The Binary Frequency Among Carbon-Enhanced, s-Process Rich, Metal-Poor Stars

Abstract

We discuss radial velocities for a sample of carbon-enhanced, s-process rich, very metal-poor stars (CEMP-s hereafter), analyzed with high-resolution spectroscopy obtained over multiple epochs. We find that ~68% of the stars in the sample show evidence of radial velocity variations. The expected detection fraction for these stars, adopting the measured binary fraction in the field (~60%), and assuming that they share the same period and eccentricity distribution, is ~22%. Even if one assumes that the true binary fraction of these stars is 100%, the expected detection percentage is ~36%. These values indicate that the binary fraction among CEMP-s stars is higher than the field binary fraction, suggesting that all of these objects are in double (or multiple) systems. The fact that the observed frequency of velocity variation exceeds the expected detection fraction in the case of an assumed binary fraction of 100% is likely due to a more restricted distribution of orbital periods for these objects, as compared to normal field binaries. Our results indicate that CEMP-s stars are the metal-poor analogues of classical CH-stars.

22 pages, Accepted for publication on ApJ

References in corpus (22)

• The Extremely Metal-Poor, Neutron-Capture-Rich Star CS 22892-052: A Comprehensive Abundance Analysis
• The Y^2 Stellar Evolutionary Tracks
• O/Fe in metal-poor main sequence and subgiant stars
• A Subaru/HDS study of Lead (Pb) abundances in eight s-process-element-rich, metal-poor stars
• First Stars II. Elemental abundances in the extremely metal-poor star CS 22949--037: A diagnostic of early massive supernovae
• Neutron Capture Elements in s-Process-Rich, Very Metal-Poor Stars
• The stellar content of the Hamburg/ESO survey. II. A large, homogeneously-selected sample of high latitude carbon stars
• The Chemical Composition of Carbon-Rich, Very Metal-Poor Stars: A New Class of Mildly Carbon-Rich Objects Without Excess of Neutron-Capture Elements
• Abundance Analysis of HE2148-1247, A Star With Extremely Enhanced Neutron Capture Elements
• Stellar Archaeology: a Keck Pilot Program on Extremely Metal- Poor Stars From the Hamburg/ESO Survey. III. The Lead (Pb) Star HE 0024-2523
• More lead stars
• First stars IV.CS 29497-030: Evidence for operation of the s-process at very low metallicity
• Chemical Composition of the Carbon-rich, Extremely Metal-Poor Star CS 29498--043: A New Class of Extremely Metal-Poor Stars with Excesses of Magnesium and Silicon
• New analysis of the two carbon-rich stars CS 22948-27 and CS 29497-34 : binarity and neutron-capture elements
• The stellar content of the Hamburg/ESO survey. I. Automated selection of DA white dwarfs
• The Isotopic Mixture of Barium in the Metal-poor Subgiant HD 140283
• Ultra-Lithium-Deficient Halo Stars and Blue Stragglers: A Common Origin?
• Chemical composition of carbon-rich, very metal-poor subgiant LP625-44 observed with the Subaru/HDS
• Rapid rotation of ultra-Li-depleted halo stars and their association with blue stragglers
• Binary Blue Metal-Poor Stars: Evidence for AGB Mass Transfer
• A CCD Imaging Search for Wide Metal-Poor Binaries
• The surface carbon and nitrogen abundances in models of ultra metal-poor stars

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• 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
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• The Close Binary Fraction of Solar-type Stars is Strongly Anti-correlated with Metallicity
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• Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy
• The intermediate neutron-capture process and carbon-enhanced metal-poor stars
• 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
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• First stars X. The nature of three unevolved Carbon-Enhanced Metal-Poor stars
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• An Extremely Carbon-rich, Extremely Metal-poor Star in the Segue 1 System
• The Diverse Origins of Neutron-Capture Elements in the Metal-Poor Star HD 94028: Possible Detection of Products of i-process Nucleosynthesis
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• Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution. I. Detailed analysis of 15 binary stars with known orbital periods
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• Three-dimensional hydrodynamical simulations of mass transfer in binary systems by a free wind
• Gone with the wind: the impact of wind mass transfer on the orbital evolution of AGB binary systems
• 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
• Gravitational instability in protostellar disks at low metallicities
• Binary Stars in the New Millennium
• The incidence of binaries in Globular Cluster stellar populations
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• The Pristine Inner Galaxy Survey (PIGS) III: carbon-enhanced metal-poor stars in the bulge
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• The Chemical Abundances of Stars in the Halo (CASH) Project. III. A New Classification Scheme for Carbon-Enhanced Metal-poor Stars with S-process Element Enhancement
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