New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12

TL;DR

This paper reports the discovery of over six thousand new white dwarf and subdwarf stars in SDSS DR12, providing detailed spectral analysis, classifications, and population distributions, significantly expanding the known sample of these stellar remnants.

Contribution

It presents a large, spectroscopically confirmed catalog of white dwarf and subdwarf stars with detailed atmospheric parameters and classifications, including new types and binary systems, based on SDSS DR12 data.

Findings

Discovered 6576 new white dwarf and subdwarf stars.

Provided atmospheric parameters and classifications for these stars.

Analyzed the mass distribution of hydrogen-dominated white dwarfs.

Abstract

We report the discovery of 6576 new spectroscopically confirmed white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12. We obtain Teff, log g and mass for hydrogen atmosphere white dwarf stars (DAs) and helium atmosphere white dwarf stars (DBs), estimate the calcium/helium abundances for the white dwarf stars with metallic lines (DZs) and carbon/helium for carbon dominated spectra DQs. We found one central star of a planetary nebula, one ultra-compact helium binary (AM CVn), one oxygen line dominated white dwarf, 15 hot DO/PG1159s, 12 new cataclysmic variables, 36 magnetic white dwarf stars, 54 DQs, 115 helium dominated white dwarfs, 148 white dwarf+main sequence star binaries, 236 metal polluted white dwarfs, 300 continuum spectra DCs, 230 hot subdwarfs, 2936 new hydrogen dominated white dwarf stars, and 2675 cool hydrogen dominated subdwarf stars. We calculate the mass distribution of all 5883 DAs with S/N>15 in DR12, including the ones in DR7 and DR10, with an average S/N=26, corrected to the 3D convection scale, and also the distribution after correcting for the observed volume, using 1/Vmax.