The Mantis Network II: examining the 3D high-resolution observable properties of the UHJs WASP-121b and WASP-189b through GCM modelling

Abstract

The atmospheres of ultra hot Jupiters (UHJs) are prime targets for the detection of molecules and atoms at both low and high spectral resolution. We study the atmospheres of the UHJs WASP-121b and WASP-189b by performing 3D general circulation models (GCMs) of these planets using high temperature correlated-k opacity schemes with ultra-violet (UV) absorbing species included. The GCM results are then post-processed at low and high spectral resolutions and compared to available data. The high resolution results are cross-correlated with molecular and atomic templates to produce mock molecular detections. Our GCM models produce similar temperature-pressure (T-p) structure trends to previous 1D radiative-convective equilibrium models of UHJs. Furthermore, the inclusion of UV opacities greatly shapes the thermal and dynamical properties of the high-altitude, low-pressure regions of the UHJ atmospheres, with sharp T-p inversions due to the absorption of UV light. This suggests that optical wavelength, high-resolution observations probe a dynamically distinct upper atmospheric region, rather than the deeper jet forming layers.

An atlas of resolved spectral features in the transmission spectrum of WASP-189 b with MAROON-X

“…For both terminators, we averaged the profiles over the observable longitudes between 75.94 and 104.06 deg (trailing) and between 255.94 and 284.06 deg (leading). Figure 4 shows the temperature-pressure profiles for both terminators, consistent with the GCM results that the leading terminator is generally colder (Lee et al 2022). These models were calculated assuming an equilibrium temperature of 2641 K (Anderson et al 2018).…”

“…To determine the line depth, centre, and width, we fitted a Gaussian function to the observed lines. We further computed atmospheric models for the leading and trailing terminator for comparison, using the temperature-pressure profiles from Lee et al (2022).…”

Magnetic Drag and 3D Effects in Theoretical High-resolution Emission Spectra of Ultrahot Jupiters: the Case of WASP-76b

“…Partially due to their already significant computational time, most GCMs do not have an explicit treatment for magnetic effects in their simulated atmospheres. One commonly used treatment is applying a global uniform Rayleigh drag timescale to the atmosphere such as in GCMs from Tan & Komacek (2019); Carone et al (2020); Deitrick et al (2020); Lee et al (2022). Notably this timescale is also sometimes used to encompass a variety of effects, also including hydrodynamical ones.…”

Small but mighty: High-resolution spectroscopy of ultra-hot Jupiter atmospheres with compact telescopes

“…Their atmospheres are generally simpler to interpret due to relatively stable equilibrium conditions at pressures of higher than 10 −4 bars (Kitzmann et al 2018;Fossati et al 2021;Lee et al 2022). Though non-local thermodynamic equilibrium (NLTE) effects and deviations from chemical equilibrium can occur in the upper and lower layers, respectively (Fossati et al 2021;Arcangeli et al 2021), the majority of the transmission spectra of UHJs are predicted to probe regions where equilibrium assumptions hold (Kitzmann et al 2018;Lee et al 2022). Indeed, they are ideal test targets for exploring the extent to which telescope size can limit atmospheric studies.…”