[Mesa-users] Parameters for make_co_wd with higher initial mass (4M+)

[Evan Bauer]

Hi Tyler,

Thanks for sharing! I’ve now run the model, and I’m seeing the failure you reported. It looks like it’s coming from something going wrong with the EOS in the core when it tries to start crystallizing near the end of the run. I’ll need to check with Adam Jermyn (developer of the Skye EOS that we use in WD cores) to better understand what’s going wrong there. However, you can get around the problem by adding the following lines to the &eos portion of your inlist:

   Skye_min_gamma_for_solid = 100
   Skye_max_gamma_for_liquid = 300

The Skye paper has some discussion related to these controls and crystallizing white dwarfs in section 6.5: https://ui.adsabs.harvard.edu/abs/2021ApJ...913...72J/abstract <https://ui.adsabs.harvard.edu/abs/2021ApJ...913...72J/abstract>

Cheers,
Evan


> On Mar 30, 2022, at 12:37 PM, TYLER THOMAS FREDRICK <tfredrick at wisc.edu> wrote:
> 
> Sorry for the delayed reply, Evan.
> 
> After re-running the tests with the new models, I found that most of them worked. The only ones that did not work were the diffusion tests for the WD stars with initial masses of 4M and 6M. The termination code was the same for both and is pasted below:
> 
> stopping because of problems dt < min_timestep_limit
> terminated evolution: cannot find acceptable model
> termination code: min_timestep_limit
>  failed to reach target for Teff
>  after_evolve_extras ierr          -1
>  after_evolve_loop ierr          -1
> 
> This is again using version r21.12.1. I’ve attached the inlists of for the diffusion test case, as well as the starting model I am using for the 4M case. If you could look into this, that would be greatly appreciated!
> 
> 
>> On Mar 24, 2022, at 12:56 PM, Evan Bauer <evan.bauer.astro at gmail.com <mailto:evan.bauer.astro at gmail.com>> wrote:
>> 
>> Hi Tyler,
>> 
>> (please keep replies on the mesa-users list so other can see when and how problems get solved)
>> 
>> I’m happy to take a look at the cooling and diffusion tests to see what might be causing problems. What kind of starting model are you using in those cases? Can you send an example of something I could run to reproduce the problems that you’re seeing in those tests?
>> 
>> Cheers,
>> Evan
>> 
>>> On Mar 23, 2022, at 11:06 PM, TYLER THOMAS FREDRICK <tfredrick at wisc.edu <mailto:tfredrick at wisc.edu>> wrote:
>>> 
>>> Hi Evan,
>>> 
>>> Yes, I am using r21.12.1. The issues were resolved with the changes you suggested, thank you! On another note, a similar issue occurs with higher masses for the cooling and diffusion tests. Would the same changes also work for them?
>>> 
>>> Tyler T. Fredrick
>>> Midshipman 1/C, USNR
>>> Undergraduate, Astronomy-Physics,
>>> Physics, Mathematics, B.S.
>>> University of Wisconsin-Madison
>>> 715.550.0100
>>> From: Evan Bauer <evan.bauer.astro at gmail.com <mailto:evan.bauer.astro at gmail.com>>
>>> Sent: Wednesday, March 23, 2022 12:28:42 PM
>>> To: TYLER THOMAS FREDRICK <tfredrick at wisc.edu <mailto:tfredrick at wisc.edu>>
>>> Cc: mesa-users <mesa-users at lists.mesastar.org <mailto:mesa-users at lists.mesastar.org>>
>>> Subject: Re: [Mesa-users] Parameters for make_co_wd with higher initial mass (4M+)
>>>  
>>> Hi Tyler,
>>> 
>>> What MESA version are you using? This test case does struggle for more massive WDs in r21.12.1. I added a few changes since the latest public release that seem to help it for more massive WDs, but those changes haven’t been included in a public release yet. Here’s a summary of the commit:
>>> https://github.com/MESAHub/mesa/commit/0a955404ffd00164e3bf354a58afa6a4882e4f6e <https://github.com/MESAHub/mesa/commit/0a955404ffd00164e3bf354a58afa6a4882e4f6e>
>>> 
>>> If you include those changes in your inlists, does it resolve the problem?
>>> 
>>> Cheers,
>>> Evan
>>> 
>>>> On Mar 23, 2022, at 12:31 PM, TYLER THOMAS FREDRICK via Mesa-users <mesa-users at lists.mesastar.org <mailto:mesa-users at lists.mesastar.org>> wrote:
>>>> 
>>>> Hi all,
>>>> 
>>>> I’m currently using the make_co_wd test case to create white dwarf models of varying initial masses. When reaching an initial mass of 4M, the time step for the calculations drop to a very low amount, and it takes an excessive number of models to get to the final luminosity value. The only parameter from the common inlist that was changed was the initial mass, but I’m assuming there might be other parameters that need to be changed.
>>>> 
>>>> I’ve attached the common variable inlist as a reference. Any ideas would be greatly appreciated!
>>>> 
>>>> Sincerely,
>>>> 
>>>> Tyler 
>>>> 
>>>> 
>>>> <inlist_common>_______________________________________________
>>>> mesa-users at lists.mesastar.org <mailto:mesa-users at lists.mesastar.org>
>>>> https://lists.mesastar.org/mailman/listinfo/mesa-users <https://lists.mesastar.org/mailman/listinfo/mesa-users>
>>>> 
>>> 
>> 
> 
> <4M_wd.mod><inlist_wd_diff><inlist_wd_diff_header><rn>

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