[Mesa-users] 2.0 M_sun star did not reach the AGB phase

[Ebrahim Hassani]

Dear Francis

Thank you very much for your comments and explanations. I think, in the
case of our studies, it is better to use the
mesa-r15140/star/test_suite/1M_pre_ms_to_wd star just for low-mass stars
(e.g. stars lower than ~ 2 M_Sun).

Thank you again for all your help.


Best wishes
Ebrahim



On Sun, Sep 12, 2021 at 10:52 AM Francis Timmes <fxt44 at mac.com> wrote:

> log_L_lower_limit always refers to a stopping condition in any inlist:
>
>
> https://docs.mesastar.org/en/r15140/reference/controls.html#log-l-lower-limit
>
> evolving a model completely through the agb phase can be challenging
> and usually requires, as mentioned below, much smaller timesteps than
> the default set of timestep controllers that are apparently being used.
> non-convergence of the solver can take many forms, including the form
> indicated in your terminal output.
>
> fxt
>
> p.s. - in the future, please use plain text copy & paste.
> its often clearer and always more bandwidth friendly than
> sending everyone on mesa-users a ~0.6 mb screenshot image.
>
>
>
>
>
>
> > On Sep 6, 2021, at 6:58 PM, Ebrahim Hassani <ee.haji at gmail.com> wrote:
> >
> > Hi dear Francis,
> >
> > Thank you very much for your attention and also for your answers.
> >
> > After reviewing the code several times, I could find the problem with my
> code. In fact, I had changed the value of the log_L_lower_limit variable in
> the inlist_start file from 1 to -4. After returning the value of
> log_L_lower_limit to 1, the code worked correctly and I  could evolve the
> 1_M_Sun star until the white dwarf phase. Honestly speaking, I don't know
> what the value of log_L_lower_limit determines in the inlist_start file
> (but in the inlist_to_wd file, the value of log_L_lower_limit determines
> the stopping condition for the star).
> >
> > After correcting the above-mentioned mistake, I could run the code for
> stars with 1.0-2.0 solar masses successfully (and until the white dwarf
> phase). But when I increased the mass of the star to 2.5 solar mass (or
> higher masses e.g. 3.0 M_Sun), I encountered a new problem. The attached
> file is the screenshot of the final error message that I had got for the
> 2.5 solar-mass star. The code produced the same problem for other higher
> mass stars (e.g. 3.0 M_Sun) too. This time stars are evolving until the AGB
> phase, but they don't evolve further, and then they don't reach the white
> dwarf phase.
> >
> > May I ask again what might be the reason for the new error message? It
> is worth stressing that, this problem happens just for high-mass stars
> (2.5-3.0 solar masses) and not for low-mass ones (1.0-2.0 solar masses). My
> guess is, this problem happens because of the new source of energy that we
> defined in the src/run_star_extras.f90 file and through dark matter
> annihilation, but I am not sure about this.
> >
> > I would really appreciate any of your feedback and any comments
> >
> >
> > All the best
> > Ebrahim
> >
> >
> >
> > On Mon, Sep 6, 2021 at 5:34 AM Francis Timmes <fxt44 at mac.com> wrote:
> > hi ebrahim,
> >
> > your other_mesh_delta_coeff_factor routine is sufficiently complicated
> > that you may need to do additional debugging. in addition, there is an
> > apparent reliance on the default timestep controls; tightening those
> > should be considered.
> >
> > if the model works to your satisfaction for a mass of 1.0, then i
> suggest
> > making some plots of what the model is doing and also noting what
> > physical variable (central temperature, central density, etc) controls
> the timesteps.
> > then try a model with a smaller mass change, say, 1.1 msun. what changes
> and why?
> > repeat this analysis for a mass of 1.2 and so on. perhaps by the time
> you get
> > to 1.5 msun or so it will be clearer why your model is stalling. also,
> note that
> > helium ignition is rather different for 1.0 msun that it is for 2 msun
> ...
> >
> > happy hunting!
> >
> > fxt
> >
> >
> >
> >
> >
> >
> > > On Aug 29, 2021, at 9:46 PM, Ebrahim Hassani via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
> > >
> > > Dear mesa-users
> > >
> > > I used 1M_pre_ms_to_wd star in mesa-r15140/star/test_suite to consider
> dark matter effects in stars. I could edit and run the code successfully.
> But when I changed the mass of the star from 1.0 M_sun to 2.0 M_sun the
> code again worked without any problem. But for the 2.0 M_sun star, the star
> did not finish the run. It took about 10^5 steps until now and it did not
> reach the AGB phase or later phases. In addition, until 10^5 step, the mass
> of the star did not reduce due to e.g. stellar winds, etc.
> > >
> > > The code of the 2.0 M_sun star is available at (see the attached files
> too):
> > >
> https://drive.google.com/file/d/1FpFxApMOeZ6tK2Pzr3XbkAk1ZKqhsQhm/view?usp=sharing
> > >
> > > I used this code (in jupyter notebook) to plot the H-R diagram (see
> the attached files too):
> > >
> https://drive.google.com/file/d/1iDOTf6L1sJXUkeO3cupHQOas-RIaRnwc/view?usp=sharing
> > >
> > > It is worth mentioning that I mostly edited the run_star_extras.f90
> file in the src folder to consider dark matter effects. I also uncommented
> "max_model_number = ..." command in inlist files. I also changed the amount
> of "log_L_lower_limit" values in inlist files.
> > >
> > > May I ask what might be the possible problem of the code that it did
> not reach to AGB phases? And how can I solve this problem?
> > >
> > > I would greatly appreciate any of your comments.
> > >
> > >
> > > Best regards,
> > > Ebrahim Hassani
> > >
> <Cap_Rate.ipynb><2M_pre_ms_to_wd_Mwimp_1D2_Rho_0.zip>_______________________________________________
> > > mesa-users at lists.mesastar.org
> > > https://lists.mesastar.org/mailman/listinfo/mesa-users
> > >
> >
> > <ScreenShoot_Ubuntut.png>
>
>
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