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Cloudless Atmospheres for Young Low-gravity Substellar Objects
- Source :
- The Astrophysical journal letters, The Astrophysical journal letters, Bristol : IOP Publishing, 2017, 850 (1), ⟨10.3847/1538-4357/aa9214⟩, The Astrophysical journal letters, 2017, 850 (1), ⟨10.3847/1538-4357/aa9214⟩
- Publication Year :
- 2017
- Publisher :
- HAL CCSD, 2017.
-
Abstract
- Atmospheric modeling of low-gravity (VL-G) young brown dwarfs remains a challenge. The presence of very thick clouds has been suggested because of their extremely red near-infrared (NIR) spectra, but no cloud models provide a good fit to the data with a radius compatible with evolutionary models for these objects. We show that cloudless atmospheres assuming a temperature gradient reduction caused by fingering convection provides a very good model to match the observed VL-G NIR spectra. The sequence of extremely red colors in the NIR for atmospheres with effective temperature from ~2000 K down to ~1200 K is very well reproduced with predicted radii typical of young low-gravity objects. Future observations with NIRSPEC and MIRI on the James Webb Space Telescope (JWST) will provide more constrains in the mid-infrared, helping to confirm/refute whether or not the NIR reddening is caused by fingering convection. We suggest that the presence/absence of clouds will be directly determined by the silicate absorption features that can be observed with MIRI. JWST will therefore be able to better characterize the atmosphere of these hot young brown dwarfs and their low-gravity exoplanet analogues.<br />Comment: Accepted in ApJ
- Subjects :
- 010504 meteorology & atmospheric sciences
European community
[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Brown dwarf
FOS: Physical sciences
Astrophysics::Cosmology and Extragalactic Astrophysics
01 natural sciences
Low Gravity
0103 physical sciences
Astrophysics::Solar and Stellar Astrophysics
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Solar and Stellar Astrophysics (astro-ph.SR)
ComputingMilieux_MISCELLANEOUS
0105 earth and related environmental sciences
Physics
Earth and Planetary Astrophysics (astro-ph.EP)
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph]
European research
Astrophysics::Instrumentation and Methods for Astrophysics
Astronomy
Astronomy and Astrophysics
[PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Methods observational
Work (electrical)
Astrophysics - Solar and Stellar Astrophysics
13. Climate action
Space and Planetary Science
Astrophysics::Earth and Planetary Astrophysics
Astrophysics - Earth and Planetary Astrophysics
Subjects
Details
- Language :
- English
- ISSN :
- 20418205 and 20418213
- Database :
- OpenAIRE
- Journal :
- The Astrophysical journal letters, The Astrophysical journal letters, Bristol : IOP Publishing, 2017, 850 (1), ⟨10.3847/1538-4357/aa9214⟩, The Astrophysical journal letters, 2017, 850 (1), ⟨10.3847/1538-4357/aa9214⟩
- Accession number :
- edsair.doi.dedup.....7bedec365fd89b50c3f3b82c7bb8ae0f