Model atmospheres and spectra: The role of dust
(2003) 211th Symposium of the International Astronomical Union 211. p.325-332- 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... (More)
- 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. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/306853
- author
- Allard, F ; Guillot, T ; Ludwig, Hans-Günter LU ; Hauschildt, P H ; Schweitzer, A ; Alexander, DR and Ferguson, JW
- organization
- publishing date
- 2003
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- Proceedings of the International Astronomical Union (Brown Dwarfs)
- editor
- Martín, Eduardo L.
- volume
- 211
- pages
- 325 - 332
- publisher
- Astronomical Society of the Pacific (ASP)
- conference name
- 211th Symposium of the International Astronomical Union
- conference location
- Outrigger Waikoloa Beach Hotel Waikoloa, Hawaii, United States
- conference dates
- 2002-05-20 - 2002-05-24
- external identifiers
-
- wos:000184043700071
- ISSN
- 0074-1809
- ISBN
- ISBN:1-58381-132-X
- language
- English
- LU publication?
- yes
- id
- 31e6f6e9-a18c-44f8-9ca1-26ca5e748a84 (old id 306853)
- date added to LUP
- 2016-04-01 16:19:15
- date last changed
- 2020-06-16 15:04:58
@inproceedings{31e6f6e9-a18c-44f8-9ca1-26ca5e748a84, 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.}}, author = {{Allard, F and Guillot, T and Ludwig, Hans-Günter and Hauschildt, P H and Schweitzer, A and Alexander, DR and Ferguson, JW}}, booktitle = {{Proceedings of the International Astronomical Union (Brown Dwarfs)}}, editor = {{Martín, Eduardo L.}}, isbn = {{ISBN:1-58381-132-X}}, issn = {{0074-1809}}, language = {{eng}}, pages = {{325--332}}, publisher = {{Astronomical Society of the Pacific (ASP)}}, title = {{Model atmospheres and spectra: The role of dust}}, volume = {{211}}, year = {{2003}}, }