J/MNRAS/531/137ivo://CDS.VizieR/J/MNRAS/531/137doi:10.26093/cds/vizier.75310137CDSD'Orazi V.Storm N.Casey A.R.Braga V.F.Zocchi A.Bono G.,Fabrizio M.Sneden C.Massari D.Giribaldi R.E.Bergemann M.,Campbell S.W.Casagrande L.de Grijs R.De Silva G.Lugaro M.,Zucker D.B.Bragaglia A.Feuillet D.Fiorentino G.Chaboyer B.,Dall'Ora M.Marengo M.Martinez-Vazquez C.E.Matsunaga N.Monelli M.,Mullen J.P.Nataf D.Tantalo M.Thevenin F.Vitello F.R.,Kudritzki R.-P.Bland-Hawthorn J.Buder S.Freeman K.Kos J.,Lewis G.F.Lind K.Martell S.Sharma S.Stello S.Zwitter T.2024-11-06T20:35:26Z2024-05-22T08:37:54ZCDS support team

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

cds-question@unistra.frvariable-starschemical-abundancesvisible-astronomyStellar mergers and accretion events have been crucial in shaping the evolution of the Milky Way (MW). These events have been dynamically identified and chemically characterized using red giants and main-sequence stars. RR Lyrae (RRL) variables can play a crucial role in tracing the early formation of the MW since they are ubiquitous, old (t>=10Gyr) low-mass stars and accurate distance indicators. We exploited Data Release 3 of the GALAH survey to identify 78 field RRLs suitable for chemical analysis. Using synthetic spectra calculations, we determined atmospheric parameters and abundances of Fe, Mg, Ca, Y, and Ba. Most of our stars exhibit halo-like chemical compositions, with an iron peak around [Fe/H]~-1.40, and enhanced Ca and Mg content. Notably, we discovered a metal-rich tail, with [Fe/H] values ranging from ~1 to approximately solar metallicity. This sub-group includes almost 1/4 of the sample, it is characterized by thin disc kinematics and displays sub- solar alpha-element abundances, marginally consistent with the majority of the MW stars. Surprisingly, they differ distinctly from typical MW disc stars in terms of the s-process elements Y and Ba. We took advantage of similar data available in the literature and built a total sample of 535 field RRLs for which we estimated kinematical and dynamical properties. We found that metal- rich RRLs (1/3 of the sample) likely represent an old component of the MW thin disc. We also detected RRLs with retrograde orbits and provided preliminary associations with the Gaia-Sausage-Enceladus, Helmi, Sequoia, Sagittarius, and Thamnos stellar streams.2024MNRAS.531..137Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/531/137CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/506/150 : The GALAH+ Survey DR3 (Buder+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/531/137https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/531/137http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/531/137https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/531/137https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/531/137http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/531/137GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/531/137/table1 (Atmospheric parameters and abundances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/531/137/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/531/137/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/531/137/table1?GETtext/xml+votable180.050000true90.97866568.24229110.0055555555555555566/1028 4733 18627 18633 19070 19167 19256 22603 22745 22952 23613 24205 24663 24724 27660 29264 29696 30956 31104 31173 31807 33033 33432 33516 33665 34774 38207 38213 38233 38511 38513 38864 39081 39670 41146 41292 41367 42700 42810 43211 43317 43377 43407 43487 43496 43612 43788 43913 43931 44233 44242 44352 44575 45243 45324 45539 45720 45864 45923 45998 46627 46640 47159 47165 47181 47251 47355 47358 47425 47459 47475 47478 47568 47598 47821 48091 48285https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/531/137?format=asciiOpticaldefaultJ/MNRAS/531/137/table1Atmospheric parameters and abundancesSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGALAHGALAH identifiermeta.id;meta.mainTeffEffective temperatureKphys.temperature.effectiveinte_TeffEffective temperature errorKstat.error;phys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloate_loggSurface gravitylog(cm.s**-2)stat.errorfloatVmicMicro-turbulence velocitykm/sphys.veloc.microTurbfloate_VmicMicro-turbulence velocity errorkm/sstat.errorfloat[Fe/H]Abundance [Fe/H]phys.abund.Fefloate_[Fe/H]Error on [Fe/H]stat.error;phys.abund.Fefloat[Mg/Fe]? Abundance [Mg/Fe]phys.abundfloatnullablee_[Mg/Fe]? Error on [Mg/Fe]stat.error;phys.abundfloatnullable[Ca/Fe]? Abundance [Ca/Fe]phys.abundfloatnullablee_[Ca/Fe]? Error on [Ca/Fe]stat.error;phys.abundfloatnullable[Si/Fe]? Abundance [Si/Fe]phys.abundfloatnullablee_[Si/Fe]? Error on [Si/Fe]stat.error;phys.abundfloatnullable[Y/Fe]? Abundance [Y/Fe]phys.abundfloatnullablee_[Y/Fe]? Error on [Y/Fe]stat.error;phys.abundfloatnullable[Ba/Fe]? Abundance [Ba/Fe]phys.abundfloatnullablee_[Ba/Fe]? Error on [Ba/Fe]stat.error;phys.abundfloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main