On the central abundances of Active Galactic Nuclei and Star-forming
  Galaxies
  We examine the relation between oxygen abundances in the narrow-line regions
(NLRs) of active galactic nuclei (AGNs) estimated from the optical emission
lines through the strong-line method (the theoretical calibration of
Storchi-Bergmann et al.(1998)), via the direct Te-method, and the central
intersect abundances in the host galaxies determined from the radial abundance
gradients. We found that the Te-method underestimates the oxygen abundances by
up to ~2 dex (with average value of ~0.8 dex) compared to the abundances
derived through the strong-line method. This confirms the existence of the
so-called "temperature problem" in AGNs. We also found that the abundances in
the centres of galaxies obtained from their spectra trough the strong-line
method are close to or slightly lower than the central intersect abundances
estimated from the radial abundance gradient both in AGNs and Star-forming
galaxies. The oxygen abundance of the NLR is usually lower than the maximum
attainable abundance in galaxies (~2 times the solar value). This suggests that
there is no extraordinary chemical enrichment of the NLRs of AGNs.
