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The Infrared Continuum of Active Galaxies

M. Contini·S. M. Viegas·M. A. Prieto
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Abstract

We discuss the different physical processes contributing to the infrared continuum of AGN, assuming that both photoionization from the active center and shocks ionize and heat the gas and dust contained in an ensemble of clouds surrounding the nucleus. Radiation transfer of primary and secondary radiation throughout a cloud is calculated consistently with collisional processes due to the shock. We consider that the observed continuum corresponds to reprocessed radiation from both dust and gas in the clouds. The model is applied to the continuum of Seyfert galaxies from which best estimate of the nuclear, stellar subtracted, emission is available. The results show that radiation-dominated high velocity clouds are more numerous in Seyfert 1-1.5 whereas shock-dominated low velocity clouds are dominant in Seyfert type 2 in full agreement with the unified model for AGN. In type 2 objects, radiation is partly suppressed by a central dusty medium with a high dust-to-gas ratio. A grid of models is used to provide a phenomenological analysis of the observed infrared spectral energy distribution.

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M. Contini, S. M. Viegas, M. A. Prieto. 2003-11-19. The Infrared Continuum of Active Galaxies. https://doi.org/10.1111/j.1365-2966.2004.07430.x

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