SDSS DR7 WHITE DWARF CATALOG

Abstract

We present a new catalog of spectroscopically-confirmed white dwarf stars\nfrom the Sloan Digital Sky Survey Data Release 7 spectroscopic catalog. We find\n20,407 white dwarf spectra, representing 19,712 stars, and provide atmospheric\nmodel fits to 14,120 DA and 1011 DB white dwarf spectra from 12,843 and 923\nstars, respectively. These numbers represent a more than factor of two increase\nin the total number of white dwarf stars from the previous SDSS white dwarf\ncatalog based on DR4 data. Our distribution of subtypes varies from previous\ncatalogs due to our more conservative, manual classifications of each star in\nour catalog, supplementing our automatic fits. In particular, we find a large\nnumber of magnetic white dwarf stars whose small Zeeman splittings mimic\nincreased Stark broadening that would otherwise result in an overestimated\nlog(g) if fit as a non-magnetic white dwarf. We calculate mean DA and DB masses\nfor our clean, non-magnetic sample and find the DB mean mass is statistically\nlarger than that for the DAs.\n