NSEoS (Neutron Star Equation of State) is a library that aims to provide the useful tools to calculate the composition, the equation of state, and observables of neutron stars according to different nuclear models. Please contact [email protected] if you have any questions.
git clone https://github.com/thomascarreau/NSEoS
You can find five example apps in NSEoS/source/apps/:
-
nseos, to calculate the composition, the equation of state, and other observables of cold isolated neutron stars for a given nuclear model. -
gs_ocrust, to calculate the ground state of the outer crust for a given nuclear mass table. -
bayes, for the Bayesian inference of neutron star observables. For published results, see Carreau, Thomas, Francesca Gulminelli, and Jérôme Margueron. "Bayesian analysis of the crust-core transition with a compressible liquid-drop model." The European Physical Journal A 55.10 (2019): 188 and Carreau, Thomas, Francesca Gulminelli, and Jérôme Margueron. "General predictions for the neutron star crustal moment of inertia." Physical Review C 100.5 (2019): 055803. -
crust_crystallization, to calculate the crust composition and the equation of state at the crystallization temperature for a given nuclear model. For published results, see Carreau, T., et al. "Crystallization of the inner crust of a neutron star and the influence of shell effects." Astronomy & Astrophysics 635 (2020): A84. -
mcp_icrust, to calculate the composition of the the multicomponent Coulomb plasma in the free neutron regime with a perturbative implementation of the nuclear statistical equilibrium for a given nuclear model at a given temperature. For published results, see Carreau, T., A. F. Fantina, and F. Gulminelli. "Inner crust of a neutron star at the point of crystallization in a multicomponent approach." Astronomy & Astrophysics 640 (2020): A77.
Feel free to write new apps using the functions of the library and to contact [email protected] if you wish to contribute.
In NSEoS/source/apps/nseos:
make
./nseos set.in crust.out core.out eos.out tov.out
The first output file gives you the crust composition: number density, mass of the cluster, global asymmetry in the cluster, number of charges, cluster density, gas density, and radius of the cell. The second output file gives you the core composition: number density, fraction of protons, electrons, and muons. The third output file gives you the equation of state: mass density and pressure. Finally, the last output file gives you the Tolman-Oppenheimer-Volkoff solution: central density, central pressure, radius, mass, core radius, core mass, normalized moment of inertia, fraction of moment of inertia residing in the crust, tidal love number, and dimensionless tidal deformability.
In NSEoS/source/apps/gs_ocrust:
make
./gs_ocrust mass_table.data outfile
Nuclear mass tables can be found in NSEoS/source/input/mass_tables. The
format of the tables is Z, N, mass excess. You can use
the script mergeTables.py to merge two mass tables. For example, if you want
to complete AME2012 data with HFB-24 theoretical masses then run:
python3 mergeTables.py ame2012.data hfb24.data ame2012_plus_hfb24.data
Note that it requires NumPy library.
In NSEoS/source/apps/bayes:
make
./bayes
The output files give you the posterior distribution of parameters and
observables, as well as the equation of state and the
Tolman-Oppenheimer-Volkoff solution for each set of empirical parameters of the
posterior distribution. You can change the size of the prior distribution by
editing the script priorDistribution.py.
In NSEoS/source/apps/crust_crystallization:
make
./crust_crystallization set.in crust.out eos.out
The first output file gives you the crust composition at the melting temperature: number density, melting temperature, mass of the cluster, global asymmetry in the cluster, number of charges, cluster density, gas density, and radius of the cell. The second output file gives you the equation of state at the melting temperature: mass density and pressure.
In NSEoS/source/apps/mcp_icrust:
make
./mcp_icrust set.in > icrust.out
The output file gives you the composition of the multicomponent Coulomb plasma at the chosen temperature: pressure, baryon density, temperature, proton density, neutron gas density, neutron/proton chemical potential, average cell volume/cluster mass/cell mass/cluster charge, impurity parameter, most probable cluster mass/cell mass/cluster charge, and cluster mass/cell mass/cluster charge as obtained within the one-component plasma approximation.
-
BSk14:
bsk14.in -
BSk16:
bsk16.in -
BSk17:
bsk17.in -
BSk22:
bsk22.in -
BSk24:
bsk24.in -
BSk25:
bsk25.in -
BSk26:
bsk26.in -
NRAPR:
nrapr.in -
RATP:
ratp.in -
SkO:
sko.in -
SLy230a:
sly230a.in -
SLy230b:
sly230b.in -
SLy4:
sly4.in
-
DDME2:
ddme2.in -
DDMEd:
ddmed.in -
NL3:
nl3.in -
PKDD:
pkdd.in -
TM1:
tm1.in -
TW99:
tw99.in
We use the metamodeling technique to
mimic existing nuclear models with very good accuracy. The input parameters are
the successive density derivatives of nuclear matter energy (lasat0,
ksat0, qsat0, zsat0, jsym0, lsym0, ksym0, qsym0, and zsym0) and
effective masses (effm and isosplit) at saturation density (rhosat0).
If you wish to add new models in NSEoS/source/input/satdata, here is the
format:
rhosat0 lasat0 ksat0 qsat0 zsat0
jsym0 lsym0 ksym0 qsym0 zsym0
effm isosplit