[Mesa-users] Si burning on TRho plot

[Josiah Schwab]

Hi Nicholas,

> i believe the burning lines in the Trho plot show when
> the energy generation rate is 1 erg/g/s for a pure composition.
> the data is in $MESA_DIR/data/star_data/plot_info .
>
> they were constructed by running a network on a sparse grid
> of temperatures and densities and finding the 1 erg/g/s contour.
> their purpose is to provide approximate, visual indicators.
>
> as you note, this was not was not done for silicon burning.
> one could create a $MESA_DIR/data/star_data/plot_info/silicon_burn.data
> from analytical approximations to silicon burning, and then with a
> tweak or two of the relevant pgstar routines, have the si burn contour shown.

Yes, as Frank says, these are just constant eps_nuc lines to guide the
eye.  Importantly, as you move to later burning stages thermal neutrino
losses become more important, so these are not really ignition lines.

You can easily add your own line to the plot using the pgstar option

  TRho_Profile_fname=''

You give it the name of a data file with the line you want to draw.
There is an example of doing something like that in the custom_rates
test_suite case.

Hope that helps,
Josiah

P.S.  PGSTAR plots also have the idea of a "decorator", which is a
user-supplied routine in run_star_extras that can draw whatever you want
in the plot.  Unfortunately, that functionality is broken in r10398 fot
the TRho_Profile profile plot.  (It's a trivial fix that has already
been made.)  If you really want to go that route, I attached the patch.


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