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Dusty Torus Formation by Anisotropic Radiative Pressure Feedback of Active Galactic Nuclei. Shuang-Nan Zhang Institute of High Energy Physics and National Astronomical Observatories of China Chinese Academy of Sciences. Liu,Y. & Zhang, S.N., 2011, ApJL, 728, L44. The unified model of AGN.
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Dusty Torus Formation by Anisotropic Radiative Pressure Feedback of Active Galactic Nuclei Shuang-Nan Zhang Institute of High Energy Physics and National Astronomical Observatories of China Chinese Academy of Sciences Liu,Y. & Zhang, S.N., 2011, ApJL, 728, L44
The unified model of AGN Formation? Dusty torus Evolution?
AGN feedback The normal of the accretion disk • The distribution of the dust is anisotropic • The UV/optical radiation from the accretion disk is also anisotropic • The effect of radiation pressure is significant due to the presence of dust observer A~500
The evolution of AGNs A B C Momentum effect of radiation
Evaporation radius The inner radius of dust Energy effect of radiation
NH-L/LEdd plane Raimundo, Fabian, Bauer et al. 2010
The fraction of type 2 AGNs Hasinger 2008
The inner radius of dust Suganuma et al. 2006
The evolution of dusty torus Bright, with torus, but without BLR
Weak line quasars Shemmer et al. 2009; EW<5 A; continuum similar to normal quasars
Evidence of hot dust in WLQ Black body from hot dust Diamond-Stanic et al. 2009
Radio quiet BL Lac Plotkin et al. 2009 No obvious emission lines
Variability • Observations are quite limited • Weaker than radio loud BL Lac? • Need more observations Plotkin et al. 2010
Conclusions • The distribution of dusty gas should also be anisotropic due to the influence of the anisotropic disk radiation • This model can explain the presence of some obscured AGNs with high Eddington ratios and can also quantitatively reproduce the observed decreasing fractionof type 2 AGNs with increasing luminosity. • Our model predicts the existence of bright AGNswith dusty tori, but without broad line regions. • Weak line quasars and radio quite BL Lac Objects? Liu,Y. & Zhang, S.N., 2011, ApJL, 728, L44