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arXiv · 1207.1562

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

M. Contini·V. Cracco·S. Ciroi·G. La Mura
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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.

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M. Contini, V. Cracco, S. Ciroi, G. La Mura. 2012-07-06. Distribution of the heavy elements throughout the extended narrow line region of the Seyfert galaxy NGC 7212. https://doi.org/10.1051/0004-6361%2F201219184

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