Atmósferas de Enanas Blancas Frías

ROHRMANN, R. D.

Tafí del Valle

Congreso; Segundas Jornadas de Astrofísica Estelar; 2011

White dwarf (WD) stars are de most common end-product of stellar evolution. Due to the high degree of electron degeneracy in the interior of WDs, the non-degenerate outer layers and specially their atmospheres, control the loss of energy into outer space and therefore the cooling of these objects. Detailed atmosphere models provide the adequate surface boundary condition for the computation of evolutionary stellar models. Furthemore, atmosphere models are necessary to evaluate the emergent flux from the star, which is required to interpret the spectra, luminosities and colors of observed WDs. Progress in our understanding of cool WDs and their observational appearances is closely related to the advances of atmosphere physics. Analysis of cool WD atmospheres demands the use of numerical codes dealing with radiative transfer, convection, non-ideal gas effects, pressure-induced opacities, as well as pressure ionization, partial degeneration and electron thermal conduction in ultracool WDs.