar metallicity ([Fe/H]=-3.38+/-0.06(statistical)+/-0.20(systematic)). The low metallicity dispersion and the chemical abundances of the C-19 stars show that this stream is the tidal remnant of the most metal-poor globular cluster ever discovered, and is significantly below the purported metallicity floor: clusters with significantly lower metallicities than observed today existed in the past and contributed their stars to the Milky Way halo.2022Natur.601...45Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/other/Nat/601.45CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/other/Nat/601.45https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/other/Nat/601.45http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/other/Nat/601.45https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/other/Nat/601.45https://vizier.iucaa.in/viz-bin/votable?-source=J/other/Nat/601.45http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/other/Nat/601.45GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/other/Nat/601.45/table1 (List of potential C-19 member from the STREAMFINDER sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/other/Nat/601.45/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/other/Nat/601.45/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/other/Nat/601.45/table1?GETtext/xml+votable180.050000true352.063054835.67124580.005555555555555556Cone search capability for table J/other/Nat/601.45/table2 (Summary of observations for the C-19 candidate stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/other/Nat/601.45/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/other/Nat/601.45/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/other/Nat/601.45/table2?GETtext/xml+votable180.050000true354.770130.25090.0055555555555555565/5020 6/13585 13589-13590 20058-20059 20084 20086 20089 20092-20093 20095 20261 20266-20267 20352-20353 20355 20358-20359 20365 20376 20378 20400 20403 20406 20409 20412-20413 20458https://cdsarc.cds.unistra.fr/viz-bin/moc/J/other/Nat/601.45?format=asciidefaultJ/other/Nat/601.45/table1List of potential C-19 member from the STREAMFINDER samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR2Gaia DR2 IDmeta.id;meta.mainRA_ICRSRight ascension (ICRS) at Ep=2015.5degpos.eq.ra;meta.main_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexedDE_ICRSDeclination (ICRS) at Ep=2015.5degpos.eq.dec;meta.mainG0magDeredenned G magnitudemagphot.mag;em.optfloate_G0magError on G magnitudemagstat.error;phot.magfloat(BP-RP)0Deredenned BP-RP colour indexmagphot.color;em.opt.B;em.opt.Rfloate_(BP-RP)0Error on BP-RPmagstat.errorfloatPlxParallaxarcsecpos.parallax.trigfloate_PlxParallax errorarcsecstat.error;pos.parallaxfloatpmRA*Proper motion along RA, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloate_pmRA*Error on pmRA*mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion along DEmas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloat[Fe/H]? Pristime metallicity (1)phys.abund.ZfloatnullableNoteNote (2)meta.notecharJ/other/Nat/601.45/table2Summary of observations for the C-19 candidate starsSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintmoreGTC/OSIRIS stellar parameters and abundancesmeta.ref.urlcharNameName (Pristine LLL.ll+BB.bb)meta.id;meta.maincharprimaryRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainGmagG magnitudemagphot.mag;em.optfloat[Fe/H]Pristine metallicityphys.abund.ZfloatTexpExposure timestime.duration;obs.exposurecharS/NSignal to noise at 600nm (Gemini/GRACES) and 420nm (GTC/OSIRIS)stat.snrintRVRadial velocitykm/sphys.veloc;pos.heliocentricfloate_RV? Radial velocity errorkm/sstat.errorfloatnullableObsObservatorymeta.id;instr.obstycharComCommentmeta.notecharJ/other/Nat/601.45/table3Spectroscopic parameters and 1DLTE chemical abundances for the Gemini/GRACES spectrae_P3? Error of value of Param for Pristine 355.27+27.74 (1)stat.errorfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintParamParametermeta.notecharl_P1Limit flag on P1meta.code.errorcharP1Value of Param for Pristine 354.77+30.25stat.fit.paramfloate_P1? Error of Value of Param for Pristine 354.77+30.25 (1)stat.errorfloatnullableP2Value of Param for Pristine 355.13+27.98stat.fit.paramfloate_P2Error of Value of Param for Pristine 355.13+27.98 (1)stat.errorfloatl_P3Limit flag on P3meta.code.errorcharP3Value of Param for Pristine 355.27+27.74stat.fit.paramfloatJ/other/Nat/601.45/table4Spectral lines and atomic data used for the chemical abundances for the Gemini/GRACES spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength0.1nmem.wldoubleElElementphys.atmol.elementcharxiEnergyeVphys.energy;phys.atmol.levelfloatloggfOscillator strengthphys.atmol.oscStrengthfloatEW1? Equivalent width for Pristine 355.1+27.90.1pmspect.line.eqWidthintnullablen_EW1Note on EW1 (1)meta.notecharl_EW2Limit flag on EW2meta.code.errorcharEW2? Equivalent width for Pristine 354.7+30.20.1pmspect.line.eqWidthintnullablen_EW2Note on EW2 (1)meta.notecharl_EW3Limit flag on EW2meta.code.errorcharEW3? Equivalent width for Pristine 355.2+27.70.1pmspect.line.eqWidthintnullablen_EW3Note on EW3 (1)meta.notecharNLTEcorra? NLTE correction estimates from the INSPECT (http://www.inspect-stars.com) and/or MPIA database (http://nlte.mpia.de) (2)0.1pmarith.factorfloatnullableNLTEcorrb? NLTE corrections from the private calculations of coauthor L. Mashonkina (http://www.inasan.rssi.ru/~lima/pristine). Only the NaI NLTE corrections show some star to star variations due to the differences in the line strengths (the average from the three0.1pmarith.factorfloatnullableJ/other/Nat/601.45/table5Stellar parameters and abundances of C-19 stars observed with GTC/OSIRISCode[PW] Code (1)meta.codecharNameName (Pristine LLL.ll+BB.bb)meta.id;meta.maincharTeffEffective temperatureKphys.temperature.effectiveinte_TeffEffective temperature errorKstat.error;phys.temperature.effectiveintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintloggSurface gravitylog(cm.s**-2)phys.gravityfloatn_logg[lu] Note pn logg (2)meta.notechare_logg? Surface gravity errorlog(cm.s**-2)stat.errorfloatnullable[M/H]Abundance [M/H]phys.abundfloate_[M/H]Abundance [M/H]stat.error;phys.abundfloat[Ca/H]? Abundance [Ca/H]phys.abundfloatnullablee_[Ca/H]? Abundance [Ca/H] errorstat.error;phys.abundfloatnullable[Fe/H]? Abundance [Fe/H]phys.abund.Fefloatnullablee_[Fe/H]? Abundance [FeM/H] errorstat.error;phys.abund.Fefloatnullable[C/Fe]? Abundance [C/Fe]phys.abundfloatnullablee_[C/Fe]? Abundance [C/Fe] errorstat.error;phys.abundfloatnullable