AMDL-format lacking structure coefficients c_thn

[pjuelsgaard]

Hi all.
I'm trying to run NAd calculations with an AMDL file. As such, I am missing some structure coefficients, namely the nabla_ad and c_thn.
nabla_ad = adiabatic temperature gradient, if I am not mistaken, but what is c_thn?

I am thinking of modifying the amdl-reading routine on my local installation in order to read such a modified amdl-file, so I can do NAd calculations on it.

Kind regards
- Peter Juelsgaard

[warrick]

Hi Peter,

I don't know what c_thn is but, as far as I know, AMDL models are only defined (via Jørgen Christensen–Dalsgaard's ADIPLS program) to contain the information required for adiabatic calculations. I don't think AMDL models have the data necessary for non-adiabatic calculations. For non-adiabatic calculations, you probably want a different stellar model format, support for which depends on how you're producing the equilibrium model. I'm not sure if FGONG or OSC files might have the necessary information but GYRE stellar models should.

Cheers,
Warrick

[rhtownsend]

Warrick is right -- AMDL files don't contain sufficient information to perform non-adiabatic calculations. Unfortunately, this means (unless the AMDL format is extended) that models created by ASTEC cannot be used for non-adiabatic studies.

By the way, c_thn and other coefficients are defined here:

https://gyre.readthedocs.io/en/stable/r ... efficients

c_thn is a dimensionless measure of the optically thin cooling rate.