The Most Metal-Poor Candidates in SDSS-I DR-5

Beers, Timothy C.; Lee, Y.; Sivarani, T.; Marsteller, B.; Krugler, J.; Wilhelm, R.; Allende Prieto, C.; Norris, J.; Johnson, J.; Ivans, I.; Yanny, B.; Rockosi, C.; Morrison, H.; Newberg, H. J.; Knapp, J.
Bibliographical reference

2007 AAS/AAPT Joint Meeting, American Astronomical Society Meeting 209, #168.08; Bulletin of the American Astronomical Society, Vol. 38, p.1139

Advertised on:
12
2006
Number of authors
15
IAC number of authors
0
Citations
2
Refereed citations
2
Description
There are some 194,000 R = 2000 stellar spectra reported in the final public release of the Sloan Digital Sky Survey (SDSS-I), known as DR-5. Setting aside the stars observed during the course of early tests for the Sloan Extension for Galactic Understanding and Exploration (SEGUE), which will be considered in the future, this leaves a total of about 168,000 stellar spectra. The stars in this sample were targeted for a wide variety of reasons, and hence do not represent a sample from which an unbiased metallicity distribution function (MDF) of stars in the halo or thick-disk populations may be drawn. However, there exist some 6500 stars with estimated metallicities [Fe/H] < -2.0 and effective temperatures in the range 5000K < Teff < 7000K among this sample, based on application of the SDSS/SEGUE spectroscopic analysis pipeline described in other contributions at this meeting. This sample represents, by a factor of more than three, the largest database of very metal-poor stars yet assembled. A least 1000 of these stars have g < 16.5, and hence are amenable to high-resolution spectroscopic studies with presently available large-aperture telescopes. We report on the catalog of these stars, and consider the shape of the low-metallicity tail of the halo MDF derived from these data. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS Web Site is http://www.sdss.org/.