J/ApJ/806/228 Ab initio EOS for water-hydrogen mixtures (Soubiran+, 2015)
Miscibility calculations for water and hydrogen in giant planets.
Soubiran F., Militzer B.
<Astrophys. J., 806, 228 (2015)>
=2015ApJ...806..228S 2015ApJ...806..228S (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Planets
Keywords: equation of state; planets and satellites: gaseous planets;
planets and satellites: individual: (Jupiter, Saturn, Uranus, Neptune)
Abstract:
We present results from ab initio simulations of liquid water-hydrogen
mixtures in the range from 2 to 70GPa and from 1000 to 6000K, covering
conditions in the interiors of ice giant planets and parts of the
outer envelope of gas giant planets. In addition to computing the
pressure and the internal energy, we derive the Gibbs free energy by
performing a thermodynamic integration. For all conditions under
consideration, our simulations predict hydrogen and water to mix in
all proportions. The thermodynamic behavior of the mixture can be well
described with an ideal mixing approximation. We suggest that a
substantial fraction of water and hydrogen in giant planets may occur
in homogeneously mixed form rather than in separate layers. The extent
of mixing depends on the planet's interior dynamics and its conditions
of formation, in particular on how much hydrogen was present when icy
planetesimals were delivered. Based on our results, we do not predict
water-hydrogen mixtures to phase separate during any stage of the
evolution of giant planets. We also show that the hydrogen content of
an exoplanet is much higher if the mixed interior is assumed.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 131 Equation of state of water-hydrogen mixtures
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See also:
J/ApJ/774/148 : Ab initio EOS for hydrogen-helium mixtures (Militzer+, 2013)
J/ApJ/750/52 : Jupiter model with improved EOS (Nettelmann+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 K Temp [1000/6000] Temperature
6- 11 F6.4 --- Conc [0/1] Water concentration
13- 18 F6.4 g/cm3 Den [0.1/2.6] Mass density
20- 25 F6.3 GPa P [1.3/89.3] Pressure
27- 31 F5.3 GPa e_P [0.01/0.4] Uncertainty in P
33- 40 F8.4 eV IntE [-13.92/-3.17] Internal energy (1)
42- 47 F6.4 eV e_IntE [0.0009/0.04] Uncertainty in IntE (1)
49- 56 F8.4 eV Gibbs [-22.44/-5.09] Gibbs free energy (1)
58- 63 F6.4 eV e_Gibbs [0.003/0.05] Uncertainty in Gibbs (1)
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Note (1): In units of eV/molecule.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Oct-2015