Four-hundred Very Metal-poor Stars studied with LAMOST and Subaru. I. Survey Design, Follow-up Program, and Binary Frequency

Abstract

The chemical abundances of very metal-poor stars provide important constraints on the nucleosynthesis of the first generation of stars and early chemical evolution of the Galaxy. We have obtained high-resolution spectra with the Subaru Telescope for candidates of very metal-poor stars selected with a large survey of Galactic stars carried out with LAMOST. In this series of papers, we report on the elemental abundances of about 400 very metal-poor stars and discuss the kinematics of the sample obtained by combining the radial velocities measured in this study and recent astrometry obtained with Gaia. This paper provides an overview of our survey and follow-up program, and reports radial velocities for the whole sample. We identify seven double-lined spectroscopic binaries from our high-resolution spectra, for which radial velocities of the components are reported. We discuss the frequency of such relatively short-period binaries at very low metallicity.

arXiv comment24 pages, 9 figures, 5 tables, to appear in ApJ

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Cited by in corpus (13)

• Four-hundred Very Metal-Poor Stars Studied with LAMOST and Subaru. II. Elemental abundances
• On the inconsistency of [C/Fe] abundances and the fractions of carbon-enhanced metal-poor stars among various stellar surveys
• True Pair-instability Supernova Descendant: Implications for the First Stars' Mass Distribution
• Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. III. Dynamically Tagged Groups and Chemodynamical Properties
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• A Catalog of 12,766 Carbon-enhanced Metal-poor Stars from LAMOST Data Release 8
• Detection of the actinide Th in an r-process-enhanced star with accretion origin
• Unevolved Li-rich stars at low metallicity: a possible formation pathway through novae
• Main-sequence Turnoff Stars as Probes of the Ancient Galactic Relic: Chemo-dynamical Analysis of a Pilot Sample
• Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. IV. Heavy Element Enhanced Stars