make_co_wd
This test builds a carbon-oxygen white dwarf starting from a specified pre main-sequence mass. It does this by running through a series of inlists for different stages of evolution. By default, the first two steps (pre main-sequence and main-sequence through core helium burning) are skipped so that the test will run in a reasonable amount of time, and the test produces a 0.6 \({\rm M}_\odot\) white dwarf from a roughly 3 \({\rm M}_\odot\) progenitor.
Starting from the beginning to produce a white dwarf descended from a
progenitor of different mass or metallicity can be accomplished by
editing the values assigned to initial_mass
or initial_z
in
inlist_common
.
Larger values for initial_mass
can be used to produce more massive
carbon-oxygen white dwarfs, but note that this test produces only an
approximate initial-to-final-mass relation (IFMR). The test is
designed to truncate the AGB evolution at the beginning of the
thermally-pulsing AGB (TP-AGB) stage, which can be difficult and/or
resource-intensive to model.
The five steps in this procedure are:
1. inlist_zams
(optional)
This step starts from the pre main-sequence to produce a ZAMS model
with the initial mass and metallicity specified in inlist_common
.
2. inlist_to_end_he_core_burn
(optional)
This step evolves from ZAMS through the end of core helium burning.
3. inlist_co_core
This step evolves to near the end of shell helium burning, producing the final C/O core profile in the interior. This step terminates when a thermal pulse occurs in the helium shell.
4. inlist_remove_env
This step removes the AGB envelope using the star_relax_to_star_cut
method in src/run_star_extras.f90
. The location of the cut is
specified using x_ctrl(1)
to leave \(10^{-3}\) \({\rm M}_\odot\) of the
hydrogen envelope. After the relaxation ends, residual burning will
reduce the final hydrogen envelope mass to around
\(10^{-4}\) \({\rm M}_\odot\) (for the default 0.6 \({\rm M}_\odot\) white dwarf).
5. inlist_settle
This step turns on diffusion in the young proto-WD model to allow the model to settle into a stratified envelope structure with a pure hydrogen atmosphere. This final step ends when the white dwarf has cooled down to reach a luminosity of 1 \({\rm L}_\odot\).