Probing the physics of narrow-line regions of Seyfert galaxies I: The
  case of NGC 5427
  We have used the Wide Field Spectrograph (WiFeS) on the ANU 2.3m telescope at
Siding Spring to observe the nearby, nearly face-on, Seyfert 2 galaxy, NGC
5427. We have obtained integral field spectroscopy of both the nuclear regions
and the HII regions in the spiral arms. We have constrained the chemical
abundance in the interstellar medium of the extended narrow line region (ENLR)
by measuring the abundance gradient in the circum-nuclear \ion{H}{ii} regions
to determine the nuclear chemical abundances, and to use these to in turn
determine the EUV spectral energy distribution for comparison with theoretical
models. We find a very high nuclear abundance, $\sim 3.0$ times solar, with
clear evidence of a nuclear enhancement of N and He, possibly caused by massive
star formation in the extended ($\sim 100$pc) central disk structure. The
circum-nuclear narrow-line region spectrum is fit by a radiation pressure
dominated photoionisation model model with an input EUV spectrum from a Black
Hole with mass $5\times10^7 M_{\odot}$ radiating at $\sim 0.1$ of its Eddington
luminosity. The bolometric luminosity is closely constrained to be $\log
L_{\mathrm bol.} = 44.3\pm 0.1$ erg s$^{-1}$. The EUV spectrum characterised by
a soft accretion disk and a harder component extending to above 15keV. The ENLR
region is extended in the NW-SE direction. The line ratio variation in
circum-nuclear spaxels can be understood as the result of mixing \ion{H}{ii}
regions with an ENLR having a radius-invariant spectrum.
