[Mesa-users] Evolution of pop III stars up to core-collapse with rotation

[Rob Farmer]

Hi,
There are python codes available for making kippenhans, but for now the
simplest is to let mesa make them for you.

Add:
mixing_regions 40
burning_regions 40
to your history_columns file

and add:
kipp_win_flag=.true.
in your pgstar inlist

Rob



On Thu, 1 Apr 2021 at 01:13, Ramandeep Gill <rsgill.rg at gmail.com> wrote:

> Hi Rob,
>
> Thanks for writing back. Let me first answer your questions and then I
> can provide some more details.
>
> The model fails during Carbon ignition in the core. For your reference
> I've attached two screenshots of the output just before the code
> crashes. Fig.1 shows the Carbon fraction with C_cntr = 0.000131 and
> this the lowest I've obtained with the current setup. The figure also
> shows the current time step which is very small. The code crashes very
> soon after this and that's shown in Fig. 2, just to give you some idea
> of the error messages before it crashes. The time step is being
> determined by max_increase, and I don't really know what that means.
>
> I'll have to look into how to produce a Kippenhahn diagram. A quick
> search on google revealed that many have written python scripts to do
> just that. So, I might adopt one of them.
>
> Finally, I looked at the MESA instrument paper II, which presents the
> evolution of a 40 M_sun star with rotation for a low Z = 1e-5. I was
> able to get the inlist for this paper from MESA marketplace. This
> seemed like a perfect example for my case. I tried it with the most
> recent version of MESA, and after fixing a few flags that have been
> changed in the recent version, I was able to run it. However, it
> crashed very quickly while core H ignition. Perhaps there's a way to
> run this example with the latest version. Or I can try to install the
> same version, if it's still available, that was used for that paper
> and then run it.
>
> Thanks,
> Ramandeep
>
> NB: In my original message I attached inlist_CC but it's missing some
> flags that initialize the rotation. It's not the inlist that was used
> to produce the attached HR diagram. So, I'm attaching the proper
> inlist here. Sorry for the confusion.
>
>
> On Wed, Mar 31, 2021 at 1:20 AM Rob Farmer <robert.j.farmer37 at gmail.com>
> wrote:
> >
> > Hi,
> >
> > The envelopes of massive stars are difficult things to get right. I
> would not worry (for now) so much about the envelope, instead worry about
> what the star is doing internally. How close to core collapse did your
> model get? Has it ignited carbon or later fuels? Try looking at a kippenhan
> diagram. If you look over the recent timesteps before the model crashes,
> what is limiting the timestep?
> >
> > Rob
> >
> >
> >
> > On Tue, 30 Mar 2021 at 22:13, Ramandeep Gill via Mesa-users <
> mesa-users at lists.mesastar.org> wrote:
> >>
> >> Hello MESA experts,
> >>
> >> I'm trying to obtain the pre-core-collapse structure of massive pop
> >> III stars to study the launching and propagation of GRB jets in these
> >> stars. In the end, I'm looking to obtain the density and angular
> >> momentum radial profile of the star.
> >>
> >> To this end, I've tried a few inlists, starting from the bare minimum
> >> one used for introductory MESA tutorials as well as more advanced ones
> >> from the MESA test suite and any that I could find online. The end
> >> result in all is that after core He depletion, the code crashes most
> >> of the time or, if I manage to somehow stabilize it, settles onto a
> >> spurious solution with a lot of wild oscillations.
> >>
> >> I attach an HR diagram from one of the runs for which I used the
> >> inlist from the 'make_pre_ccsn_IIp' test suite example. The evolution
> >> up to H core depletion, He core depletion, and that beyond He core
> >> depletion is color coded. You can see that the last part of the
> >> evolution results in spurious oscillations, after which the code many
> >> times crashes or keeps chugging along at smaller and smaller time
> >> steps.
> >>
> >> To reproduce these results, I'm attaching two inlists. One produces
> >> the evolution up to ZAMS and the second is designed to take it from
> >> there up to the core collapse (CC) stage. I'm using version r15140 of
> >> MESA.
> >>
> >> At this point, I can use some help from MESA experts. What I'm looking
> >> for is help in creating a basic inlist without any advanced effects
> >> that can evolve the star to the core collapse stage. Advanced effects
> >> can come later once I have a working solution for massive pop III
> >> stars.
> >>
> >> I was hoping to reproduce the results of Yoon, Dierks, & Langer (2012)
> >> shown in their Fig. 1 & 2. They show the evolution only up to He core
> >> depletion. In my case, I need to go beyond this to the core collapse
> >> stage with and without rotation.
> >>
> >> I'll really appreciate any help that you can offer. Please let me know
> >> if you need any further info from me and forgive me if I haven't been
> >> so clear in describing the problem.
> >>
> >> Thanks,
> >> Ramandeep
> >> --
> >> Ramandeep Gill
> >> Postdoctoral Fellow
> >> George Washington University
> >> The Open University of Israel
> >> http://www.ramandeepgill.com
> >> _______________________________________________
> >> mesa-users at lists.mesastar.org
> >> https://lists.mesastar.org/mailman/listinfo/mesa-users
> >>
>
>
> --
> Ramandeep Gill
> Postdoctoral Fellow
> George Washington University
> The Open University of Israel
> http://www.ramandeepgill.com
>
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