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Description
This is the Sloan Digital Sky Survey (SDSS) Data Release 4 (DR4) Catalog of White Dwarfs (WDs) and Hot Subdwarf (SD) stars. It contains 9316 spectroscopically confirmed white dwarfs which have been selected through photometric cuts and spectroscopic modeling, backed up by a set of visual inspections. About 6000 of the WD stars are new discoveries, roughly doubling the number of spectroscopically confirmed WD stars. The authors have analyzed the stars by performing temperature and surface gravity fits to grids of pure hydrogen and helium atmospheres. Among the rare outliers are a set of presumed helium-core DA WDs with estimated masses below 0.3 solar masses, including two candidates that may be the lowest-mass WDs yet found. This catalog also contains a list of 928 hot SD stars. The SDSS DR4 (Adelman-McCarthy et al. 2006, ApJS, 162, 38; see also <a href="http://www.sdss.org/dr4/">http://www.sdss.org/dr4/</a> ) contains 800,000 spectra from 4783 square degrees. The authors have used automated techniques supplemented by visual classification to select 13,000 candidates. An extensive analysis of these objects has yielded 9316 white dwarfs, including 8000 DA, 713 DB, 41 DO or PG1159, 289 DC, 104 DQ, and 133 DZ types, as well as 928 hot subdwarf stars. As well as the 10,244 primary spectra, the authors have also presented 774 duplicate spectra of WD stars and 60 duplicate spectra of SD stars. Thus, the present table has 11,078 (=10,244 + 774 + 60) entries. Much more information on the SDSS is available at the project's web site at <a href="http://www.sdss.org/">http://www.sdss.org/</a>. This table was created by the HEASARC in February 2007 based on the merger of Table 1B and 1C obtained from the electronic ApJS website. This is a service provided by NASA HEASARC .
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