Reproducing O II Temperature from Luridiana, Morisset & Shaw (2015)

[Yu Voon Ng 黃宇文]

Hi all,

I have been attempting to reproduce the results from Table 7 in Luridiana, Morisset & Shaw (2015), and most values appear to be consistent. However, I encountered a discrepancy when calculating the O II temperature using the following PyNeb script:

pn.atomicData.includeFitsPath()
pn.atomicData.setDataFileDict('IRAF_09')
O2 = pn.Atom('O', 2)
T_O2 = O2.getTemDen(100, den=100, to_eval="(L(3726) + L(3729)) / (L(7319) + L(7320) + L(7330) + L(7331))")

The resulting temperature is approximately 6840 K, whereas the value reported in the paper is 7480 K.

Would you be able to advise on whether I might be missing a step or misinterpreting part of the calculation?

Thank you very much for your time and help.

Best regards,
Yu Voon

[Christophe Morisset]

Hi Yu Voon,

I'm not sure the fits files are still usable, they are here for historical reasons, but are not aimed to be used. Some errors have been detected in some of the fit files. But the (corrected) data they include are now available in the .dat format.

You can list the data files corresponding to the IRAF_09 set using:

pn.atomicData.getPredefinedDataFileDict('IRAF_09')

And look for the ion you are interested with. For the OII, the corresponding atomic data are obtained using the .dat following format:

pn.atomicData.setDataFile('o_ii_coll_P76-McLB93-v1.dat')

pn.atomicData.setDataFile('o_ii_atom_WFD96.dat')

Which gives back the 7480 K you found in the paper. Using the actual preferred values, the same line ratio leads to Te = 7723 K.

Hope it helps,

Christophe