Radiation hydrodynamics simulations of dust layers in brown dwarfs

Bernd Freytag

CRAL-ENS, Lyon, France

Dust concentration in a brown dwarf atmosphere, play mpg-movie (73 MB)

Dust grains that form in the atmosphere of a brown dwarf sink down under the influence of gravity and vanish from the atmosphere. To investigate the processes that can bring back the material we performed radiation-hydrodynamics simulations with CO5BOLD that cover the upper part of the convection zone and the atmosphere including the dust cloud layers. I will describe these simulations and our dust model that is simple enough to be included in RHD simulations and -- hopefully -- still contains the essential physics of dust formation, transport, and destruction, as well as the interaction of dust and radiation.

Keywords: 1D 2D (3D) approximations boundary conditions dust properties finite differences hydrodynamics opacities