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Stellar Equations Of State

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Contact us:
J.D. Maldonado
F.X.Timmes, my vitae

Before using the routines below, you should glance at the web pages that describe them: "The Accuracy, Consistency, and Speed of Five Equations of State for Stellar Hydrodynamics", and "The Accuracy, Consistency, and Speed Of An Electron-Positron Equation Of State Based On Table Interpolation Of The Helmholtz Free Energy".

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Pressure comparison
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Exact solution comparison
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Thermodynamic Consistency


Helmholtz EOS
plus a free energy data file
helm_table.dat
plus a fortran include file
vector_eos.dek
Nadyozhin EOS
plus a fortran include file
vector_eos.dek
Iben EOS
plus a fortran include file
vector_eos.dek
Weaver EOS
plus a fortran include file
vector_eos.dek
Arnett EOS
plus three asci data files
eos.d   eos1.d   eos8.d
plus two fortran include files:
arnett_eos.dek   vector_eos.dek
Timmes EOS
plus three fortran include files:
implno.dek
const.dek
vector_eos.dek


Comments: The Helmholtz EOS executes the fastest, displays perfect thermodynamic consistency, has a maximum error of 1e-6, and is the stellar EOS of choice in the FLASH code.

The Nadyozhin EOS is the fastest of the analytic routines, has very good thermodynamic consistency, a maximum error of 1e-5, and is avaliable in the FLASH code.

The Timmes EOS is as slow as molasses during a North Dakota winter, but it computes the non-interacting electron-positron equation of state with no approximations, is exact to machine precision in IEEE double precision arithmetic, has excellent thermodynamic consistency, and serves as the reference point for comparisons to the other EOS routines. In fact, the Helmholtz free energy table for the Helmholtz EOS was calculated from the Timmes EOS.

The helm_table.dat file for the Helmholtz EOS spans 10-12 ≤ density (g cm-3) ≤ 1015 and 103 ≤ temperature (K) ≤ 1013. Contact me if you need something different.
 



Please cite the relevant references if you publish a piece of work that use these codes, pieces of these codes, or modified versions of them. If you're nice, offer co-authorship of the publication. At best, you'll love these programs so much that you'll send great wads of cash to me.