[Mesa-users] How to create C/O white dwarf of different abundances.

[Francis Timmes]

if you add:

show_net_reactions_info = .true.

to your star_job inlist mesa will print out information 
about each reaction in your network and which category it is in.

the file

$MESA_DIR/data/rates_data/reactions.list

has a list of some reactions and includes a column indicating 
the "category" of each reaction. for example, c12(a,g) is 
categorized as burn_c.

fxt






> On Oct 26, 2020, at 6:48 PM, harish sorrout <harishsorrout at gmail.com> wrote:
> 
> Thanks Francis, 
> 
> I have noticed one thing during the evolution of pre- main sequence to WD. At one stage of evolution temp. Was not enough to burn carbon and oxygen, but maximum energy was contributing from 
> Burn_c and burn_o reaction rate .  Can you please enlighten me in this regard.
> 
>  Thank you in advance.
> 
> On Mon, 26 Oct, 2020, 09:59 Francis Timmes, <fxt44 at mac.com> wrote:
> hi harish,
> 
> one approach is to evolve a ~0.5 to ~7 msun model from the pre-main sequence to a white dwarf.
> starting from a set of pre-main sequence initial conditions, precise predictions for the 
> properties of the white dwarf model, especially the mass fraction profiles, do not exist due 
> to the nonlinear system of equations being approximated. for example, variations in the 
> carbon and oxygen profiles of the white dwarf model can be caused by the nuclear reaction rates, 
> mixing and mass loss models, mass resolution, and time resolution. one can explore this approach 
> in mesa by experimenting with the 1M_pre_ms_to_wd test suite case.
> 
> another approach is to build an ab initio white dwarf model. by ab initio one means calculations 
> that begin with a white dwarf model, as opposed to a white dwarf model that is the result of 
> a stellar evolution calculation from the pre-main sequence. a potential disadvantage (or advantage) 
> of ab initio white dwarf models is that the imposed initial mass fraction profiles may not be 
> attainable by a stellar model evolved from the pre-main sequence. one can explore this approach 
> in mesa by experimenting with josiah schwab's wd_builder https://github.com/jschwab/wd_builder .
> 
> have fun!
> 
> fxt
> 
> 
> 
> 
> 
> > On Oct 24, 2020, at 8:02 AM, harish sorrout via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> > 
> > Hello,
> >  I want to create models of C/O white dwarf with different carbon oxygen abundance. So, which should be changed in inlist for such changes. 
> > should i change reaction rates or net name.
> > kindly advise.
> > thank you in advance
> > Harish kumar
>