mesa-users] Problem creating low Z stars and ZAMS models

[Alessandro Patruno]

Hi Bill,

thanks for the quick reply.

I tried to evolve the star in the low_z suite  and the behaviour is the
same: MS of ~7 Gyr
instead of ~12 Gyr.
After your suggestion I also tried to evolve the model directly from the new
zams sequence of Z = 0.0001 (created with create_zams),
 and the result is the same. I also used the 635th-low z model,  and again
same situation.
Both tests were done in the low_z suite, so I am not using rlo here.

So I'm doing something wrong in both create_zams and low_z, while I presume
rlo is working
properly but uses the corrupted input files of low_z and create_zams.

I attach here the inlists in low_Z and the Z=0.0001 ZAMS sequence model
(PopII.data).

Cheers,

Ale





On Wed, Nov 3, 2010 at 1:10 AM, Bill Paxton <paxton at kitp.ucsb.edu> wrote:

> Hi Ale,
>
> On Nov 2, 2010, at 4:35 PM, Alessandro Patruno wrote:
>
> > Hi everyone,
> >
> > I was playing a bit with the test_suite
> > "low_z" and "create_zams" but I found two problems
> > I can't solve easily
> >
> > 1. How do I tell MESA to use a ZAMS model file that I created with
> > "create_zams" instead of the default ones ? I just created a Z=0.0001
> > ZAMS sequence (for Population II stars) and I'd like to use it now to
> load
> > initial stellar models...
>
>
> The control you want is called 'zams_filename' which is set by default to
> 'zams_z2m2.data'.
> The code tries to open the zams file first in the current directory and, if
> that fails, next
> in mesa/data/star_data/zams_models.
>
>
> >
> >
> > 2. I am creating a single star, a main sequence star of 0.9 Msun,
> > with Z=0.0001. So I use "low_z" in the test_suite.
> > My "inlist_low_z" has the lines:
> >
> > &star_job
> >       mesa_data_dir = '../../../data' ! for eos and opacity tables
> >       create_pre_main_sequence_model = .true.
> >       save_model_number=635'
> >       save_model_filename='0p9-z0001.dat'
> >
> >
> > I start with a pre-main sequence model
> > and then let the evolution go until the code tells
> > me "starting main sequence". This happens at the 635-th time step
> > (that's why I wrote save_model_number=635).
> > I save the model in the file (0p9-z0001.dat), and I load it in the
> > test_suite called "rlo" to do binary evolution.
> >
> > The inlist_test_rlo file has these lines n the &star_job section:
> >
> > &star_job
> >
> >       mesa_data_dir = '../../../data' ! for eos and opacity tables
> >       log_columns_file = 'log_columns.list'
> >
> >       load_saved_model=.true.
> >       saved_model_name='../low_z/0p9-z0001.dat'
> >
> >       pgstar_flag = .true.
> >
> >
> > I place the donor at a very large orbital separation (something like
> 10^10 days)
> > to "simulate" a single star evolution before doing the real
> > binary evolution later.
> > However, the evolution is weird, the main sequence lasts for ~7.5 Gyr
> > (instead of the expected 12 Gyr)
> > and the evolution is very quick with the star becoming fully radiative
> > at some point...
> >
> > Any idea what did I do wrong ??
>
> Please send the saved model and the inlists so I can try to recreate the
> problem.
>
> BTW: does the saved model evolve reasonably if you run it outside of the
> rlo setup?
>
> >
> > Many thanks, I really appreciate your support !
>
> You are very welcome!
>
> Cheers,
> Bill
>
>
>
>
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