[mesa-users] Question about abundances in the 1 Msun test problem

[Manos Chatzopoulos]

I just experimented with the set_uniform_xa_from_file option and I am a 
happy customer too, though
for the inexperienced MESA user some relevant "flags" in the inlist that 
allows the control of the
abundances might be a more straightforward option. Very useful thread, 
thank you all guys!

Manos
> i’m not one to generate unnecessary work or endless options.
> personally, i use set_uniform_xa_from_file when i want to set
> an exact composition. let’s try an mini-experiment on sensing
> what the community thinks would be useful.
>
> mesa-users:
> is the current two completely general schemes and the proposed options
> for choosing between "dump missing metals in the most massive isotope”
> and "renormalize the metals” sufficient for your immediate purposes or
> is additional flexibility needed? no response means you are ok with the
> current adjustability.
>
> fxt
>
>
>
>
> On Aug 6, 2014, at 8:00 PM, Bill Paxton <paxton at kitp.ucsb.edu> wrote:
>
>> On Aug 6, 2014, at 7:42 PM, Francis Timmes wrote:
>>
>>> how about a third option, “dump into the most abundant isotope”?
>>> for this particular case, a touch more h1 may be the least perturbing solution.
>> Hi Frank,
>>
>> yes, i know i did something other than what you recommended. ;D
>> the reason is that it was easy to do what i did, and it is a bit harder to do
>> what you suggested given the current way the code is structured.
>> it currently gets the X and Y info from the user and then picks
>> a set of metal mass fractions from a given set to provide the
>> remaining Z.  So transferring from Z to X or Y isn't currently
>> an easy to implement option whereas changing the choice
>> of metals is.    so i did the easy one first.
>>
>> i can see it now --- after adding a 3rd option to add to the most
>> abundant, we'll need a 4th option that lets the user specify
>> which element to use for the extra, and then 5th that says
>> split the extra between H1 and He4, and then a 6th that
>> says distribute the extra over all the isotopes, and then ....
>>
>> everyone should keep in mind that we already have 2
>> completely general ways to see any uniform composition
>> by giving the set of desired mass fractions.    one is
>> set_uniform_xa_from_file and the other is set_to_xa_for_accretion.
>>
>> so at some point we'll stop adding options and just say
>> "use one of the general schemes".    but if you think it is
>> important to add “dump into the most abundant isotope”
>> then i'll take another look at how to do it.   you say.
>>
>> -Bill
>>
>>
>>


-- 
Dr. Manos Chatzopoulos
Enrico Fermi Postdoctoral Fellow
Department of Astronomy & Astrophysics
FLASH Center for Computational Science
University of Chicago