The cosmological evolution of dust clouds in brown dwarf atmospheres

Link:
Autor/in:
Erscheinungsjahr:
2009
Medientyp:
Text
Schlagworte:
  • Mass
  • Stars
  • L/T transition
  • Galaxies
  • Planets
  • Mass
  • Stars
  • L/T transition
  • Galaxies
  • Planets
Beschreibung:
  • We present our latest DRIFT-PHOENIX model results for dust cloud formation in cool atmospheres and investigate the influence of the metallicity [M/H] on the dust cloud structure on the example of a typical mid-L dwarf (Teff=2000K, log(g)=5.0). Our new dust model simulates the formation of T1O2 seed particles (nucleation) and their subsequent gravitational settling, accompanied by kinetic growth and evaporation of seven solid species on top of these seeds. The gas phase depletion by each of the considered surface reactions and the element replenishment by convective up-mixing are consistently coupled into this mechanism. The result is a stationary cloud structure in phase-non-equilibrium. We observe a comparably low decrease of the dust particle number density and a weak increase of the mean grain size in the lower dust cloud for decreasing metallicities down to [M/H]=-4.0. For even lower metallicities to [M/H]=-6.0, these trends are reversed. © 2009 American Institute of Physics.
Lizenz:
  • info:eu-repo/semantics/closedAccess
Quellsystem:
Forschungsinformationssystem der UHH
Interne Metadaten
Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/6756125c-a82e-4e87-b78f-ff3a432407ce