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

[Alessandro Patruno]

Hi Aaron,

you are totally right, I just realized that I was using a 0.9 instead of 0.8
Msun...
Sorry if I wasted your time and thanks for the answer.
Everything is working perfectly !

A.


On Wed, Nov 3, 2010 at 12:04 PM, Aaron Dotter <aaron.dotter at gmail.com>wrote:

> Dear Ale,
>
> If you want a model with a main sequence lifetime of ~12 Gyr for Z=10^-4, I
> recommend choosing M ~ 0.8 Msun. For 0.9 Msun, 7-8 Gyr is perfectly
> reasonable.
>
> If  you look at the MESA paper, we have an example of 0.8 Msun, Z=10^-4
> from four different codes and they all have MS lifetimes of ~12 Gyr (see
> figure 19).
>
> Best wishes,
> Aaron
>
>
>
> On Tue, Nov 2, 2010 at 6:35 PM, Alessandro Patruno <ale.patruno at gmail.com>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...
>>
>>
>> 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 ??
>>
>> Many thanks, I really appreciate your support !
>>
>> Ale
>>
>>
>> ------------------------------------------------------------------------------
>> Achieve Improved Network Security with IP and DNS Reputation.
>> Defend against bad network traffic, including botnets, malware,
>> phishing sites, and compromised hosts - saving your company time,
>> money, and embarrassment.   Learn More!
>> http://p.sf.net/sfu/hpdev2dev-nov
>> _______________________________________________
>> mesa-users mailing list
>> mesa-users at lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/mesa-users
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.mesastar.org/pipermail/mesa-users/attachments/20101103/6a84a4b2/attachment.html>