Mass distribution of DA white dwarfs in the first Data Release of the Sloan Digital Sky Survey
/ Authors
/ Abstract
We investigate the sample of 1175 new nonmagnetic DA white dwarfs with the effective temperatures $T_{\rm eff} \ge 12\,000$ K, which were extracted from the Data Release 1 of the Sloan Digital Sky Survey. We determined masses, radii, and bolometric luminosities of stars in the sample. The above parameters were derived from the effective temperatures $T_{\rm eff} $ and surface gravities $\log g$ published in the DR1, and the new theoretical $M-R$ relations for carbon-core and oxygen-core white dwarfs. Mass distribution of white dwarfs in this sample exhibits the peak at $M=0.562~ M_\odot$ (carbon-core stars), and the tail towards higher masses. Both the shape of the mass distribution function and the empirical mass-radius relation are practically identical for white dwarfs with either pure carbon or pure oxygen cores.
Journal: Astronomy and Astrophysics