The infrared colors of 51 Eridani b: micrometereoid dust or chemical disequilibrium?

Abstract

We reanalyze near-infrared spectra of the young extrasolar giant planet 51 Eridani b which was originally presented in (Macintosh et al. 2015) and (Rajan et al. 2017) using modern atmospheric models which include a self-consistent treatment of disequilibrium chemistry due to turbulent vertical mixing. In addition, we investigate the possibility that significant opacity from micrometeors or other impactors in the planet's atmosphere may be responsible for shaping the observed spectral energy distribution (SED). We find that disequilibrium chemistry is useful for describing the mid-infrared colors of the planet's spectra, especially in regards to photometric data at M band around 4.5 $\mu$m which is the result of super-equilibrium abundances of carbon monoxide, while the micrometeors are unlikely to play a pivotal role in shaping the SED. The best-fitting, micrometeroid-dust-free, disequilibrium chemistry, patchy cloud model has the following parameters: effective temperature $T_{\text{eff}}=681$ K with clouds (or without clouds, i.e. the grid temperature $T_{\text{grid}}$ = 900 K), surface gravity $g$ = 1000 m/s${}^2$, sedimentation efficiency $f_{\text{sed}}$ = 10, vertical eddy diffusion coefficient $K_{\text{zz}}$ = 10${}^3$ cm${}^2$/s, cloud hole fraction $f_{\text{hole}}$ = 0.2, and planet radius $R_{\text{planet}}$ = 1.0 R${}_{\text{Jup}}$.

22 pages, 14 figures, Accepted to AJ

References in corpus (31)

• The fast spin-rotation of a young extrasolar planet
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• A new set of atmosphere and evolution models for cool T-Y brown dwarfs and giant exoplanets
• Retrieving the Aerosol Complex Refractive Index using PyMieScatt: A Mie Computational Package with Visualization Capabilities
• Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets
• Exoplanet Reflected Light Spectroscopy with PICASO
• Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b
• The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b
• A Systematic Study of Departures from Chemical Equilibrium in the Atmospheres of Substellar Mass Objects
• Irregular Satellites of the Planets: Products of Capture in the Early Solar System
• Characterizing 51 Eri b from 1-5 $\mu$m: a partly-cloudy exoplanet
• PICASO 3.0: A One-Dimensional Climate Model for Giant Planets and Brown Dwarfs
• Cloud busting: enstatite and quartz clouds in the atmosphere of 2M2224-0158
• Gemini Planet Imager Spectroscopy of the HR 8799 planets c and d
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• Observations of Disequilibrium CO Chemistry in the Coldest Brown Dwarfs
• A large spectroscopic sample of L and T dwarfs from UKIDSS LAS: peculiar objects, binaries, and space density
• Gas and dust in the Beta Pictoris Moving Group as seen by the Herschel Space Observatory
• Detection and Bulk Properties of the HR 8799 Planets with High Resolution Spectroscopy
• A Direct Imaging Survey of Spitzer detected debris disks: Occurrence of giant planets in dusty systems
• Hubble Space Telescope UV and H$\alpha$ Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b
• Gemini Planet Imager Observational Calibrations I: Overview of the GPI Data Reduction Pipeline
• The Sonora Substellar Atmosphere Models. II. Cholla: A Grid of Cloud-free, Solar Metallicity Models in Chemical Disequilibrium for the JWST Era
• Probing the Extent of Vertical Mixing in Brown Dwarf Atmospheres with Disequilibrium Chemistry
• Correlations between the stellar, planetary and debris components of exoplanet systems observed by $\text{Herschel}$
• Exploring the Role of Sub-micron Sized Dust Grains in the Atmospheres of Red L0 - L6 Dwarfs
• Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
• Retrieval study of cool, directly imaged exoplanet 51 Eri b
• Gemini Planet Imager Observational Calibrations VI: Photometric and Spectroscopic Calibration for the Integral Field Spectrograph
• An Approximation for the Capture Radius of Gaseous Protoplanets
• Dust Accretion onto Exoplanets

Cited by in corpus (3)

• The Sonora Substellar Atmosphere Models. IV. Elf Owl: Atmospheric Mixing and Chemical Disequilibrium with Varying Metallicity and C/O Ratios
• JWST-TST High Contrast: Living on the Wedge, or, NIRCam Bar Coronagraphy Reveals CO${}_2$ in the HR 8799 and 51 Eri Exoplanets' Atmospheres
• Direct Spectroscopy of 51 Eridani b with JWST NIRSpec