Keck/KPIC Emission Spectroscopy of WASP-33b

Abstract

We present Keck/KPIC high-resolution ($R\sim 35,000$) $K$-band thermal emission spectroscopy of the ultra-hot Jupiter WASP-33b. The use of KPIC's single-mode fibers greatly improves both blaze and line-spread stabilities relative to slit spectrographs, enhancing the cross-correlation detection strength. We retrieve the dayside emission spectrum with a nested sampling pipeline which fits for orbital parameters, the atmospheric pressure-temperature profile, and molecular abundances.We strongly detect the thermally-inverted dayside and measure mass-mixing ratios for CO ($\log \mathrm{C}{\mathrm{O}}_{\mathrm{MMR}}=-1.1_{-0.6}^{+0.4}$), H${}_2$O ($\log {\mathrm{H}}_2{\mathrm{O}}_{\mathrm{MMR}}=-4.1_{-0.9}^{+0.7}$) and OH ($\log \mathrm{O}{\mathrm{H}}_{\mathrm{MMR}}=-2.1_{-1.1}^{+0.5}$), suggesting near-complete dayside photodissociation of H${}_2$O. The retrieved abundances suggest a carbon- and possibly metal-enriched atmosphere, with a gas-phase C/O ratio of $0.8_{-0.2}^{+0.1}$, consistent with the accretion of high-metallicity gas near the CO${}_2$ snow line and post-disk migration or with accretion between the soot and H${}_2$O snow lines. We also find tentative evidence for ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}\sim 50$, consistent with values expected in protoplanetary disks, as well as tentative evidence for a metal-enriched atmosphere (2--15$\times$ solar). These observations demonstrate KPIC's ability to characterize close-in planets and the utility of KPIC's improved instrumental stability for cross-correlation techniques.

arXiv commentAccepted in AJ, 26 pages, 12 figures

References in corpus (74)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• The WASP Project and the SuperWASP Cameras
• The effects of snowlines on C/O in planetary atmospheres
• The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b
• Precipitating Condensation Clouds in Substellar Atmospheres
• ExoMol molecular line lists XXX: a complete high-accuracy line list for water
• A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres
• petitRADTRANS: a Python radiative transfer package for exoplanet characterization and retrieval
• Hot Jupiters from Secular Planet--Planet Interactions
• The signature of orbital motion from the dayside of the planet tau Bootis b
• The Rossiter-McLaughlin effect and analytic radial velocity curves for transiting extrasolar planetary systems
• Pulkovo Compilation of Radial Velocities for 35495 Hipparcos Stars in a Common System
• Planetary Spectrum Generator: an accurate online radiative transfer suite for atmospheres, comets, small bodies and exoplanets
• Nightside condensation of iron in an ultra-hot giant exoplanet
• Line-profile tomography of exoplanet transits -- II. A gas-giant planet transiting a rapidly-rotating A5 star
• Stellar Limb-Darkening Coefficients for CoRot and Kepler
• Retrieving Temperatures and Abundances of Exoplanet Atmospheres with High-Resolution Cross-Correlation Spectroscopy
• A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
• Chemical enrichment of giant planets and discs due to pebble drift
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Observing transiting planets with JWST -- Prime targets and their synthetic spectral observations
• ExoCross: a general program for generating spectra from molecular line lists
• A solar C/O and sub-solar metallicity in a hot Jupiter atmosphere
• Atmospheric Signatures of Giant Exoplanet Formation by Pebble Accretion
• Atmospheric characterization of the ultra-hot Jupiter MASCARA-2b/KELT-20b
• Connecting Giant Planet Atmosphere and Interior Modeling: Constraints on Atmospheric Metal Enrichment
• Near-IR Direct Detection of Water Vapor in Tau Boo b
• Carbon isotope fractionation in protoplanetary disks
• Where is the Water? Jupiter-like C/H ratio but strong H${}_2$O depletion found on $\tau$ Boötis b using SPIRou
• Ionized calcium in the atmospheres of two ultra-hot exoplanets WASP-33b and KELT-9b
• Metal enrichment leads to low atmospheric C/O ratios in transiting giant exoplanets
• Phase curves of WASP-33b and HD 149026b and a New Correlation Between Phase Curve Offset and Irradiation Temperature
• A New Window into Planet Formation and Migration: Refractory-to-Volatile Elemental Ratios in Ultra-hot Jupiters
• Decomposing the Iron Cross-Correlation Signal of the Ultra-Hot Jupiter WASP-76b in Transmission using 3D Monte-Carlo Radiative Transfer
• Mass loss rate and local thermodynamic state of KELT-9 b thermosphere from the hydrogen Balmer series
• Connecting planet formation and astrochemistry: A main sequence for C/O in hot-exoplanetary atmospheres
• Detecting isotopologues in exoplanet atmospheres using ground-based high-dispersion spectroscopy
• A unique hot Jupiter spectral sequence with evidence for compositional diversity
• Measurement of the Nodal Precession of WASP-33 b via Doppler Tomography
• Detection and Bulk Properties of the HR 8799 Planets with High Resolution Spectroscopy
• The Roasting Marshmallows Program with IGRINS on Gemini South I: Composition and Climate of the Ultra Hot Jupiter WASP-18 b
• Breaking Degeneracies in Formation Histories by Measuring Refractory Content in Gas Giants
• WASP-33: The first delta Scuti exoplanet host star
• First Detection of Hydroxyl Radical Emission from an Exoplanet Atmosphere: High-dispersion Characterization of WASP-33b using Subaru/IRD
• Detection of Fe and evidence for TiO in the dayside emission spectrum of WASP-33b
• ExoMol line lists -- XLIV. IR and UV line list for silicon monoxide (SiO)
• Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot
• An optical transmission spectrum of the ultra-hot Jupiter WASP-33b. First indication of AlO in an exoplanet
• Thermal emission from WASP-33b, the hottest known planet
• The 12CO/13CO isotopologue ratio of a young, isolated brown dwarf. Possibly distinct formation pathways of super-Jupiters and brown dwarfs
• Detection of the hydrogen Balmer lines in the ultra-hot Jupiter WASP-33b
• Pulsation analysis and its impact on primary transit modeling in WASP-33
• High-resolution detection of neutral oxygen and non-LTE effects in the atmosphere of KELT-9b
• Time-resolved rotational velocities in the upper atmosphere of WASP-33 b
• Atmospheric characterization of the ultra-hot Jupiter WASP-33b: Detection of Ti and V emission lines and retrieval of a broadened line profile
• Detection of CO emission lines in the dayside atmospheres of WASP-33b and WASP-189b with GIANO
• Towards multi-dimensional analysis of transmission spectroscopy. Part II: Day-night induced biases in retrievals from hot to ultra-hot Jupiters
• An exact, generalised Laplace resonance in the HR 8799 planetary system
• Is TiO emission present in the ultra-hot Jupiter WASP-33b? A reassessment using the improved ExoMol Toto line list
• Silicon in the dayside atmospheres of two ultra-hot Jupiters
• Pseudo-2D Modelling of Heat Redistribution Through H${}_2$ Thermal Dissociation/Recombination: Consequences for Ultra-Hot Jupiters
• The PEPSI Exoplanet Transit Survey (PETS). II. A Deep Search for Thermal Inversion Agents in KELT-20 b/MASCARA-2 b with Emission and Transmission Spectroscopy
• SimAb: A simple, fast and flexible model to assess the effects of planet formation on the atmospheric composition of gas giants
• Strong H${}_2$O and CO emission features in the spectrum of KELT-20b driven by stellar UV irradiation
• Phase II of the Keck Planet Imager and Characterizer: system-level laboratory characterization and preliminary on-sky commissioning
• Nodal Precession and Tidal Evolution of Two Hot-Jupiters: WASP-33 b and KELT-9 b
• Simulating the Multi-Epoch Direct Detection Technique to Isolate the Thermal Emission of the Non-Transiting Hot Jupiter HD187123B
• SPORK That Spectrum: Increasing Detection Significances from High-Resolution Exoplanet Spectroscopy with Novel Smoothing Algorithms
• Contrast and Temperature Dependence of Multi-Epoch High-Resolution Cross-Correlation Exoplanet Spectroscopy
• Reinvestigation of the Multi-Epoch Direct Detections of HD 88133 b and Upsilon Andromedae b

Cited by in corpus (10)

• The ESO SupJup Survey III: Confirmation of 13CO in YSES 1 b and Atmospheric Detection of YSES 1 c with CRIRES+
• Technical description and performance of the phase II version of the Keck Planet Imager and Characterizer
• New perspectives on MASCARA-1b: A combined analysis of pre- and post-eclipse emission data using CRIRES+
• Retrieving day- and nightside atmospheric properties of the ultra-hot Jupiter TOI-2109b. Detection of Fe and CO emission lines and evidence for inefficient heat transport
• Fringing analysis and forward modeling of Keck Planet Imager and Characterizer (KPIC) spectra
• Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions
• An Early Look at the Performance of IGRINS-2 at Gemini-North with Application to the ultrahot Jupiter, WASP-33 b
• Quantifying thermal water dissociation in the dayside photosphere of WASP-121 b using NIRPS
• HST/WFC3 Constraints on the Abundances of OH and FeH in the Atmosphere of the Ultra-Hot Neptune LTT-9779 b
• Thermal emission spectra of the ultra-hot Jupiter WASP-33 b