Author:
Allard France,Guillot Tristan,Ludwig Hans-Günter,Hauschildt Peter H,Schweitzer Andreas,Alexander David R.,Ferguson Jason W.
Abstract
Brown dwarf atmospheres form molecules, then high temperature condensates (corundum, titanates, silicates, and iron compounds), and then low temperature condensates (ices) as they cool down over time. These produce large opacities which govern entirely their spectral energy distribution. Just as it is important to know molecular opacities (TiO, H2O, CH4, etc.) with accuracy, it is imperative to understand the interplay of processes (e.g. condensation, sedimentation, coagulation, convection) that determines the radial and size distribution of grains. Limiting case models have shown that young, hot brown (L) dwarfs form dust mostly in equilibrium, while at much cooler stages (late T dwarfs) all high temperature condensates have sedimented out of their photospheres. But this process is gradual and all intermediate classes of brown dwarfs can partly be understood in terms of partial sedimentation of dust. With new models accounting for these processes, we describe the effects they may have upon brown dwarf spectral properties.
Publisher
Cambridge University Press (CUP)
Reference14 articles.
1. Analysis of Keck HIRES Spectra of Early L‐Type Dwarfs
2. Clouds and Chemistry: Ultracool Dwarf Atmospheric Properties from Optical and Infrared Colors
3. Spectral Energy Distributions for Disk and Halo M Dwarfs
4. Evolutionary Models for Very Low‐Mass Stars and Brown Dwarfs with Dusty Atmospheres
5. Dahn C. C. , Harris H. C. , Vrba F. J. , Guetter H. H. , Canzian B. , Henden A. A. , Levine S. E. , Luginbuhl C. B. , Monet A. K. B. , Monet D. G. , Pier J. R. , Stone R. C. , Walker R. L. , Burgasser A. J. , Gizis J. E. , Kirkpatrick J. D. , Liebert J. , & Reid I. N. 2002, AJ, in press
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