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chianti-atomic / ChiantiPy

ChiantiPy is a python package to calculate the radiative properties of astrophysical plasmas based on the CHIANTI atomic database
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Clarify Continuum Units #296

Open gmduvvuri opened 3 years ago

gmduvvuri commented 3 years ago

Hello,

I am not clear on the units of the intensity returned by different continuum processes. Could you add documentation to the ion.twoPhoton(wvl) and associated methods?

My current understanding based on the CHIANTI User Guide and ChiantiPy documentation is that continuum.FreeFree['intensity'] and continuum.FreeBound['intensity'] are both in units of: while ion.TwoPhoton['intensity'] is in units of . But I see in the spectrum module that these quantities are added together, so one of them must be incorrectly signed.

Thank you for your time, Girish.

kdere commented 3 years ago

it should be cm^+3 so that when multiplied by the line-of-sight emission measure (integral of n_e*n_H dl cm^-5) the final units are cm^-2 thanks for letting me know Ken

gmduvvuri commented 3 years ago

Am I correct in my understanding that the ion.TwoPhoton['intensity'] returns the expression in Equation 63 of the CHIANTI User guide divided by ? The full expression being: ?

kdere commented 3 years ago

It has been a long time since that was coded and written. It is probably true. Sorry but I do not have the time to dig into it right now. Ken