Spectroscopic Studies of Extremely Metal-Poor Stars with Subaru/HDS:I. Observational Data

Abstract

We have obtained high-resolution (R $\simeq$ 50,000 or 90,000), high-quality (S/N $\ga$ 100) spectra of 22 very metal-poor stars ([Fe/H] $\la$ -2.5) with the High Dispersion Spectrograph fabricated for the 8.2m Subaru Telescope. The spectra cover the wavelength range from 3500 to 5100 Å; equivalent widths are measured for isolated lines of numerous elemental species, including the $\alpha$ elements, the iron-peak elements, and the light and heavy neutron-capture elements. Errors in the measurements and comparisons with previous studies are discussed. These data will be used to perform detailed abundance analyses in the following papers of this series. Radial velocities are also reported, and are compared with previous studies. At least one moderately r-process-enhanced metal-poor star, HD 186478, exhibits evidence of a small-amplitude radial velocity variation, confirming the binary status noted previously. During the course of this initial program, we have discovered a new moderately r-process-enhanced, very metal-poor star, CS 30306-132 ([Fe/H] $=-2.4$; [Eu/Fe] $=+0.85$), which is discussed in detail in the companion paper.

arXiv comment31 pages, 17 Postscript figures, accepted for publication in ApJS

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• Composition of the Innermost Core Collapse Supernova Ejecta
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• The Hamburg/ESO R-process Enhanced Star survey (HERES) III. HE 0338-3945 and the formation of the r+s stars
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• Non-LTE Line-Formation and Abundances of Sulfur and Zinc in F, G, and K Stars
• The Most Metal-Poor Stars. III. The Metallicity Distribution Function and CEMP Fraction
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• The role of binaries in the enrichment of the early Galactic halo. II. Carbon-Enhanced Metal-Poor Stars - CEMP-no stars
• The extremely low-metallicity tail of the Sculptor dwarf spheroidal galaxy
• A Search for Nitrogen-Enhanced Metal-Poor Stars
• Neutron-Capture Nucleosynthesis in the First Stars
• Principal Component Analysis on Chemical Abundances Spaces
• The Stellar Abundances for Galactic Archaeology (SAGA) Database III - Analysis of Enrichment Histories for Elements and Two Modes of Star Formation during the Early Evolution of Milky Way
• The Most Metal-Poor Stars. I. Discovery, Data, and Atmospheric Parameters
• 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
• New Abundance Determinations of Cadmium, Lutetium, and Osmium in the r-process Enriched Star BD+173248
• Chemical Inhomogeneities in the Milky Way Stellar Halo
• Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. IV. The alpha-Element-Enhanced Metal-Poor Star BS16934-002
• Chemistry of the Most Metal-poor Stars in the Bulge and the z > 10 Universe
• The role of binaries in the enrichment of the early Galactic halo. I. r-process-enhanced metal-poor stars
• Detailed Abundances of 15 Stars in the Metal-Poor Globular Cluster NGC 4833
• High-resolution abundance analysis of HD 140283
• Spectroscopic Studies of Extremely Metal-Poor Stars with the Subaru High Dispersion Spectrograph. V. The Zn-Enhanced Metal-Poor Star BS 16920-017
• Origin of the heavy elements in HD 140283. Measurement of europium abundance
• Silicon and Strontium abundances of very metal-poor stars determined from near-infrared spectra