Just a Module#
This document describes how to use the MESA equation of state, opacity, and nuclear reaction networks outside of MESA.
1. Equation of State#
cd my_eos
cp $MESA_DIR/eos/test/src/sample_eos.f90 .
Edit sample_eos.f90 and change the variable
my_mesa_dir = '../..'
to your $MESA_DIR, or use a blank string, in which case your $MESA_DIR is automagically used
my_mesa_dir = ''
while you are editing sample_eos.f90, take some time to explore the source code. Save and exit sample_eos.f90. Now take some time to explore the makefile, and use it to build the executable
make
Run the interactive executable, named sample_eos
./sample_eos
loading eos tables
give the temperature, density, and mass fractions (h1, he4, c12, n14, o16, ne20, mg24) =>
hit return for T = 1e9 K, Rho = 1e9 g/cc, x(c12) = 1 ; enter -1 to stop
T = 1.000000E+09 Rho = 1.000000E+04 abar = 1.200000E+01 zbar = 6.000000E+00
h1 = 0.000000E+00 he4 = 0.000000E+00 c12 = 1.000000E+00 n14 = 0.000000E+00
o16 = 0.000000E+00 ne20 = 0.000000E+00 mg24 = 0.000000E+00
quantity value d/d(Rho) d/d(T) d^2/d(Rho)^2 d^2/d(Rho)d(T) d^2/d(T)^2
p tot = 3.033664E+21 4.616282E+16 1.098950E+13 7.389591E+11 -2.632100E+07 3.148155E+04
p gas = 5.117530E+20 4.616282E+16 9.018528E+11 7.389591E+11 -2.632100E+07 1.218618E+03
p rad = 2.521911E+21 0.000000E+00 1.008764E+13 0.000000E+00 0.000000E+00 3.026293E+04
e tot = 8.606704E+17 -7.955833E+13 3.425527E+09 1.626134E+10 -3.604408E+05 1.309327E+01
e gas = 1.040971E+17 -3.900997E+12 3.992340E+08 1.129877E+09 -5.781150E+04 4.014391E+00
e rad = 7.565733E+17 -7.565733E+13 3.026293E+09 1.513147E+10 -3.026293E+05 9.078880E+00
s tot = 1.476688E+09 -1.098950E+05 3.425527E+00 2.186704E+01 -3.604408E-04 9.667743E-09
s gas = 4.679233E+08 -9.018528E+03 3.992340E-01 1.691755E+00 -5.781150E-05 3.615157E-09
s rad = 1.008764E+09 -1.008764E+05 3.026293E+00 2.017529E+01 -3.026293E-04 6.052587E-09
n_ion = 5.018451E+26 5.018451E+22 0.000000E+00
n_ele = 3.200158E+27 2.870797E+23 1.414171E+18
eta_e = -4.182056E+00 9.451310E-05 -1.319764E-09
cv = 3.425527E+09 -3.604408E+05 1.309327E+01
cp = 2.958707E+10 -5.803942E+06 2.045230E+02
gamma_1 = 1.314315E+00 5.192048E-06 -3.807384E-10
gamma_2 = 1.322910E+00 9.783797E-07 -1.079536E-10
gamma_3 = 1.320812E+00 2.002091E-06 -1.740076E-10
grad_ad = 2.440906E-01 5.590452E-07 -6.168458E-11
chi_t = 3.622516E+00 -5.143301E-05 2.381262E-09
chi_d = 1.521685E-01 1.443976E-05 -5.143301E-10
c_sound = 6.310334E+08 -2.640054E+04 1.141379E+00
dsp = 2.220446E-16 dpe = 7.993606E-15 dsp = -2.331468E-15
give the temperature, density, and mass fractions (h1, he4, c12, n14, o16, ne20, mg24) =>
hit return for T = 1e9 K, Rho = 1e9 g/cc, x(c12) = 1 ; enter -1 to stop
-1
STOP normal termination
For homework, edit sample_eos.f90 to write out \(\partial{T}/\partial{\rho}|_{S}\). As mentioned in sample_eos.f90, it can be useful to look at the integer indices contained in $MESA_DIR/eos/public/eos_def.f90.
2. Opacity#
cd my_kap
cp $MESA_DIR/kap/test/src/sample_kap.f90 .
cp $MESA_DIR/kap/test/sample_kap_agb.model .
Edit sample_kap.f90 and change the variable
my_mesa_dir = '../..'
to your $MESA_DIR, or use a blank string, in which case your $MESA_DIR is automagically used
my_mesa_dir = ''
while you are editing sample_kap.f90, take some time to explore the source code. Save and exit sample_kap.f90. Now take some time to explore the makefile, and use it to build the executable
make
Run the executable, named sample_kap, which reads a mesa model file and writes out the opacity and its derivatives at each cell
./sample_kap
Npts 1331
Nspec 31
Z_init 1.0000000000000000E-002
write kap_test.data
Explore the output with, for example,
head -4 kap_test.data
grid log_T log_Rho kappa kappa_CO dlnK_dlnRho dlnK_dlnT
1 3.5585465937700458E+000 -8.4473997504616456E+000 1.7963661540128417E-003 1.7963661540128417E-003 5.9324713626960102E-001 7.7443291473465914E+000
2 3.5585885995787634E+000 -8.4471065383083204E+000 1.7984321714713182E-003 1.7984321714713182E-003 5.9331124051888307E-001 7.7411914141868570E+000
3 3.5586446634268447E+000 -8.4467158120772723E+000 1.8011910725944315E-003 1.8011910725944315E-003 5.9339708647788947E-001 7.7370154334784580E+000
3. Nuclear Reaction Networks#
cd my_net
cp $MESA_DIR/net/test/src/sample_net.f90 .
Edit sample_net.f90 and change the variable
my_mesa_dir = '../..'
to your $MESA_DIR, or use a blank string, in which case your $MESA_DIR is automagically used
my_mesa_dir = ''
while you are editing sample_net.f90, take some time to explore the source code. Save and exit sample_net.f90. Now take some time to explore the makefile, and use it to build the executable
make
Run the interactive executable, named sample_net
./sample_net
load approx21.net
give the temperature, density, and mass fractions (h1, he4, c12, n14, o16, ne20, mg24) =>
hit return for T = 1e9 K, Rho = 1e4 g/cc, x(c12) = 1 ; enter -1 to stop
T = 1.000000E+09 Rho = 1.000000E+04 abar = 1.200000E+01 zbar = 6.000000E+00
h1 = 0.000000E+00 he4 = 0.000000E+00 c12 = 1.000000E+00 n14 = 0.000000E+00
o16 = 0.000000E+00 ne20 = 0.000000E+00 mg24 = 0.000000E+00
d(h1)/dt = 0.000000E+00 d(he4)/dt = 5.582829E-09 d(c12)/dt = -3.349697E-08 d(n14)/dt = 0.000000E+00
d(o16)/dt = 0.000000E+00 d(ne20)/dt = 2.791414E-08 d(mg24)/dt = 0.000000E+00
1 - sum = -6.617445E-24
eps_nuc = 6.217517E+09 erg/g/sec
give the temperature, density, and mass fractions (h1, he4, c12, n14, o16, ne20, mg24) =>
hit return for T = 1e9 K, Rho = 1e4 g/cc, x(c12) = 1 ; enter -1 to stop
-1
STOP normal termination
For homework, edit sample_net.f90 and change the network and associated write statements.