Spectroscopic Studies of Extremly Metal-Poor Stars with Subaru/HDS:II.The r-process Elements, Including Thorium

Abstract

We present the abundance analyses for the neutron-capture elements, and discuss the observed abundance distributions in very metal-poor stars with excesses of r-process elements. As has been found by previous abundance studies, the star-to-star scatter in the abundances of neutron-capture elements are very large. The abundance patterns of the heavy neutron-capture elements (56 $\le$ Z $\le$ 70) in seven objects with moderate to large excesses of the neutron-capture elements are similar to that of the solar system r-process component. These results strongly suggest that the heavy neutron-capture elements in these objects are primarily synthesized by the r-process. On the other hand, the abundance ratios of the light neutron-capture elements (38 $\le$ Z $\le$ 46) exhibit a rather large dispersion. Our inspection of the correlation between Sr and Ba abundances in very metal-poor stars reveals that the dispersion of the Sr abundances clearly decreases with increasing Ba abundance. This results support previous suggestions that the light neutron-capture elements are likely to have been produced in different astrophysical sites from those associated with the production of the heavier ones. The Th/Eu abundance ratios (log(Th/Eu)) measured for the seven r-process-enhanced stars range from -0.10 to -0.59. Since these very metal-poor stars are believed to be formed in the early Galaxy, this result means that a small dispersion appears in the abundance ratios between Th and rare-earth elements, such as Eu, in very metal-poor stars. In order to apply the Th/Eu ratios to estimates of stellar ages, further understanding for the Th production by the r-process nucleosynthesis is required.

53 pages, 26 Postscript figures, accepted for publication in ApJ

References in corpus (36)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• Neutron capture in low mass Asymptotic Giant Branch stars: cross sections and abundance signatures
• Neutron-Capture Elements in the Early Galaxy: Insights from a Large Sample of Metal-Poor Giants
• The Extremely Metal-Poor, Neutron-Capture-Rich Star CS 22892-052: A Comprehensive Abundance Analysis
• The extreme r-element rich, iron-poor halo giant CS31082-001: Implications for the r-process site(s) and radioactive cosmochronology
• Measurement of stellar age from uranium decay
• The Chemical Composition and Age of the Metal-Poor Halo Star BD +17^\circ 3248
• Nucleosynthesis in neutrino-driven winds: II. Implications for heavy element synthesis
• The r-Process Enriched Low Metallicity Giant HD 115444
• Extremely Metal-Poor Stars. VIII. High-Resolution, High-Signal-To-Noise Analysis of Five Stars with [Fe/H] < -3.5
• Evidence of Multiple r-Process Sites in the Early Galaxy: New Observations of CS 22892-052
• R-Process Abundances and Chronometers in Metal-Poor Stars
• General relativistic effects on neutrino-driven wind from young, hot neutron star and the r-process nucleosynthesis
• A Subaru/HDS study of Lead (Pb) abundances in eight s-process-element-rich, metal-poor stars
• Tuning the Clock: Uranium and Thorium Chronometers Applied to CS 31082-001
• Measuring Galactic Extinction: A Test
• Probing the Neutron-Capture Nucleosynthesis History of Galactic Matter
• Neutron Capture Elements in s-Process-Rich, Very Metal-Poor Stars
• Enrichment of the r-process Element Europium in the Galactic Halo
• A Search for Stars of Very Low Metal Abundance. V. Photoelectric UBV Photometry of Metal-Weak Candidates from the Northern HK Survey
• The r-process in supernova explosions from the collapse of O-Ne-Mg cores
• The r-process in the neutrino winds of core-collapse supernovae and U-Th cosmochronology
• Th Ages for Metal-Poor Stars
• The r-process in the early Galaxy
• Prompt Iron Enrichment, Two r-Process Components, and Abundances in Very Metal-Poor Stars
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: On-Orbit Radiometer Characterization
• r-Process in Prompt Supernova Explosions Revisited
• Detection of low Eu abundances in extremely metal-poor stars and the origin of r-process elements
• Chemical composition of carbon-rich, very metal-poor subgiant LP625-44 observed with the Subaru/HDS
• Stellar Abundances in the Early Galaxy and Two r-Process Components
• Binary Blue Metal-Poor Stars: Evidence for AGB Mass Transfer
• r-Process Abundance Universality and Actinide Cosmochronology
• The INT Search for Metal-Poor Stars. Spectroscopic Observations and Classification via Artificial Neural Networks
• Probing the Site for r-Process Nucleosyntheis with Abundances of Barium and Magnesium in Extremely Metal-Poor Stars
• Chemical Compositions of Four Metal-poor Giants

Cited by in corpus (229)

• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• Galactic chemical evolution: Carbon through Zinc
• The s Process: Nuclear Physics, Stellar Models, Observations
• Nucleosynthesis Yields of Core-Collapse Supernovae and Hypernovae, and Galactic Chemical Evolution
• Origin of the Heaviest Elements: the Rapid Neutron-Capture Process
• Carbon Enhanced Metal-Poor Stars. I. Chemical Compositions of 26 Stars
• The Hamburg/ESO R-process Enhanced Star survey (HERES) II. Spectroscopic analysis of the survey sample
• A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars
• The Stellar Abundances for Galactic Archeology (SAGA) Database - Compilation of the Characteristics of Known Extremely Metal-Poor Stars
• Quantifying the uncertainties of chemical evolution studies. II. Stellar yields
• Detailed Abundances for 28 Metal-poor Stars: Stellar Relics in the Milky Way
• The r-process nucleosynthesis in the various jet-like explosions of magnetorotational core-collapse supernovae
• Supernova Nucleosynthesis in Population III 13 -- 50 $M_{\odot }$ Stars and Abundance Patterns of Extremely Metal-Poor Stars
• Neutrino-driven winds in the aftermath of a neutron star merger: nucleosynthesis and electromagnetic transients
• Chemodynamical Simulations of the Milky Way Galaxy
• The s-Process in Low Metallicity Stars. II. Interpretation of High-Resolution Spectroscopic Observations with AGB models
• Near-UV Observations of HD221170: New Insights into the Nature of r-Process-Rich Stars
• Short-lived Nuclei in the Early Solar System: Possible AGB Sources
• The NIR Ca II triplet at low metallicity - Searching for extremely low-metallicity stars in classical dwarf galaxies
• Neutron-capture elements in the very metal-poor star HD122563
• The Most Metal-Poor Stars. IV. The Two Populations With [Fe/H] < -3.0
• HE1327-2326, an unevolved star with [Fe/H]<-5.0. I. A Comprehensive Abundance Analysis
• Production of Light Element Primary Process nuclei in neutrino-driven winds
• Is HE0107-5240 A Primordial Star? -- The Characteristics of Extremely Metal-Poor Carbon-Rich Stars --
• New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars
• Spectroscopic Studies of Very Metal-Poor Stars with the Subaru High Dispersion Spectrograph. III. Light Neutron-Capture Elements
• Bright Metal-Poor Stars from the Hamburg/ESO Survey. I. Selection and Follow-up Observations from 329 Fields
• The intermediate r-process in core-collapse supernovae driven by the magneto-rotational instability
• The Role of Type Ia Supernovae in Chemical Evolution I: Lifetime of Type Ia Supernovae and Galactic Supernova Rates
• Complete element abundances of nine stars in the r-process galaxy Reticulum II
• Binarity in Carbon-Enhanced Metal-Poor stars
• The Ubiquity of the Rapid Neutron-Capture Process
• High-Resolution Spectroscopy of Extremely Metal-Poor Stars from SDSS/SEGUE: I. Atmospheric Parameters and Chemical Compositions
• Explorations of the r-Processes: Comparisons between Calculations and Observations of Low-Metallicity Stars
• The atmospheric parameters and spectral interpolator for the stars of MILES
• Chemical abundances of the Milky Way thick disk and stellar halo II.: sodium, iron-peak and neutron-capture elements
• Nucleosynthesis in the Early Galaxy
• Neutrino-driven wind simulations and nucleosynthesis of heavy elements
• r-Process Nucleosynthesis: Connecting Rare-Isotope Beam Facilities with the Cosmos
• The $R$-Process Alliance: First Release from the Southern Search for $r$-Process-Enhanced Stars in the Galactic Halo
• Extremely metal-poor stars in classical dwarf spheroidal galaxies: Fornax, Sculptor and Sextans
• The Hamburg/ESO R-process Enhanced Star survey (HERES) III. HE 0338-3945 and the formation of the r+s stars
• Silver and palladium help unveil the nature of a second r-process
• Neutron-capture elements in the very metal-poor star HD88609: another st ar with excesses of light neutron-capture elements
• Abundance Profiling of Extremely Metal-Poor Stars and Supernova Properties in the Early Universe
• The Hamburg/ESO R-process Enhanced Star survey (HERES). I. Project description, and discovery of two stars with strong enhancements of neutron-capture elements
• New Hubble Space Telescope Observations of Heavy Elements in Four Metal-Poor Stars
• JINAbase: A database for chemical abundances of metal-poor stars
• Stellar Archaeology -- Exploring the Universe with Metal-Poor Stars
• HST Observations of Heavy Elements in Metal-Poor Galactic Halo Stars
• High-Resolution Spectroscopic Study of Extremely Metal-Poor Star Candidates from the SkyMapper Survey
• The role of neutron star mergers in the chemical evolution of the Galactic halo
• Deriving Stellar Effective Temperatures of Metal-Poor Stars with the Excitation Potential Method
• The Origin of Carbon-Enhancement and Initial Mass Function of Extremely Metal-Poor Stars in the Galactic Halo
• Stellar Yields of Rotating First Stars. II. Pair Instability Supernovae and Comparison with Observations
• The End of Nucleosynthesis: Production of Lead and Thorium in the Early Galaxy
• Beta Decays of Isotones with Neutron Magic Number of N=126 and R-process Nucleosynthesis
• r-Process Calculations and Galactic Chemical Evolution
• Chemical Composition of Extremely Metal-Poor Stars in the Sextans Dwarf Spheroidal Galaxy
• The s-process in the Galactic halo: the fifth signature of spinstars in the early Universe?
• Four-hundred Very Metal-Poor Stars Studied with LAMOST and Subaru. II. Elemental abundances
• The Stellar Abundances for Galactic Archaeology (SAGA) Database II - Implications for Mixing and Nucleosynthesis in Extremely Metal-Poor Stars and Chemical Enrichment of the Galaxy
• Evolution of the Barium abundance in the early Galaxy from a NLTE analysis of the Ba lines in a homogeneous sample of EMP stars
• Enrichment of r-process elements in dwarf spheroidal galaxies in chemo-dynamical evolution model
• Neutron Star Mergers as the Origin of r-Process Elements in the Galactic Halo Based on the Sub-halo Clustering Scenario
• Iron-Group Abundances in the Metal-Poor Main Sequence Turnoff Star HD~84937
• CS 30322-023: an ultra metal-poor TP-AGB star?
• The chemical evolution of Barium and Europium in the Milky Way
• New analysis of the two carbon-rich stars CS 22948-27 and CS 29497-34 : binarity and neutron-capture elements
• Nucleosynthesis Modes in the High-Entropy-Wind of Type II Supernovae: Comparison of Calculations with Halo-Star Observations
• The Hamburg/ESO R-process Enhanced Star survey (HERES) IV. Detailed abundance analysis and age dating of the strongly r-process enhanced stars CS 29491-069 and HE 1219-0312
• Abundances of Sr, Y, and Zr in Metal-Poor Stars and Implications for Chemical Evolution in the Early Galaxy
• An inhomogeneous model for the Galactic halo: a possible explanation for the spread observed in s- and r-process elements
• A Search for Nitrogen-Enhanced Metal-Poor Stars
• Relative contributions of the weak, main and fission-recycling r-process
• Elemental abundances and classification of CEMP stars
• Explaining the Ba, Y, Sr, and Eu abundance scatter in metal-poor halo stars: constraints to the r-process
• The Hamburg/ESO R-process Enhanced Star survey (HERES). V. Detailed abundance analysis of the r-process enhanced star HE 2327-5642
• Principal Component Analysis on Chemical Abundances Spaces
• How many nucleosynthesis processes exist at low metallicity?
• The R-process Alliance: First Magellan/MIKE Release from the Southern Search for R-Process-enhanced Stars
• Kinematics of Highly R-Process-Enhanced Field Stars: Evidence for an Accretion Origin and Detection of Several Groups from Disrupted Satellites
• The r-process in the neutrino-driven wind from a black-hole torus
• The first carbon-enhanced metal-poor star found in the Sculptor dwarf spheroidal
• The Hamburg/ESO R-process Enhanced Star survey (HERES) X. HE 2252-4225, one more r-process enhanced and actinide-boost halo star
• Detailed Abundances of Two Very Metal-Poor Stars in Dwarf Galaxies
• Are There Any Stars Lacking Neutron-Capture Elements? Evidence from Strontium and Barium
• Chemical Analysis of the Ninth Magnitude Carbon-Enhanced Metal-Poor Star BD+44 493
• The early days of the Sculptor dwarf spheroidal galaxy
• The formation of the Milky Way halo and its dwarf satellites; a NLTE-1D abundance analysis. II. Early chemical enrichment
• Broadband UBVRI Photometry of Horizontal-Branch and Metal-Poor Candidates from the HK and Hamburg/ESO Surveys. I
• Nine New Metal-Poor Stars on the Subgiant and Red Horizontal Branches with High Levels of r-process Enhancement
• Estimation of Carbon Abundances in Metal-Poor Stars. I. Application to the "Strong G-band" stars of Beers, Preston, & Shectman
• Metal-Poor Stars and the Chemical Enrichment of the Universe
• Supernova neutrinos and nucleosynthesis
• The first determination of the actinide Th abundance for a red giant of the Ursa Minor dwarf galaxy
• Carbon and Strontium Abundances of Metal-Poor Stars
• Sensitivity of r-Process Nucleosynthesis to Light-Element Nuclear Reactions
• Extreme Enhancements of r-process Elements in the Cool Metal-Poor Main-Sequence Star SDSS J2357-0052
• From actinides to zinc: Using the full abundance pattern of the brightest star in Reticulum II to distinguish between different r-process sites
• Chemical Inhomogeneities in the Milky Way Stellar Halo
• Heavy elements and chemical enrichment in globular clusters
• Cosmic Neutron Star Merger Rate and Gravitational Waves constrained by the R Process Nucleosynthesis
• Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. IV. The alpha-Element-Enhanced Metal-Poor Star BS16934-002
• The lanthanide fraction distribution in metal-poor stars: a test of neutron star mergers as the dominant r-process site
• The Hobby-Eberly Telescope "Chemical Abundances of Stars in the Halo" (CASH) Project. I. The Lithium-, s-, and r-Enhanced Metal-Poor Giant HKII 17435-00532
• Contribution of Neutron Star Mergers to the R-process Chemical Evolution in the Hierarchical Galaxy Formation
• The R-Process Alliance: Chemo-Dynamically Tagged Groups of Halo $r$-Process-Enhanced Stars Reveal a Shared Chemical-Evolution History
• Neutron-capture elements in the metal-poor globular cluster M15
• The New Model of Chemical Evolution of r-process Elements Based on The Hierarchical Galaxy Formation I: Ba and Eu
• A comparison of the s- and r-process element evolution in local dwarf spheroidal galaxies and in the Milky Way
• The age of the Galactic thin disk from Th/Eu nucleocosmochronology III. Extended sample
• Nucleosynthesis and observation of the heaviest elements
• Fission Cycling in a Supernova r-process
• Computational issues in chemo-dynamical modelling of the formation and evolution of galaxies
• Detailed Abundance Analysis of the Brightest Star in Segue 2, the Least Massive Galaxy
• The K2 Galactic Archaeology Program Data Release 3: Age-abundance patterns in C1-C8 and C10-C18
• Statistical equilibrium of silicon in the atmospheres of metal-poor stars
• Element abundance patterns in stars indicate fission of nuclei heavier than uranium
• The value-added catalogue for LAMOST DR8 low-resolution spectra
• Nuclear physics uncertainties in neutrino-driven, neutron-rich supernova ejecta
• Analysis of 26 Barium Stars II. Contributions of s-, r- and p-processes in the production of heavy elements
• Stochastic Chemical Evolution of Galactic Subhalos and the Origin of r-Process Elements
• Stellar abundances and presolar grains trace the nucleosynthetic origin of molybdenum and ruthenium
• The origin of low [alpha/Fe] ratios in extremely metal-poor stars
• Early chemo-dynamical evolution of dwarf galaxies deduced from enrichment of r-process elements
• Abundances of disk and Bulge giants from high-resolution optical spectra III. Sc, V, Cr, Mn, Co, Ni
• Metal-poor stars observed with the automated planet finder telescope. I. Discovery of five carbon-enhanced metal-poor stars from LAMOST
• Neutron star mergers as the astrophysical site of the r-process in the Milky Way and its satellite galaxies
• Empirical Abundance Scaling Laws and Implications for the Gamma-Process in Core-Collapse Supernovae
• Carbon-Enhanced Metal-Poor Stars. Osmium and Iridium Abundances in the Neutron-Capture-Enhanced Subgiants CS31062-050 and LP625-44
• The 139La(n,gamma) cross section: key for the onset of the s process
• Constraining nucleosynthesis in neutrino-driven winds: observations, simulations and nuclear physics
• The R-Process Alliance: Abundance Universality among Some Elements at and between the First and Second R-Process Peaks
• The Hamburg/ESO R-process Enhanced Star survey (HERES) IX. Constraining pure r-process Ba/Eu abundance ratio from observations of r-II stars
• The chemical evolution of the dwarf Spheroidal galaxy Sextans
• High-resolution abundance analysis of HD 140283
• Chemical Compositions of Kinematically Selected Outer Halo Stars
• Constraints on stellar rotation from the evolution of Sr and Ba in the Galactic halo
• Thorium in solar twins: implications for habitability in rocky planets
• The R-Process Alliance: J1521-3538, a very metal-poor, extremely r-process-enhanced star with [Eu/Fe]=+2.2, and the class of r-III stars
• Tracing Pop III supernovae with extreme energies through the Sculptor dwarf spheroidal galaxy
• Origin of highly $r$-process-enhanced stars in a cosmological zoom-in simulation of a Milky Way-like galaxy
• R-process-rich stellar streams in the Milky Way
• Four-hundred Very Metal-poor Stars studied with LAMOST and Subaru. I. Survey Design, Follow-up Program, and Binary Frequency
• The R-Process Alliance: Chemo-Dynamically Tagged Groups II. An Extended Sample of Halo $r$-Process-Enhanced Stars
• $r$-process nucleosynthesis from compact binary mergers
• Enrichment of Heavy Elements in the red giant S15-19 in the Sextans Dwarf Spheroidal Galaxy
• Neutron-capture elements in dwarf galaxies II: Challenges for the s- and i-processes at low metallicity
• New Neutron-Capture Measurements in 23 Open Clusters. I. The R-Process
• Diversity of Abundance Patterns of Light Neutron-capture Elements in Very-metal-poor Stars
• Chemical Evolution of R-process Elements in Stars (CERES). I. Stellar parameters and chemical abundances from Na to Zr
• Nucleosynthesis Constraints on the Energy Growth Timescale of a Core-collapse Supernova Explosion
• Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. V. The Zn-Enhanced Metal-Poor Star BS 16920-017
• Common envelope jets supernova r-process yields can reproduce $[Eu/Fe]$ abundance evolution in the Galaxy
• Thorium-rich halo star HD221170: further evidence against the universality of the r-process
• Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances
• nu-Process Nucleosynthesis in Population III Core-Collapse Supernovae
• The Origin of the Heaviest Metals in Most Ultra-Faint Dwarf Galaxies
• New s-process path and its implication to 187Re-187Os nucleo-cosmochronometer
• Looking for imprints of the first stellar generations in metal-poor bulge field stars
• The Hamburg/ESO R-process Enhanced Star survey (HERES) VI. The Galactic Chemical Evolution of Silicon
• The Hamburg/ESO R-process Enhanced Star survey (HERES)VII. Thorium abundances in metal-poor stars
• Study of Neutron-Capture Element Abundances in Metal-Poor Stars
• Enrichment of Strontium in Dwarf Galaxies
• The contribution from rotating massive stars to the enrichment in Sr and Ba of the Milky Way
• LAMOST J2217+2104: a new member of carbon-enhanced extremely metal-poor stars with excesses of Mg and Si
• Pre-supernova mixing in CEMP-no source stars
• Investigation of the Puzzling Abundance Pattern in the Stars of the Fornax Dwarf Spheroidal Galaxy
• Reconstructing Masses of Merging Neutron Stars from Stellar $R$-Process Abundance Signatures
• Enrichment of the Galactic disc with neutron capture elements: Sr
• Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. III. Dynamically Tagged Groups and Chemodynamical Properties
• Decoding the compositions of four bright $r$-process-enhanced stars
• Chemical Evolution of Ytterbium in the Galactic Disk
• A spectroscopic survey of faint, high-Galactic-latitude red clump stars. I. The high resolution sample
• Abundance analysis of SDSS J134338.67+484426.6; an extremely metal-poor star from the MARVELS pre-survey
• Neutron stars mergers in a stochastic chemical evolution model: impact of time delay distributions
• The formation of the Milky Way halo and its dwarf satellites: A NLTE-1D abundance analysis. V. The Sextans galaxy
• Inferring the velocity of early massive stars from the abundances of extremely metal-poor stars
• Supernova Neutrino-Effects on R-Process Nucleosynthesis in Black Hole Formation
• Nucleosynthesis in Primordial Hypernovae
• A Critique of the Spite Plateau, and the Astration of Primordial Lithium
• Accuracy of spectroscopy-based radioactive dating of stars
• Carbon Abundances of Metal-Poor Star Determined from the C I 1.068-1.069 micron Lines
• s-process Enirchment of Ultrafaint Dwarf Galaxies
• Finding $r$-II sibling stars in the Milky Way with the Greedy Optimistic Clustering algorithm
• Impact of AGB stars on the chemical evolution of neutron-capture elements
• HCT/HESP study of two carbon stars from the LAMOST survey
• Chemical abundance analysis of extremely metal-poor stars in the Sextans dwarf spheroidal galaxy
• Spectroscopic study of four metal-poor carbon stars from the Hamburg/ESO Survey: On confirming the low-mass nature of their companions
• Observational nuclear astrophysics: neutron-capture element abundances in old, metal-poor stars
• The formation of the Milky Way halo and its dwarf satellites: a NLTE-1D abundance analysis. IV. Segue 1, Triangulum II, and Coma Berenices UFDs
• Neutron-capture elements in dwarf galaxies III: A homogenized analysis of 13 dwarf spheroidal and ultra-faint galaxies
• Palladium and silver abundances in stars with [Fe/H] > -2.6
• A holistic abundance analysis of r-rich stars
• Chemical Evolution of R-process Elements in Stars (CERES). III. Chemical abundances of neutron capture elements from Ba to Eu
• Chemodynamical study of two CEMP-no stars from the Hamburg/ESO Survey
• Study of the element abundances in HD 140283: the abundance robustness of the weak r- and main r-process stars
• Extremely Metal-Poor Stars and a Hierarchical Chemical Evolution Model
• High-resolution spectroscopic observations of the new CEMP-s star CD-50${}^{\circ }$776
• Is Germanium (Ge, Z=32) A Neutron-Capture Element?
• Europium enrichment and hierarchical formation of the Galactic halo
• Abundance Analysis of New $r$-Process-Enhanced Stars from the HESP-GOMPA Survey
• The study of s-process nucleosynthesis based on barium stars, CEMP-s and CEMP-r/s stars
• Probing the nucleosynthetic contribution of low-metallicity, low-mass star companions of CEMP stars
• A Sr-Rich Star on the Main Sequence of Omega Centauri
• An Actinide-boost Star Discovered in the Gaia-Sausage-Enceladus
• Estimating R-Process Yields from Abundances of the Metal-Poor Stars
• Detection of the actinide Th in an r-process-enhanced star with accretion origin
• Fuzzy Cluster Analysis: Application to Determining Metallicities for Very Metal-poor Stars
• First Star Survivors as Metal-Rich Halo Stars that Experienced Supernova Explosions in Binary Systems
• Chemical Evolution of the Juvenile Universe
• The neutron-capture and alpha-elements abundance ratios scatter in old stellar populations. Cosmological simulations of the stellar halo
• Efficient Searches for r-Process-Enhanced, Metal-Poor Stars
• LAMOST J045019.27+394758.7, with peculiar abundances of N, Na, V, Zn, is possibly a Sculptor dwarf galaxy escapee
• The yields of r-process elements and chemical evolution of the Galaxy
• An Alternative Formation Scenario for Uranium-rich Giants: Engulfing a Earth-like Planet
• Nucleosynthesis in Rotating massive stars and Abundances in the Early Galaxy
• Heavy Elements -- They came out of the blue
• Th/Eu abundance ratio of red giants in the Kepler Field
• "In-System" Fission-Events: An Insight into Puzzles of Exoplanets and Stars?
• Footprints of the weak s-process in the carbon-enhanced metal-poor star ET0097
• Study of The Abundance Patterns in The Metal-Poor Stellar Stream
• Supernova Nucleosynthesis in the Early Universe
• Silicon and Strontium abundances of very metal-poor stars determined from near-infrared spectra
• Early Cosmic Chemical Evolution: Relating the Origin of a Diffuse Intergalactic Medium and the First Long-Lived Stars
• Barium lines in high-quality spectra of two metal-poor giants in the Galactic halo
• The Origins of Neutron-capture Elements In Globular Cluster M22
• On the Chemical Composition of the Evolved Very Bright Metal-Poor Star HD 1936