A spatially resolved study of ionized regions in galaxies at different ...

4.4. Discussion 131
IIZw71 Knot B
IIZw71 Knot C
12 + log(O + /H + ) 7.67 ± 0.23 7.63 ± 0.23
12 + log(O 2+ /H + ) 7.63 ± 0.19 7.57 ± 0.19
12 + log(O/H) 7.95 ± 0.21 7.90 ± 0.21
12 + log(S + /H + ) 5.94 ± 0.12 5.83 ± 0.13
12 + log(S 2+ /H + ) 6.00 ± 0.26 5.85 ± 0.26
ICF(S + + S 2+ ) 1.15 ± 0.13 1.14 ± 0.12
12 + log(S/H) 6.33 ± 0.24 6.20 ± 0.24
log(S/O) -1.62 ± 0.31 -1.70 ± 0.31
12 + log(N + /H + ) 5.87 ± 0.28 5.63 ± 0.23
12 + log(N/H) 6.15 ± 0.40 5.90 ± 0.38
log(N/O) -1.48 ± 0.37 -1.68 ± 0.32
12 + log(Ne 2+ /H + ) 7.12 ± 0.29 7.06 ± 0.28
ICF(Ne 2+ ) 1.22 ± 0.13 1.23 ± 0.14
12 + log(Ne/H) 7.19 ± 0.35 7.13 ± 0.35
log(Ne/O) -0.75 ± 0.30 -0.77 ± 0.30
12 + log(Ar 2+ /H + ) 5.61 ± 0.22 5.57 ± 0.19
ICF(Ar 2+ ) 1.16 ± 0.03 1.16 ± 0.04
12 + log(Ar/H) 5.65 ± 0.26 5.60 ± 0.26
log(Ar/O) -2.29 ± 0.30 -2.29 ± 0.30
Table 4.8: Ionic chemical abundances derived from forbidden emission lines, ICFs and total chemical
abundances for elements heavier than helium for knots B and C of IIZw71.
4.4 Discussion
4.4.1 Gaseous physical conditions and element abundances
Densities and temperatures
Four electron temperatures – T e ([Oiii]), T e ([Oii]), T e ([Siii]) and T e ([Sii])– have been
estimated in all the knots of J1657. [Nii] λ 5755 is detected, but has poor signal. The good
quality of the data allows us to reach accuracies, for Knot A, of the order of 2%, 4%, 5%
and 7% for T e ([Oiii]), T e ([Oii]), T e ([Siii]), and T e ([Sii]), respectively.
Unfortunately, for IIZw71 only T e ([Oiii]) could be estimated directly. Thus, in this section
we are going to discuss only the results obtained for J1657 when comparing with models.
The knots of J1657 and IIZw71 show temperatures within a relatively narrow range,
between 12000 and 14800 K for T e ([Oiii]). It is worth to remember that the adopted selection