Native-resolution retrievals on 0.97-5.27 micron JWST spectra of VHS 1256 b find a ~79% cloud deck, solar-like metallicity and C/O, and depleted 18O in a partially cloudy disequilibrium atmosphere.
Uniform Atmospheric Retrieval Analysis of Ultracool Dwarfs I: Characterizing Benchmarks, Gl570D and HD3651B
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
Interpreting the spectra of brown dwarfs is key to determining the fundamental physical and chemical processes occurring in their atmospheres. Powerful Bayesian atmospheric retrieval tools have recently been applied to both exoplanet and brown dwarf spectra to tease out the thermal structures and molecular abundances to understand those processes. In this manuscript we develop a significantly upgraded retrieval method and apply it to the SpeX spectral library data of two benchmark late T-dwarfs, Gl570D and HD3651B, to establish the validity of our upgraded forward model parameterization and Bayesian estimator. Our retrieved metallicities, gravities, and effective temperature are consistent with the metallicity and presumed ages of the systems. We add the carbon-to-oxygen ratio as a new dimension to benchmark systems and find good agreement between carbon-to-oxygens ratio derived in the brown dwarfs and the host stars. Furthermore, we have for the first time unambiguously determined the presence of ammonia in the low-resolution spectra of these two late T-dwarfs. We also show that the retrieved results are not significantly impacted by the possible presence of clouds, though some quantities are significantly impacted by uncertainties in photometry. This investigation represents a watershed study in establishing the utility of atmospheric retrieval approaches on brown dwarf spectra.
fields
astro-ph.EP 4years
2026 4verdicts
UNVERDICTED 4representative citing papers
GRAVITY+ observations yield a 12CO/13CO ratio of 91^{+24}_{-17} in β Pictoris b consistent with solar/ISM values and a tentative 1.4% atmospheric variability amplitude.
Panchromatic JWST spectrum of WASP-121 b detects SiO and measures refractory-to-volatile ratios 3x stellar, consistent with mixed solid-gas accretion or migration with continued solid accretion.
Retrievals on six isolated brown dwarfs yield near-solar C/O (0.51-0.63), metallicities, and 12C/13C ratios (91-155) supporting molecular cloud fragmentation origin.
citing papers explorer
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Native-resolution retrievals of VHS 1256-1257 b spanning the JWST/NIRSpec wavelength range: Chemical composition of a partially cloudy atmosphere
Native-resolution retrievals on 0.97-5.27 micron JWST spectra of VHS 1256 b find a ~79% cloud deck, solar-like metallicity and C/O, and depleted 18O in a partially cloudy disequilibrium atmosphere.
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$^{13}$CO and potential variability in $\beta$ Pictoris b with GRAVITY+
GRAVITY+ observations yield a 12CO/13CO ratio of 91^{+24}_{-17} in β Pictoris b consistent with solar/ISM values and a tentative 1.4% atmospheric variability amplitude.
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The panchromatic JWST dayside spectrum of WASP-121 b reveals a refractory-rich formation
Panchromatic JWST spectrum of WASP-121 b detects SiO and measures refractory-to-volatile ratios 3x stellar, consistent with mixed solid-gas accretion or migration with continued solid accretion.
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The ESO SupJup Survey XI. Atmospheric properties of six isolated M- and L-type dwarfs with CRIRES+
Retrievals on six isolated brown dwarfs yield near-solar C/O (0.51-0.63), metallicities, and 12C/13C ratios (91-155) supporting molecular cloud fragmentation origin.