A Catalog of Spectroscopically Confirmed White Dwarfs from the Sloan Digital Sky Survey Data Release 4

Abstract

We present a catalog of 9316 spectroscopically confirmed white dwarfs from\nthe Sloan Digital Sky Survey Data Release 4. We have selected the stars through\nphotometric cuts and spectroscopic modeling, backed up by a set of visual\ninspections. Roughly 6000 of the stars are new discoveries, roughly doubling\nthe number of spectroscopically confirmed white dwarfs. We analyze the stars by\nperforming temperature and surface gravity fits to grids of pure hydrogen and\nhelium atmospheres. Among the rare outliers are a set of presumed helium-core\nDA white dwarfs with estimated masses below 0.3 Msun, including two candidates\nthat may be the lowest masses yet found. We also present a list of 928 hot\nsubdwarfs.\n