[FLASH-USERS] confusion regarding abar and zbar

[John ZuHone]

Hi Jon,

> On Sep 16, 2015, at 11:47 AM, Jonathan Slavin <jslavin at cfa.harvard.edu <mailto:jslavin at cfa.harvard.edu>> wrote:
> 
> Ah, okay that wasn't clear to me.  That will work for this case without cooling, but what this is essentially doing is decreasing the mean mass per particle as a kludge for including electron pressure.  When cooling is included then, the number density, n = rho/m, will be too high.  I'm referring to optically thin radiative cooling, e.g. using the Sutherland & Dopita cooling curve.  In that case what you need is n(H)*n(e).  I suppose I could kludge that as well...

Yes, you are correct. I have a cooling curve set up using the AtomDB data and this is also what I have to do. Dean’s point is that the Gamma EOS is pretty ignorant (by design), it doesn’t know anything about what the gas is made up of in what proportions or whether or not it’s ionized or not, etc. It just knows what the equation of state is supposed to be, and you only need Abar for the temperature, which is not used in hydro anyway since that uses the internal energy (though of course you need it for cooling).

Best,

John
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