Lithium abundances in CEMP stars

Abstract

Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical imprints of more massive stars (M > 0.8 Msun) that are now extinct. In particular, it is expected that the observed abundance of Li should deviate in these stars from the standard Spite lithium plateau. We study here a sample of 11 metal-poor stars and a double-lined spectroscopic binary with -1.8 <[Fe/H]< -3.3 observed with VLT/UVES spectrograph. Among these 12 metal-poor stars, there are 8 CEMP stars for which we measure or constrain the Li abundance. In contrast to previous arguments, we demonstrate that an appropriate regime of dilution permits the existence of "Li-Spite plateau and C-rich" stars, whereas some of the "Li-depleted and C-rich" stars call for an unidentified additional depletion mechanism that cannot be explained by dilution alone. We find evidence that rotation is related to the Li depletion in some CEMP stars. Additionally, we report on a newly recognized double-lined spectroscopic binary star in our sample. For this star, we develop a new technique from which estimates of stellar parameters and luminosity ratios can be derived based on a high-resolution spectrum alone, without the need for input from evolutionary models.

62 pages, 16 figures, accepted for publication in ApJ

References in corpus (76)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Evolution of binary stars and the effect of tides on binary populations
• Theoretical isochrones in several photometric systems I. Johnson-Cousins-Glass, HST/WFPC2, HST/NICMOS, Washington, and ESO Imaging Survey filter sets
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• Updated stellar yields from Asymptotic Giant Branch models
• Carbon Enhanced Metal-Poor Stars. I. Chemical Compositions of 26 Stars
• The extreme r-element rich, iron-poor halo giant CS31082-001: Implications for the r-process site(s) and radioactive cosmochronology
• Lithium isotopic abundances in metal-poor halo stars
• Evolution, nucleosynthesis and yields of low mass AGB stars
• The Stellar Abundances for Galactic Archeology (SAGA) Database - Compilation of the Characteristics of Known Extremely Metal-Poor Stars
• First-generation black-hole-forming supernovae and the metal abundance pattern of a very iron-poor star
• The Victoria-Regina Stellar Models: Evolutionary Tracks and Isochrones for a Wide Range in Mass and Metallicity that Allow for Empirically Constrained Amounts of Convective Core Overshooting
• The early star generations: the dominant effect of rotation on the CNO yields
• The Binary Frequency Among Carbon-Enhanced, s-Process Rich, Metal-Poor Stars
• Thermohaline mixing: A physical mechanism governing the photospheric composition of low-mass giants
• Stellar Models and Yields of Asymptotic Giant Branch Stars
• Thermohaline instability and rotation-induced mixing. I - Low- and intermediate-mass solar metallicity stars up to the end of the AGB
• Implications of WMAP observations on Li abundance and stellar evolution models
• Cool bottom processes on the thermally-pulsing AGB and the isotopic composition of circumstellar dust grains
• Very low metallicity massive star models: Pre-SN evolution and primary nitrogen production
• HE 0557-4840 - Ultra-Metal-Poor and Carbon-Rich
• The metal-poor end of the Spite plateau. 1: Stellar parameters, metallicities and lithium abundances
• A holistic approach to carbon-enhanced metal-poor stars
• First stars VII. Lithium in extremely metal poor dwarfs
• HE0107-5240, A Chemically Ancient Star.I. A Detailed Abundance Analysis
• Hydrodynamical stellar models including rotation, internal gravity waves and atomic diffusion. I. Formalism and tests on Pop I dwarfs
• Parameterising the third dredge-up in asymptotic giant branch stars
• The Frequency of Carbon-Enhanced Metal-Poor Stars in the Galaxy from the HERES sample
• Is HE0107-5240 A Primordial Star? -- The Characteristics of Extremely Metal-Poor Carbon-Rich Stars --
• A Subaru/HDS study of Lead (Pb) abundances in eight s-process-element-rich, metal-poor stars
• The stellar content of the Hamburg/ESO survey. IV. Selection of candidate metal-poor stars
• Lithium Abundances of Extremely Metal-Poor Turn-off Stars
• First Stars II. Elemental abundances in the extremely metal-poor star CS 22949--037: A diagnostic of early massive supernovae
• HE 1327-2326, an unevolved star with [Fe/H]<-5.0. II. New 3D-1D corrected abundances from a VLT/UVES spectrum
• The Hamburg/ESO R-process Enhanced Star survey (HERES) III. HE 0338-3945 and the formation of the r+s stars
• Evolution and Nucleosynthesis of Extremely Metal Poor & Metal-Free Low- and Intermediate-Mass Stars I: Stellar Yield Tables and the CEMPs
• Population Synthesis of Binary Carbon-enhanced Metal-poor Stars
• Neutron Capture Elements in s-Process-Rich, Very Metal-Poor Stars
• Observational evidence for a broken Li Spite plateau and mass-dependent Li depletion
• s-Process in Low Metallicity Stars. I. Theoretical Predictions
• The Chemical Composition of Carbon-Rich, Very Metal-Poor Stars: A New Class of Mildly Carbon-Rich Objects Without Excess of Neutron-Capture Elements
• Evolution and Yields of Extremely Metal Poor Intermediate Mass Stars
• Carbon-Enhanced Metal-Poor Stars. III. Main-Sequence Turn-Off Stars from the SDSS/SEGUE Sample
• Stellar Archaeology: a Keck Pilot Program on Extremely Metal- Poor Stars From the Hamburg/ESO Survey. III. The Lead (Pb) Star HE 0024-2523
• Are C-rich ultra iron poor stars also He-rich?
• Carbon Stars in the Hamburg/ESO Survey: Abundances
• First stars IV.CS 29497-030: Evidence for operation of the s-process at very low metallicity
• First stars X. The nature of three unevolved Carbon-Enhanced Metal-Poor stars
• Numerical Simulations of Thermohaline Convection: Implications for Extra-Mixing in Low-Mass RGB Stars
• Analysis of the carbon-rich very metal-poor dwarf G77-61
• Thermohaline mixing and gravitational settling in carbon-enhanced metal-poor stars
• CS 30322-023: an ultra metal-poor TP-AGB star?
• CS22964-161: A Double-Lined Carbon- and s-Process-Enhanced Metal-Poor Binary Star
• New analysis of the two carbon-rich stars CS 22948-27 and CS 29497-34 : binarity and neutron-capture elements
• Three carbon-enhanced metal-poor dwarf stars from the SDSS - Chemical abundances from CO^5BOLD 3D hydrodynamical model atmospheres
• A Search for Nitrogen-Enhanced Metal-Poor Stars
• Observational evidence for a different IMF in the early Galaxy
• The depletion of carbon by extra mixing in metal-poor giants
• The effects of thermohaline mixing on low-metallicity asymptotic giant branch stars
• Ultra-Lithium-Deficient Halo Stars and Blue Stragglers: A Common Origin?
• Deep Mixing in Evolved Stars. II. Interpreting Li Abundances in RGB and AGB Stars
• The evolution of low-metallicity asymptotic giant branch stars and the formation of carbon-enhanced metal-poor stars
• 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
• Rapid rotation of ultra-Li-depleted halo stars and their association with blue stragglers
• Evolution of Low- and Intermediate-Mass Stars with [Fe/H] <= -2.5
• Binary Blue Metal-Poor Stars: Evidence for AGB Mass Transfer
• First Stars XI. Chemical composition of the extremely metal-poor dwarfs in the binary CS 22876--032
• Extremely Metal-Poor Stars. VII. The Most Metal-Poor Dwarf, CS 22876-032
• The role of lithium production in massive AGB and super--AGB stars for the understanding of multiple populations in Globular Clusters
• Light element abundances in carbon-enhanced metal-poor stars
• Lithium abundances and extra mixing processes in evolved stars of M67
• First detection of a lithium rich carbon star in the Draco dwarf galaxy: evidence for a young stellar population
• Beryllium abundances along the evolutionary sequence of the open cluster IC 4651 - New test for hydrodynamical stellar models
• Carbon-Enhanced Metal-Poor Stars. Osmium and Iridium Abundances in the Neutron-Capture-Enhanced Subgiants CS31062-050 and LP625-44
• [O/Fe] Estimates for Carbon-Enhanced Metal-Poor Stars from Near-IR Spectroscopy
• Correlation between technetium and lithium in a sample of oxygen-rich AGB variables

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• Chemical evolution with rotating massive star yields: I. The solar neighbourhood and the s-process elements
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• CH in stellar atmospheres: an extensive linelist
• Observational Constraints on First-Star Nucleosynthesis. I. Evidence for Multiple Progenitors of CEMP-no Stars
• TOPoS: II. On the bimodality of carbon abundance in CEMP stars. Implications on the early chemical evolution of galaxies
• Binarity in Carbon-Enhanced Metal-Poor stars
• Carbon-enhanced metal-poor stars: the most pristine objects?
• An Elemental Assay of Very, Extremely, and Ultra Metal-Poor Stars
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• JINAbase: A database for chemical abundances of metal-poor stars
• Four-hundred Very Metal-Poor Stars Studied with LAMOST and Subaru. II. Elemental abundances
• The role of binaries in the enrichment of the early Galactic halo. II. Carbon-Enhanced Metal-Poor Stars - CEMP-no stars
• Exploring the Origin of Lithium, Carbon, Strontium and Barium with four new Ultra Metal-Poor Stars
• Cannibals in the thick disk: the young $\alpha -$rich stars as evolved blue stragglers
• Metal-Poor Stars Observed with the Magellan Telescope. III. New Extremely and Ultra Metal-Poor Stars from SDSS/SEGUE and Insights on the Formation of Ultra Metal-Poor Stars
• 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
• Lithium-Rich Giants in Globular Clusters
• From actinides to zinc: Using the full abundance pattern of the brightest star in Reticulum II to distinguish between different r-process sites
• Learning about the intermediate neutron-capture process from lead abundances
• High-resolution spectroscopic studies of ultra metal-poor stars found in LAMOST survey
• The R-Process Alliance: Chemo-Dynamically Tagged Groups of Halo $r$-Process-Enhanced Stars Reveal a Shared Chemical-Evolution History
• Hubble Space Telescope Near-Ultraviolet Spectroscopy of the Bright CEMP-no Star BD+44 493
• High-resolution spectroscopy of extremely metal-poor stars from SDSS/SEGUE. III. Unevolved Stars with $[Fe/H]\lesssim -3.5$
• The S2 Stream: the shreds of a primitive dwarf galaxy
• Constraints on CEMP-no progenitors from nuclear astrophysics
• The low Sr/Ba ratio on some extremely metal-poor stars
• Lithium in CEMP-no stars: A new constraint on the lithium depletion mechanism in the early universe
• The R-Process Alliance: Chemo-Dynamically Tagged Groups II. An Extended Sample of Halo $r$-Process-Enhanced Stars
• Carbon-enhanced Metal-poor Stars in SDSS/SEGUE. II. Comparison of CEMP Star Frequencies with Binary Population Synthesis Models
• How much mass and angular momentum can the progenitors of carbon-enriched stars accrete?
• Abundance analysis of a CEMP-no star in the Carina dwarf spheroidal galaxy
• On the 12C/13C isotopic ratio at the dawn of chemical evolution
• Gaia-Sausage-Enceladus star formation history as revealed by detailed elemental abundances
• Investigation of a sample of carbon-enhanced metal-poor stars observed with FORS and GMOS
• Seven New Carbon-Enhanced Metal-Poor RR Lyrae Stars
• Inferring the velocity of early massive stars from the abundances of extremely metal-poor stars
• Modelling the nucleosynthetic properties of carbon-enhanced metal-poor RR Lyrae stars
• The metal-poor end of the Spite plateau. II. Detailed chemical investigation
• Chemical composition of two bright extremely metal-poor stars from the SDSS MARVELS pre-survey
• The pristine nature of SMSS 1605$-$1443 revealed by ESPRESSO
• Detailed abundances in a sample of very metal poor stars
• Matter accretion in metal-poor stars down to extremely metal-poor stars and the lithium problem
• Rotational mixing in carbon-enhanced metal-poor stars with s-process enrichment
• Europium enrichment and hierarchical formation of the Galactic halo
• Something borrowed, something blue: The nature of blue metal-poor stars inferred from their colours and chemical abundances
• Field Blue Stragglers and Related Mass Transfer Issues
• The true nature of HE0057-5959, the most metal-poor Li-rich star
• First Star Survivors as Metal-Rich Halo Stars that Experienced Supernova Explosions in Binary Systems
• Fuzzy Cluster Analysis: Application to Determining Metallicities for Very Metal-poor Stars
• Recent Advances in Understanding R-Process Nucleosynthesis in Metal-Poor Stars and Stellar Systems
• An empirical metallicity tracer in CEMP and C-normal stars
• Dynamical mass of a solar-like oscillator at the main-sequence turnoff from Gaia astrometry & ground-based spectroscopy
• Gaia-Sausage-Enceladus: Lithium evolution from early red-giant-branch and main-sequence stars