J/A+A/690/A331ivo://CDS.VizieR/J/A+A/690/A331doi:10.26093/cds/vizier.36900331CDSSitnova T.M.Yuan Z.Matsuno T.Mashonkina L.I.Alexeeva S.A.,Holmbeck E.Sestito F.Lombardo L.Banerjee P.Martin N.F.Jian F.2025-02-27T20:01:49Z2024-10-18T10:18:52ZCDS support team

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

cds-question@unistra.frmilky-way-galaxychemical-abundancesDwarf galaxy streams encode rich information that is essential to understand early galaxy formation and nucleosynthesis channels. Due to various timescales of star formation history in their progenitors, they serve as "snapshots" that record different stages of galactic chemical evolution. This study focuses on the Cetus stream stripped from a low-mass dwarf galaxy. We aim to uncover its chemical evolution history as well as different channels of its elements production from the detailed elemental abundances. We provide a comprehensive analysis of the chemical composition of 22 member stars based on their high-resolution spectra. We derive abundances for up to 28 chemical species from C to Dy and, for 20 of them, we account for the departures from the local thermodynamic equilibrium (non-LTE effects). We confirm that the Cetus stream has a mean metallicity [Fe/H]=-2.11+/-0.21. All observed Cetus stars are alpha enhanced with [alpha/Fe]~0.3. The absence of the alpha-"knee" implies the star formation stopped before iron production in type Ia supernovae (SNe Ia) became substantial. Neutron capture element abundances suggest that both r-process and main s-process contributed to their origin. The decrease in [Eu/Ba] from a typical r-process value [Eu/Ba]=0.7 to 0.3 with increasing [Ba/H] indicates a distinct contribution of the r- and s-processes in chemical composition of different Cetus stars. For barium, the r-process contribution varies from 100% to 20% in different sample stars, with an average value of 50%. Our abundance analysis indicates that the star formation in the Cetus progenitor ceased after the onset of the main s-process in low-intermediate mass asymptotic giant branch stars but before SNe Ia played an important role. A distinct evolution scenario is revealed by comparing the abundances in the Ursa Minor dwarf spheroidal galaxy, showing the diversity and uniqueness in the chemical evolution of low-mass dwarf galaxies.2024A&A...690A.331Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/690/A331CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/690/A331https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/690/A331http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/690/A331https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/690/A331https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/690/A331http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/690/A331GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/690/A331/stars (Studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A331/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A331/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A331/stars?GETtext/xml+votable180.050000true44.1522597044123.833142888070.0055555555555555566/782 976 2068 2126 2274 2786 11704 13629 17414 17436 17460 17618 17649 17784 17799 17817 17852 17997 19860 20026 35588 35613 35783https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/690/A331?format=asciidefaultJ/A+A/690/A331/starsStudied starsDEJ2000Declination (J2000)degpos.eq.dec;meta.mainDataDisplay data in tables 2 and 4meta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Stellar ID in Gaia DR3 cataloguemeta.id;meta.mainRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/690/A331/table2NLTE and LTE abundances from individual lines and their atomic datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Stellar ID in Gaia DR3 cataloguemeta.id;meta.mainElChemical element and its ionisation stagephys.atmol.element;phys.atmol.ionizationcharlambdaWavelength in angstroms0.1nmem.wlfloatEexcExcitation energy in electron-VoltseVphys.atmol.excitationfloatloggfDecimal logarithm of the adopted gf-valuephys.absorption.coefffloatl_EWUpper limit flag on EWmeta.code.error;spect.line.eqWidthcharEW? Equivalent width in milliangstroms0.1pmspect.line.eqWidthfloatnullableepsLTE? LTE abundance (logeps(H)=12)phys.abundfloatnullableepsNLTE? NLTE abundance (logeps(H)=12)phys.abundfloatnullableJ/A+A/690/A331/table4NLTE and LTE abundance ratios of the Cetus starsNlinesNumber of spectral linesmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Stellar ID in Gaia DR3 cataloguemeta.id;meta.mainElChemical element and its ionisation stagephys.atmol.element;phys.atmol.ionizationcharl_[El/H]LTEUpper limit flag on [El/H]LTEmeta.code.error;phys.abundchar[El/H]LTELTE abundance [El/H] with respect to solarphys.abundfloate_[El/H]LTE[] Uncertainty in LTE abundancestat.error;phys.abundfloat[El/Fe]LTELTE abundance ratio [El/Fe] with respect to solarphys.abundfloat[El/H]NLTE? NLTE abundance [El/H] with respect to solarphys.abundfloatnullablee_[El/H]NLTE[]? Uncertainty in NLTE abundancestat.error;phys.abundfloatnullable[El/Fe]NLTE? NLTE abundance ratio [El/Fe] with respect to solarphys.abundfloatnullable