We present radial velocities, equivalent widths, model atmosphere parameters,
and abundances or upper limits for 53 species of 48 elements derived from high
resolution optical spectroscopy of 313 metal-poor stars. A majority of these
stars were selected from the metal-poor candidates of the HK Survey of Beers,
Preston, and Shectman. We derive detailed abundances for 61% of these stars for
the first time. Spectra were obtained during a 10-year observing campaign using
the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at
Las Campanas Observatory, the Robert G. Tull Coude Spectrograph on the Harlan
J. Smith Telescope at McDonald Observatory, and the High Resolution
Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform
a standard LTE abundance analysis using MARCS model atmospheres, and we apply
line-by-line statistical corrections to minimize systematic abundance
differences arising when different sets of lines are available for analysis. We
identify several abundance correlations with effective temperature. A
comparison with previous abundance analyses reveals significant differences in
stellar parameters, which we investigate in detail. Our metallicities are, on
average, lower by approx. 0.25 dex for red giants and approx. 0.04 dex for
subgiants. Our sample contains 19 stars with [Fe/H] < -3.5, 84 stars with
[Fe/H] < -3.0, and 210 stars with [Fe/H] < -2.5. Detailed abundances are
presented here or elsewhere for 91% of the 209 stars with [Fe/H] < -2.5 as
estimated from medium resolution spectroscopy by Beers, Preston, and Shectman.
We will discuss the interpretation of these abundances in subsequent papers.Comment: Accepted for publication in the Astronomical Journal. 60 pages, 59
figures, 18 tables. Machine-readable versions of the long tables can be found
in the ancillary data file
