Masses, Radii, and Bolometric Luminosities of DA White Dwarfs in the First Data Release of the Sloan Digital Sky Survey

摘要

We extracted from the Data Release 1 of the Sloan Digital Sky Survey 1175 new nonmagnetic DA white dwarfs with effective temperatures Tell 12000K. We determined masses, radii, and bolometric luminosities of stars in the sample, based on the new theoretical M-R relations of white dwarfs with carbon cores and oxygen cores, and the effective temperatures Tell- and surface gravities log g published in the DR1. Mass distribution of white dwarfs in the sample is slightly asymmetrical towards both higher and lower masses, and exhibits the peak at 0.562M masses (carbon core white dwarfs). Both the shape of the mass distribution and the empirical mass-radius relation are practically identical for white dwarfs with either pure carbon or pure oxygen cores.