A Grid of Non‐LTE Model Atmospheres for White Dwarfs in Cataclysmic Variables

Open Access
Publisher Website
Google Scholar
Abstract
We have calculated a grid of non-LTE (NLTE) line-blanketed model atmospheres for white dwarfs in cataclysmic variable (CV) systems using our stellar atmosphere code PHOENIX. The grid covers the temperature range 20,000-500,000 K for solar abundances and 10-2 and 10-4 solar metal abundance. The effective temperature resolution is 10,000 K in the range 20,000-200,000 K and is 20,000 K in the range 200,000-500,000 K. The models include a large number of NLTE levels for light metals such as CNO and heavy metals such as Ni and Fe. The necessity of using self-consistent NLTE line-blanketed model atmospheres for the analysis of white dwarfs is well known and reaffirmed here. We discuss the importance of metal opacity, especially metals heavier than Ca, in the atmospheres of CV primaries. We also compare our grid to previously published models and discuss the general improvements offered by our models. In addition, a specific model from our grid is compared to a Hubble Space Telescope observation of U Gem and predictions for Far-Ultraviolet Spectroscopic Explorer (FUSE) observations are made.