Near-UV Observations of CS29497-030: New Constraints on Neutron-Capture Nucleosynthesis Processes

Abstract

Employing spectra obtained with the new Keck I HIRES near-UV sensitive detector, we have performed a comprehensive chemical composition analysis of the binary blue metal-poor star CS29497-030. Abundances for 29 elements and upper limits for an additional seven have been derived, concentrating on elements largely produced via neutron-capture nucleosynthesis. Included in our analysis are the two elements that define the termination point of the slow neutron-capture process, lead and bismuth. We determine an extremely high value of [Pb/Fe] = +3.65 +/- 0.07 (sigma = 0.13) from three features, supporting the single-feature result obtained in previous studies. We also detect Bi for the first time in a metal-poor star. Our derived Bi/Pb ratio is in accord with those predicted from the most recent FRANEC calculations of the slow neutron-capture process in low-mass AGB stars. We find that the neutron-capture elemental abundances of CS29497-030 are best explained by an AGB model that also includes very significant amounts of pre-enrichment of rapid neutron-capture process material in the protostellar cloud out of which the CS29497-030 binary system formed. Thus, CS29497-030 is both an ``r+s'' and ``extrinsic AGB'' star. Furthermore, we find that the mass of the AGB model can be further constrained by the abundance of the light odd-element [Na/Fe] which is sensitive to the neutron excess.

arXiv comment7 pages = 4 + 2 colour encapsulated postscript figures + 1 table; to appear in ApJ Letters; additional jpeg figure available at ftp://www.astro.caltech.edu/users/iii/cs29497030

References in corpus (12)

• Neutron capture in low mass Asymptotic Giant Branch stars: cross sections and abundance signatures
• The Rise of the s-Process in the Galaxy
• s Process in low-mass Asymptotic Giant Branch Stars
• Galactic chemical evolution of heavy elements: from Barium to Europium
• A Subaru/HDS study of Lead (Pb) abundances in eight s-process-element-rich, metal-poor stars
• Abundance Analysis of HE2148-1247, A Star With Extremely Enhanced Neutron Capture Elements
• More lead stars
• First stars IV.CS 29497-030: Evidence for operation of the s-process at very low metallicity
• New analysis of the two carbon-rich stars CS 22948-27 and CS 29497-34 : binarity and neutron-capture elements
• The s-process in metal-poor stars: Abundances for 22 neutron-capture elements in CS 31062-050
• Low-mass supernovae in the early Galactic halo: source of the double r/s-process enriched halo stars?
• Binary Blue Metal-Poor Stars: Evidence for AGB Mass Transfer

Cited by in corpus (60)

• The s Process: Nuclear Physics, Stellar Models, Observations
• Carbon Enhanced Metal-Poor Stars. I. Chemical Compositions of 26 Stars
• A Search for Stars of Very Low Metal Abundance. VI. Detailed Abundances of 313 Metal-Poor Stars
• 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
• The intermediate neutron-capture process and carbon-enhanced metal-poor stars
• From Nuclei to the Cosmos: Tracing Heavy-Element Production with the Oldest 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
• Iron and s-elements abundance variations in NGC5286: comparison with anomalous globular clusters and Milky Way satellites
• The Hamburg/ESO R-process Enhanced Star survey (HERES) III. HE 0338-3945 and the formation of the r+s stars
• JINAbase: A database for chemical abundances of metal-poor stars
• Stellar Archaeology -- Exploring the Universe with Metal-Poor Stars
• s-Process in Low Metallicity Stars. I. Theoretical Predictions
• Carbon-Enhanced Metal-Poor Stars. III. Main-Sequence Turn-Off Stars from the SDSS/SEGUE Sample
• Characterizing the Chemistry of the Milky Way Stellar Halo: Detailed Chemical Analysis of a Metal-Poor Stellar Stream
• s-Process in Low Metallicity Stars. III. Individual analysis of CEMP-s and CEMP-s/r with AGB models
• The Origin of Carbon-Enhancement and Initial Mass Function of Extremely Metal-Poor Stars in the Galactic Halo
• The End of Nucleosynthesis: Production of Lead and Thorium in the Early Galaxy
• First stars X. The nature of three unevolved Carbon-Enhanced Metal-Poor stars
• The Branchings of the Main s-process: Their Sensitivity to alpha-induced Reactions on 13C and 22Ne and to the Uncertainties of the Nuclear Network
• CS 30322-023: an ultra metal-poor TP-AGB star?
• CS22964-161: A Double-Lined Carbon- and s-Process-Enhanced Metal-Poor Binary Star
• Improved Laboratory Transition Probabilities for Er II and Applications to the Erbium Abundances of the Sun and Five r-Process Rich, Metal-Poor Stars
• A Search for Nitrogen-Enhanced Metal-Poor Stars
• Elemental abundances and classification of CEMP stars
• Detailed Abundances of Two Very Metal-Poor Stars in Dwarf Galaxies
• TOPoS: IV. Chemical abundances from high-resolution observations of seven EMP stars
• The Pristine Survey IV: Approaching the Galactic metallicity floor with the discovery of an ultra metal-poor star
• Metal-Poor Stars Observed with the Magellan Telescope I. Constraints on Progenitor Mass and Metallicity of AGB Stars Undergoing s-Process Nucleosynthesis
• Nine New Metal-Poor Stars on the Subgiant and Red Horizontal Branches with High Levels of r-process Enhancement
• Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution. I. Detailed analysis of 15 binary stars with known orbital periods
• Non-LTE effects on the lead and thorium abundance determinations for cool stars
• Learning about the intermediate neutron-capture process from lead abundances
• 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
• Constraints of the physics of low-mass AGB stars from CH and CEMP stars
• How plausible are the proposed formation scenarios of CEMP-r/s stars?
• Rubidium and lead abundances in giant stars of the globular clusters M 13 and NGC 6752
• Hubble Space Telescope Near-Ultraviolet Spectroscopy of Bright CEMP-s Stars
• Chemical abundances in bright giants of the globular cluster M62 (NGC 6266)
• Fluorine in carbon-enhanced metal-poor stars: a binary scenario
• Enrichment of Very Metal-Poor Stars with Both r-Process and s-Process Elements from 8-10 M_\odot Stars
• The R-Process Alliance: Discovery of the first metal-poor star with a combined r- and s-process element signature
• Spectroscopic study of CEMP-(s & r/s) stars- Revisiting classification criteria and formation scenarios, highlighting i-process nucleosynthesis
• Carbon-Enhanced Metal-Poor Stars. Osmium and Iridium Abundances in the Neutron-Capture-Enhanced Subgiants CS31062-050 and LP625-44
• The Chemical Compositions of Very Metal-Poor Stars HD 122563 and HD 140283; A View From the Infrared
• The 139La(n,gamma) cross section: key for the onset of the s process
• Neutron-capture elements in the s- and r-process-rich stars: Constraints on neutron-capture nucleosynthesis processes
• Investigation of a sample of carbon-enhanced metal-poor stars observed with FORS and GMOS
• Detection of Pb II in the Ultraviolet Spectra of Three Metal-Poor Stars
• HCT/HESP study of two carbon stars from the LAMOST survey
• Observational nuclear astrophysics: neutron-capture element abundances in old, metal-poor stars
• Constraining Nucleosynthesis in Two CEMP Progenitors Using Fluorine
• Investigation for the enrichment pattern of the element abundances in r+s star HE 0338-3945: a special r-II star?
• The intermediate neutron capture process. I. Development of the i-process in low-metallicity low-mass AGB stars
• The study of s-process nucleosynthesis based on barium stars, CEMP-s and CEMP-r/s stars
• Investigation of the single neutron exposure model for the s-process: the primary nature of the neutron source
• The true nature of HE0057-5959, the most metal-poor Li-rich star
• i-process nucleosynthesis: observational evidences from CEMP stars
• CEMP-s and CEMP-s/r stars: last update