Microlab 3: Opacities and initial mixture

Copy the test suite $MESA_DIR/star/test_suite/1M_pre_ms_to_wd somewhere outside $MESA_DIR. Once you are in the newly copied work directory, copy the following files into it

cp $MESA_DIR/star/test_suite/20M_pre_ms_to_core_collapse/r*_nomodfiles .

This test suite runs multiple inlists consecutively and these files will allow us to restart from a photo instead of a .mod file when running the next inlist. Create a new file nano run_all (or any other text editor) and copy into it the following

./rn_nomodfiles inlist_start_header
./re_nomodfiles . inlist_to_end_core_h_burn_header
./re_nomodfiles . inlist_to_start_he_core_flash_header

Finally, make this file executable with

chmod +x run_all

In the &kap section of inlist_start, inlist_to_end_core_h_burn and inlist_to_start_he_core_flash change

kap_file_prefix = ''     ! Either gn93, gs98, a09, OP_gs98, or OP_a09_nans_removed_by_hand
kap_lowT_prefix = ''     ! Either lowT_fa05_gn93, lowT_fa05_gs98, or lowT_fa05_a09p
kap_CO_prefix   = ''     ! Either gn93_co, gs98_co, or a09_co

to a specific mixture (i.e. the relative abundances of metals). Distribute the different options amongst your table, but use the same mixture for all three controls.

In the &star_job section of inlist_start add

initial_zfracs = … ! 2 = GN93, 3 = GS98, 6 = A09

using the corresponding mixture.

Tip

Full article references can be found in $MESA_DIR/chem/public/chem_def.f90.

In the &controls section of inlist_to_start_he_core_flash change

max_model_number = 400

Compile and run a model by ./run_all, plot log_Teff vs. log_L with MESA Explorer, and compare the result with your table. The history file will be in LOGS. Give the history file a more appropriate name.

mv history.data history_<your_mixture>.data

Compare for example the highest effective temperature reached. What is the impact of the opacity on the evolution track?