An Equation of State for Low-Mass Stars and Giant Planets

TLDR

Background: from first line: "We present new equations of state (EOS) for hydrogen and helium, intended for applications to low-mass stars (M < 1 Msun), brown dwarfs, and giant planets." Also maybe context: "view Abstract Citations (940) References (55) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS" but that's not content. So background: new EOS for H and He for low-mass stars, brown dwarfs, giant planets. Purpose: from first line also: "We present new equations of state (EOS) for hydrogen and helium, intended for applications to low-mass stars (M < 1 Msun), brown dwarfs, and giant planets." Also from [Purpose, Findings] line: "In this paper, we present extensive tabular results for both the H and He EOS, together with a critical analysis." So purpose: to present new EOS and tabular results with analysis. Mechanism: many lines. Summarize: They cover wide T and P ranges, include new treatments of partial dissociation and ionization, hydrogen EOS based on nonideal interactions, helium simplified model, free energy minimization method, additive volume rule for mixtures, etc.

Abstract

view Abstract Citations (940) References (55) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS An Equation of State for Low-Mass Stars and Giant Planets Saumon, D. ; Chabrier, G. ; van Horn, H. M. Abstract We present new equations of state (EOS) for hydrogen and helium, intended for applications to low-mass stars (M < 1 Msun), brown dwarfs, and giant planets. They cover the range 2.10 <log T(K) < 7.06 and 4 <log P (dyn cm-2) < 19 and include new physical treatments of partial dissociation and ionization caused by both pressure and temperature effects. The hydrogen EOS is based on a careful study of nonideal interactions. In the case of helium, the principal features of the EOS physics are retained in a simplified model. The calculation is based on the free energy,minimization method, and a detailed account of the physical model has been published elsewhere. Mixtures of hydrogen and helium are obtained with the additive volume rule and an additional ideal entropy-of-mixing term. In this paper, we present extensive tabular results for both the H and He EOS, together with a critical analysis. Part of this analysis is based on a comparison with other EOS commonly used in astrophysics. Both EOS everywhere satisfy the requirements of thermal and mechanical stability and are thermodynamically consistent over most of the phase diagram. A complete set of the tables is available in the AAS CD-ROM Series, Vol. 5, and by anonymous FTP. Publication: The Astrophysical Journal Supplement Series Pub Date: August 1995 DOI: 10.1086/192204 Bibcode: 1995ApJS...99..713S Keywords: EQUATION OF STATE; STARS: INTERIORS; STARS: LOW-MASS; BROWN DWARFS; STARS: PLANETARY SYSTEMS full text sources ADS |