On the electron temperatures in high-metallicity HII regions
  The electron temperatures of high-metallicity (12+log(O/H) > 8.2) HII regions
have been studied. The empirical ff relations which express the nebular-to-
auroral [OIII] line ratio Q_3,O (as well as the nebular-to-auroral [OII] line
ratio Q_2,O, and the nebular-to-auroral [NII] line ratio Q_2,N) in terms of the
nebular R_3 and R_2 line fluxes in spectra of high-metallicity HII regions are
derived, and the electron temperatures t_3,O, t_2,O, and t_2,N in a number of
extragalactic HII regions are also determined. Furthermore, the t_2 - t_3
diagram is discussed. It is found that there is a one-to-one correspondence
between t_2 and t_3 electron temperatures for HII regions with a weak nebular
R_3 lines (logR_ < 0.5). The derived t_2,N - t_3,O relation for these HII
regions is similar to commonly used t_2 - t_3 relations. The HII regions with a
strong nebular R_3 line flux (logR_3 > 0.5) do not follow this relation. A
discrepancy between t_2,N and t_2,O temperatures is found, being the t_2,N
temperatures systematically lower than t_2,O ones. The differences are small at
low electron temperatures and increases with increasing electron temperatures
up to 10% at t=1. The uncertainties in the atomic data may be the cause of this
discrepancy.
