Investigating Radiation Levitation in White Dwarf Stars by Large-Scale Molecular-Dynamics Simulations

It has been observed that the abundance of heavy elements in the atmospheres of white dwarf stars does not match exactly with prevailing stellar models. The phenomenon of radiative levitation is one possible explanation, wherein due to the high opacity of heavy elements such as C, Si, and Fe, these elements are "levitated" against the force of gravity within a plasma of Hydrogen and/or Helium. This mechanism is not entirely understood at the microscopic level; the effect of plasma density and temperature conditions is particularly uncertain. To clarify these effects we use large-scale molecular dynamics simulations to model interparticle interactions and radiative force. By scanning different density/temperature conditions of the white dwarf atmosphere, this study will reveal where radiation levitation may play a role to redistribute heavy elements in white dwarf stars.