Modeling extrasolar planetary atmospheres
Modeling extrasolar planetary atmospheres
Planetary Systems as Potential Sites for LifeSpecial Session SpS6 - Aug. 11th, 11h-11h20
France AllardDirectrice de Recherche, CNRS
Centre de Recherche Astrophysique de Lyon
Planetary Systems as Potential Sites for LifeSpecial Session SpS6 - Aug. 11th, 11h-11h20
France AllardDirectrice de Recherche, CNRS
Centre de Recherche Astrophysique de Lyon
Typical flux distributionTypical flux distribution
Very generally a planet will:
a) reflected stellar light. It dominates at the stellar peak of emission.
b) thermal emission of the rest of the stellar light.
c) thermal emission from the interior (like brown dwarfs).
Very generally a planet will:
a) reflected stellar light. It dominates at the stellar peak of emission.
b) thermal emission of the rest of the stellar light.
c) thermal emission from the interior (like brown dwarfs).
7
5
Web Simulator ONLINE!
• Offers synthetic spectra and thermal structures of published model grids and the relevant publications.
• Computes synthetic spectra, with/without irradiation by a parent star, and photometry for:
main sequence stars
brown dwarfs (1 Myrs - 10 Gyrs)
extrasolar giant planets
telluric exoplanets
• Computes isochrones and finds the parameters of a star by chi-square fitting of colors and/or mags to the isochrones.
• Rosseland/Planck as well as monochromatic opacity tables calculations
http://phoenix.ens-lyon.fr/simulator
NOW OPEN!
Static 1D radiative model: reconstruction of the
surface
Static 1D radiative model: reconstruction of the
surface
Barman, Hauschildt & Allard (ApJ 632, p1132, 2005)Barman, Hauschildt & Allard (ApJ 632, p1132, 2005)
For each block Tint so as all thermal structures meet the same adiabat below the photosphere
night side Teff= 500K
HD209458b
1995K
Orbital PhasesOrbital Phases
Luminosity ratio as a function of orbital phase. 0.0 corresponds to a transit (night side only). 0.5 is when the planet is occulted by the star.
Luminosity ratio as a function of orbital phase. 0.0 corresponds to a transit (night side only). 0.5 is when the planet is occulted by the star.
Barman, Hauschildt &Barman, Hauschildt & Allard (ApJ 632, p.1132, 2005) Allard (ApJ 632, p.1132, 2005)
HD209458b H2O detection!
HD209458b H2O detection!
Barman (ApJ 661, L191, 2007)
Time-dependant 1D radiative(assumes wind velocity)
600K day-to-night contrast!
Time-dependant 1D radiative(assumes wind velocity)
600K day-to-night contrast!
Equatorial cut of the atmosphere between the 10-6 and 10-bar levels for an equatorial wind velocity of a) 0.5 km s-1; b) 1 km s-1; and c) 2 km s-1. The level where condensation of sodium occurs (black line) goes deeper as the night wears on (anti-clockwise) and is deepest at the morning limb. Below 10 bar, the temperature field (not shown here) is uniform and depends only on the bottom boundary condition.
radiative time constant which increases with depth and reaches about 8 h at 0.1 bar and 2.3 days at 1 bar.
Equatorial cut of the atmosphere between the 10-6 and 10-bar levels for an equatorial wind velocity of a) 0.5 km s-1; b) 1 km s-1; and c) 2 km s-1. The level where condensation of sodium occurs (black line) goes deeper as the night wears on (anti-clockwise) and is deepest at the morning limb. Below 10 bar, the temperature field (not shown here) is uniform and depends only on the bottom boundary condition.
radiative time constant which increases with depth and reaches about 8 h at 0.1 bar and 2.3 days at 1 bar.
Iro, Bezard & Guillot (A&A 436, p719, 2005)
Quasi-2D, single layered fluid dynamics
Quasi-2D, single layered fluid dynamics
[Left] Equatorial and polar views of potential vorticity (a flow tracer) in a specific hot Jupiter model from Cho et al. (2003, 2007). Note the prominent circumpolar vortices formed as a result of potential vorticity conservation. [Right] Corresponding zonally averaged wind profile, characterized by a small number of broad jets (three in this case).
Fig 3 of Showman, Menou & Cho (2007)
Cho et al. (2003, 2007)
Radiative (grey) Hydrodynamics
with Rotation!
Radiative (grey) Hydrodynamics
with Rotation!
The temperature at the photosphere of a planet rotating with a period of 3 days. The upper panel shows the distribution over the entire planet, while the lower panel highlights the temperature structure on the night-side from = /2 to = 3/2. A clear day-night delineation persists, despite complicated dynamical structure, due to substantial radiation near the terminators.
Day side extended isotherm: 1200K for a start at 1200K.
Night side has 310 to 500K for a start at 100K.
Jets near terminator: 500K
The temperature at the photosphere of a planet rotating with a period of 3 days. The upper panel shows the distribution over the entire planet, while the lower panel highlights the temperature structure on the night-side from = /2 to = 3/2. A clear day-night delineation persists, despite complicated dynamical structure, due to substantial radiation near the terminators.
Day side extended isotherm: 1200K for a start at 1200K.
Night side has 310 to 500K for a start at 100K.
Jets near terminator: 500K
Dobbs-Dixon & Lin (2007)astro-ph/0704.3269
night side
whole
Hydrodynamical 3D model based on radiative timescales by Iro05
Hydrodynamical 3D model based on radiative timescales by Iro05
Global temperature maps: model atmosphere spanning ∼15 pressure scale heights between the input top layer and the bottom boundary at 3 kbar, using 40 layers evenly spaced in log pressure with a P-T profile generated at evenly spaced longitudes (in 5° increments) and latitudes (in 4° increments) for 72 longitude and 44 latitude points (=3168 P-T profiles). Arrows show the direction and relative magnitudes of winds. Each longitude minor tick mark is 18°, and each latitude minor tick mark is 9°. Each panel uses the same temperature shading scheme.
Strong winds (3-9 km/s = 6500-20000 mph) predicted to form under substellar point - offsets hottest point viewed, shifts phase.
Cooper & Showman (2006)
Global temperature maps: model atmosphere spanning ∼15 pressure scale heights between the input top layer and the bottom boundary at 3 kbar, using 40 layers evenly spaced in log pressure with a P-T profile generated at evenly spaced longitudes (in 5° increments) and latitudes (in 4° increments) for 72 longitude and 44 latitude points (=3168 P-T profiles). Arrows show the direction and relative magnitudes of winds. Each longitude minor tick mark is 18°, and each latitude minor tick mark is 9°. Each panel uses the same temperature shading scheme.
Strong winds (3-9 km/s = 6500-20000 mph) predicted to form under substellar point - offsets hottest point viewed, shifts phase.
Cooper & Showman (2006)
8 km s-1= static
W-to-E 35°
W-to-E 60°
Orbital phase Orbital phase
Planetary emergent flux density (ergs s-1 cm-2 Hz-1) vs. wavelength as a function of orbital phase for equilibrium chemistry. The dashed black curve is the flux of a 1330 K blackbody, which plots behind the dark blue curve at λ > 4 μm. Normalized Spitzer band passes are shown in dotted lines at the bottom and standard H, K, L, and M bands are shown at the top.
Planetary emergent flux density (ergs s-1 cm-2 Hz-1) vs. wavelength as a function of orbital phase for equilibrium chemistry. The dashed black curve is the flux of a 1330 K blackbody, which plots behind the dark blue curve at λ > 4 μm. Normalized Spitzer band passes are shown in dotted lines at the bottom and standard H, K, L, and M bands are shown at the top.
Fortney, Cooper, Showman, Marley, & Freedman (ApJ 652, 746, 2006)
HD189733bHD189733b
Simulations vs transit observations. The overall transmission spectrum is shaped by the water absorption in the infrared (Tinetti et al., 2007b) but methane is needed to explain the NIR (Swain, Vasisht, Tinetti, 2008). At shorter wavelength, the increasing flatness of the spectrum could be explained by hazes. Broad band photometry is not enough to distinguish the different additional molecules.
Figs. 1 & 2 of Tinetti & Baulieu (2008)
2D RHD simulations of cloud formation
in brown dwarf atmospheres
2D RHD simulations of cloud formation
in brown dwarf atmospheres
CO5BOLD models (Bernd Freytag), gas and grains (Mg2SiO4) opacities from Phoenix, cloud model (dust size-bin distribution), nucleation, condensation, coagulation rates, and sedimentation velocity according to Rossow (1978). In red the dust mass density is indicated, while in green the entropy is shown to indicate the convection zone.
CO5BOLD models (Bernd Freytag), gas and grains (Mg2SiO4) opacities from Phoenix, cloud model (dust size-bin distribution), nucleation, condensation, coagulation rates, and sedimentation velocity according to Rossow (1978). In red the dust mass density is indicated, while in green the entropy is shown to indicate the convection zone.
W350 x H80 km2 over 36 hours
QuickTime™ et undécompresseur codec YUV420
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Gravity Waves !!!
EGPs: the CoRoT-3b caseEGPs: the CoRoT-3b case
Temperature inversion in outer layers
Temperature raises above condensation temperature
Dust only forms in the optically thin upper layers
CoRot-3b = black curve CoRot-3b = red curves
No stellar irradiation
Half-sphere redistribution
Main actors of exoplanet’s field
Main actors of exoplanet’s field
authors geometry opacities chemistry radiative transfer
Barman et al. ‘01, ‘05, ‘06Barman ‘08
1D, hydrostaticGlobal 3D reconstruction
Gas + dust CE, NLTE, Photo-ionization
Spherical symmetry, ALI
Sudarsky etal. ‘03,‘05,‘06Burrows etal.‘03,’04,’05,’06
1D, hydrostatic Gas + dust CE Plan-parallel, ALI
Seager et al. ‘98, ‘00, ‘05 1D, hydrostatic Gas + dust CE Plan-parallel (Feautrier)
Fortney et al. ‘05, ‘06 1D, hydrostatic Gas + dust CE by table interpolation
Plan-parallel, two-stream, NO scattering
Brown ‘01, Tinetti et al. ‘08
Ray tracing, hydrostatic Ad-hoc rotation
Gas + dust CE, Photo-ionizationPhotochemistry
Goukenleuque et al. ‘00, Iro et al. ‘05
1D, time relaxation, Ad-hoc rotation, Global 3D reconstruction
Gas + dust CE not updated with time
Plan-parallel, two-stream, WITH scattering
Freytag et al. ‘09 Local 3D Hydrodynamics, winds Gas + dust CE 3D (Feautrier)
Showman & Guillot ‘02 Local 3D hydrodynamics, winds - - Radiative gradient from RT models
Dobbs-Dixon & Lin ‘07 Global 3D hydrodynamics, rotation
Dust only CE Diffusion approximation
Cho et al. ‘96, ‘01, ‘03, ‘07Menou ‘03
Global 2D (single layered) hydrodynamics, rotation
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