High-resolution atmospheric retrievals of WASP-121b transmission spectroscopy with ESPRESSO: Consistent relative abundance constraints across multiple epochs and instruments

Abstract

Recent progress in high-resolution transmission spectroscopy has offered new avenues in which to characterise the atmospheres of transiting exoplanets. High-resolution cross-correlation spectroscopy allows for the unambiguous detection of molecules/atoms. It has also been used to map both atmospheric dynamics and longitudinal variations in the abundance of species across the morning and evening limbs. We present multiple VLT/ESPRESSO observations of the ultra-hot Jupiter WASP-121b, from which we constrain relative abundances of various neutral metals consistently across all observations, whilst accounting for the distortion of the exoplanet's signal caused by traditional data processing techniques. We also constrain planetary orbital velocities and $T$-$P$ profiles. We compare our abundance constraints with previous constraints using VLT/UVES transmission spectroscopy of WASP-121b, and find our results to be consistent between observations, and also in agreement with stellar values for species previously detected in the atmosphere of WASP-121b. Our retrieval framework can also be used to identify potential exospheric species, resulting in extended absorption features beyond the transit equivalent Roche limit of WASP-121b ($R_{\mathrm{eqRL}}$ $\sim$ 1.3 $R_{\mathrm{p}}$). H$\alpha$, Fe II, and Ca II were found to extend to high altitudes ($1.54\pm 0.04$ $R_{\mathrm{p}}$, $1.17\pm 0.01$ $R_{\mathrm{p}}$, and $2.52\pm 0.34$ $R_{\mathrm{p}}$, respectively), which are broadly consistent with literature values. The consistency of our constraints across multiple high-resolution observations is a strong validation of our model filtering and retrieval framework, as well as the stability of the atmosphere over the timescales of months/years, and could allow for planet formation processes to be inferred from future ground-based observations of exoplanetary atmospheres.

20 pages, 12 figures, 3 tables, accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (41)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• EXOFAST: A fast exoplanetary fitting suite in IDL
• petitRADTRANS: a Python radiative transfer package for exoplanet characterization and retrieval
• On the radiative equilibrium of irradiated planetary atmospheres
• Atmospheric Retrieval for Super-Earths: Uniquely Constraining the Atmospheric Composition with Transmission Spectroscopy
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• Towards Chemical Constraints on Hot Jupiter Migration
• An ultrahot gas-giant exoplanet with a stratosphere
• Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy
• A solar C/O and sub-solar metallicity in a hot Jupiter atmosphere
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b
• High-Resolution Spectroscopic Detection of TiO and Stratosphere in the Day-side of WASP-33b
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO
• Hot Jupiters: Origins, Structure, Atmospheres
• Ionized calcium in the atmospheres of two ultra-hot exoplanets WASP-33b and KELT-9b
• Detection of sodium in the atmosphere of WASP-69b
• ESPRESSO high resolution transmission spectroscopy of WASP-76b
• Decomposing the Iron Cross-Correlation Signal of the Ultra-Hot Jupiter WASP-76b in Transmission using 3D Monte-Carlo Radiative Transfer
• An emission spectrum for WASP-121b measured across the 0.8-1.1 micron wavelength range using the Hubble Space Telescope
• Relative abundance constraints from high-resolution optical transmission spectroscopy of WASP-121b, and a fast model-filtering technique for accelerating retrievals
• Detection of ionized calcium in the atmosphere of the ultra-hot Jupiter KELT-9b
• Wind of Change: retrieving exoplanet atmospheric winds from high-resolution spectroscopy
• Confirmation of Asymmetric Iron Absorption in WASP-76b with HARPS
• p-winds: an open-source Python code to model planetary outflows and upper atmospheres
• TRIDENT: A Rapid 3D Radiative Transfer Model for Exoplanet Transmission Spectra
• Diurnal variations in the stratosphere of the ultrahot giant exoplanet WASP-121b
• An inventory of atomic species in the atmosphere of WASP-121b using UVES high-resolution spectroscopy
• Confirmation of water emission in the dayside spectrum of the ultrahot Jupiter WASP-121b
• Detection of Fe\,{\sc i} Emission in the Day-side Spectrum of WASP-33b
• WASP-127b: A misaligned planet with a partly cloudy atmosphere and tenuous sodium signature seen by ESPRESSO
• HyDRA-H: Simultaneous Hybrid Retrieval of Exoplanetary Emission Spectra
• Neutral Cr and V in the atmosphere of ultra hot jupiter WASP-121 b
• A Spectral Survey of WASP-19b with ESPRESSO
• Gemini/GMOS Optical Transmission Spectroscopy of WASP-121b: signs of variability in an ultra-hot Jupiter?
• Swift UVOT near-UV transit observations of WASP-121 b
• Is TiO emission present in the ultra-hot Jupiter WASP-33b? A reassessment using the improved ExoMol Toto line list
• If you like C/O variations, you should have put a ring on it
• The secondary transit of the hot Jupiter WASP-121b at 2 $\mu$m

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