Innermost structure and near-infrared radiation of dusty clumpy tori in active galactic nuclei. (arXiv:1306.0188v1 [astro-ph.HE])

Innermost structure and near-infrared radiation of dusty clumpy tori in active galactic nuclei. (arXiv:1306.0188v1 [astro-ph.HE]):
The dusty clumpy torus surrounds the central black hole (BH) and the
accretion disk in active galactic nuclei, and governs the growth of
super-massive BHs via gas fueling towards the central engine. Near-infrared
(NIR) monitoring observations have revealed that the torus inner radius is
determined by the dust sublimation process. However, the observed radii are
systematically smaller than the theoretical predictions by a factor of three.

We take into account the anisotropic illumination by the central accretion
disk to the torus, and calculate the innermost structure of the torus and the
NIR time variablity. We then show that the anisotropy naturally solves the
systematic descrepancy and that the viewing angle is the primary source to
produce an object-to-object scatter of the NIR time delay. Dynamics of clumps
at the innermost region of the torus will be unveiled via future
high-resolution X-ray spectroscopy (e.g., Astro-H).