Distribution of the heavy elements throughout the extended narrow line region of the Seyfert galaxy NGC 7212

Abstract

The latest observations of line and continuum spectra emitted from the extended narrow line region (ENLR) of the Seyfert 2 galaxy NGC 7212 are analysed using models accounting for photoionization from the active nucleus and shocks. The results show that relatively high (500--800 \kms) shock velocities appear on the edge of the cone and outside of it. The model-inferred AGN flux, which is lower than $10^{-11}$ photons cm${}^{-2}$ s${}^{-1}$ eV${}^{-1}$ at the Lyman limit, is more typical of low-luminosity AGN, and less so for Seyfert 2 galaxies. The preshock densities are characteristic of the ENLR and range between 80--150 cm${}^{-3}$. Nitrogen and sulphur are found depleted by a factor lower than 2, particularly at the eastern edge. Oxygen is depleted at several locations. The Fe/H ratio is approximately solar, whereas the Ne/H relative abundance is unusually high, 1.5--2 times the solar value. Modelling the continuum spectral energy distribution (SED), we have found radio synchrotron radiation generated by the Fermi mechanism at the shock front, whereas the X-rays are produced by the bremsstrahlung from a relatively high temperature plasma.

17 pages, 14 figures, accepted for publication in A&A

References in corpus (7)

• The VLA Low-frequency Sky Survey
• Size and properties of the narrow-line region in Seyfert-1 galaxies from spatially-resolved optical spectroscopy
• The K-band properties of Seyfert 2 galaxies
• The Narrow Line Region of the Seyfert 2 galaxy Mrk 78. An infrared view
• The origin of gas in the Extended Narrow Line Region of nearby Seyfert galaxies.I. NGC 7212
• Evidences of merging in the Seyfert galaxy NGC 3393 revealed by modelling the spectra
• Near-infrared spectra of Seyfert galaxies and line production mechanisms

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• Deconstructing the narrow-line region of the nearest obscured quasar
• HST emission-line images of nearby 3CR radio galaxies: two photoionization, accretion and feedback modes
• The merger Seyfert galaxy Arp 220. Line and continuum absorption and emission
• Activity and quiescence in galaxies at redshifts 1.4<z<3.5. The role of the starburst temperature