[mesa-users] How to change the definition of helium core mass in MESA when constructing ZAHB models

[Bill Paxton]

Hello Zhenxin,

I'm CC'ing this to the mesa-users list since that's the place for this sort of correspondence.

As you guessed, mesa uses the H1 mass fraction to define the location of the H/He transitiion,
i.e., the top of the He core is defined to be the outermost location where H1 mass fraction is <= h1_boundary_limit.

If you'd like to have log information about the location of peak H burning, the easiest thing to do is use
some or all of the following optional log file entries (and them to your log_columns.list).

      
      ! info about location where have max rate of hydrogen burning (PP and CNO)
      !max_eps_h ! erg/g/s
      !max_eps_h_lgT ! log10 temperature at location of max burn
      !max_eps_h_lgRho ! log10 density at location of max burn
      !max_eps_h_m ! mass coordinate at location of max burn (Msun units)
      !max_eps_h_xm ! mass exterior to location of max burn (Msun units)
      !max_eps_h_lgP ! log10 pressure at location of max burn
      !max_eps_h_lgR ! log10 radius at location of max burn
      !max_eps_h_opacity ! opacity at location of max burn

Cheers,
Bill





On Mar 26, 2012, at 1:10 AM, 雷振新 wrote:

> Dear professor Bill Paxton,
> 
> I'am glad to write to you. my name is Zhenxin Lei, a student from YunNan observatory 
> 
> in China. I want to use MESA to construct ZAHB moedls, but I don't know that how do you 
> 
> defined the helium core mass at helium flash or at ZAHB point. In the document, named 
> 
> 'star/test_suite/create_zahb/inlist_create_zahb', I find the default value of h1_oundary_limit is 0.35. Is this the 
> 
> definition of helium core in MESA? If I want to change the definition of helium core
> 
> (e.g. I want to use the energy generation rate in H buring shell to define the helium 
> 
> core.), how and where I can do this ?
> 
> Thank you very much for your attention 
> 
> 
> Best whishes
> 
> 
> Zhenxin
> 
> 
> 
> 
> 
> 
> 
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>