Examining line broadening approximations using Xenomorph : a simulation line broadening program

White dwarfs are particularly interesting due to their broad application to the field of astronomy (cosmochronology, SN Ia progenitors, asteroseismology). Examining distributions of white dwarf masses and temperatures, it is evident that there is some flaw in our ability to make physical atmosphere models. Tremblay and Bergeron (2009) used an {\it ad hoc} treatment of line broadening and derived significantly different surface gravity and temperatures for white dwarfs, demonstrating the importance of the line broadneing treatment in determining stellar parameters for high surface gravity stars. This thesis presents a new line broadening program, Xenomorph, based on simulation techniques. Xenomorph is used to examine various approximations used in line broadening calculations used in white dwarf atmospheres. Some approximations, like including fine structure and lower state perturbations, have small, if detectable effects. Ion motions during a transition can make features commonly seen in Stark profiles less pronounced and leads to an increase in the FWHM of the lines. Including a more complete basis set at higher densities will result in extra features, including asymmetries that has been observed in many experiments.