A grid of self-consistent MSG (MARCS-StaticWeather-GGchem) cool stellar, sub-stellar, and exoplanetary model atmospheres

Abstract

Computation of a grid of self consistent 1D model atmospheres of cool stars, sub-stellar objects and exoplanets in the effective temperature range 300K to 3000K, including cloud formation, chemical non-equilibrium effects, and stellar irradiation. The models are called MSG, because they are based on an iterative coupling between three well tested codes, the MARCS stellar atmosphere code, the StaticWeather cloud formation code and the GGchem chemical equilibrium code. It includes up-to-date molecular and atomic opacities, cloud formation and advanced chemical equilibrium calculations, and involves new numerical methods at low temperatures to allow robust convergence. The coupling between the MARCS radiative transfer and GGchem chemical equilibrium computations has made it possibly effectively to reach convergence based on electron pressure for the warmer models and gas pressure for the cooler models, enabling self-consistent modelling of stellar, sub-stellar and exoplanetary objects in a very wide range of effective temperatures. Here we describe the basic details of the models, with illustrative examples of cloudy and irradiated models as well as models based on non-equilibrium chemistry. The qualitative changes in the relative abundances of TiO, H2O, CH4, NH3, and other molecules in our models follow the observationally defined M, L, T (and Y) sequences, but reveal more complex and depth dependent abundance changes, and therefore a spectral classification depending on more parameters. The self consistent coupling to Static-Weather cloud computations, allows detailed comparison between nucleation and observed relative dimming of different spectral bands, with advanced applications for new identification methods of potential exoplanetary biology.

References in corpus (64)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• A high accuracy computed water line list
• ExoMol molecular line lists XXX: a complete high-accuracy line list for water
• The ExoMol database: molecular line lists for exoplanet and other hot atmospheres
• The NextGen Model Atmosphere grid: II. Spherically symmetric model atmospheres for giant stars with effective temperatures between 3000 and 6800~K
• ExoMol: molecular line lists for exoplanet and other atmospheres
• ExoMol line lists III: An improved hot rotation-vibration line list for HCN and HNC
• CH in stellar atmospheres: an extensive linelist
• Atmospheric Chemistry in Giant Planets, Brown Dwarfs, and Low-Mass Dwarf Stars II. Sulfur and Phosphorus
• ExoMol Molecular linelists -- XXXIII. The spectrum of Titanium Oxide
• Equilibrium chemistry down to 100 K - Impact of silicates and phyllosilicates on carbon/oxygen ratio
• KROME - a package to embed chemistry in astrophysical simulations
• ExoMol molecular line lists XXXV: a rotation-vibration line list for hot ammonia
• The 2020 release of the ExoMol database: molecular line lists for exoplanet and other hot atmospheres
• A comparison of chemistry and dust cloud formation in ultracool dwarf model atmospheres
• Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets
• ExoMol line lists XVIII. The high temperature spectrum of VO
• ExoMol line lists -- XXXIX. Ro-vibrational molecular line list for CO${}_2$
• ExoMol molecular line lists - XIV: The rotation-vibration spectrum of hot SO${}_2$
• ExoMol line lists VII: The rotation-vibration spectrum of phosphine up to 1500 K
• A hybrid line list for CH${}_4$ and hot methane continuum
• The ExoMolOP Database: Cross-sections and k-tables for Molecules of Interest in High-Temperature Exoplanet Atmospheres
• Dynamic mineral clouds on HD 189733b I. 3D RHD with kinetic, non-equilibrium cloud formation
• Consistent simulations of substellar atmospheres and non-equilibrium dust-cloud formation
• Mie Scattering by Ensembles of Particles with Very Large Size Parameters
• HELIOS-K 2.0 Opacity Calculator and Open-source Opacity Database for Exoplanetary Atmospheres
• Three Dimensional Radiative Hydrodynamical Simulations of the Highly Irradiated Short Period Exoplanet HD189733b
• Partition functions and equilibrium constants for diatomic molecules and atoms of astrophysical interest
• New study of the line profiles of sodium perturbed by H2
• Self-luminous and irradiated exoplanetary atmospheres explored with HELIOS
• New CrH Opacities for the Study of L and Brown Dwarf Atmospheres
• ExoMol molecular line lists: IX The spectrum of AlO
• PICASO 3.0: A One-Dimensional Climate Model for Giant Planets and Brown Dwarfs
• The Intrinsic Temperature and Radiative-Convective Boundary Depth in the Atmospheres of Hot Jupiters
• Exploring the substellar temperature regime down to ~550K
• A library of ATMO forward model transmission spectra for hot Jupiter exoplanets
• Numerical simulations of surface convection in a late M-dwarf
• CRIRES spectroscopy and empirical line-by-line identification of FeH molecular absorption in an M dwarf
• The mineral clouds on HD 209458b and HD189733b
• ExoMol line lists VIII: A variationally computed line list for hot formaldehyde
• TEA: A Code for Calculating Thermochemical Equilibrium Abundances
• Near-infrared absorption properties of oxygen-rich stardust analogues: The influence of coloring metal ions
• Spectroscopic Constants, Abundances, and Opacities of the TiH Molecule
• ExoMol molecular line lists - XXIII: spectra of PO and PS
• ExoMol line lists XXIV: A new hot line list for silicon monohydride, SiH
• Geometry of giant star model atmospheres: A consistency test
• Radiative cooling functions for primordial molecules
• Modelling the local and global cloud formation on HD 189733b
• ExoMol line lists XXVIII: The rovibronic spectrum of AlH
• ExoMol line lists -- XLIV. IR and UV line list for silicon monoxide (SiO)
• ExoMol line lists XXXI: Spectroscopy of lowest eights electronic states of C${}_2$
• Cloud property trends in hot and ultra-hot giant gas planets (WASP-43b, WASP-103b, WASP-121b, HAT-P-7b, and WASP-18b)
• ExoMol molecular line lists X: The spectrum of sodium hydride
• ExoMol molecular line lists XII: Line Lists for 8 isotopologues of CS
• ExoMol molecular line lists XXXVI: $X{}^2\Pi -X{}^2\Pi$ and $A{}^2{\Sigma }^{+}-X{}^2\Pi$ transitions of SH
• Exomol molecular line lists VI: A high temperature line list for Phosphorus Nitride
• ExoMol molecular line lists - XXVI: spectra of SH and NS
• ExoMol line lists XXV: A hot line list for silicon sulphide, SiS
• Model atmospheres of sub-stellar mass objects
• ExoMol line lists -- XLV. Rovibronic molecular line lists of calcium monohydride (CaH) and magnesium monohydride (MgH)
• No evidence for radius inflation in hot Jupiters from vertical advection of heat
• An Improved Near-Infrared Spectrum of the Archetype Y Dwarf WISEP J182831.08+265037.8
• Self-consistent atmosphere modeling with cloud formation for low-mass stars and exoplanets
• Mineral Snowflakes on Exoplanets and Brown Dwarfs: Coagulation and Fragmentation of Cloud Particles with {\sc HyLandS}

Cited by in corpus (2)

• The $\text{MSG}$ model for cloudy substellar atmospheres: A grid of self-consistent substellar atmosphere models with microphysical cloud formation
• Accelerating exoplanet climate modelling: A machine learning approach to complement 3D GCM grid simulations