S II transition probabilities have inconsistent references
two Froese Fischer papers published within a year of one another have discrepant values, NIST recommends the first paper, we use the second. Two emails from Bob Rubin follow:
the NIST recommendations, and their effects of density diagnostics: I changed these to those recommended in the new
"Critically Evaluated Atomic Transition Probabilities for Sulfur S I-S XV" Podobedova, L. I.; Kelleher, D. E.; Wiese, W. L. Journal of Physical and Chemical Reference Data, Volume 38, Issue 2, pp. 171-439 (2009).
Surprisingly these made a significant difference in the derived N_e [S II] probably because the level 3 critical density at T_e = 9000 K is ~1000 cm-3 now. Before, we got N_e [S II] 1047 & with new A-values, dropped to 750 cm-3.
Bob's email on the differences:
Hi Gary,
You must mean:
20 2006ADNDT..92..607F 1.000 09/2006 A E C U Froese Fischer, Charlotte; Tachiev, Georgio; Irimia, Andrei Relativistic energy levels, lifetimes, and transition probabilities for the sodium-like to argon-like sequences.
The recommended data cites original source:
24 2005PhyS...71..172I 1.000 01/2005 A E R C U Irimia, Andrei; Froese Fischer, Charlotte Breit Pauli Oscillator Strengths, Lifetimes and Einstein A Coefficients in Singly Ionized Sulphur
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You would think that these should be same just published both places. However when I look at 2006, ADNDT, 92, 607 the table for S II looks messed up. For instance the wavelengths are WAY OFF 6531.42 and 6543.50! The A-values do NOT agree at all with those in 2005, PhyS, 71, 172
See p. 746
Multiplet
Terms gi gk Type k (A# ) S fik Aki (s-1)
Z = 16: P-like transition data
3p3-3p3
4So 2Do 4 4 E2 6543.50 5.830e-03 8.735e-13 1.361e-04
4 6 E2 6531.42 1.350e-02 2.034e-12 2.120e-04
4 4 M1 6543.50 2.449e-05 3.784e-12 5.895e-04
4 6 M1 6531.42 8.717e-07 1.349e-13 1.406e-05
3p3-3p3
4So 2Po 4 2 M1 4029.43 3.796e-04 9.524e-11 7.825e-02
4 4 M1 4024.47 1.881e-03 4.726e-10 1.946e-01
3p3-3s3p4
4So 4P 4 2 E1 1266.96 9.907e