Spectral distances to DA white dwarfs

Very good correlations are shown to exist between our spectroscopically based photometric distance estimates and those derived from trigonometric parallaxes. We investigate the uncertainties involved in our distance estimates, as well as discuss the circumstances where such techniques are most likely to fail.

We apply our techniques to the large sample of Sloan Digital Sky Survey DA white dwarfs where automated fitting of HI Balmer profiles yields spectrometric temperatures and gravities. We determine simple empirical corrections to these temperatures and gravities with respect to published slit spectroscopy. After applying these T_eff_-logg corrections as well as appropriate interstellar extinction corrections, where necessary, we derive spectroscopically based photometric distances for 7062 DA stars from this sample.