Correcting NIRISS charge migration reveals KELT-7 b as a metal-enriched (~92x solar) ultra-hot Jupiter with H2O, CO2 and TiO but no H- or clouds, orbiting a young metal-rich star.
New study of the line profiles of sodium perturbed by H2
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
The opacity of alkali atoms, most importantly of Na and K, plays a crucial role in the atmospheres of brown dwarfs and exoplanets. We present a comprehensive study of NaH2 collisional profiles at temperatures from 500 to 3000 K, the temperatures prevailing in the atmosphere of brown dwarfs and Jupiter-mass planets.The relevant H2 perturber densities reach several 10^19 cm^-3 in hot Teff > 1500 K Jupiter-mass planets and can exceed 10^20 cm^-3 for more massive or cooler objects. Accurate pressure-broadened profiles that are valid at high densities of H2 should be incorporated into spectral models. Unified profiles of sodium perturbed by molecular hydrogen were calculated in the semi-classical approach using up-to-date molecular data.New NaH2 collisional profiles and their effects on the synthetic spectra of brown dwarfs and hot Jupiters computed with petitCODE are presented.
fields
astro-ph.EP 2years
2026 2verdicts
CONDITIONAL 2representative citing papers
A quench-pressure parameterisation with two free parameters recovers unbiased C/O and [M/H] from synthetic JWST spectra with vertical mixing, and tentatively detects quenching and photochemical H2S depletion in HD 189733b NIRCam data.
citing papers explorer
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Mitigating Charge Migration in JWST NIRISS Reveals That KELT-7 b is a Metal-enriched Ultra-hot Jupiter Orbiting a Young Metal-rich Star
Correcting NIRISS charge migration reveals KELT-7 b as a metal-enriched (~92x solar) ultra-hot Jupiter with H2O, CO2 and TiO but no H- or clouds, orbiting a young metal-rich star.
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A parameterised approach to disequilibrium retrievals in the JWST era: Application to NIRCam observations of HD 189733b
A quench-pressure parameterisation with two free parameters recovers unbiased C/O and [M/H] from synthetic JWST spectra with vertical mixing, and tentatively detects quenching and photochemical H2S depletion in HD 189733b NIRCam data.