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Warped discs and the Unified Scheme

Published online by Cambridge University Press:  01 August 2006

Andrew Lawrence*
Affiliation:
Institute for Astronomy, University of Edinburgh Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK email: al@roe.ac.uk
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Abstract

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The standard torus picture for explaining the difference between Type I and Type II AGN is physically unlikely and provides no natural explanation for a number of simple facts - the average covering factor, the broad range of covering factors, and the characteristic reprocessing distance. Parsec scale warped discs are a strong alternative. A very simple “misaligned disc” model produces good agreement with covering factor statistics, but predicts too many off-axis emission line cones. I discuss possible ways to improve such a model.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2007

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